Podcasts about cxcr3

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.02.24.529840v1?rss=1 Authors: Koupourtidou, C., Schwarz, V., Aliee, H., Frerich, S., Fischer-Sternjak, J., Bocchi, R., Simon-Ebert, T., Dichgans, M., Goetz, M., Theis, F. J., Ninkovic, J. Abstract: Traumatic brain injury leads to a highly orchestrated immune- and glial cell response partially responsible for long-lasting disability and the development of secondary neurodegenerative diseases. A holistic understanding of the mechanisms controlling the responses of specific cell types and their crosstalk is required to develop an efficient strategy for better regeneration. Here, we combined spatial and single-cell transcriptomics to chart the transcriptomic signature of the injured murine cerebral cortex, and identified specific states of astrocytes, microglia, and oligodendrocyte precursor cells contributing to this signature. Interestingly, these cellular populations share a large fraction of injury-regulated genes, including inflammatory programs downstream of the innate immune-associated pathways Cxcr3 and Tlr1/2. Systemic manipulation of these pathways decreased the reactivity state of glial cells associated with poor regeneration. The functional relevance of the newly discovered shared signature of glial cells highlights the importance of our resource enabling comprehensive analysis of early events after brain injury. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.08.30.503668v1?rss=1 Authors: Licht-Murava, A., Meadows, S. M., Palaguachi, F., Song, S. C., Bram, Y., Zhou, C., Jackvony, S., Schwartz, R. E., Froemke, R. C., Orr, A. L., Orr, A. G. Abstract: TDP-43 pathology is prevalent in dementia but the cell type-specific effects of TDP-43 are not clear and therapeutic strategies to alleviate TDP-43-linked cognitive decline are lacking. We found that patients with Alzheimer's disease (AD) or frontotemporal dementia (FTD) have aberrant TDP-43 accumulation in hippocampal astrocytes. In mouse models, induction of widespread or hippocampus-targeted accumulation in astrocytic TDP-43 caused progressive memory loss and localized changes in antiviral gene expression. These changes were cell-autonomous and correlated with impaired astrocytic defense against infectious viruses. Among the changes, astrocytes had elevated levels of interferon-inducible chemokines and neurons had elevated levels of the corresponding chemokine receptor CXCR3 in presynaptic terminals. CXCR3 stimulation altered presynaptic function and promoted neuronal hyperexcitability, akin to the effects of astrocytic TDP-43, and blockade of CXCR3 reduced this activity. Ablation of CXCR3 also prevented TDP-43-linked memory loss. Thus, astrocytic TDP-43 dysfunction contributes to cognitive impairment through aberrant chemokine-mediated astrocytic-neuronal interactions. Copy rights belong to original authors. Visit the link for more info Podcast created by PaperPlayer

For more details, visit #DrGPCR Podcast Episode #64 page https://www.drgpcr.com/episode-64-with-dr-dylan-eiger/ ------------------------------------------- About Dylan Eiger Dylan Eiger is currently an MD/Ph.D. student at Duke University School of Medicine. He received his B.S. in Chemistry from Duke University in 2016 where he worked in the lab of Dr. Stephen Craig and studied polymer chemistry and material science. He is currently finishing his Ph.D. in the lab of Dr. Sudarshan Rajagopal, a former postdoctoral fellow of Dr. Robert J. Lefkowitz. Dylan's graduate research focuses on the mechanisms underlying biased signaling at GPCRs, specifically, the role of differential receptor phosphorylation (phosphorylation barcodes) and subcellular GPCR signaling in directing functionally selective responses. He primarily studies the chemokine receptor CXCR3 as it has three naturally occurring ligands and thus serves as an endogenous example of biased agonism. After finishing his MD/Ph.D., Dylan plans to complete his residency training in Internal Medicine and subsequently pursue fellowship training in Cardiology. He hopes to continue his research on biased agonism at GPCRs with a particular focus on the treatment of cardiovascular disease. Dylan Eiger on the web LinkedIn Twitter PubMed Website ------------------------------------------- We aspire to provide opportunities to connect, share, form trusting partnerships, grow, and thrive together. Fill out the Ecosystem waitlist form today to be the first to explore our brand new and improved space! For more details, visit our website http://www.DrGPCR.com/Ecosystem/. ------------------------------------------- Are you a #GPCR professional? - Register to become a Virtual Cafe speaker http://www.drgpcr.com/virtual-cafe/ - Subscribe to our Monthly Newsletter http://www.drgpcr.com/newsletter/ - Listen and subscribe to #DrGPCR Podcasts http://www.drgpcr.com/podcast/ - Support #DrGPCR Ecosystem with your Donation. http://www.drgpcr.com/sponsors/ - Reserve your spots for the next #DrGPCR Virtual Cafe http://www.drgpcr.com/virtual-cafe/ - Watch recorded #DRGPCR Virtual Cafe presentations: https://www.youtube.com/channel/UCJvKL3smMEEXBulKdgT_yCw - Share your feedback with us: http://www.drgpcr.com/audience-survey/

Hello Gut Check Project fans. Welcome to Gut Check Project and KBMD health family. I'm Eric Rieger here with my awesome co host, Dr. Kenneth Brown. We have another special show. We just keep we just keep outdoing ourselves with smart people. I'm like I normally I've well I'm becoming very comfortable being the stupidest person on these zoom calls right now this is like this is the new norm, me being the absolute dumbest person on the screen right now.If you're the well, that's thank you. That's really weird. And and if you're the dumbest, then this is gonna be a really, really intelligent show. So today, Episode Number 52. We have a special guest. This is Dr. Charlene Van Buiten. She is an Assistant Professor of food science and Human Nutrition at Colorado State University. Hello, Charlene. How are you doing today?I'm doing well. How are you guys Doing great. We're doing great. I'm not going to introduce the paperwork that we're going to get into. But what I am interested...before we get into some incredible information about your research around celiac disease, and how essentially people can stave off long term inflammation. We always like to get to know a little bit about you. But we did print off your resume. And it looks to me like from all of the stuff that you do in the CV, that you started sometime in the womb getting things done.So you've been like publishing papers in utero somehow.Yeah, yeah. It's it's a really rare skill. So.So where are you? Where do you Where are you from originally?Originally I'm from Connecticut, grew up there. And then did my bachelor's degree at University of Connecticut in nutrition.Nice. And how long have you been at Colorado State?I've been at Colorado State about a year and a half now. So I got about six good months before everything shut down. Still happy to be here. It's a nice place to be locked down in at least.Yeah, yeah. Yeah. Yeah. Absolutely. The northern part of Colorado. It's it's definitely beautiful up there. So before you read Colorado State, let's see where else you were a postdoctoral fellow, obviously. And then, is there any other stops along the way that really leapt out to you and ended up pushing you into Colorado State to do you know, good nutrition for human?Um, yeah, I would say probably the most important step in my whole academic journey was at Penn State where I did my PhD in food science. That's kind of where all of the research that we'll talk about today was really conceived. It was just kind of a one off idea that my PhD advisor and I had just one day, you know, oh, what if we looked at interactions between gluten and tannins, and then, you know, I kind of went back to my office, first year PhD student really excited. And all of a sudden, it was like all of these ideas just in terms of the chemical interactions and what this means for nutrition just designed this whole project. And in a really rare case of circumstances, everything I had designed in my first year of my PhD ended up being what I eventually did over the course of the next five years. I don't think anybody is ever that lucky. Yeah, and the project turned into what you all were able to read before inviting me here. We will definitely dive deep into that. But I'm really curious. So I've, we have the CV here that shows your academic pursuit. I want to know why Charlene, Dr. Charlene, Dr. Charlene decided to do the study of food science and nutrition. Let's just start from there. And then I get the passion once you've latched on to something, but I'm always curious how people find their way like, like, how you how you got there.Yeah, I think I discovered Food Science a little earlier than the average person. Most people will get into it in college, having followed a path of chemistry or biochemistry, and then realizing they can apply all of these concepts to food. But I actually was in the Future Farmers of America when I was in high school. And I thought that I wanted to be a vet, and then realize that I was not really into like blood or sick animals or anything. And one of my teachers was like, we have this competition. It's called food science. you design a food product, you talk about safety and everything. And I was sure sounds cool. And the first day that I met with that team for this competition, we got a textbook chapter on canning. And I was reading about canning, and I was like, I was really interesting. Like, if you can something it'll last a really long time. Or if it's done incorrectly, it can be so dangerous that it can kill you. Kind of dichotomy there. I was like, food science is crazy. And just from there was like obsessed with it. And, yeah, I was for nutrition, grad school for food science.This kind of reminds me of the whole mycology thing that we were talking about before. Where like you might find a brave food canner and you might find an old food canner but you won't find them in the same person. I'm going to just dabble in some aggressive