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24 Cards in this Set
- Front
- Back
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How common is autoimmunity? More in what gender?
Three mechanisms for cause? |
-3rd most common category
-more in females -antibody, immune complex, Tcell |
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Negative selection for self reactivity in thymus helped out with what gene?
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AIRE - AutoImmune REgulator gene, makes lots of self-antigen in thymus
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What two co-stimulatory signals are needed to bypass anergy?
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CD80/86 and cytokines
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Who presents CD80/86?
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professional APCs (mainly dendrites and macrophages, sometimes B cells or endothelial cells)
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Under what 5 conditions could auto-reactive T cells form ?
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-low affinity self-antigens escape negative selection
-inflammation that creates rare self-antigens -cross reactivity with microbe antigens -Treg cell failure -Th17 cell activation |
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What Treg cell gene is important in autoimmunity?
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Fox3p
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What 4 ways can Treg cells be suppressed?
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-cytokines (TGFbeta, IL10, IL35)
-lysis of T and B cells -dusruption of dendritic cells -disruption of T cell metabolism |
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Th17 cells are induced by what 2 molecules?
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TGFbeta, IL6
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Examples of genes predisposing to autoimmunity?
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HLA I, HLAII, cytokine, apoptosis, complement, signaling
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Why would HLA mutations be risk factors?
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In Thymus with negative selection: mutations bad at presenting or binding self-antigens
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5 ways infection can trigger autoimmunity?
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-disrupt tissue barrier
-cause release of IFNalpha -molecular mimicry -superantigen -pathogen binding to self protein |
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Why more autoimmunity with women?
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-Th2 bias in females
-immune cells have sex hormone receptors -cytokines on hormone producing cells -men get more infections |
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5 factors leading to Autoimmunity
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-sex hormones
-toxins/infections -mutations (HLA, signaling, cytokine, apoptosis...) -Treg reduced -Th17 enhanced |
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Myasthenia gravis
-antigen? -consequence? |
-acetylcholine receptor
-progressive weakness |
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Rheumatoid : physical progression includes
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-loss of cartilage
-hyperplasia of synovial membrane -bone resorption |
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Rheumatoid synovium: molecular progression includes
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cytokines in synovium
neutrophils in synovial fluid proteases that degrade connective tissue lymphocyte recruitment complement activation |
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Epitope spreading is?
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the number of autoantigens increasing because of chronic autoimmune response
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therapies to autoimmune disease?
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corticosteroids
IFNbeta anti-TNFalpha anti-integrin statins |
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alloantigens include?
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MHC (major) and
minor histocompatibility complexes |
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Differences between direct and indirect allorecognition?
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-Direct: donor APC migrates to host lymph node to stimulate host T cells
-Indirect: host APC processes donor tissue and presents peptides |
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types of transplant rejection: timing and causes and results?
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-hyperaccute: w/in 48hours b/c ABO or HLA antibodies...organ shutdown
-acute: 1wk to 1 yr b/c HLAs...macrophage, antibody, CTC -chronic: many years post transplant b/c minor histocompatability....progressive vasculatits b/c of Th1 and macrophages |
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4 types of immunosupressive therapy
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-cyclosporin : inhibit transcription factors for cytokine synthesis (NF-AT)
-corticosteroids: inhibit synthesis of cytokines, ahdesion molecules -anti CD3 monoclonal antibodies : deplete circulating T cells -Azothioprine : anti-(DNA precursor) |
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Graft versus host disease happens when and in whom? What donor cells, what host targets?
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-in immunodeficient host, 1wk to 1month
-donor leukocytes (CTC, Th1, NK, macrophages) -host epithelium |
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Two reasons trophoblast is not rejected?
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only express HLA I C, and low levels at that
impair CD80/86 expression |
