Term
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Definition
| Signal transduction in T cells. Have ITAM's. Also stabilize TCR on cell surface. CD3 = T cell marker! |
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Definition
| T cell co-receptors. Bind MHC Class II and I respectively. |
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Term
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Definition
| T cell costimulator receptor. Binds B7 (CD80/CD86) of APC's to receive second "go-ahead" signal. |
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Term
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Definition
Integrin adhesion molecule that binds to ICAM-1.
-T-cells: helps bind T cell to APC during activation. Helps T cells home to lymph nodes via HEV.
-Endothelium: binds ICAM-1 on cells that will diapedese into tissues.
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Term
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Definition
| "Very late antigen-4." Adhesion molecule on activated T cell expressed AFTER activation. Binds to VCAM-1 to help activated T cells get into infected tissues. |
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Term
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Definition
-CD40L on ag-stimulated T cell binds CD40 of APC to induce it to express B7 and secrete cytokines (IL-12) to enhance T cell differentiation.
-CD40L also triggers isotype switching in B cells
-Hyper IgM Syndrome = CD40L defect |
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Term
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Definition
| Secreted by CD4 (and CD8) T cells after ag recognition. Binds to IL-2R (has CD25) on T cell itself to promote clonal expansion of T-cell. |
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Term
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Definition
-High affinity part of IL-2R (alpha chain)
-CD25 alpha chain upregulated after signal transduction to increase affinity of IL-2R |
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Term
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Definition
Found only on pro APC's. Costimulator that gives second signal ("go-ahead") to T cell when binds to CD28.
-CTLA-4 may also bind B7 - INHIBITORY |
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Term
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Definition
-Secreted by macs and DC's to activate NK cells and TH1 to secrete IFN-gamma.
-Secreted by APC ("signal 3") to stimulate differentiation into TH1 cell. Release triggered by binding of CD40L to CD40. |
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Term
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Definition
-Secreted by TH2 cells and mast cells.
-Promotes isotype switching to IgE.
-Stimulates differentiation to TH2. |
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Term
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Definition
| Secreted by TH2 cells, mast cells. Activates eosinophils. |
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Term
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Definition
| -Secreted by NK cells and TH1 to activate macs. -Secreted by T cells. Makes all cells upregulate Class I MHC in case of infection, stimulates some Ab responses. -Secreted by TH1 cells. Suppresses IL-4 production so no TH2 response (immune deviation). |
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Term
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Definition
-Secreted by CD4 T cells and many cancer cells. -Inhibitory cytokine-generally inhibits T cell proliferation.
-Differentiation and activation of Tregs. |
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Term
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Definition
| Secrete IFN-gamma. Activate macrophages for killing, and increase Ab and complement secretion so opsonization can facilitate killing by macs. |
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Term
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Definition
| Secrete IL-4 to stimulate B cells to make IgG and IgE (allergic response). Secrete IL-5 to activate eosinophils - protect against helminths. |
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Term
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Definition
| Secrete IL-17. Play big role in inflammatory diseases (ie. arthritis). |
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Term
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Definition
T cell accessory molecule that binds to B7 and causes T cell to respond LESS well to APC.
-Gives T cell activation system balance
-Important for inducing anergy to self-ag's |
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Term
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Definition
| Secreted by macrophages in tissues that have engulfed ligands. Stimulate upregulation of selectin (CD62-E) on endothelium, AND integrins on leukocytes. FEVER. |
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Term
| Leukocyte Adhesion Deficiency (LAD) |
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Definition
| Missing CD18, which is partnered with the following to make integrins: -CD11b/Mac1/CR3 - no homing of macs or neutrophils to tissues -CD11a (LFA-1) - no homing of T cells to lymph nodes -CD11c/CR4 - defect in DC activation |
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Term
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Definition
| Takes out most of acquired immune system AND NK cells. Cause of death = No NK cells |
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Term
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Definition
| All cells can make it. Attracts neutrophils to site of infection. |
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Term
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Definition
Alpha - DC's, macs.
Beta - Fibroblasts.
-Puts all cells in anti-viral state, upregulates MHC Class I
-Activate NK cells |
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Term
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Definition
HLA A, B, C.
-Beta 2 microglobulin
-Alpha 1 and alpha 2 = peptide binding cleft
-Alpha 3 = CD8 binding site |
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Term
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Definition
-HLA DP, DQ, DR
-Alpha 1 and beta 1 = peptide binding cleft
-Beta 2 = CD8 binding site. |
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Term
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Definition
| Secreted by stromal cells in thymus/BM. Proliferation of immature T and B cells with lots diff ag receptors. |
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Term
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Definition
| Sphingosine-1-phosphate receptor. Expressed on activated T cells that need to travel in the BLOOD. |
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Term
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Definition
| Homes T cells to HEV in lymph node. |
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Term
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Definition
| Homes DC's and T cells to the T cell zone of lymph nodes and spleen. |
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Term
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Definition
| Targets intraepithelial lymphocytes and Tregs to gut mucosa. |
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Term
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Definition
-Made by TH2 cells and macs to inhibit activated macs.
-Secreted by TH2 cells to inhibit TH1 (immune deviation).
-Secreted by Tregs to inhibit DC secretion of IL-12, therefore inhibiting TH1 cells. |
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Term
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Definition
| Costimulation of B cells (signal 2). CD21/CR2 bind C3d covered microbes. |
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Term
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Definition
-Bound to naive B cells.
-Primary response, pentameric, low affinity
-Activation of Classical Complement Pathway
-Intermediate levels in blood |
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Term
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Definition
-Membrane-bound ONLY. B2 cells but not B1.
