Podcasts about cd25

Multiple Sclerosis News Today's multimedia associate, Price Wooldridge, reads a news article about how the myelin sheath on specific neurons that suppress excess electric activity in other nerve cells may disrupt cognitive abilities of brain. And reads the column by Ed Tobias, The MS Wire, “MS News That Caught My Eye Last Week: Brain Atrophy, CD25, Neurodynamic Therapy, Anxiety”. =================================== Are you interested in learning more about multiple sclerosis? If so, please visit: https://multiplesclerosisnewstoday.com/ ===================================== To join in on conversations regarding multiple sclerosis, please visit: https://multiplesclerosisnewstoday.com/forums/

本期节目，你将惯例听到诸位主播坐在一起（或远程连线），回顾一下过去一年各自的人生经历，以及进行一波例行的年度推荐环节~因时长原因，新春节目将分割放送，分别为驻京主播，驻上海、深圳及日本、新西兰分部主播（……），敬请期待！【6:00】鸟TIME——邪会今年的同人创作回顾，CD25的一次出展经历【56:30】紫陌TIME——安利一本书，告诉大家什么是都市传说【1:13:10】跑题环节——告诉大家什么是邪会都市传说（×）【1:23:22】琴酒TIME——试玩了一年手游的中年社畜个人向总结再安利下广播催更群：471737502～或者赞助我们：https://afdian.net/@fyxhcnVOICE：琴酒；紫陌红尘；浴火不死鸟最后祝大家，新春快乐，好好工作，好好生活，多吃蔬菜。

Hi folks!I didn't get to come home for lunch today so this episode had to happen on the go! This is Take 2 of a conversation with myself about patience as the plans are reinvented.It was a pretty long day, but there is light at the end of the tunnel.Much love,jFind out more at https://creativedrive.pinecast.co

When Benji's wife began creating YouTube videos in 2011. Benji saw the potential to create a massive business. He quit his job in real estate and focused his time 100% into creating online content. As they grew, Benji created his own influencer channel and has since been recognized on Forbes’ as “Top 20 Must-Watch YouTube Channels." Creative Disruption Podcast with Ricky Ray Butler and Derral Eves Insights and stories from leading creators, writers, producers and marketers on how the worlds of advertising, entertainment, and data science are converging. Subscribe To YouTube

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Activation of immune cells is the all-important first step in mounting an immune response. Immune cell activation is a popular area of research because so much happens that is key to the downstream goal of fighting infection, cancer, and disease. There are many ways to measure immune cell activation, and they all have utility. Methods can be grouped into four main categories: Proliferation Assays, Cytokine Measurement, Surface Antigen Expression, and Cytotoxicity. In this webinar, we'll discuss specific assays in each of these categories, the joys and pitfalls of each assay, and recommendations on how to choose the best method. You will learn tips and strategies for successful assay development using the following methods: Proliferation: - 3H-Thymidine Uptake - Bromodeoxyuridine Uptake (BrdU) - ATP Luminescence - Fluorescent Dye Reduction (CFSE) Cytokine Measurement: - Multiplex vs. Single Cytokine - Choice of Cytokine (IFNg, TNFa, IL-6, IL-1?, etc.) - Kinetics of Cytokine Release Surface Antigen Expression: - CD69, CD25, PD-1, etc. - Combine with CFSE, Ki67 or BrdU - Kinetics are Important Cytotoxicity: - Two-Label Flow Cytometry - Calcein AM Dye Release - Luciferase Transduced Targets - Annexin V

Episode 25 already?! Wow, the silver jubilee. Give us a moment to bask in this ~1 year of existence (thanks to you all!). This week, we spent some time reflecting on our progress, share the evolution of our message, and hint at future projects. There is a lot headed for you all and we are excited to share soon!

Hyperstyles. CD25 | Full-On Fusion | Tracklist can be found at: https://soundcloud.com/lentej/ Enjoy and dance on!

