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16 Cards in this Set
- Front
- Back
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What role does IL-2 play in cell-mediated immunity (T-cell)?
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1. THO binds antigen + B7.
THO then releases IL-2 in autocrine matter to stimulate T cell prolif and T cell apoptosis. # induction/regulation of Tcells. 2. Stimulates proli/diff of NKC and B cells. |
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What is function of IL-12 in cell-mediated immunity?
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1. THO diff into TH1.
2. Promotes NKCs. # intracellular organisms- innate immune & cell-mediated. |
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What is function of INF-gamma in cell-mediated immunity?
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Produced by T cells and NKCs. Activate macrophages.
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What is function of What is function of TNF-alpha in cell-mediated immunity?
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1. Produced by activated mononuclear phagocytes.
Recruits neutrophils and monocytes to site of infection. 2. Stimulates vascular endothelial cells to express adhesion molecules 3. Induces macrophages & endothelial cells to secrete chemokines. |
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What is diff b/w Th1 and Th2 responses.
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Th1: Proinflammatory.
Release IL-2, IFN-gamma,TNF-beta. Hallmark of th1=production of IFN-gamma. Th2: Anti-inflammatory humoral response/allergic immune response. Release IL4,5 & 10. |
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Explain how CD4 T cells activate macrophages.
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Th1 produces INF-gamma which activates macrophages.
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Describe 3 characteristics of the activated Macrophage.
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Activated by IFN-gamma.
1. + expression of FcgammaRI receptors 2. + expression of MHC Class II 3. + production of O2- and water |
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What is contact sensitivity and give examples.
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T cell-mediated, delayed type hypersensitivity reaction (Type 4)in the skin on contact with a particular chemical agent.
Poison ivy (catechols), cosmetics, metals, clothing. |
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What is a type II reaction and give example.
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IgG mediated hypersensitivity in tissues. Effector=FcR+ cells (phagocytes, NKC cells).
Ex: Drug allergy, myasthenia gravas. |
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What is a Type III reaction and give example.
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IgG mediated.
IgG:antigen complex in circulation. Effectors: FcR+ cells(phagocytes & NK cells),Complement. Ex: serum sickness, arthus reaction. |
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Compare complement-mediated cell lysis & antibody-dependent cytotoxicity.
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complement-mediated cell lysis = Kupfer cell and splenic macrophage phagocytosis
^opsonin dependent phagocytosis = complement-mediated cell lysis and phagocytosis ^ antibody-dependent cell cytotoxicity (ADCC) = NK cell killing without phagocytosis |
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What diagnostic tests are used to evaluate Type II and type III tissue injury?
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Type II: Use immunofluorescence to detect the presence of Ab. Test for foreign substance in blood.
Type III: Use stain immunoflourescence to ID clumps (immune complexes) in tissues. |
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Give examples of autoimmune disease mediated by autoantibodies by Type 1-4.
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Type 1: none.
2: myasthenia gravis, autoimmune hemolytic anemia, Graves disease, Goodpasture's disease 3: systemic lupus, polyarteritis, post-streptococcal nephritis 4. Type 1 diabetes, MS |
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Explain autoimmune disease mediated by T cells.
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Lack of CD4+,25+ cells which suppress T cells by cell-cell contact.
Examples are Type I diabetes & MS. |
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Explain role of MHC in autoimmunity.
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Class I and II MHC vary in their ability to present self. If self isn't presented properly in thymus, the self-reactive cells aren't eliminated. Not a change in positive and negative, but a change in the amount of antigen presented at critical points.
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How is molecular mimicry implicated in autoimmune disease?
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Infectious agents share determinants with self antigens.
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