food canning and see what happens. They don't walk around anymore. We were we have Paul Paul Stamets was talking about that. And then the other mycologists, we've talked to mycologists that actually discuss that they feel the same way where it's like, look, you can have a mushroom that will save you. But if you prepare it wrong, or eat the wrong one, you're gonna die. If you have food canning, you can have food forever. But if you do it wrong, you can die. Well, that is awesome. So reading your article, or reading your paper, which is a review of your thesis, which tells me that you know this essentially better than anybody in the entire world because you did a thesis on something that I have been searching for for a very, very, very long time. I developed Atrantil to help people with bloating and irritable bowel syndrome. And then we started learning I late started learning about these effects of polyphenols came across your article, your review, which is titled gliadin sequestration as a novel therapy for celiac disease, a prospective application for polyphenols. This is the thing that really I've been looking for for a long time, we've known the benefits of polyphenols, but you're the first person that has been able to explain why I'm gluten sensitive. And once I start, once I started taking Atrantil whenever I would eat gluten, I didn't have issues, and I really couldn't explain it. We've had patients that say, when I, you know, when I take these large polyphenolic compounds that are in Atrantil, I can eat wheat. Why is it I didn't know I couldn't actually say from a molecular reason. And then I came across your paper. And this is absolutely fantastic. It's 32 pages of incredible material. And 185 references my goodness, you put some work into this congratulations on putting together what I think is the most comprehension review of polyphenols in the setting of celiac disease. So once again, if anybody listened to this, know somebody that has celiac disease, or has a family member, or has celiac themselves, this is something that really we need to share as a community. We need to get this out there and your work is really pivotal to explain the science, which is so cool. So let's jump into it. Because it's awesome.Yeah, I don't even know where to start. Because you you described multiple different mechanisms of action on why polyphenols begin to work. So what drove you to to put these two associations together? Why celiac disease and why polyphenols?So at the time that we came up with this project, I had recently joined my graduate advisor Ryan Elias at Penn State, I joined his lab, and he was doing a lot of work on wine quality. So as a food chemist, you know, we're looking at oxidation of polyphenols, how that can affect wine astringency, etc. And so I was, you know, showed up to grad school thinking I was going to work on wine. And then we found these papers that were studying protein polyphenol interactions using tannic acid with peanut allergens. And so that was an interesting paper doing a little bit more reading, thinking about that. And then thinking about, you know, still wine. And I came across these papers that were using gluten as a fining agent and red wine. So fining is the interaction between polyphenols and wine and a protein that will actually precipitate those polyphenols and take them out of wine to kind of soften the mouthfeel. And so I saw that and knowing that gluten is this immunostimulatory protein, I was like, why are they doing this? That seems crazy to me, and Is it hurting people and you know, it's not labeled, because it's something that's not technically in the product, because it's falling out as a solid. And that was just sort of the the end of the string on that ball of yarn that we kind of started to unravel. Um, and looking at that in terms of a food processing aid, I thought, what if we looked at this from the perspective of a nutraceutical? So if we know these interactions are happening already. Can we flip this around and put it in the human body? Can these interactions still occur? What is happening to the protein? How does that affect the actual mechanism of the disease? And, you know, we just came up with all of these questions from there, but it really started with gluten as a fining agent in wine.That's incredible. That is a that is a lot to peel back as you're starting your sort of academic career to take this on, and then suddenly go down a rabbit hole and you end up over here with a disease. That is, and thank you. I mean, that is crazy to take on that. You just discussed layers and layers that I imagine you were looking at an article that then led to another one led to another one and then you finally went, oh, this is way bigger than I thought.Yeah, there's 185 references on the paper. It's just like the tip of the iceberg.Well just to reset for everyone to those who suffer from celiac disease, obviously know about gluten and want to avoid gluten, but maybe not everyone understands why gliadin specifically, is what it is, is what we're concerned with with its blog. So why don't you explain a little bit about gliadin itselfto ours. So gluten is a heterogeneous protein made up of two subunits. So we have the gliadin, as well as glutenin. And those two proteins will come together forming inter and intra molecular bonds in order to form this gluten protein kind of as a whole. But it's the gliadin that has these repeat motifs in its amino acid primary sequence. And it's usually a prolene. That's one amino acid away from a glutamine, that's going to get recognized in the human body by an enzyme called tissue transglutaminase, or transglutaminase. Two, and that gets a deamidated. And then that's the area of the protein that's recognized by antigen presenting cells. So it really comes down to the amino acid sequence in the gliadin, versus what's typically seen in glutenin. So step back, what you just described is exactly what happens to 1% of the population because celiac disease is the most prevalent autoimmune situation, or autoimmune disease that's there. And what you just described was the amino acids, the prolene, and the glutamine actually form the gliadin. My hearing that right, so those two forms of gliadin.Right, so they're found within the structure of gliadin. So gliadins really are a class of proteins. There's alpha, beta, omega. And then within that alpha one, alpha two, alpha three, there are so many types of gliadins. But sort of this consistent pattern that we see in those gliadins is a really high percentage of prolene, as well as glutamine.Okay.So, in your article, you did describe something that I was I wanted to clarify on this, you described the prolamin glutamine residues and the sulfurus component a pro amine assisting in the ability to find these disulfide bonds, all of that, is that why gluten makes things spongy, because of these disulfide bonds is used in so many things.Yeah. Yeah. So disulfide bonds are formed within the structure of gluten over the course of hydration, oxidation and mechanical kneading. So that's what you see when you're making like bread or pasta, and that dough sort of starts to really come together. That's a result of the formation of disulfide bonds.Nice.Which is what makes it yeah, which it's that texture that everybody that we're that's which is why when you get gluten free bread, you're like, no. Not the same.Yeah, it kind of forms that balloon structure to leavening.Yeah. So I'm gonna I have actually sent back some some gluten free pasta. Can I have some more disulfide bonds in here?Yeah, they don't have that in a shaker Ken. It's not there.That is that is impressive. So what why why gliadin. Why gliadin because we know that gluten is formed of of these two different proteins. But why gliadin being the more problematic protein in the in the gluten molecule.So gliadin is more problematic, because as I mentioned, that higher frequency of the amino acid residues, the prolene, and the glutamine just found in that particular order prolene, something else, glutamine is what's going to make it more recognized by the body. It's also this high amount of prolene results in almost like an unraveled protein structure. And that is something that's recognized structurally by the body as being a problem, it's more difficult for enzymes to break down gliadin because of all of those prolenes, because of that unraveled structure, and then that unraveled structure allows it to be it allows it to interact with that tissue, transglutaminase enzyme as well.So let me stop you right there. So you said something, and that's kind of what I wanted you to say is that gliadins are resistant to digestive enzymes. So you have this thing that your body can't readily break down. So as a scientist, my patients ask, what's the deal? Why is celiac on the rise? Why is it exponentially in the rise? Why are more people saying that they have gluten intolerance, whether or not comedians will make fun of that like, like, it's like, it's something that's in your head, but I am very gluten intolerant, but I don't have celiac disease. So why do you think we're seeing more of it?There are quite a few ideas as to why we're seeing more celiac disease and I know that one of the prevailing hypotheses is kind of based on exposure on whether people have been exposed to gluten at certain times in their life, it's also associated with an overall increase in autoimmune disorders worldwide. So I think that there's probably a link there for sure.So you talked about this, and I'm jumping ahead, but you did show how gliadin can actually create some paracellular leakage, so, so to speak, or that so I see a lot of my patients that will have celiac disease and then show up with another autoimmune disease. So the question is, do we really is one of the reasons why we're seeing so much autoimmune disease like Crohn's and ulcerative colitis could it be precipitated by an inflammatory process in the gut, beginning in the gut? And I just bring this up, because maybe you're at the tip of the iceberg on possibly one of the causes of why we are developing so many autoimmune diseases. What's your theory