[intro music]   Hello, and welcome to Episode Thirty-One of Multiple Sclerosis Discovery, the podcast of the MS Discovery Forum. I’m your host, Dan Keller.   This week’s podcast features an interview with Dr. Lloyd Kasper about the gut microbiome and its role in MS. But to begin, here is a brief summary of some of the latest developments on the MS Discovery Forum at msdiscovery.org.   Last week our parent organization, the Accelerated Cure Project, launched its latest endeavor called “iConquerMS.” iConquerMS aims to enroll 20,000 people living with MS to play an active role in research, empowering them to securely submit their health data, influence the studies that are carried out by the initiative, and stay informed about the research. Visit iConquerMS.org for more information.   Vision and sensorimotor problems go together in some MS patients. A recent publication in the journal Neurology examined the relationship between MRI measures of the spinal cord and retina in patients with MS. The investigators found some correlation between the two types of metrics, but they also found that damage in each structure had independent relationships with disability. Read the full story in our “news and future directions” section.   And lastly, our previous podcast contained an error. We mentioned a story about a proof-of-concept study of a novel way to monitor lesion repair. However, the story was withheld from publication due to a delay in the release of the research article. The story is now live on our website.   [transition music]   Now to the interview. Dr. Lloyd Kasper is a faculty member of the Geisel School of Medicine at Dartmouth College. He met with MSDF Executive Editor, Bob Finn, to talk about his research on the gut microbiome and MS.   Interviewer – Robert Finn Dr. Kasper, welcome.   Interviewee – Lloyd Kasper Thank you.   MSDF So to start, why on earth would someone interested in a neurological disease such as MS concern himself with bacteria in the intestines; what’s the connection?   Dr. Kasper That’s actually a very valid question. And the answer to that question is pretty straightforward, is that there’s a very clear brain-gut access so that the brain talks to the gut primary modulating the physiology of the gut through secretion of a variety of molecules, vasoactive proteins, etc. That in turn affects the motility of the gut. By affecting the motility of the gut, you also affect everything that’s inside the gut, which is – as you mentioned just previously – the 100 trillion bacteria that each and every one of us in this world has. And those bacteria in response to the changes in motility shift their behavior, because these are living organisms, and they secrete a wide range of metabolites.   For the purposes of simplicity, you can look at those metabolites and the effect of those various metabolites on the immune system, taking into account that the gut is the largest immune system in our body – 80% of our immune cells are in the gut. So you’ll have this clear interaction between the brain, its activity physiologically on the gut, and the gut’s activity on the bacteria, and then the bacteria’s activity back on the immune system which leads to issues related to the brain.   MSDF So you partly answered my next question. There are microbiomes in other places besides the gut – the skin, the urinogenital tract, etc. Do those other microbiomes have any affect or any relationship to multiple sclerosis, do you think?   Dr. Kasper First of all, the association between the gut microbiome and MS has not yet been fully established, there’s experimental data that would suggest that there is a relationship between the two but that’s still at the experimental level. There really has been very little exploration of the other microbiomes within the body. Remember, the microbiome is not just the microflora. What the microbiome is is the genome of the flora in its relationship to the genome of its host. So when you look at the genomics of MS, for example, in the host – which there’s a lot of work that’s being done – you’re only looking at a fraction of the genetic material that’s involved in this relationship between the gut and the body that it’s in OR any of the other sites that we have microflora – our mouth, as you pointed out; our ears – inside of our ears; our lungs. Those are all areas that bacteria in our body exists in balance with us to achieve a homeostasis. The reason for looking at the gut microbiome is that because it’s the largest, probably the most complex as well.   MSDF So you focused much of your attention on a single bacterial species. Let me see if I pronounce this correctly – Bacteroides fragilis– am I close?   Dr. Kasper Correct.   MSDF And a single substance that it produces, polysaccharide A, or PSA – which has no relation to prostate specific antigen. Why are you focusing on that species and that product?   Dr. Kasper Well, there is mounting evidence that there are several phyla that colonize the gut. The two major phyla of interest are Firmicutes, which are gram-positive aerobes, and Bacteroides, which are gram-negative anaerobes. I’m talking about at the phyla level over which there is no kingdom, phylum, class, order, family, genus, species. Under each one of those phyla there are many different species. We’ve focused in on primarily Bacteroides because Bacteroides fragilis is a very common commensal that essentially inhabits in the neighborhood of 80-90% of all mankind in the world. Bacteroides as a phyla has been associated with the induction of regulatory T cells. Regulatory T cells live in the colon, in and around the colon, and that’s where Bacteroides live. And it’s been shown that Bacteroides as a phyla have the capacity to drive regulatory T cells.   The reason it’s important in MS is because there is a known deficit in the regulatory T cell population in patients with MS. And we chose Bacteroides fragilis because of all the Bacteroides species, that’s the one that we actually know most about immunologically. There’s at least 20 or 25 years’ worth of very, very important data that shows how this particular molecule, this polysaccharide A – and it’s a polysaccharide, it’s not a peptide, it’s a polysaccharide – how this polysaccharide can drive the immune system to a regulatory phenotype that’s associated with the induction of regulatory T cells, production of IL10, all those factors which are important in MS which we know are deficient in those with MS.   MSDF When you say drive the immune system, drive T regs, what do you mean by that?   Dr. Kasper Basically, these bacteria have the capacity to convert effector cells, which would be CD4 positive CD25 negative cells to a regulatory phenotype, which would be CD4 CD25 positive associated with sort of the standard-bearer of regulatory cells, which is Foxp3, which is a nuclear antigen that’s been characterized with it. So this molecule has a remarkable capacity to do that both in vivo and our studies show you can do that actually in vitro as well. So you can take cells that are negative that would be considered naïve or effector-type cells, culture them with this PSA molecule, and convert them to regulatory cells which we know are important in controlling the disease.   MSDF So remind me whether you want more or fewer of these regulatory T cells.   Dr. Kasper It depends where you are in life. To give you sort of a circumstantial argument, we know that Firmicutes, which is that other major phyla, has been associated with a number of disease states, including obesity – just to name one – atherosclerosis, but we also know that the Firmicutes have the capacity to drive IL-17. The regulatory T cells are cells that control the IL-17 response, so it’s important to have regulatory T cells to control the IL-17. We know experimentally that IL-17 drives the experimental form of multiple sclerosis EAE, and there is mounting data – and pretty conclusive, I think – MS is probably at least in part driven by IL-17 cells. So you need these regulatory T cells to control that IL-17 response which is probably being driven by the Firmicutes population. And I’m oversimplifying this, because you remember, you’ve got a hundred trillion cells downstairs making god knows how many different metabolites with over a million genes. So what I’m presenting to you is a very simplified version of this remarkably complex organ.   