adaptive immunity definition
Adaptive Immunity Definition. Adaptive immunity is an important part of the immune system. It is protection from an infectious disease agent that is mediated by B-and T-lymphocytes following exposure to specific antigen, and characterized by immunological memory.ell-mediated immunity does not involve antibodies but rather involves the activation of macrophages, natural killer cells (NK), antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen.