NK cell differential activation induced by Mycobacterium bovis BCG substrains and nontuberculous mycobacteria. (INC7P.420)

Abstract Mycobacterium bovis BCG is the only available vaccine against tuberculosis. Although widespread used, it is effectiveness is variable and protection conferred might be limited as following factors; BCG substrains used for vaccination, exposure to Nontuberculous mycobacteria and different components innate immune response interaction are not yet completely understood. When NK cells, are stimulated with BCG substrains proliferate and IFNγ production is induced, but recognition pathway and actual activation profiles existence remain obscure. To evaluate the activation profile of human NK cells isolated from PBMC of 20 healthy individuals. The NK cells were cultured and stimulated with BCG substrains or Nontuberculous mycobacteria species to induce an activation profile, assessed by flow cytometry. The activated NK cells were differentially recognized and induced by each BCG substrains used. Five different BCG substrains and Nontuberculous mycobacteria were included but, only BCG Mexico, M. avium and M. scrofulaceum were able to induce NK cells activation. We have shown that the differential recognitions to BCG substrains or Nontuberculous mycobacteria on NK cells occurred this could imply highly tuned response regarding cytokines promoting and enhanced impact in the regulation of immune response.