Fig. 1

A classical switch between Th-1/Th-2 immune response in paratuberculosis: Navi Th cell differentiate into subpopulation of effectors Th cells when bind to antigen presented by antigen presenting cell (APC). In MAP infection the early differentiated effectors T helper1 (Th1) cell promote protective cell mediate immune response. Th1 cell secrets cytokines such as interferon-gamma (INF-γ) and Interleukin-12(IL-12) and promote the activation of macrophages. In the later stages of infection T helper 2 (Th2) and regulatory T cell are dominant. Th2 and T-reg cell secret anti-inflammatory cytokines such as IL-4, IL-5, IL-10, IL-13 and TGF-β. These anti-inflammatory cytokines block the activation of macrophages and also down-regulate the cytokines secreted by Th1 cell and prevent cell mediated immune response while promote humoral response mediated by Th2 cell