on as on how we raise these crops, and how gluten has sort of or the wheat has changed over the years from the amber waves of grain to short, stocky plants?Well, in terms of the molecular profile of the gluten itself, I'm not as familiar with that research as probably some other more agronomy focused individuals are, but in terms of actual food products, so what we end up seeing in bread and pasta, the overall gluten content really hasn't changed over time.Really? Okay. That's actually something that I think I was, I've told my patients wrong. I've told them that we're probably getting more gluten, which is one of the reasons why we can have thatNo but I found it interesting, though, because you did reference the alpha beta and omega different gliadin subunits. And then even from there, there's sub sub units of one, two, three, and four, possibly, and as you said, I don't want to press you on this. But maybe maybe the the expression is just simply different from all of those different units over time, depending upon the mean, GMO, or not GMO or hybrid, or, who knows, it's hard to it's hard to say.Yeah, it's also difficult when considering whether there are differences based on those individual gliadins. Because that prolene x glutamine pattern shows up in all of them. repeatedly. Yeah. And in my, in some of my papers, I've focused on alpha two gliadin as one of these specific proteins. And that one just happens to have many, many overlapping at the topes in terms of recognition and celiac disease, but it's certainly not exclusive to just that one subunit.Can you comment on these different subunits? And in your paper, you discussed the the starting point of causing an inflammatory cascade with interleukin 15? I believe it was 15 Have you? Can you comment on that, and that's in the relationship for my gastroenterology colleagues, to lymphocytes because we always look for intraepithelial lymphocytes. And I think you show the mechanism through IL 15.Right, so in the celiac disease inflammatory cascade, we start with the recognition of gliadin by the CXCR3 receptor on intestinal epithelial cells. And that's one of the prevailing hypotheses in terms of pathogenesis is that the CXCR3 receptor will stimulate the release of zonulin zonulin will then trigger that paracellular leakage that you mentioned earlier. And as the gliadin passes through the laminapropria, then we see this release of IL 15 from the intestinal epithelial cells and that IL 15 is what's going to recruit those intraepithelial lymphocytes. And so that infiltration of those lymphocytes into the intestinal barrier is one of the Hallmark one of the Hallmark traits of celiac disease from the clinical perspective, as I'm sure you're very familiar with Marsh scores. For example,Let's back that up. Because that is a key, everything you just said. But I want my colleagues to understand this because as somebody who is a strong believer in intestinal permeability, aka leaky gut on Google, but intestinal permeability, from talking to my colleagues leading to other things, let's let's walk it back. You discussed how gliadin binds to CXCR3 which is fancy and everything but dumb it down for me really quick gliadin leads to this which leads to zonulin which leads to this so that I can tell my patients and my colleagues can tell their patients. This is this is the process of why I want you to avoid or to avoid gluten to avoid gliadin.So I guess what you would tell patients is basically that their intestinal lining is extremely sensitive to this individual protein and when they take in this protein their body is it's it's mounting a response almost as if there is an invader an immune response to this protein if that is helpful.And you showed it is helpful because zonulin is something that I look for I actually found a lab that can order that so I can look and see, okay, I believe that you do have some intestinal permeability. We know that infection, bacterial overgrowth, and in talks that I've given, I say that high ingestion of gluten does this lead to increased zonulin. I didn't have a mechanism how it did, but now we realize it. You just explained it. So it makes it like every time you dial it down a little further, you're like, no, I believe it more now. So I've been saying that for a long time. Yeah, that is really cool. So yeah, so you, in your science have shown that zonulin leads to intestinal permeability.I was not the person to discover that. But there there is a I believe...You have the opportunity to own it right now. Nobody else has stuck their flag in it.I'm not gonna take credit.You can credit for everything you want. Until somebody else calls me right now and says "that's mine!"Brilliant, man. Yeah, yeah, there there is the mucosal immunology lab at Massachusetts General Hospital, Dr. Alessio Fasano who headed that work. Yeah, I would love to take credit for it, but I think that would follow my career in a negative way.Alessio Fasano basically, I would fly and just listen to him lecture and then leave the whole rest of the, you know, the lecture yet Alessio Fasano is one of my heroes. So yeah, for sure. That's that that's why I thought it was funny. If you claimed it. He seems to have relaxed a little bit over the years, he needs to get back at it. That is awesome. Um, let's talk a little bit about the whole section that you have on treatments, because you did a great job of summarizing different treatments that pharmaceutical companies different people have tried to do. I'm very keen to well, anyways, I'll let you get into it, because he did a great job of reviewing all of it and to show what has promise what doesn't what's there, what has failed in clinical trials, before we even begin to discuss the polyphenols because then the rest of your paper is about, I believe that this is probably the best mechanism. So do you remember some of the stuff that you have in the paper about a few of the different mechanisms that different pharmaceutical companies are looking at?Yeah, for sure. So they can kind of be broken down into two major classes. So I think of them really as patient focused versus protein focused and the patient focused therapies are going to be kind of your immunomodulators things that are affecting the individuals the individual's immune response, that inflammatory cascade through for example, Nexvax was a vaccine that was I think it got to phase two trials and then eventually was, was shut down. We have larazotide acetate, which is a zonulin inhibitor. That one is in I believe, phase three trials now, which is pretty exciting. And those that target the immune response. I also I have to mention my favorite, which is the hook worms. So a hookworm infection can actually mediate immune responses, then take down what would be this overactive immune response and celiac disease, immunosuppressive effects of hookworms have been.So we have looked at trying to use worms for Crohn's disease for the same for the same reason. How does it do it in celiac disease?So in celiac disease, it just dampens the immune response. And what they've shown is that in vivo, individuals who've been infected with hookworms have a decreased IL 15 release upon stimulation with gluten.Interesting. That's the thing where we always say that in third world countries, you don't see autoimmune diseases. A lot of us argued that as to why. Yeah, so that's probably my favorite that I haven't done. But then we have the the protein focused therapies, which I think the most notable are the enzymes. So if you're orally taking in an enzyme that will help break down gluten further, that's one that's been shown to be effective, also some antibodies that will bind to gluten and prevent its digestion. So it's kind of a similar mechanism to what I talked about with polyphenols and those protein focused are basically going to either break down or further sequester. gluten from digestion. .Yeah, you got into a little bit about how these proteins bind and how there's different mechanisms with polyphenols really quick. The nexvax, was that, was that ImmusanT? Do you know the company that was doing it?Yes,So years ago. So Bob Anderson is a guess is a PhD gastroenterologist out of Australia. I had hooked up with him when we were just beginning the whole concept of using polyphenols to treat IBS. And, and it shows how difficult it is to really take a concept. And take it all the way through to something you can get through the FDA because it was like 8, 10 years ago that he was working on this, and it started a company. And then when you said that I was reading your paper, I was like, oh, it didn't work. That guy put his life. I mean, put his heart and soul into it. And so shout out to Dr. Anderson, who really kind of, I think, hopefully his next version will be able to do this. So we can have a vaccine. Everybody's talking vaccines right now. So we'd love to have the old vaccine.It's a hot topic.That's awesome. You wanna ask anything about that? About all of that? Yeah. Man, you must be tired. Thanks, Ken. That was awesome. No, I find it incredibly interesting the way that you've had this pathway to to figure out what proteins are the biggest threat. I was surprised from what you had written specifically about hookworms. And I was just thinking about the, you know, those who who wouldn't have an inflammatory issue because they weren't wearing shoes. Isn't that how you transmit hookworms is through the soles of the feet?I do not remember my parasitology right now, do you know Charlene?I'm not sure I'm pretty sure they were orally administered, at least in the studies.I'm sure in the study they were. My version was the was the old version. We're gonna see if hookworms work here, everybody take your shoes off. That vat right there has placebos or that vat has hookworms just jump around and see what happens.So remember before we recorded and started this episode, we told you we'd leave all of the all of the mistakes in that joke didn't work. And that's fine. It happens occasionally.But I think it's really important because leading up to that you're discussing all these different ways that pharmaceutical companies are