MSDF So is this leading toward clinical utility for polysaccharide A?   Dr. Kasper We hope so.   MSDF Can you tell me more about that?   Dr. Kasper Well, again, our experimental data – at least in EAE – demonstrates that animals that have been induced with EAE are protected by this polysaccharide. Animals that have EAE, we can therapeutically treat them with this. So this is the first demonstration that a commensal-derived bacterial product that’s within essentially pretty much all of mankind has the capacity to induce regulatory T cells. We don’t know if MS patients are deficient in this or they have the genetic makeup that they can’t respond to it, or whatever it may be. As I said, there’s a real complexity. But the simple observation as we know is that if we take animals that are susceptible to EAE and we treat the prophylactically or therapeutically, we’re able to protect them very, very nicely against the disease process.   And now we have preliminary data in humans that we can take human cells in vitro out of a person and we can drive those human cells from an effector CD4-positive CD25-negative phenotype to a regulatory phenotype by this molecule; just five days of exposure and you see this very nice conversion that’s associated with increased IL10 protection, etc.   MSDF Do you imagine that the PSA molecule itself, if drug development goes on, is there any chemistry that needs to be done before it might possibly be therapeutic?   Dr. Kasper A lot of the chemistry has been done. We have a pretty good idea of what the molecule looks like, it’s a repeating polysaccharide chain. And we know what the conditions are at least in animals as far as innate response molecules – TLRs, toll-like receptors, etc. So as far as the molecule itself, I think we have a pretty good understanding. As I said, there’s about 20 years’ worth of very solid biology behind this molecule. So how far we are away from the clinic at this point is a matter of time, resources, and money to be able to move it from the experimental stage that we’re in into the clinic.   MSDF So you’re not the only research group working on the connection between the gut microbiome and multiple sclerosis. I wonder if you can talk a little bit about how your research fits in with the various other approaches that are going on.   Dr. Kasper Our research has been focused primarily on immune regulation – how to get the disease under control, at least experimentally and hopefully in MS patients. Most of the other labs are looking primarily at what bacteria or bacteria populations are responsible for affecting the disease; what’s driving the disease. We’ve sort of kept away from that because we were fortunate in being able to find this one molecule derived from a bacteria, as I said, that much of mankind is colonized with, so we’ve been focused mostly on how to regulate the disease rather than what’s driving the disease.   MSDF Now, as you know, there’s been a lot of talk and controversy about the role of diet in multiple sclerosis. Do you think that gut bacteria and the substances they product may provide that missing link connecting diet with MS.   Dr. Kasper I think that diet’s going to turn out to be one of the more critical environmental factors that’s associated with the disease process.   MSDF Can you say a little bit more about that?   Dr. Kasper Well, if you look at all the risk factors that we know for MS, that being genetics, obesity, smoking, gender – just to name a few – there’s about six or seven of them. Every one of those risk factors is associated with the microbiome. The common denominator for all the risk factors we know so far in MS is the microbiome, and that includes genetics. As I said, the microbiome is a two-way street; it induces things in us and we do things in turn to it, so it’s a binary system. So our speculations – and we just had a paper published in FEBs – Federation of Experimental Biology – is we’re speculating that the gut microbiome is the major environmental risk factor for MS because it includes all of the known risk factors.   So how can you adjust that? Well, the most logical way is diet, right, because it’s the change in the human diet over the last hundred years that may be accountable for the rise in the disease process. It may also be the change in the diet in Africa as well as Asia which were relatively unknown for MS, but now the incidents in Asia as well as in Africa is approaching about the same as it is in the United States and Europe. So as diet has changed, so has the incidence of the disease gone up. So I’m speculating that diet will turn out to be a very important factor in controlling the microflora, which in turn allows for the balance, the homeostasis, in individuals.   MSDF Well, very interesting. We’ve come to the end of our time, but is there anything you’d like to add, any important questions that I haven’t asked that I should have asked?   Dr. Kasper No. I think the question about the diet, you know, where do you go from here? Because it’s going to take years and years for scientists and clinicians to sort out what’s actually going on in the microbiome. We’re at the tip of the iceberg in this really, because not only is it the immunology that’s important but it’s the physiology and the physiologic changes that the gut microbiome may be creating in people. So as we get better definition of what activities are going on in the microbiome, the greater the likelihood we’ll have of understanding a whole range of human diseases. And not just MS, but that’s all other autoimmune diseases, cancer, obesity, you know, it’s a long list.   And it may ultimately turn out that it’s a clue to our understanding of cancer, for example, because as the microflora shifts as we grow older – which it does – perhaps what we’re seeing is that early on we have bacteria that induce inflammatory processes – which is why MS is a disease of young people – that tends to peter out as you get older. It’s a well-known thing. It doesn’t go away but it tends to peter out. But that may be parallel to the shift in the microflora that’s going on. So early on in the western diet you’re having mostly Firmicutes. As we get older that shifts to more of Bacteroides, which has more regulation. What does more regulation equal? Well, you’re down-regulating the immune system, and as we get older what do we become susceptible? Cancer. So there’s a real balance that’s going on here. And I think a lot of the clues to human biology as far as disease state are going to ultimately be related to the microbiome.   MSDF Dr. Kasper, thank you very much.   Dr. Kasper Thank you.   [transition music]   Thank you for listening to Episode Thirty-One of Multiple Sclerosis Discovery. This podcast was produced by the MS Discovery Forum, MSDF, the premier source of independent news and information on MS research. MSDF’s executive editor is Robert Finn. Msdiscovery.org is part of the non-profit Accelerated Cure Project for Multiple Sclerosis. Robert McBurney is our President and CEO, and Hollie Schmidt is vice president of scientific operations.   Msdiscovery.org aims to focus attention on what is known and not yet known about the causes of MS and related conditions, their pathological mechanisms, and potential ways to intervene. By communicating this information in a way that builds bridges among different disciplines, we hope to open new routes toward significant clinical advances.   We’re interested in your opinions. Please join the discussion on one of our online forums or send comments, criticisms, and suggestions to editor@msdiscovery.org.    [outro music]  

