Cell Mediated Immunity And Antigen Recognition - 2.2 PDF

**[Cell mediated immunity and antigen recognition - 2.2]** **T cell development** 1. - 2. 3. - - 4. - 5. - - 6. 7. - 8. - 9.  Most important: Th1 - cell mediated = promote inflammation Release - - Th2 - humoral = r...

**[Cell mediated immunity and antigen recognition - 2.2]** **T cell development** 1. - 2. 3. - - 4. - 5. - - 6. 7. - 8. - 9.  Most important: Th1 - cell mediated = promote inflammation Release - - Th2 - humoral = reduce inflammation Release: - - - Th17 = promote inflammation Linked to periodontal disease Release: - - - Treg = reduce inflammation Release: - -  **MHC** MHC-I activates cytotoxic T cells MHC-II activates helper T-cells MHC-I and cytotoxic T-cell interactions - cell mediated 1. 2. 3. 4. 5. 6. 7. 8. 9. MHC-II AG presentation to CD4 T-cells - humoral MCH-II is made of 2 subunits Binds longer peptides than MHC-I Shape of AG binding groove allows ends of peptide to stick out Activates helper T-cells **Induction phase of cell mediated immunity** 1. 2. 3. 4. 5. 6. 7. **T-cell recruitment to sites of infection**  **T-cell receptors:** CD28 + B7 of macrophage CD8 + MHC-I CD4 + MHC-II LFA-1 + ICAM-1 of high endothelial venule VLA-4 + VCAM of high endothelial venule CXCR3 + CXCL10 chemokine E/P selectin ligand + E/P selectin **Effector phase of cell mediated immunity** **T-cell responses to extracellular microbes**  **CD4+ AND T-cell subset responses** **T-cell responses to intracellular microbes**  Infected macrophage may have MHC-I with viral AG so acted on by cytotoxic T-cells **CTL-mediated lysis of target cells** **T-cell killing of infected cells** 1. 2. 3. 4. 5. 6. Cytoplasmic bridge forms between cytotoxic T-cell and infected cell Serine esterases eg granzymes released