trying to do it and people are trying to figure it out use it's really not always like the hookworms oral ingestion, not soles of the feet. But I do think hookworms happen because you get exposed to it. So then this is when you propose why polyphenols. So now this is the peeling back where now you're going to discuss polyphenols. So looking at all those different mechanisms, why do you 30,000 foot view, why do you think polyphenols will be beneficial, and then we'll dial down to the different steps, you've got some great charts and steps A through F on how it works and some incredible science on everything. So why did you think the polyphenols would do this in the very, very, very beginning?So in the very beginning, it seemed like there was probably a pretty good chance that polyphenols would be able to be beneficial because we knew from those studies with using gluten as a fining agent in wine, that there would be an interaction between gluten and these polyphenols. And then we have sort of this added benefit of knowing that polyphenols are generally safe, you know, people consume them every day, as long as they're eating fruits and vegetables. And we know that they have these other beneficial effects for so for example, they have these antioxidant, anti inflammatory effects that are occurring when these compounds are not interacting with protein. So we know that they're already generally a pretty good thing. And protein polyphenol interactions are just kind of this natural phenomenon that we see all the time in many different contexts. So just starting out it seemed like it was probably going to be a slam dunk.That's awesome. All right now, oh, where was it page for this page 19. That little picture sums ups a lot of important things that little picture right there sums up about 15 or 12 pages of material. So this is the your graph here shows stepwise why you can demonstrate how a and then we'll get into this after you go through this but a large polyphenolic compound with more branches can do some of these things. So this is kind of the steps A through F on how these polyphenols may help us deal with gliadin. So on your first part right here, can you please explain the physical sequestration of native gliadins.So with native glutens that's going to be your gliadin before it interacts with any of your digestive enzymes in your gastrointestinal tract. So that would be the form of gliadin, that's going to show up in, for example, a slice of bread. So these are going to be higher molecular weight proteins that are fully intact and haven't been digested at all. And these are able to interact with polyphenols through a variety of molecular mechanisms. So we see a lot of hydrogen bonding, we see ring stacking, one of my earlier papers really gets into the weeds in terms of the types of bonds that are formed from but we see these interactions and the formation of this precipitate and solution. So if you were to combine a solution of polyphenols in a solution of gliadin, you would see it actually form a solid and start to fall out of solution, which is a pretty good indicator that there is a physical interaction going on. So it's kind of the first step. And we see that also with gliadins that have been digested by pepsin and triptan which are two digestive enzymes.What what polyphenol did you start with specifically, what type of polyphenols?So I specifically first was interested in Epigallocatechin Gallate, which is the primary catechin found in green tea. I was interested in egcg because because of its prevalence in green tea, and we know that it has all of these other beneficial effects, it was being studied, in terms of its anti obesity and anti inflammatory effects by another group at Penn State at the time. So it seems like the one to target and some of my later more applied work used green tea extract. So that would also combine other types of catechins and smaller phenolic compounds.Nice. We're gonna get into that and a little bit here. All right, then in your beautiful little graph here. Step two hydrolyzed gliadins.Yeah, so what I just mentioned hydrolyzed gliadins, that would be those which have encountered pepsin and triptan. So breaking those proteins down into smaller digested fragments. And we see the same sort of precipitation forming the same kind of haze formation when we combine those in solution.So basically, we're talking about a larger gliadin molecule versus a smaller one. Regardless, the polyphenols are going to suck up, grab it, and sink down to the bottom. What was that called in wine again? Would you consider this fining also, even though it's not in the wine industry? Can we use theIt is the same molecular mechanism. But it's, I mean, fining I think, refers more to the processing. But we do see protein and polyphenol interactions similar to this in a lot of different areas of science. So again, in wine, because it's sort of the root of this project, we see interactions between small prolene rich proteins and polyphenols in astringency. So like if you take a sip of red wine and you kind of get that drying sensation on your tongue, that's actually the polyphenols from the wine, precipitating your salivary proteins, which are also rich in prolene.So that was I always wondered that also. So okay, so quick question, which is interesting. So if it well, I'll save it for later because I want to go through the mechanisms first. So that's two mechanisms, but I got so many questions for you related to all this stuff. Then there's the aspect of digestive enzyme inhibition.Right. So um, this is actually I think one of the one of the really interesting parts of this study is polyphenols have been noted for anti nutritional properties and the prevention of protein digestion, and a few different studies in the past, showing that individuals have a high intake of polyphenols, they actually can sometimes have issues with protein absorption. So one of the reasons is the direct interactions with protein like we just mentioned, between the polyphenols and gliadin. But another is the fact that these polyphenols can directly inhibit the action of digestive enzymes through either binding directly to the enzyme and kind of changing the shape of the enzyme preventing it from being able to preventing it from being able to hydrolyze its substrate or binding in that same binding pocket for the enzyme and preventing the substrate from even getting in.So that's fascinating. So there's there is a little bit of a debatable thing because when working with scientists in the cattle industry, there's actually some data to show that when you give sheep and cattle large like tannins, they actually have improved nutrition and but they're ruminants and then people try extrapolates the ruminants over here. And then we've worked with some scientists that have actually said, well, the binding, if it binds to the protein, not necessarily the protease or the lipase, or whatever pancreatic enzyme it is, that when it gets since the actual large tannin does not get absorbed, it stays intraluminal, the body can digest the protein off, and then the tannin keeps going. So there's it's interesting because I think that there is some debate a little bit where like you have people like Anna Hagerman that are talking about how it can be an anti nutritional thing. And then you've got these other people in sports nutrition saying no, actually, you can improve the overall nutritional value of foods by taking it with a polyphenol. And so it's it's a fascinating area. And I think that it's kind of a moving target we have seen in clinic in my clinical practice, and in the studies that we've done, we've seen beneficial results using polyphenols. And I think that's why it can do some different things like work as a fasting mimetic molecule and things like that. That's That's really interesting. I did not know that it has the potential to bind to the digestive enzyme. I had not come across that before wild. So...Yeah, because enzymes are proteins. The next one, improved barrier integrity and transport and decreased transport. So um, there have been some studies that have shown in individuals with leaky gut or intestinal permeability, that polyphenols are able to just directly affect intestinal barrier function. And I showed in one of my studies actually, in our untreated controls that we saw an increase in barrier integrity, when we just use green tea extract, compared to the control, so in the absence of gliadin, we still saw an increase in transepithelial electrical resistance,Improved leaky gut, do you have a mechanism for that when it's not related to gliadin?Um, so in terms of improving it, when it's not related to gliadin, it's most likely just related to the inflammatory cascade. And, you know, the gut is kind of just always in flux, and always producing, you know, interleukin 6 810, just everything and kind of mediating that response, I think, can expose potentially some underlying permeability, that it can then reverse.I love that you say that because we talk a lot about other things that create intestinal inflammation like high fructose corn syrup, polyunsaturated fatty acids, like soybean oil, and things like that, that have been shown to create an inflammatory response. So you said something really interesting. We're talking about gliadin here, but you this also shows that it can help with the leaky gut, intestinal permeability, whatever you want to say, when it doesn't even it isn't related to gliadin it can actually do that related to the inflammatory cascade, and we talk a lot about inflammation on the show all the time. inflammation is good when you need it. Bad when it stays there all the time. And unfortunately, our diets I think that we tend to keep it inflamed, if you eat the typical, you know, American diet, the sad diet, you're gonna you're gonna have an inflamed gut, you need to protect it. Definitely. And you haven't gotten to zonulin yet have you?We talked about Zonulin a little earlier.No, like during during the cascade that you had written down with your hand. The reason why I say that is because you had long before in conjunction with the leaky