Immunity & infection
Human respiratory syncytial virus (hRSV) is the principal cause of childhood hospitalizations due to severe lower respiratory tract infection. HRSV infection alters the function of inmune cells that are primordial in the acquisition of immunity to pathogens, such as dendritics cells (DCs) and T cells. Consequences over the epithelial lung after immune response against hRSV infection and on the predisposition a susceptibility to a sub sequential infection still remain unknown. Here we evaluated the whether hRSV may generate a susceptible environment to sub sequential infection using as a model the infection Mycobacterium bovis which belongs to the Mycobacterim tuberculosis complex. Our data suggest the pre-infection with hRSV and then on tenth day post infection the mice is challenged with M. bovis increased the pathology in the lung. Importantly, this also observation also correlated with increased viral and bacterial loads, as observed by increased copies of M. bovis 16S rRNA gene, suggesting that clearance of infecting bacilli was also impaired due to hRSV pre-exposition. Futher, our results suggested that this poor anti-mycobacterial response is not due to a decrease in the T-cell response to mycobacterial antigens, but due to alterations in the functionality of APCs in the lungs of hRSV-infected mice.
This work was supported by grants CONICYT/FONDECYT POSTDOCTORANDO No. 3140455 FONDECYT 1070352; FONDEF D061008; FONDEF D11I1080; and the Millennium Institute on Immunology and Immunotherapy (P09/016-F).