402827.fig.009a
(a)
402827.fig.009b
(b)
Figure 9: Model describing effects of GSH in growth control of M. tb. (a) Enhancing the levels of GSH in DCs decreases the synthesis of IL-10 polarizing the CD4 T cell response to a Th1 type. M. tb infection and conditions that will decrease the levels of GSH, such as BSO treatment will enhance the synthesis of IL-10 leading to a Th2 CD4+ T cell response. Th2 CD4+ T cell response will promote antibody production and will not result in control of M. tb infection and in contrast will favor the intracellular growth of M. tb. Enhancing the levels of GSH in DCs decreases the production of IL-1, a proinflammatory cytokine. Excess of IL-1 can cause fever, necrosis, and inflammation. Enhancing GSH in DCs induces increased synthesis of IL-12 thereby favoring a Th1 CD4+ T cell response. (b) Enhancing the levels of GSH in CD4+ T cells (regulatory and nonregulatory T cells) decreases the synthesis of TGF-β and IL-10 (immunosuppressive cytokines) thereby augmenting the host responses to control M. tb infection.