Immune Responses of CD4 T-Cells of MDR-TB Patients to M. Tuberculosis Total Lipid Antigens

Background: CD4T-cell have a central role in protective immune responses to Mycobacterium tuberculosis (M. tuberculosis) protein antigens, but function of these cells in response to M. tuberculosis total lipid antigens has remained unclear. The present study was undertaken to determine role of CD4 T cells in the MDR-TB patients against M. tuberculosis total lipid antigens. Materials and Methods: CD4Tcells were isolated from MDR-TB patients and stimulated with M. tuberculosis total lipid antigens. Proliferative responses and cytokine secretion were assessed by MTT and ELISA, respectively. Results: Our study results showed that proliferative responses of stimulated CD4Tcells to M. tuberculosis total lipid antigens and IFN-γ production in MDR-TB patients were significantly lower than those of the PPD-positive subjects (P<0.05) whereas, IL-4 production in the MDR-TB patients was elevated(P<0.05). Conclusion: Responses of CD4T -cells of MDR-TB patients to total lipid antigens was significantly lower than that of PPDpositive healthy subjects. Therefore, it seems that M. tuberculosis lipid antigens, as protein antigens, have an important role in specific immune response. (Tanaffos 2007; 6(1): 59-65)