-Very low levels
-Necessary for isotype switching |
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Term
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Definition
-Secondary response, highest levels in blood, monomeric -Neutralization -Opsonization -Activates Classical Complement Pathway -ADCC -Neonatal immunity - transferred to placenta via FcRn -Feedback inhibition of B cell activation (CD32)
-IFN-gamma induces switch to IgG |
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Term
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Definition
-Secreted Ab only, monomer/dimer/trimer
-Mucosal immunity - agglutinates/neutralizes microbes
-Breast milk
-Isotype switching induced by TGF-beta |
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Term
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Definition
-Secreted Ab only
-Isotype switching induced by IL-4 (TH2 cells)
-Bound WITHOUT ag to mast cells and eosinophils so get IMMEDIATE hypersensitivity and worm killing! |
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Term
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Definition
| Inhibitory B cell receptor. Excess IgG bound to ag binds CD32 and send negative signals to B cell - turns off Ab production. |
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Term
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Definition
| FcR on macs and neutrophils. Binds Fc region of IgG to phagocytose opsonized ag's. |
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Term
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Definition
| NK cells. Ab Dependent Cytoxicity (ADCC). |
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Definition
-Opsonin. Binds CR1 on phagocytes.
-Component of C3 and C5 convertases |
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Term
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Definition
| Binds CR2 (CD21) to activate B cells. |
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Term
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Definition
| All stimulate inflammation! All are chemokines that attract leukocytes. |
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Term
| T regulatory cells (Tregs) |
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Definition
-Self-reactive cells NOT killed by neg selection in thymus or in periphery
-Foxp3, IL-2, and TGF-beta stim Treg development
-High constitutive levels of CD25 (IL-2R)
-Development and fxn depend on Foxp3 (TF)
-Inhibit prolif, activation, and effector fxn of T cells!
-Direct contact - DC express less B7 and IL-12
-IL-10 decreases IL-12 secretion by DC's so no TH1 cells
-TGF-beta generally inhibits T cell prolif |
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Term
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Definition
| C1 Inhibitor. Blocks C1q to inhibit Classical Complement Pathway. |
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Term
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Definition
Decay-accelerating Factor. Membrane protein expressed on all cells, esp. RBC's. Prevents formation of C3 convertase!
-Alt Pathway - prevents binding of Factor B
-Classical Pathway - prevents binding of C4b |
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Term
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Definition
-Cleaves C3b to iC3b (opsonin) and C4b
-Needs help from membrane-bound cofactors (MCP, CR1, Factor H) |
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Term
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Definition
| Membrane Cofactor Protein. Helps Factor I cleave C3b and C4b to inhibit formation of C3 convertase. |
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Term
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Definition
| Displaces Factor B so that Factor I can cleave C3b and prevent formation of C3 convertase. |
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Term
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Definition
| Membrane-bound protein on host cells that prevent binding of C9 - no MAC can kill it! |
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Term
| Hereditary Angioneurotic Edema |
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Definition
| Defect in C1 INH. Classical Complement Pathway activated more often than should be --> release of inflammatory mediators (bradykinin) --> edema. |
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Term
| Paroxysmal Nocturnal Hemoglobinuria |
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Definition
Defect in DAF and MCP on RBC's. No regulation of complement cascade --> hemolysis.
-No DAF - C3b buildup on RBC's
-No MCP - no Factor I to inactivate C3b to iC3b |
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Term
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Definition
-Increased bacterial infections because no production of iC3b for opsonization and B cell activation
-Decreased C3 because nothing is preventing cleavage of C3 to C3b! |
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Term
| Autoimmune Hemolytic Anemia (Rh Disease) |
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Definition
-Type 2 Hypersensitivity
-Ab's against RBC proteins (Rh, I protein)
-Opsonization and phagocytosis of RBC's
-Hemolysis, anemia |
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Term
| Autoimmune Thrombocytic Purpura |
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Definition
-Type 2 Hypersensitivity
-Ab's against GpIIa/IIIb on platelets
-Opsonization and phagocytosis of platelets
-Bleeding |
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Term
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Definition
-Type 2 Hypersensitivity
-Ab's against demosglein-3 (desmosomes)
-Ab-mediated activation of proteases, disruption of intercellular adhesions
-Skin bullae, blisters, erosion of skin
-Ashkenazi Jews, HLA D4/DQ3 |
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Term
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Definition
-Type 2 Hypersensitivity
-Ab's against BM proteins in glomeruli and alveoli
-Complement and Fc mediated inflammation
-Nephritis, lung hemorrhages |
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Term
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Definition
-Type 2 Hypersensitivity
-Ab's against Strep cross-react with heart
-Inflammation, mac activation
-Myocarditis, arthritis |
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Term
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Definition
-Type 2 Hypersensitivity
-Ab's against Nm receptors at NMJ's
-Blocking of ligand, complement fixation, downreg of receptors
-Muscle weakness, paralysis |
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Term
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Definition
-Type 2 Hypersensitivity
-Ab binds to TSH receptor and STIMULATES it
-Hyperthyroidism! Thyroiditis but no tissue destruction |
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Term
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Definition
-Type 2 Hypersensitivity
-Ab's against thyroglobulin and TPO prevent production of T3/T4
-Hypothyroidism! Thyroiditis AND tissue destruction |
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Term
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Definition
-Type 2 Hypersensitivity
-Ab's against GIF
-No absorption of Vit B12, macrocytic anemia, abnormal erythropoeisis |
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