1. Immune Response to HIV Infection June 28, 2001 Ms. Jane Coyle-Morris Wyeth-Ayerst Research

2. Immune Response to HIV Infection b Immunology b HIV Biology b Immune Response to HIV Infection

3. Role of Antibodies

4. Antibody interaction with Complement Proteins

5. Cytotoxic T-Cells

6. Central Role of Helper T-Cells

7. Macrophage Large, irregularly-shaped phagocytic cells that act as the body’s scavengers. Macrophages engulf and consume foreign material such as bacteria and viruses.

8. T Cells Arise from stem cells in the bone marrow then migrate to the thymus gland where they develop the ability to recognize foreign antigens in a specific manner.

9. Helper T Cells (T H ) Detect infection and initiate both humoral and cell-mediated responses (CD4 cells)

10. Cytotoxic T Cells (T C ) Recruited by T H to lyse infected body cells (CD8 cells)

11. Cell Marker Proteins b CD4: cell marker found on the surface of T H and macrophages; acts as a receptor for HIV b CD8: cell marker found on the surface of T C

12. B Cells and Plasma Cells b B Cells: precursors of plasma cells, specialized to recognize particular foreign antigens b Plasma Cells: derived from B cells, they produce antibodies to specific antigens marking them for destruction

13. Major Histocompatibility Complex (MHC) b Proteins markers found on the surface of the body’s cells to signal “self” from “non- self”. MHC-I can be found on every cell in the body while MHC-II is found only on B cells, T cells and macrophages.

14. Cytokines b Soluble proteins secreted by the cells of the immune system to signal activation and proliferation of the appropriate components of the immune response. IL-1 is released from macrophages and signals activation of T cells. Activated T cells produce IL-2 which signals proliferation of T cell clones and also helps B cells to start secreting antibodies.

15. Cytokines

16. The Immune Response

17. Central Role of CD4 T Cell

18. HIV Biology

19. HIV in Action

20. Natural Course of HIV Infection

21. Overview

22. Immune Response to HIV Infection b Immunology: humoral vs. cell-mediated b HIV biology: complex series of events leading to viral entry and course of infection; evasion of immune system b Immune response to HIV: weak humoral response, strong cell-mediated response diminished over time by depletion of helper T-cells

23. AIDS/HIV Internet Sites b Www.ama-assn.org/special/hiv/hivhome.htm b www.planetq.com/aidsvl/index.html b www.thebody.com/cgi-bin/body.cgi b www.cdc.gov/ b www.pbs.org/wgbh/nova/aids/ b www.roche-hiv.com/default.htm