gut protection. You had mentioned that zonulin contributes to leaky gut. And since we had mentioned it earlier, and he hadn't put it on there, they're probably controlling the, or keeping the decrease of zonulin, after having enough polyphenols would also lend toWell, now that he brings it up. So you wrote that gliadin binds to myd88, which ultimately releases the zonulin. So does it prevent the binding to the myd88? Is that how it prevents zonulin from from being released?We don't know the precise mechanism in terms of what interactions it's actually preventing. So where it's really targeting that inflammatory cascade, it would make sense based on our data, that the polyphenols are sequestering the gliadin and preventing it from binding to anything else. But in terms of studies where we actually pinpoint that mechanism, those haven't been done yet. So I think it would be really interesting to do some of this either in vitro or ex vivo if we were able to get tissue cultures to see how that affects really the zonulin release because that's kind of the the linchpin in that mechanism.So that's fascinating. So I've had you know, I've always I treat a lot of small intestinal bacterial overgrowth SIBO patients and I will check them and they will have increased levels of zonulin. I assume it's related to the bacterial inflammatory cascade and we treat it and it goes down. Treat them with Atrantil and it goes down. And I'm assuming it's I got rid of the bacteria, but you just brought up something interesting. There may be something more nuanced going on.Or SIBO I mean a lot of a lot of different options.Yeah. So that's, I think that's, that's another angle. It just shows how much I think there's so much cool chemistry, cool physiology, cool applications of this, that you're that you're really tapping into. And you're, you're bringing up your own questions, you're gonna have a long career chasing your own thoughts. So. And then, we already talked about the anti inflammatory activity, NF Kappa beta, and things like that, that you basically discussed, which is the overall decreasing of the inflammatory response. And then the final one that you discuss in this in this in this figure is the transglutaminase downregulation. Can you explain that that one I was struggling with.Yeah, so that actually is from a really recent paper by a group out of Louisiana State University. And they found that when treating intestinal cells in vitro with Coco polyphenols, they saw a down reveal a down regulation of tissue transglutaminase. So when we have this exposure of gliadin, to our intestinal cells, transglutaminase is released kind of as a response to epithelial damage. It's an enzyme that is found in everyone's body that's associated with wound healing. So when the intestinal when your intestinal barrier is kind of infiltrated by intestinal epithelial lymphocyte, intestinal lymphocytes, sorry. When you see that infiltration, and that damage that's occurring, that's when transglutaminase is released. And what they found in vitro was that we're not seeing that release of transglutaminase when polyphenols were added to that culture.That's super cool. You probably don't have a direct MLA on that yet, but it's definitely been noticed as a as a decrease. Is that what you're saying?Right, yeah.Okay. Now that that's very, very cool, though. I don't think I'd ever heard that before at all.No, that is really cool. And the mechanisms that how you're going to all of this is just absolutely incredible. Alright, so let's dumb it down real quick, for me. I need my prolene and my saliva. And now I understand why, so can you tell me how fat...so like if I eat a ribeye and then take a big, bold Cabernet? Why the Cabernet doesn't have that astringency while I'm eating a fat I've always wondered...Yeah, so fat will coat your tongue. And it's basically creating a layer between the proteins that are in your saliva and inhibiting that binding.So it's, it's making the tannin just slide over the prolene is what you're saying?Um, yeah, you could explain it that way.Well, that's, I'm gonna explain it that way to myself. I'm not gonna get more complex. I'm just gonna go you're just doing this to let it slide over. I liked the way she said, "you could do that."Alright, so in theory, we have done I mean, it's, it's not fining because it's the but but you need to come up with your own term when when polyphenols bind gliadin and sink to the bottom. So shining, Charlene fining and it's Charlening. So when you're Charlening gliadin down in there and then if I take so if I put a bunch of gliadin in this cup and then I put a bunch of polyphenols in there and it it Charlenings it down Charlenings, can I turn that into a verb? Yeah, you did. You just did!So when I'm Charlening the gliadin to the bottom of the cup, and I mix it up and I swallow it. This is the other concept I'm trying to think of does the body then it goes down. I don't feel the astringency because it's already bound to the gliadin or whatever. It's I'm not getting that but will the body then break off? Will the enzyme since the polyphenol is tied to the gliadin? Will my body break off that Charlening molecule? In other words, will it can it still digest the protein that is attached to it?So in terms of whether it can still digest the protein, our data says that it will not so doing an in vitro digestion of polyphenols and gliadins that have been sort of pre combined before all of the pH fluctuations before the introduction of pepsin and trypsin. We've found that that complexation will prevent The digestion of gliadins of native gliadins. And it will prevent the formation of the smaller molecular weight fragments that stimulate the inflammatory response.So since it binds so strongly to the prolene, glutamine aspect, if you have a protein that doesn't have that, do you think that there will be less affinity and it will come apart?Well, that's definitely something we're interested in, in looking at. Now that I have some grad students working on this project, we're really interested in seeing how kind of the matrix effect of everything else in the gut can affect these interactions and affect the stability. So one thing that I think suggests that we'll still see some success with this nutraceutical treatment is the fact that polyphenols generally have a greater affinity to bind to proteins that have a high frequency of prolene. And the high frequency of prolene that we see in gliadin is is fairly unique. We don't really see that much in other food proteins. So it's something we'll need to investigate, but there's definitely a chanceWhat are some other high prolene foods that we typically eat?High prolene foods that we eat? I think you got me on that one. But in terms of the kind of major food proteins that we study, in the lab, so I remember doing some sort of preliminary work with like beta lactam globulin and some casein when I was in grad school. And just to kind of look at precipitation, those definitely have less prolene than than gliadins do. In terms of others that have high amounts of prolene, I'd have to look into that. I remember looking once as to why everybody did why there's a lot of soy issues. And I did see that soy has high prolene compared to other proteins. And so I'm wondering if that's one of the reasons why a lot of people have issues with soy also. I don't know,I that's definitely something that's that's worth looking into. Because it is the high prolene content that kind of gives gliadin that unraveled structure that makes it difficult to break down enzymatically. That's definitely something to look at, but not something I have I've heard or read.You've been slacking CharlenePoor CVs only 17 pages long.You know, you sit there you, you come up with the term Charlening, and you're just resting on your laurels making money off that Trademark. All right. Now my favorite, favorite part of this whole thing you said in your article studies into mechanisms have shown phenolics with large branching structures with greater potential interaction have greater affinity for interacting with gliadin. So that's something that a lot of people don't really understand is that these polyphenolic compounds come in varying shapes and sizes. I this is I'm setting this up, because the scientists that we've been working with in South America, the quebracho Colorado is one of the largest stable polyphenols that we the original research I was doing is because it's both acid stable, and its basic stable, which means it can stay intraluminal in the in the intestine, and then the scientists we've worked with one of them in an in vitro digestion showed that when this becomes fermented, in other words, with our microbiome, that it actually she did a gas chromatograph and showed all these different molecules that came off, one of them being egcg, and other one being quercetin and another one being rutin. And you're like, holy cow, wait a minute, these large building blocks actually have all these smaller phenolic molecules in it. And all the studies have been done on smaller phenolic molecules, because the prior studies were done on that. And you're going to grab a molecule that's already been done. I forgot his name but the but the gastroenterologist that uses egcg to look at ulcerative colitis, and then that guy, because somebody else did it, and that's the proof of concept. What is really interesting is this whole science is using these large if I gave you the largest, most hydroxyl bond, you know, molecule, would this be the thing that would work that I guess your paragraph implies that,Yeah, so it's actually really interesting. And some studies that I've completed that we're kind of working on getting out there at the moment, sort of take this idea of size versus actual shape. So when we talk about polyphenols and their and their structure, we're taking into consideration the molecular weight, but also the branching like you mentioned. So if we compare molecules like Thea Flavin, which is found in black tea versus egcg, which is found in green tea, they have relatively comparable molecular weights. But egcg has this hydroxylation that almost makes it from like arms. And it has this more flexible bendable structure.You lost me though. Would you show that one more time? What does it do?Yeah. So it kind of has these arms that are almost able to wrap around a protein whereas Thea Flavin has, if you look at the structure of this Benzotropolone ring, which is just as large, bulky, sort of ring structure, and it doesn't have sort of that same flexibility as egcg has. So even though Theo Flavin actually is a little bit larger, egcg is able to bind better. So it really comes down to the structure dictating the function of the molecule, which kind of brings it to my lab and my fascination with all of this the food structure and function lab. Yeah, figuring out how structure can affect the function of these molecules with...Oh! That's why you called it that. Food structure and function. Your website. I was like, that's an odd name for website, foodstructureandfunctionlab.com. And now it makes sense, not just the food, or the structure, but it happens to be that the two combine to make a function.Those are really interrelated and biochemistry andFood structure function lab. Sorry, I want to make sure everybody hears that food structure, function lab.comStructure and function lab. Okay just say it one more time.Foodstructureandfunctionlab.comThere we go. Sorry to interrupt. I just want to make sure that peopleNo you're fine. But yeah, conceptually, that is something that I just think is so fascinating how the structure can really affect the function in terms of health. SoSo as a, butt doctor, the thing that's going to blow, take that all up to another level is how the microbiome is involved with us, then we're, like, everything you're doing is fascinating. It's so cool. And then you start fermenting it and seeing what happens, and some pretty incredible magic happens. SoRight, yeah, so fermentation, but then some of the work that I did, during my postdoc at Rutgers University, we were looking at alternative mechanisms for polyphenols to affect the gut microbiome, because we saw with, um, I believe it was cranberry polyphenols, as well as Grapeseed, extract someone before me, and found that supplementation of those polyphenols to an individual with diabetes resulted in the increase of this growth of akkermansia ophelia. And so we're trying to look at how this can why this happens, you know, like, what is the mechanism? And so one of the things that we really got interested in was the potential for polyphenols to act as radical scavengers in the lumen. So whether they're being broken down by the gut bacteria, whether they're scavenging radicals, whether they have an antibiotic capacity, I mean, there are so many options, and it's so fascinating. So, yeah, sorry to go off on that tangent,TThat's pretty much the world I live in because I see my goal. What we have seen through fecal studies, actually, is that when my patients take a either a diet large and polyphenols, or they supplement with Atrantil we have seen an increase in microbial diversity. And then once you have an increase in microbial diversity, you start having different species of bacteria which can do these beneficial things like the anti diabetic, anti obesogenic and then you have the anti. And then people are now looking into that. And that's sort of this whole new field of science called the postbiotics. It's like, what does the so we're almost describing that these become prebiotic, like, we're just something that is not digested and then your own microbiome, but what we're seeing is, is that it's not a one to one, you have to have a diverse microbiome to get the full benefit of these polyphenols. So you can have the structure and function but you also have to have the ability to produce these postbiotics, like have you ever heard of a molecule called urolithin urolithin a urolithin B, you know, things like that. Lactic acid gets, you know, kicks off and we know that that helps, you know with apoptosis and Mitophagy and there's a lot of there's a lot of stuff to uncover. This is a lot of really cool things. What do you think? Alright, so just sum this up. Sorry about that. We covered so much material. So to sum up your whole paper here and in just a couple sentences, because there's a lot that we just talked about, and I want to hear it in your words. How would you describe what you just what we just talked about in just a couple sentences?So overall, we are focusing on developing a nutraceutical approach to treating celiac disease via the natural phenomenon of protein polyphenol interactions, and keeping gliadin from being digested and being recognized by the immune system.She did it in one sentence Ken. Yeah she did. Wow. All right, what's your lab gonna do next? What are you guys working on?We are continuing to pursue this project. It was kind of on a hiatus as I did my postdoc working on a different project. But now that I have my own lab, but I have a couple of graduate students who are really targeting that sort of structure and function angle, we're looking at extracts from different polyphenol rich foods for their ability to basically elicit the same effects that I observed with green tea extract. And we're also trying to kind of target those downstream mechanisms that I discussed in the paper. So what is the impact of polyphenol supplementation on for example, the activity of tissue transglutaminase? What is the impact on the recognition of these proteins by antigen presenting cells? I'm kind of trying to go downstream and sort of look at this. The potential of polyphenols from really every angle of celiac disease.That's awesome. You said you have two graduate students working for you right nowI actually have four right now. Yeah, I have a few that are working. I have two that are working on the celiac disease project. And then two more that are working on another project based on protein polyphenol interactions. We're looking at using novel plant proteins as delivery systems of anthocyanins. Oh, wow, that's awesome. Can you do me a huge favor and subtle debate between me and Eric? Can you just take two of those and have one of your graduate students swallow hookworms have the other one just walk around on hookworms to seeWe haven't even had a hiatus to have this debate.I have a student who an undergrad who really wants to work in my lab, so I'll pitch that project to him.Poor undergrad doing anything. to get into graduate. Hookworm internship. Nice. Well, Dr. Charlene Van Buitin. Thank you so much PhD as Assistant Professor of food science and Human Nutrition at Colorado State University. I can't thank you enough for coming. Oh, yeah. Without I want to repeat your your website foodstructureandfunctionlab.com correct? Everything will be listed in show notes will have links to your study as well as your own personal website and Ken, any closing remarks?Your social media hashtag, there's no way you're as smart as I am. Do you have any social media or anything? Do you want to get out there? I'm on Twitter, cbvanbuitin. If anyone has questions or is interested, I don't share that much science on there. Mostly insight to working in academia. But yeah, that's that's really all I'm on.So if you want hard hitting political opinions. Go to her Twitter account. Not at all. Thank you so much. Don't go anywhere once we wrap up the show. But gut check project fans, that is going to be episode number 52. Be sure and check show notes. So you can connect with Dr. Van Buiten. And, again, if you have anyone in your life or yourself suffer from celiac disease, we think that this information could be of just huge, great consequences for you and your family. 100% and this is why we do this this is we get an opportunity to meet brilliant people like you, thank you for taking the time to do this. And hopefully this will this will get somebody to call you lab. Hopefully we'll be able to do some sort of collab, I would love to collaborate with your lab. We can we'll talk more about that. But maybe another scientist goes, Oh, this is a little piece I was looking for. This is how we help each other as a community. I'm a clinician, you're a bench researcher. I'm going to apply whatever you tell me and see if it works and just thank you for doing everything that you do.Thanks. Thanks so much for having me.Absolutely. That's episode number 52. We'll see y'all next time. Like and share. See you next time. Bye bye.

Introduction: The chemokine CXCL10 is produced during infection and inflammation to activate the chemokine receptor CXCR3, an important regulator of lymphocyte trafficking and activation. The goal of this study was to assess the contributions of CXCL10 to the pathogenesis of experimental septic shock in mice. Methods: Septic shock was induced by cecal ligation and puncture (CLP) in mice resuscitated with lactated Ringer's solution and, in some cases, the broad spectrum antibiotic Primaxin. Studies were performed in CXCL10 knockout mice and mice treated with anti-CXCL10 immunoglobulin G (IgG). Endpoints included leukocyte trafficking and activation, core body temperature, plasma cytokine concentrations, bacterial clearance and survival. Results: CXCL10 was present at high concentrations in plasma and peritoneal cavity during CLP-induced septic shock. Survival was significantly improved in CXCL10 knockout (CXCL10KO) mice and mice treated with anti-CXCL10 IgG compared to controls. CXCL10KO mice and mice treated with anti-CXCL10 IgG showed attenuated hypothermia, lower concentrations of interleukin-6 (IL-6) and macrophage inhibitory protein-2 (MIP-2) in plasma and lessened natural killer (NK) cell activation compared to control mice. Compared to control mice, bacterial burden in blood and lungs was lower in CXCL10-deficient mice but not in mice treated with anti-CXCL10 IgG. Treatment of mice with anti-CXCL10 IgG plus fluids and Primaxin at 2 or 6 hours after CLP significantly improved survival compared to mice treated with non-specific IgG under the same conditions. Conclusions: CXCL10 plays a role in the pathogenesis of CLP-induced septic shock and could serve as a therapeutic target during the acute phase of septic shock.

