SYNERGISTIC MECHANISM BETWEEN INFLUENZAA VIRUS AND Streptococcus

MELINA CIAN; PAULO CORTES; NUBIA YANDAR; JOSE ECHENIQUE

ROSARIO

Encuentro; L Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 2014

SAIB

InfluenzaA virus (IAV) and Streptococcus pneumoniae (S. pneumoniae) are considered as two of the most important human pathogens, and co-infections with both agents usually lead to severe respiratory disease and occasionally, death. We previously described that S. pneumoniae remains alive intracellularly for several hours in an endothelial cell model. Here, we have established a co-infection model to analyze the synergism between IAV and S. pneumoniae during the first hours of viral infection. We found that IAV favors S. pneumoniae uptake in a dose dependent manner. In addition, prior viral infection significantly increases bacterial survival. We focused our study in signaling mechanisms that would allow pneumococcus to sense environmental changes produced by IAV that favors its intracellular survival. We found that the histidine kinase VisR, which belong to the uncharacterized two-component system VisR (named Vis by viral infection sensing), is essential for increased pneumococcal survival in IAV-infected endothelial cells, since its absence abolished viral effect over bacteria, in the same way as if the cells were not virus infected. This is the first report of a two-component system that sense environmental changes in the virus-infected cells, and this model could be useful to understand the synergistic mechanism between both pathogens.