Adaptive Immune System Introduction PDF

**[Adaptive Immune System: Introduction - 2.1]** Innate = physical barriers + non specific defences Adaptive = specific choreographed defences - - - - - - Components: - - - - 1. 2. Porphyromonas gingivalis - initially extracellular then intracellular ![](media/imag...

**[Adaptive Immune System: Introduction - 2.1]** Innate = physical barriers + non specific defences Adaptive = specific choreographed defences - - - - - - Components: - - - - 1. 2. Porphyromonas gingivalis - initially extracellular then intracellular   **Lymph nodes**  Cell in LN produce chemokines to attract dendritic cells Lymph nodes for oral cavity = tonsils and adenoids **Spleen** Also contains macrophages to clean up RBC and infection  Mechanical barriers: - - - Circulating effector proteins: - - - Inflammatory cytokines: - - - - - - - - - - - - - - - - - - Effector cells: - - - - - - - - - - - - - - - - - - - - - - Properties of cells: - - - - - **Non reactivity to self** Peripheral tolerance occurs in lymphoid tissues as a back up  **Humoral immunity** Receptors: B lymphocyte - - - Macrophage - - - Naive T helper cell - - - - Cytotoxic T cell - - Cytokines released: Humoral immunity Macrophage → IL1 T cell → IL2 (autocrine) T cell - IL4 (clonal expansion to activate B-cells) and IL5 (causes B-cell differentiation into plasma or memory B cell) T cell - IL6 and IL5 (cause plasma cells to secrete AB) Cell mediated immunity Cytotoxic T-cell → granzymes (activate pro-apoptotic genes in infected cell) and perforin Virus infected cell → BAX and BCL2 (releases cytochrome C) Exogenous 1. 2. 3. 4. 5. Interacting proteins 1. 2. 3. 4. = T-cell now activated and releases autocrine IL-2 which binds onto T-cell - - 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 T-helper can form: - - IL4 causes B-cell proliferation (clonal expansion) to form plasma cells IL5 causes activation of B-cells and differentiation → plasma cells (stim by IL5 and IL6) or memory B-cell IL5 and IL6 causes plasma cells to secrete AB AB can cause: - - - - - **Cell mediated immunity** Endogenous Cancerous or viral infected cells Apoptosis: 1. 2. 3. **Defective humoral and cell mediated immunity in dentistry** - - - - - - - - Lichen planus - - -  Mechanism of action 1. 2. 3. 4. 5. **Pemphigous** Mechanism of action -  **Sjogrens syndrome** - Both humoral and cell-mediated mechanisms: - - Types of T cells  Key terms: - - - - - - - - - -