Unique cytokine profiles of CD4+T cell to Acr, HBHA and MDP-1 antigens in different clinical stage of mycobacterium tuberculosis infection

Background Developing a novel assay accurately diagnosing clinical stage of tuberculosis (TB) may revolutionize mycobacterium tuberculosis (MTB) control programs. Information of cytokine profile of CD4+T cells recognizing various MTB antigens remains limited. Aims To characterize cytokine profile of a CD4+T cell subset that recognizes various MTB related antigens in different clinical stage using intra-cellular cytokine staining (ICS) assay. Methods 83 TB patients with different clinical stage (24 active, 24 on-treatment, 19 after therapy and 16 contact cases) and 18 healthy controls were recruited. Fresh peripheral blood mononuclear cells were cultured with MTB related antigens and the cytokine profile (IFN-γ, TNF-α, IL-2, IL-10, IL-13, IL-17) of CD4+/CD3+ cell was analyzed by ICS. Results IFN-γ and TNF-α response to ESAT-6/CFP10, and the frequency of MTB specific polyfunctional CD4+T cells were significantly associated with active TB (p<0.0001). Interestingly, the highest IL-10 response to Acr but not to ESAT-6/CFP10 was observed in contact cases than all TB cases and controls (median % IL-10 positive in CD4+T cells: 0.011, 0.00662, and 0.00445, p<0.0001). In after therapy cases, IL-2 response to HBHA and MDP-1 was significantly higher than that of control cells exposed to medium alone (median % IL-2 positive in CD4+T cells: 0.016, 0.016, and 0.00843, p<0.0001). IL-17 response against HBHA was significantly high in both active and on-treatment patients. Conclusions There are characteristic cytokine profiles of CD4+T cell to different MTB antigens in different clinical stage of MTB infection.