What is the role of the macrophage during antibody formation?
High-Yield Explanation
The macrophage phagocytizes exogenous antigens (for example a bacterium), degrading the antigen into small epitopes and presenting them, on MHC class II molecules on its surface, to CD4 T helper cells. Macrophages do not activate cytotoxic CD8 T lymphocytes. The major activator of cytotoxic CD8 T lymphocytes is IL-2 from CD4+ THl cells. Delayed hypersensitivity reactions are the results of CD4+ TH1 cells. These cells do not produce antibody. They secrete gamma interferon and interleukin 2 (IL-2), stimulating more cells to become involved in the delayed hypersensitivity reaction. The cells that paicipate in lysis of virus infected cells are cytotoxic CD8+ T lymphocytes that react with MHC class I molecules containing epitopes of the virus from the infected cell. Macrophages do not paicipate in this activity. Ref: Levinson W. (2012). Chapter 58. Cellular Basis of the Immune Response. In W. Levinson (Ed), Review of Medical Microbiology & Immunology, 12e Ray C.G., Ryan K.J. (2010). Chapter 26. Corynebacterium, Listeria, andBacillus. In C.G. Ray, K.J. Ryan (Eds), Sherris Medical Microbiology, 5e.