Expressão de linfócitos T multifuncionais induzidos por antígenos de mycobacterium leprae em pacientes com hanseníase e controles contactantes

Abstract

Leprosy is a chronic infectious disease caused by Mycobacterium leprae. It is estimated that less than 1% of the individuals infected with M. leprae develop the disease. Several authors suggest that the genetic pattern and variations in the mechanisms of the patient's immune response influence the susceptibility or resistance to disease. Multifunctional CD4 T lymphocytes are cells capable of simultaneously secreting combinations of IFN-?, IL-2 and TNF-a. Recent studies have reported the role of these cells in the production of effector immune response and memory against several pathogens. Expression of these cells is used as a parameter to evaluate the efficacy of candidate vaccine antigens. The objective of this study was to evaluate the role of antigens (crude and recombinant) of M. leprae and M. tuberculosis in the expression of multifunctional T cells as a perspective for the development of immunoprophylaxis tools. Then, to evaluate the specific immune response to crude and recombinant antigens (MLCS, PPD and ML2028), PBMC from leprosy patients and HHC were stimulated with these antigens, and the cytokine profile and the CD4+ and CD8+ multifunctional T cells (producing IFN-?, IL-2 or TNF-a) of effector and central memory were analyzed. Multiparameter analyzes by flow cytometry revealed a higher frequency of multifunctional T cells specific for M. leprae antigens in HHC than in leprosy patients. Our data indicate that HHC, when stimulated with crude and recombinant antigens, expressed more multifunctional T cells and this suggests that these cells provide a more effective immune response against M. leprae infection, which prevents the development of leprosy. These data open perspectives for the future development of immunoprophylaxis with M. leprae antigens, seeking to induce multifunction T cells expression and a Th1 immune response in individuals at risk of acquiring the disease, even considering this is a partial protection, because there would be protection against MB forms of leprosy, reducing the disease transmission.