RESUMO
We studied the effects of M. tuberculosis secretory proteins ESAT-6 and CFP-10 on the properties of vaccinal mycobacteria BCG not producing these proteins. Phagocytosis of M. bovis by macrophages, proliferation of mycobacteria in macrophages, apoptosis and necrosis of macrophages, and the production of reactive oxygen and nitrogen species were studied. It was shown that both ESAT-6 and CFP-10 significantly increased the number of phagocytized mycobacteria by increasing the number of phagocytic-active macrophages and augment the intracellular proliferation of the pathogen. At the same time, macrophages preincubated with ESAT-6 and CFP-10 reduce the production of reactive oxygen and nitrogen species and are more susceptible to apoptosis and necrosis in the presence of mycobacteria. In summary, these proteins suppress macrophage-mediated mechanisms of anti-tuberculosis resistance and impart pronounced pathogenic properties to non-pathogenic mycobacteria that do not secrete ESAT-6 and CFP-10.