Dr Christian Klein (Roche Pharma Research and Early Development, Roche Glycart AG, Schlieren, Switzerland) talks to ecancertv at the 1st Immunotherapy of Cancer Conference ( ITOC ) meeting in Munich. He describes a novel class of monomeric tumour-targeted immunocytokines that comprise a single IL-2 variant (IL2v) with abolished CD25 binding that is fused to the C-terminus of a tumour specific antibody with a heterodimeric Fc devoid of FcgR and C1q binding. For tumour targeting, human/humanized high affinity antibodies against CEA or FAP were selected. CEA- and FAP-IL2v activity was tested on effector cells by assessing the activation of P-STAT5, cell proliferation, sensitivity to Fas-induced apoptosis, expression of activation markers and cytokine release upon treatment. Compared to classical IL-2-based immunocytokines, CEA-IL2v and FAP-IL2v demonstrate superior safety, PK and tumour targeting due to abolished CD25 binding, monovalency and high-affinity to tumour antigens while failing to preferentially induce Tregs. CEA-IL2v and FAP-IL2v retain the capacity to activate and expand NK and CD8 effector T cells both in the periphery and tumour microenvironment supporting their further nonclinical and clinical investigation for immunotherapy of cancer.

Caveolin-1 (Cav1) is a scaffold protein and pathogen receptor in the mucosa of the gastrointestinal tract. Chronic infection of gastric epithelial cells by Helicobacter pylori (H. pylori) is a major risk factor for human gastric cancer (GC) where Cav1 is frequently down-regulated. However, the function of Cav1 in H. pylori infection and pathogenesis of GC remained unknown. We show here that Cav1-deficient mice, infected for 11 months with the CagA-delivery deficient H. pylori strain SS1, developed more severe gastritis and tissue damage, including loss of parietal cells and foveolar hyperplasia, and displayed lower colonisation of the gastric mucosa than wild-type B6129 littermates. Cav1-null mice showed enhanced infiltration of macrophages and B-cells and secretion of chemokines (RANTES) but had reduced levels of CD25+ regulatory T-cells. Cav1-deficient human GC cells (AGS), infected with the CagA-delivery proficient H. pylori strain G27, were more sensitive to CagA-related cytoskeletal stress morphologies ("humming bird") compared to AGS cells stably transfected with Cav1 (AGS/Cav1). Infection of AGS/Cav1 cells triggered the recruitment of p120 RhoGTPase-activating protein/deleted in liver cancer-1 (p120RhoGAP/DLC1) to Cav1 and counteracted CagA-induced cytoskeletal rearrangements. In human GC cell lines (MKN45, N87) and mouse stomach tissue, H. pylori down-regulated endogenous expression of Cav1 independently of CagA. Mechanistically, H. pylori activated sterol-responsive element-binding protein-1 (SREBP1) to repress transcription of the human Cav1 gene from sterol-responsive elements (SREs) in the proximal Cav1 promoter. These data suggested a protective role of Cav1 against H. pylori-induced inflammation and tissue damage. We propose that H. pylori exploits down-regulation of Cav1 to subvert the host's immune response and to promote signalling of its virulence factors in host cells.

CD25+ regulatory T cells develop in the thymus (nTregs), but may also be generated in the periphery upon stimulation of naive CD4 T cells under appropriate conditions (iTregs). To gain insight into the mechanisms governing iTreg development, we performed longitudinal transcriptional profiling of CD25+ T cells during their differentiation from uncommitted naive CD4 T cells. Microarray analysis of mRNA from CD25+ iTregs early after stimulation revealed expression of genes involved in cell cycle progression and T cell activation, which largely overlapped with genes expressed in CD25+ effector T cells (Teffs) used as a control. Whereas expression of these genes remained elevated in Teffs, it declined gradually in developing iTregs, resulting in a more quiescent phenotype in mature iTregs. A similar pattern of kinetics was observed for biological processes and for intracellular pathways over-represented within the expressed genes. A maximum dichotomy of transcriptional activity between iTregs and Teffs was reached at late stages of their maturation. Of interest, members of the FoxO and FoxM1 transcription factor family pathways exhibited a reciprocal expression pattern in iTregs and Teffs, suggesting a role of these transcription factors in determining T cell fate.

