PATHOLOGY

Detailed explanation-1: -Abstract. Interleukin 12 (IL-12) initiates the differentiation of naive CD4+ T cells to T helper type 1 (Th1) cells critical for resistance to intracellular pathogens such as Leishmania major.

Detailed explanation-2: -IL-12 is an antigen presenting cell–derived (APC-derived) cytokine that stimulates T cells and NK cells to secrete IFN- and augments the proliferation and cytolytic activity of these cells (14).

Detailed explanation-3: -Interferon gamma is the main Th1 cytokine.

Detailed explanation-4: -IL-12 is the prototypical innate cytokine capable of activating NK cells, and it acts synergistically with several other cytokines to elicit the production of IFN-.