Thu, 18 Oct 2012 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/15001/ https://edoc.ub.uni-muenchen.de/15001/1/Neumann_Iris.pdf Neumann, Iris

Background: The fetal immune system is characterized by a Th2 bias but it is unclear how the Th2 predominance is established. Natural killer T (NKT) cells are a rare subset of T cells with immune regulatory functions and are already activated in utero. To test the hypothesis that NKT cells are part of the regulatory network that sets the fetal Th2 predominance, percentages of Vα24(+)Vβ11(+) NKT cells expressing Th1/Th2-related chemokine receptors (CKR) were assessed in cord blood. Furthermore, IL-4 and IFN-γ secreting NKT cells were quantified within the single CKR(+) subsets. Results: Cord blood NKT cells expressed the Th2-related CCR4 and CCR8 at significantly higher frequencies compared to peripheral blood NKT cells from adults, while CXCR3+ and CCR5+ cord blood NKT cells (Th1-related) were present at lower percentages. Within CD4negCD8neg (DN) NKT cells, the frequency of IL-4 producing NKT cells was significantly higher in cord blood, while frequencies of IFN-γ secreting DN NKT cells tended to be lower. A further subanalysis showed that the higher percentage of IL-4 secreting DN NKT cells was restricted to CCR3+, CCR4+, CCR5+, CCR6+, CCR7+, CCR8+ and CXCR4+ DN subsets in cord blood. This resulted in significantly decreased IFN-γ /IL-4 ratios of CCR3+, CCR6+ and CCR8+ cord blood DN NKT cells. Sequencing of VA24AJ18 T cell receptor (TCR) transcripts in sorted cord blood Vα24Vβ11 cells confirmed the invariant TCR alpha-chain ruling out the possibility that these cells represent an unusual subset of conventional T cells. Conclusions: Despite the heterogeneity of cord blood NKT cells, we observed a clear Th2-bias at the phenotypic and functional level which was mainly found in the DN subset. Therefore, we speculate that NKT cells are important for the initiation and control of the fetal Th2 environment which is needed to maintain tolerance towards self-antigens as well as non-inherited maternal antigens.

Die Rekrutierung von Zellen ist ein komplexer, in mehreren Schritten ablaufender Mechanismus, der eine zentrale Bedeutung für zahlreiche biologische Prozesse, wie z.B. Entzündung, Transplantatabstoßung, Tumormetastasierung und Stammzell¬migration hat. Die Migration von Zellen aus dem Blutstrom oder einem Reservoir in ein Zielgewebe bzw. Zielorgan und umgekehrt wird durch zahlreiche spezifische und unspezifische Reize ausgelöst und orchestriert. Dies erfolgt zu einem großen Teil durch von Chemokinen regulierte Mechanismen. Chemokine sind chemotaktische Zytokine, welche an spezifische auf der Zelloberfläche exprimierte Chemokinrezeptoren (CCR) binden. Zellen mit entsprechenden Chemokinrezeptoren wandern entlang eines Chemokingradienten zum jeweiligen Ziel, z.B. einem Entzündungsherd oder einem Zielorgan. Erstes Ziel dieser Arbeit war die Analyse der Chemokinrezeptorexpression im kutanen T-Zell Lymphom (CTCL), einem Non-Hogkin-Lymphom mit primärer kutaner Manifestation. Der Nachweis von Chemokinrezeptoren erfolgte in vitro mit der Polymerasekettenreaktion (PCR), der Durchflusszytometrie und mit Migrations-versuchen. Der Chemokinrezeptornachweis auf Hautschnitten von CTCL-Patienten erfolgte mit der Immunhistochemie. Erstmals konnte der hautassoziierte Chemokinrezeptor CCR10 im Rahmen des CTCL nachgewiesen werden. Außerdem gelang der Nachweis der Chemokinrezeptoren CCR4, CCR7 und CXCR3 in Hautschnitten und Lymphknotenbiopsien. CXCR3 wurde erstmals im Sezary Syndrom, einer fortgeschrittenen und aggressiven CTCL-Unterform, beschrieben. In der Immunhistochemie wurde die stärkste CCR10-Expression in Sezary Syndrom-Hautschnitten festgestellt. In Biopsien von befallenen Lymphknoten zeigte sich ein auffälliges CCR10-Verteilungsmuster: CCR10-positive Zellen wurden im Lymphsinus nachgewiesen, drangen aber nur vereinzelt in den Lymphknoten ein. In peripheren, nicht-kutanen Lymphomen wurde CCR10 nicht nachgewiesen und ist somit vermutlich exklusiv auf dem primär kutanen CTCL exprimiert. Es ist davon auszugehen, dass CCR10 den Epidermotropismus vor allem in aggressiveren Stadien reguliert. Die Bedeutung von CCR10 für die lymphatische Metastasierung des CTCL ist noch nicht geklärt. CCR10 könnte in der Zukunft als Faktor für die klinische Einstufung des CTCL oder als Ziel für eine gezielte Tumortherapie dienen. Die gezielte Tumortherapie ist u.a. mit Chemokinantagonisten möglich. Sie erlauben die gezielte Beeinflussung der chemokingesteuerten Rekrutierung von Leukozyten, Stammzellen oder Tumorzellen. Deshalb wurde ein membranbindender Antagonist des Chemokins CCL5, als potentielles Agens für die lokale Therapie von Tumoren oder von Transplantatabstoßungen, generiert. Das Chemokin CCL5 und seine Rezeptoren spielen in der akuten Transplantatabstoßung und in der Tumorprogression, z.B. im Mammakarzinom, eine zentrale Rolle. Der CCL5-Antagonist Met-RANTES inhibiert in Transplantatabstoßungsmodellen die Rekrutierung von Leukozyten. Der akute Entzündungsprozess und der daraus resultierende chronische Gefäßschäden werden so vermindert. Auch in einem Tumormodell ist ein Effekt auf die lokale Tumorprogression wahrscheinlich. Der in dieser Arbeit hergestellte CCL5-Antagonist Met-RANTES(Dimer)-GPI soll eine lokale Therapie ohne systemische Nebenwirkungen ermöglichen. Durch die erstmals beschriebene Bindung eines Chemokins oder Chemokinderivats an einen Glykosylinositolphosphatidyl (GPI)-Anker soll der Antagonist effektiv in die Zellmembranen von Endothelzellen inkorporiert werden, länger auf dem Endothel verbleiben und die benötigte Proteinmenge vermindern. Zunächst wurde durch die Erweiterung des signalgebenden N-Terminus von CCL5 der CCL5-Antagonist Met-RANTES generiert. Ein Aminosäureaustausch erzeugte ein dimerisierendes Molekül, welches einfacher als die zur Polymerisierung neigende Wildform zu isolieren war. Das Protein wurde mit der PCR mit einem GPI-Anker fusioniert und in Chinese Hamster Ovary (CHO)-Zellen subkloniert. Met-RANTES(Dimer)-GPI wurde erfolgreich aus den CHO-Zellen isoliert und mit der Säulenchromatographie gereinigt. In in vitro-Versuchen wurde Met-RANTES(Dimer)-GPI effektiv in die Oberfläche von humanen Endothelzellen reinkorporiert und hemmte die transendotheliale Migration von Monozyten, welche bei der Transplantat¬abstoßung und bei der Tumorprogression eine wichtige Rolle spielen. Mit Met-RANTES(Dimer)-GPI präperfundierte Transplantate zeigen möglicherweise einen geringeren vaskulären Schaden bei der akuten Transplantatabstoßungsreaktion. Im Tumormodell soll eine Hemmung der Tumorinfiltration durch Monozyten, welche eine beschleunigte Tumorprogression verursachen, erreicht werden. Im Vergleich zu nicht GPI-gebundenen CCL5-Antagonisten würde eine lokale fokussierte Therapie ermöglicht und eine eventuell geringere zu applizierende Proteinmenge bei längerer Verweildauer erzielt. Die Ergebnisse dieser Arbeit erlauben zunächst einen genaueren Einblick in die Pathogenese des CTCL. Der Chemokinrezeptor CCR7 wird vor allem von fortgeschrittenen Formen mit lymphatischer Infiltration exprimiert. CCR10 wird erstmals im Zusammenhang mit dem CTCL beschrieben und vor allem von fortgeschrittenen Unterformen exprimiert. Desweiteren wurde ein membranbindender Chemokinantagonist hergestellt. Erstmals wird die Kombination eines Chemokins oder Chemokinderivats mit einem GPI-Anker beschrieben. Der Antagonist erlaubt eine hohe lokale Applikation ohne systemische Zirkulation des Agens. Mögliche Einsatzgebiete sind die gezielte Tumortherapie oder die Behandlung der Transplantatabstoßung.

