4. Antibodies, Antigens, “Epitopes”

14. Immunoglobulin Classes Longest lived Ab & present in colostrum. Associated with allergies. Most abundant class (except in serum).

17. Primary Lymphoid Organs The primary lymphoid organs , are bone marrow and the thymus, where lymphocytes originate and/or mature (depending on type).

18. Secondary Lymphoid Organs The secondary lymphoid organs , such as Lymph Nodes, are the sites of interaction among immune system cells including with antigens presented by Antigen Presenting Cells.

25. Each T lymphocyte has a specific role Id by the cluster of differentiation Cell Type CD (receptors) Fx T helper cell CD4 Activates B cell to produce Abs and activates cytotoxic T cells Cytotoxic T-cell – killer cell that works against cells w/ foreign intracellular Ags CD8 Goes to invasions site and secretes perforin – causes cell lysis T suppressor cell (regulatory) CD8 stops immune rx w/otherTcells

29. Clonal Selection Theory Applies to both B and T cells. B cells are associated with Ab (Ig) production. T cells are associated with cell-mediated immunity. Takes place in 2° lyphoid organs.

30. Antigen Presentation by B Cell Results in production of Abs against T-Dependent Antigens (no T-helper binding, then no Ab). Note binding by only one-half of the “Y”.

34. Immunoglobulin Actions These are now available for phago-cytosis. This is a host cell, covered with foreign antigens and therefore with antibody. Pilus as well as flagellum binding. Recall that C3b can bind directly to cell. Prevents binding to host tissues.

36. Antigen Recognition by T Cells Recognition by Cytotoxic T cell (CD8 receptor) Recognition by Helper T cell (CD4 receptor)

37. Cytotoxic Consequences Apoptosis is cellular suicide which here is induced by the CTL. I.e., they tell their “friends” (other cytotoxic T cells).

38. Stimulating T-Helper Cells Macrophages and Dendritic cells present antigens to, and thereby stimulate, T-helper cells.

39. Adaptive Immunity Good summary of Adaptive Immunity!