How the immune system protects the host from infection

The immune system is made up of sets of interacting cells. The first to res pond in an cases are the antigen-presenting cells (APCs), which are equippe d with receptors for microbial patterns. Engagement of these receptors indu ces co-stimulatory molecules on the surface of the APCs, and allows it to s timulate potent CD4 T-cell responses, and also CD8 T-cell responses. This i n turn leads to B-cell-derived antibody responses. The entire response is c ontrolled by suppressor T cells, as predicted many years ago by Richard Ger shon. (C) 2001 Editions scientifiques et medicales Elsevier SAS.