What tare the roles of Tcells CD4+ in the immune response?

Activate phagocytes in tissues activate B cells in lymphatic follicles CD4+ T cells activate B lymphocytes to produce high affinity isotype switched antibodies Effects are mediated by cytokines including CD40L that binds CD40 on macrophages, dendritic cells and B cells. CD40L and CD40 form positive self-amplification loop for activation of T cells by APCs and antibodies production by plasma B cells