Immune response activation

The graphic represents a simplified scheme of the induction and development of lymphocyte activation in the immune response. The antigen presenting cell (APC) present (part of) antigen to the lymphocyte.Presenting to a CD4+ T-cell results in the production of the cytokine interleukine-2 (IL-2) and IL-4. Autocrine regulation by IL-2 leads to the development of Th1 cells, which secrete cytokines (IFNγ and IL-2) in order to activate macrophages.

Autocrine regulation by IL-4 gives rise to the development of Th2 cells and activation and proliferation of B cells, which produce antibodies against the antigen.When the APC presents the antigen to a CD8+ T-cell also IL-2 will be produced. This cytokine regulates the development into a cytotoxic T cell. For more information on immunological diseases you are referred to the immunology chapter.