Die allogene Knochenmarks- bzw. Stammzelltransplantation wird seit den späten 70er Jahren als kurativer Behandlungsansatz bei myeloproliferativen Syndromen wie Leukämien und Lymphomen etabliert. Eine schwere und häufige (25-45%) Komplikation dieser Transplantation ist die Wirt-gegen-Spender-Erkrankung bzw. Graft-versus-Host Disease (GvHD). Die Erkrankung ist mit einer hohen Letalität von etwa 30% unter moderner Therapie verbunden und manifestiert sich häufig zunächst an der Haut. Eine zuverlässige und rasche Diagnosesicherung ist für die Früherkennung und adäquate Therapie der GvHD entscheidend. Leider ist die akute, das heißt binnen 100 Tagen nach Transplantation auftretende GvHD (aGvHD) von akuten Arzneimittelreaktionen (AR) klinisch und histologisch schwer zu unterscheiden. Etablierte Kriterien für diese Differentialdiagnostik existieren nicht. Die Feststellung des histologischen Schweregrads der aGvHD ist bislang eher untersucherabhängig, die des klinischen Schweregrads ist dermatologisch sehr grob und zur Verlaufskontrolle eher ungeeignet. Diese Punkte zu optimieren und einen Beitrag zur Aufklärung der Immunpathologie der aGvHD zu leisten waren die Hauptziele der vorliegenden Dissertation. Zwanzig Patienten mit klinisch gesicherter aGvHD nach allogener Knochenmarks- oder Blutstammzelltransplantation und dreizehn Patienten mit klinisch verifizierter AR wurden in die Studie aufgenommen. Die klinischen Befunde wurden nach dem etablierten Glucksberg-Score sowie dem neu entwickelten klinischen GvHD-Schweregrad-Score (GvHSco) klassifiziert. Zusätzlich wurden Hautproben entnommen und histopathologisch sowie immunhistochemisch (Expression von CD1a, CD2, CD11c, CD20, CD25, CD34, CD68, CD197, CD206, CD207, CD 208, CD209, CD303 und S100) analysiert. Klinische und histologische Ergebnisse wurden einzeln analysiert und miteinander korreliert. Zur besseren Beschreibung des klinischen Schweregrades der kutanen GvHD wurde der klinische GvHSco a priori entwickelt. Er bietet durch die Standardisierung und die hundertteilige Skala im Vergleich zum Glucksberg Score Vorteile bezüglich der individuellen Verlaufskontrolle. Als histologische Schweregradkriterien korrelierten epidermotrope lymphozytäre Infiltration und Kontinuitätsverluste der Basalmembran (Epidermolyse) am deutlichsten mit dem klinischen Schweregrad. Aufgrund dieser Ergebnisse wurde auf der Basis des histologischen Scores nach Lerner durch Ergänzung des Kriteriums Epidermolyse und durch besondere Gewichtung des Kriteriums Lymphozyteninfiltration der Modifizierte Histologische Score zur Abschätzung des Schweregrads akuter GvHD (GvHiScore) entwickelt. Die Vorteile dieser modifizierten Klassifikation sind die genaue, Untersucher-unabhängige Definition und die feinere Stratifizierung der Schweregrade. So wird eine bessere inter- und intraindividuelle Differenzierbarkeit erreicht. Als differentialdiagnostische Parameter sprachen hohe Zahlen reifer T-Zellen (CD2+, CD45RA+) und Makrophagen (CD68+), Epidermolyse, Basalzellballonierung, junktionales lymphozytäres Infiltrat differentialdiagnostisch für aGvHD, eosinophiles Infiltrat jedoch gegen eine aGvHD. Basierend auf diesen neuen Erkenntnissen wurde der differentialdiagnostische Test DSHIG („Differentialdiagnostischer Score mittels Histopathologie und Immunhistochemie für akute Graft versus Host Disease“) entwickelt. Der Test errechnet sich aus der Addition sieben dichotomer Kriterien. Die retrospektive Analyse des DSHIG ergibt eine Testspezifität und -sensitivität von 95% für die Differentialdiagnose „Akute GvHD“ versus „Akutes Arzneiexanthem“. Der differentialdiagnostisch vielversprechende DSHIG sollte prospektiv validiert werden. Bei der Lupusband-positiven akuten GvHD zeigte sich ein histologisch besonders schweres Bild mit ausgeprägter Epidermolyse. Ein Einfluss quoad vitam oder auf den klinischen Schweregrad ließ sich nicht zeigen. Die Lupusband-positiven Fälle traten bevorzugt in der späteren Phase von aGvHD auf. Für den klinischen Schweregrad und das Ein-Jahres-Überleben bei aGvHD günstig waren hohe Zellzahlen von IDEC (CD206+/CD11c+), plasmazytoiden Dendritischen Zellen (BDCA-2+) und Mastzellen. Diese Zusammenhänge wurden bislang nicht an Hautbiopsien gezeigt und könnten klinisch bedeutsam sein. Die in dieser Arbeit an Hand einer kleineren Fallzahl retrospektiv erstellten Scores sollten in zukünftigen Untersuchungen mit höherer Patientenzahl unabhängig prospektiv validiert werden. Die Dynamik der kutanen GvHD könnte darüber hinaus mit weitern Methoden wie durchflußzytometrischer Analyse und Gewinnung von sequentiellen Hautproben im zeitlichen Verlauf analysiert werden.

Dendritic cells (DC) play a central role in connecting innate with specific adoptive immunity resulting in target specific activation T-cells. As professional antigen presenting cells (APC) DC specifically stimulate T-effector cells, especially tumor-cytotoxic T-cells. Therefore they are regarded as interesting candidates for anti-tumor or anti-leukemic vaccination strategies. The insufficient expression of costimulatory antigens, MHC molecules and tumor-associated antigens (TAA) on the surface of cancer cells and disturbed mechanisms of apoptosis are the main reason for an ineffective immune response in oncologic diseases. It was shown that acute myeloid leukemic cells can be differentiated to leukemia-derived DC (DCleu ), regaining the stimulatory capacity of professional DC while potentially presenting the whole leukemic antigen repertoire. Thus, vaccination strategies, using ex vivo or in vivo generated DC, might induce a highly specific anti-leukemic T-cell response circumventing the cumbersome identification of leukemia-associated antigens. In this thesis DC antigen (DCA) expression profiles of mononuclear cells (MNC) and dendritic cells (DC) generated from these MNC should be analyzed. The generated MNC and DC should be compared with respect to their DC antigen (DCA) expression profiles and the DCAs value to detect and quantify (leukemia-derived) DC in different AML/MDS subtypes and under different culture conditions. Therefore MNC and DC were generated from 137 patients with acute myeloid leukemia (AML) and 49 patients with myelodysplastic syndromes (MDS) under 6 different serum free culture conditions. DCA studied were: CD1a/1b/1c, CD206, CD25, CD137L, CD83, CD86, CD80 and CD40. DC-generating media were chosen according to their different mechanisms of inducing DC-differentiation: 1. ‚Basic method‘: TNF/GM-CSF/IL-4, 2. MCM-Mimic, 3. Ca Ionophore, 4. Picibanil, 5. Poly I:C and 6. Cytokines. Quality and quantity of generated DC was estimated by Flow cytometry applying a specified, ‘DC-based’ gating-strategy. Expression and coexpression profiles of 10 different DCA as well as various costimulatory molecules, maturation markers and blast antigens were evaluated. Only those DCA qualified for the quantification of leukemia-derived DC that were not expressed on uncultured MNC fractions. AML patients presented with an average of 58 % blasts, MDS patients with 13 % blasts in MNC fractions. DCA were expressed on average on less than 7% of uncultured MNC, however some of the markers could be expressed on up to 77% of uncultured cells in single AML cases. Consequently these DCA did not qualify for detection of DC in those cases. Highest expression rates were found for CD86 and CD40 in naïve AML and for CD137L and CD40 in naïve MDS samples. Other DCA (e.g. CD1a, 1b, 1c) were only rarely found on naïve blasts. DCA expression on uncultured AML and MDS MNC varied with FAB types and cytogenetic risk. After culture in different DC-differentiating media, on average 28% DC could be generated from AML MNC and 30% from MDS MNC, depending on methods used, with an average DC viability of more than 60% and an average DC maturity of 49% (AML) and 56% (MDS). On average 36% of leukemic blasts could be converted to DC. Proportions of DCleu in the total DC fraction varied from 40-58% and were on average 49% (AML) and 43% (MDS) after culture. Average results of all culture methods tested were comparable, however every method failed to create DC in some individual cases. The most important results of this thesis are: 1. It could be shown that DCA are expressed on naïve blasts in AML and MDS in individual patients. That means that the individual patients’ DCA-profiles have to be evaluated before DC-culture to find suitable DCA to detect and quantify (leukemia-derived) DC after culture. 2. Different methods of DC-generation qualify with varying individual efficiency to generate leukemic, mature, migratory and viable DC in individual cases. 3. To select the best DC-generating method the best DC-marker (no expression on naïve blasts, high expression on DC) has to be chosen to quantify DC in individual samples. 4. The use of only one method is not sufficient to create DC in every single AML and MDS sample. However, a successful, quantitative DC/DCleu -generation is possible in every case of AML and MDS by the combination of 3 different DC-generating media, but not every blast is convertible to DC leu . 5. There is a need for new, specific DC-markers that are not expressed on naïve blasts.

Fri, 1 Jan 2010 12:00:00 +0100 https://epub.ub.uni-muenchen.de/17987/1/oa_17987.pdf Schulze-Koops, Hendrik; Lipsky, Peter E.; Skapenko, A.; Prots, I. ddc:610,

Diagnosis of systemic mastocytosis (SM) is mainly based on the morphological demonstration of compact mast cell infiltrates in various tissue sites. In almost all patients such infiltrates are detected in the bone marrow. Reliable immunohistochemical markers for the diagnosis and grading of SM have been established, but various differential diagnoses including myeloproliferative neoplasms, basophilic and eosinophilic leukemias may be very difficult to delineate. Even more challenging is the recognition of hematological neoplasms with signs of mast cell differentiation but not fulfilling diagnostic criteria for SM, especially the rare myelomastocytic leukemia. It is also important to separate the reactive state of mast cell hyperplasia from indolent variants of SM, especially those with a very low degree of bone marrow infiltration and absence of compact mast cell infiltrates. When the lymphocytic component of the SM infiltrate is very prominent, SM may be confused with an indolent lymphoma, especially lymphoplasmacytic lymphoma which almost always shows a marked reactive increase in mast cells. In aggressive and leukemic variants of SM, mast cells may be very atypical and devoid of metachromatic granules. This hypogranulation can be regarded as cellular atypia and may lead to the misdiagnosis aspect of monocytic leukemia or histiocytic neoplasm. Regarding immunohistochemical anomalies, mast cells in aggressive and leukemic SM have been found to express CD30 (Ki1-antigen). Thus, anaplastic large cell lymphoma or Hodgkin's disease may first be considered rather than SM. There is increasing evidence that most patients with long-standing adult-type urticaria pigmentosalike skin lesions have in fact indolent SM. Therefore, such skin lesions are an important clue to the correct diagnosis in these patients. However, in aggressive or leukemic SM skin lesions are usually absent and then the correct diagnosis relies on an appropriate investigation of bone marrow biopsy specimens using both SM-related immunohistochemical markers (tryptase, KIT, CD25, CD30) but also markers excluding potential differential diagnoses. Investigation for presence of the activating KIT point mutation D816V is very helpful to establish a correct diagnosis of SM in all the difficult cases exhibiting a low degree of bone marrow infiltration or puzzling morphological findings. Copyright (C) 2010 S. Karger AG, Basel

Há as T CD4 reguladoras FOXP3, há as células Tr1, há as células Th3 e ... Num artigo publicado no volume 182 do Journal of Immunology, Han et al da República Popular da China, descreve uma nova subpopulação CD4 com fenótipo imunosupressivo. Estas células sobrerepresentadas em esplenócitos de ratinhos com tumores epiteliais implantados, expressa CD69. Estas células defínidas pelos autores como CD4+ CD69+ e CD25-, não expressam FOXP3 (associado com o fenótipo regulador das células CD4+ CD25+), não produzem citocinas de maneira relevante em repouso ou após activação não específica, não respondem a um estímulo proliferativo alogénico e sobretudo impedem a proliferação de outros linfócitos CD4 específicos de um antigénio. A acção imunosupressiva é transmitida por contacto via TGF-Beta1 presente na membrana celular e modulada pela activação de CD69 e ERK. A ler se tiverem curiosidade... PS: no podcast eu refiro o volume como 189. Peço desculpa pelo erro.

