Mycobacterium bovis induce una respuesta inmune celular heterogénea en bovinos infectados naturalmente

Macrophages are considered one of the main immune mechanisms of resistance to mycobacterial infections. In addition, experimental and clinical data indicate that IFN-γ is essential for host defence against M. tuberculosis . The aim of this study was to identify macrophage capacity on controlling Mycobacterium bovis infection and lymphocyte IFN-γ production from cattle naturally exposed to M. bovis . Peripheral blood monocyte-derive macrophages from naturally infected cattle were evaluated for their ability to control the intracellular growth of M. bovis BCG. Besides, whole blood cells were stimulated with PPDB and ESAT-6+CFP-10 protein cocktail. Results show a disparity in host susceptibility to Mycobacterium bovis. A M. bovis BCG survival rate of 80 to 150 % in macrophages from naturally infected cattle was observed. While the IFN-γ production towards Purified protein derivative bovine (PPDB) and the protein cocktail was 2.5 and 2.0 optic density index, respectively. Though our data do not support a correlation between the host susceptibility to M. bovis and the production of IFN-γ in naturally infected cattle, the hypothesis that the limitations in the functioning of macrophages and T lymphocytes play a very important role in the spread of the disease cannot be discarded.