Fri, 18 Jul 2008 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/8882/ https://edoc.ub.uni-muenchen.de/8882/1/Schwarz_Johannes.pdf Schwarz, Johannes

Hintergrund und Fragestellung: Die Konfrontation des Immunsystems mit einem definierten Antigen löst eine spezifische Immunantwort aus. Die daran beteiligten TH-Zellen können anhand der von ihnen sezernierten Zytokine in TH1- und TH2-Zellen sowie in weitere Subtypen differenziert werden. Dabei sind TH1-Zellen durch die Synthese von IFN-g charakterisiert, während TH2-Zellen vorwiegend Interleukin-4 produzieren. Die gezielte Auswanderung von TH-Zellen in inflammatorische Gewebe wird unter anderem durch Chemokinrezeptoren, welche chemotaktische Zytokine (sog. Chemokine) binden, gesteuert. TH1-Zellen exprimieren bevorzugt CXCR3 und CCR5, TH2-Zellen dagegen CCR3 und CCR4. TH-Zellen sind an der Pathogenese von Typ I Allergien entscheidend beteiligt. Für die Entwicklung der hinsichtlich der Ausbildung von Typ I Allergien protektiven TH1-Zellen scheint die Auseinandersetzung des Immunsystems mit mikrobiellen Antigenen in der allerfrühesten Kindheit notwendig zu sein. Ziel der vorliegenden Arbeit war es, in einem Pilotprojekt an einem Normalkollektiv zweijähriger Kinder das Expressionsmuster oben genannter Chemokinrezeptoren auf peripheren TH-Zellen zu analysieren. In einem zweiten Schritt sollte untersucht werden, ob ein positiver Zusammenhang zwischen TH2-assoziierten Chemokinrezeptoren und der Familienanamnese hinsichtlich atopischer Erkrankungen, der klinischen Diagnose einer atopischen Dermatitis und anderen in der Allergiediagnostik eingesetzten Parametern besteht, oder sich ein negativer Zusammenhang zwischen den TH1-assoziierten Chemokinrezeptoren und oben genannten Parametern zeigen lässt. Darüber hinaus sollte überprüft werden, ob zwischen der Endotoxinexposition, als Proxy für die mikrobielle Exposition in den ersten Lebensmonaten, und dem Expressionsmuster der Chemokinrezeptoren ein Zusammenhang nachgewiesen werden kann. Ergebnisse:Die Chemokinrezeptoren CCR4, CCR5 sowie CXCR3 waren bei allen Probanden nachweisbar. CCR3 konnte bei acht von 37, IFN-g bei 33 von 42 untersuchten Probanden nachgewiesen werden. IL-4 war nicht nachweisbar. Es bestand ein positiver Trend in der Korrelation zwischen der mRNA-Expression von IFN-g und den Chemokinrezeptoren CCR5 (r=0,571) sowie CXCR3 (r=0,386). Ebenso zeigte sich ein positiver Trend in der Korrelation zwischen CCR5 und CXCR3 (r=0,273). Diese Zusammenhänge waren nicht statistisch signifikant. Dagegen korrelierte die CCR5 mRNA-Expression hochsignifikant (p=0,001) sowie die CCR4 mRNA-Expression grenzwertig signifikant (p=0,046) mit dem Endotoxingehalt in der Muttermatratze der Probanden. Schlussfolgerungen: ·In unstimulierten peripheren T-Helferzellen zweijähriger Kinder ist die Quantifizierung der Chemokinzeptoren CCR4, CCR5 sowie CXCR3 mit Hilfe der real-time RT-PCR möglich. IFN-g ist in der überwiegenden Anzahl der untersuchten Probanden nachweisbar, CCR3 nur bei wenigen, IL-4 bei keinem der Probanden. ·Die mRNA-Expression TH1-/TH2-assoziierter Chemokinrezeptoren in unstimulierten, peripheren T-Helferzellen ist für die Differenzierung von Kindern mit von Kindern ohne atopische Dermatitis nicht hilfreich. ·Dagegen scheint die mRNA-Expression von CCR5 als möglichem Marker einer TH1-Antwort mit dem Symptomenkomplex wheezing zu korrelieren. Dieser Befund muss in Studien mit großen Fallzahlen überprüft werden. Wheezing ist am häufigsten mit viralen Infektionen vergesellschaftet. Die weitere Nachuntersuchung der Kinder im Schulalter wird zeigen, bei welchen Kindern sich dennoch Asthma manifestiert. ·Die perinatale Endotoxin-Exposition ist mit einer erhöhten CCR5 mRNA-Expression peripherer TH-Zellen assoziiert. ·Damit deuten die Befunde auf eine Verwertbarkeit der CCR5 mRNA-Expression als TH1-Marker in unstimulierten peripheren TH-Zellen hin.

Background: Lymphocytes are recruited to sites of inflammation by chemokines. Accordingly, a number of chemokine receptors are differentially expressed on effector T cells. We hypothesized that selected T cells accumulate in inflammatory lung diseases involving different pulmonary compartments. To test this hypothesis the frequencies of chemokine receptor expressing T cells were compared in peripheral blood (PB) and bronchoalveolar lavage fluid (BALF) of children with chronic bronchitis and interstitial lung diseases. Methods: BAL was performed in 70 children. According to clinical, macroscopic and cytological findings 37 children were selected for the study and classified as chronic bronchitis (CB, n=17, m=7, mean age 6.6 yrs.) or interstitial lung diseases (ILD, n=20, m=13, mean age 7.0 yrs.). Patients (n=33) with other diagnoses or without cells in BALF were excluded. CD4+ and CD8+ T cells were analyzed in PB (n=30) and BALF (n=37) by flow cytometry. The percentages of CCR5+and CXCR3+ cells were determined within each T cell subset. Results are expressed as medians. For statistical analyses non-parametric tests (Wilcoxon, Mann-Whitney U) were applied. Results: In peripheral blood, the percentage of CXCR3+ T cells (16.4%, range: 0-35.2%) was higher than the percentage of CCR5+ T cells (3.9%, range: 0-19.1%; p

Memory T cells display phenotypic heterogeneity. Surface antigens previously regarded as exclusive markers of naive T cells, such as L-selectin ( CD62L), can also be detected on some memory T cells. Moreover, a fraction of CD45RO(+) ( positive for the short human isoform of CD45) memory T cells reverts to the CD45RA(+) ( positive for the long human isoform of CD45) phenotype. We analyzed patients with biopsy-proven localized Wegener's granulomatosis (WG) (n = 5), generalized WG (n = 16) and age- and sex-matched healthy controls ( n = 13) to further characterize memory T cells in WG. The cell-surface expression of CD45RO, CD45RA, CD62L, CCR3, CCR5 and CXCR3 was determined on blood-derived T cells by four-color flow cytometric analysis. The fractions of CCR5(+) and CCR3(+) cells within the CD4(+) CD45RO(+) and CD8(+) CD45RO(+) memory T cell populations were significantly expanded in localized and generalized WG. The mean percentage of Th1-type CCR5 expression was higher in localized WG. Upregulated CCR5 and CCR3 expression could also be detected on a fraction of CD45RA(+) T cells. CD62L expression was seen on approximately half of the memory T cell populations expressing chemokine receptors. This study demonstrates for the first time that expression of the inducible inflammatory chemokine receptors CCR5 and CCR3 on CD45RO(+) memory T cells, as well as on CD45RA(+) T cells ('revertants'), contributes to phenotypic heterogeneity in an autoimmune disease, namely WG. Upregulated CCR5 and CCR3 expression suggests that the cells belong to the effector memory T cell population. CCR5 and CCR3 expression on CD4(+) and CD8(+) memory T cells indicates a potential to respond to chemotactic gradients and might be important in T cell migration contributing to granuloma formation and vasculitis in WG.