Dendritische Zellen (DC) übernehmen essentielle Aufgaben in der Homöostase des Immunsys-tems und in der Induktion von Toleranz oder Immunität. Eine besondere Wechselwirkung findet hierbei zwischen DC und T-Zellen statt, welche durch die Präsentation und Erkennung von Selbstpeptiden, beziehungsweise Fremdantigenen, vermittelt wird. DC spielen eine wichtige Rolle bei der Selektion eines funktionellen T-Zell-Kompartiments im Thymus. In der vorliegenden Stu-die wurde die Funktion der Antigenpräsentation von DC für die Homöostase und die Aktivierung von CD8-T-Zellen in vivo untersucht. Diese Arbeit soll zeigen, dass die Präsentation von Selbstpeptiden auf DC die homöostatische Pro-liferation (HP) von naiven CD8-T-Zellen induziert. Nach der Depletion von T-Zellen durch Be-strahlung oder Antikörpergabe kam es zu einer HP von naiven CD8-T-Zellen. Diese Proliferation war streng MHC-abhängig. Die Expression von MHC-I auf DC reichte aus, um eine komplette HP zu erlauben, welche im Teilungsmuster, der Aktivierungsmarkermodulation und den Proliferati-onsraten jener von proliferierenden Zellen in C57BL/6-Wildtypmäusen glich. Überraschenderwei-se waren CD4-T-Zellen in der Lage, die HP von transferierten naiven CD8-T-Zellen zu inhibieren. Erst durch die Depletion von endogenen CD4-T-Zellen kam es zu Teilungen, während CD25-positive regulatorische T-Zellen keinen Einfluss auf die HP von naiven CD8-T-Zellen ausübten. DC sind essentiell um Toleranz beziehungsweise Immunität nach der Erkennung von Fremdanti-genen zu generieren. Um die Bedeutung der Antigenpräsentation auf DC genauer zu charakterisie-ren, wurde die Immunantwort in einem Mausstamm, in welchem alle Zellen MHC-I tragen zu Tie-ren, in denen nur DC MHC-I exprimieren und somit naive CD8-T-Zellen aktivieren können, un-tersucht. Hierbei wurde deutlich, dass DC ausreichten um Toleranz, als auch Immunität von nai-ven CD8-T-Zellen zu induzieren. Kam es jedoch zu einer differentiellen Antigenpräsentation nach systemischer Administration des Antigens (als Peptid oder Virus in die Blutbahn), waren antigen-präsentierende nicht-DC in der Lage, die Immunantwort abzuschwächen. Dies geschah durch In-duktion von Apoptose, wodurch die Anzahl antigenspezifischer Effektor-T-Zellen verringert und somit auch die Formation des immunologischen Gedächtnisses beeinträchtigt werden konnte. Diese Ergebnisse betonen die enorme Bedeutung der Antigenpräsentation durch DC, weisen aber auch auf die besondere Rolle der Antigenpräsentation durch andere Zelltypen als DC hin, welche in der Lage sind eine Immunantwort deutlich zu modulieren.

Introduction: Eczematous reactions to type I allergy-inducing antigens are documented in a subgroup of patients with atopic eczema. Yet, the underlying immunological mechanisms are not well understood. Material and Methods: To delineate the effect of native pollen grains on human skin of healthy and atopic individuals we performed patch tests (atopy patch test with native pollen grains, PPT). Nickel patch tests (NPT) served as an established model of contact dermatitis. Skin site biopsies were taken 6 - 96 h after allergen application and investigated immunohistochemically. Results: Histology of positive patch tests showed an influx of mononuclear cells (predominantly CD4+, CD25+, CD45RO+). This influx was detected earlier in the PPT reaction than in the immune response to nickel. A biphasic cytokine response could be detected in the PPT: IL-5 dominated in the early, IFN-gamma in the late phase. The NPT was continuously dominated by IFN-gamma. Dendritic cell subpopulations imitated the earlier kinetics of the mononuclear infiltrate. Discussion: Thus, pollen grains induce eczematous reactions in susceptible individuals. This reaction appears clinically and immunohistochemically similar to the contact hypersensitivity reaction to nickel but follows a faster kinetic and a biphasic course: Th2 and IgE in the early (24 h) and Th1 predominance in the late (96 h) phase. Copyright (c) 2007 S. Karger AG, Basel.

