The function of the immune system is to recognize foreign materials in the body and
distinguish them from normal body tissues and cells. Immune responses consist of cell-
mediated (T cells, natural killer cells, and phagocytes) or humoral (B cells, antibodies, and
complement) responses modified and regulated by cytokines. Antigen-presenting cells
(APCs) such as dendritic cells (DCs) and macrophages take up antigens, partially degrade
them, and present them to T cells in the context of major histocompatibility complex (MHC) …