Das humanpathogene Bakterium H. pylori persistiert im Gastroduodenaltrakt für Jahre oder sogar Jahrzehnte und löst durch die Kolonisation der Magenmukosa eine chronische Entzündungsreaktion aus. In den meisten Fällen bleibt diese symptomlos, es können jedoch auch schwerwiegende Erkrankungen wie ein Magen- oder Zwölffingerdarm-Geschwür oder Magenkrebs daraus hervorgehen. Obwohl die Infektion eine starke zelluläre und humorale Immunantwort hervorruft, kann H. pylori durch das Immunsystem nicht eliminiert werden. In dieser Arbeit wurde der Einfluss von H. pylori auf die Proliferation und Aktivierung von CD4+ T-Zellen untersucht. Dabei zeigte sich, dass H. pylori zwei Faktoren besitzt, um die Expansion der T-Zellen zu hemmen. Der eine, nicht näher charakterisierte Faktor scheint mit der Oberfläche der Bakterien assoziiert zu sein und inhibiert die Proliferation der T-Zellen bei direktem Kontakt der Bakterien mit den Zellen. Der zweite Faktor wurde als vakuolisierendes Zytotoxin VacA identifiziert, das, wie bisher bekannt war, in Epithelzellen die Bildung saurer Vakuolen auslöst. T-Zellen produzieren, wenn sie aktiviert werden, den Wachstumsfaktor IL- 2, beginnen sich zu vermehren und setzen eine Immunreaktion gegen das Pathogen in Gang. Das VacA-Toxin hemmt jedoch die Bildung von IL-2 und bewirkt eine Hemmung des Zellzyklus bei T-Zellen, indem es die Expression der Cycline D3 und E reprimiert. Diese sind essentiell für die Aktivierung des Retinoblastom-Proteins, das den Übergang des Zellzyklus von der G1- in die S-Phase vermittelt. Durch die Hemmung der IL-2-Produktion und die Erniedrigung der Oberflächenlokalisation von CD25, der -Kette des IL-2-Rezeptors, unterbricht VacA die Signaltransduktion, die normalerweise über den IL-2-Rezeptor zur Expression der Cycline führt. Die Hemmung der IL-2-Produktion durch VacA erfolgt auf transkriptioneller Ebene, indem die Aktivierung des Transkriptionsfaktors NFAT (Nuclear Factor of Activated T cells) verhindert wird. Die anderen für die Transkription des IL-2-Gens essentiellen Transkriptionsfaktoren AP-1 und NF-B werden durch VacA nicht beeinflusst. Die Stimulation der T-Zellen aktiviert zwei Haupt-Signalwege: einer führt über den MAPKinase / ERK-Kinase Weg zur Aktivierung von AP-1 und NF-B, der andere löst eine Erhöhung der Calcium-Konzentration im Zytoplasma aus, was die Ca2+-abhängige Phosphatase Calcineurin aktiviert. Calcineurin dephosphoryliert daraufhin den Transkriptionsfaktor NFAT und NFAT wird in den Zellkern transportiert, wo es zusammen mit AP-1 und NF-B die Transkription des IL-2-Gens initiiert. Es konnte gezeigt werden, dass VacA die Translokation von NFAT in den Kern durch Hemmung der Phosphatase-Aktivität von Calcineurin verhindert. Dies hat zur Folge, dass NFAT-abhängige Gene, wie das IL-2- Gen oder das für CD25 codierende Gen, nicht abgelesen werden können. Dass Calcineurin ein geeignetes Zielmolekül ist, um eine Immunantwort zu unterdrücken, zeigen auch die medizinisch bedeutsamen Substanzen FK506 (Tacrolimus) und Cyclosporin A. Beide V Zusammenfassung 91 Substanzen verursachen durch Hemmung von Calcineurin eine starke Immunsuppression. In DNA-Microarray-Analysen wurde untersucht, ob VacA einen ähnlich drastischen Effekt auf die Funktion der T-Zellen hat wie FK506. Dabei zeigte der Vergleich der Genexpression von VacA- und FK506-behandelten T-Zellen, dass VacA eine Untergruppe der Gene, die auch von FK506 reprimiert werden, herunterreguliert, wie z.B. die Gene für die Zytokine Macrophage Inflammatory Protein (MIP)-1, MIP-1, Single C Motif-1 (SCM-1) und SCM- 1. VacA scheint also die Genaktivität von T-Zellen ähnlich wie FK506 zu modulieren, was auf einen ähnlichen Mechanismus, nämlich die Calcineurin-Hemmung schließen lässt. Da das VacA-Toxin ein sekretiertes Protein ist, das auch in den tieferen Schichten des Magengewebes nachgewiesen werden kann, erreicht H. pylori nicht nur die vereinzelt im Magenepithel vorkommenden T-Zellen, sondern auch die T-Zellen, die bei der Infektion in die Lamina propria, eine tiefere Schicht der Magenmukosa, einwandern. Durch die Unterdrückung der T-Zell-Aktivierung und die Repression von Zytokin-Genen, die wichtig sind für die Modulation der Immunantwort, induziert H. pylori so vermutlich eine lokale Immunsuppression, die seine Eliminierung durch das Immunsystem verhindert und eine chronische Infektion des Magens ermöglicht. In einem zweiten Projekt wurde die Spaltung von CagA in ein 100 kD- und ein Tyrosinphosphoryliertes 40 kD- Fragment nach dessen Translokation in diverse Zelltypen untersucht. Dabei konnte gezeigt werden, dass die Prozessierung nicht nur in Makrophagen, sondern auch in dendritischen Zellen und in T-Zellen auftritt. Die Spaltung scheint von der Tyrosin-Phosphorylierung des CagA-Proteins und von Calcium abhängig zu sein. Dabei wurde die Ca2+-abhängige Protease Calpain in einem in vitro-Ansatz als ein CagAprozessierendes Enzym identifiziert. Auch in Makrophagen kann die Spaltung von CagA in P100 und P40P-Tyr durch den Calpain-Inhibitor Calpeptin verhindert werden. Die Tatsache, dass transloziertes CagA in allen getesteten eukaryontischen Zelltypen außer der Magenepithelzellinie AGS prozessiert wird, deutet darauf hin, dass diese Prozessierung eine biologische Bedeutung hat.

Schizophrenia has often been observed to be associated with alterations of the cellular immune system. In this study we monitored numerous immune parameters in the course of antipsychotic treatment. 40 patients diagnosed with an acute exacerbation of schizophrenia were tested before and during treatment with antipsychotics. The percentual distribution of lymphocyte subgroups (CD3, CD4, CD8, CD19, CD5, CD16/56, CD25, HLA-DR, gd, CD11a, CD11b and CD49d) was measured by FACS analysis. 20 healthy volunteers served as controls. In the acute state of psychosis a significant elevation of the B-lymphocyte fraction was observed, while the percentage of T-lymphocytes was decreased. These values levelled to those of the control group in the course of treatment. Natural killer cells, integrine expressing cells and CD5+ B-cells showed alterations in numbers after several months of treatment. The latter may be a side effect of antipsychotic treatment. The findings in the acute state of schizophrenia could be seen as a nonspecific stress reaction or an effect of the altered metabolism of neurotransmitters. On the other hand the observed changes in the immune system could be due to infectious diseases or autoimmune processes provoking the symptoms of schizophrenia.