B. abortus RNA through EGF-like ligands induces the retention of MHC-I molecules within the Golgi apparatus in human monocytes.

MILILLO M. A., VELÁSQUEZ L. N., DELPINO M. V., TROTTA A., POZNERN R. G., ISTURIZ M. A., GIAMBARTOLOMEI G. H., BARRIONUEVO P.

Congreso; LXIII Reunión Anual de la Sociedad Argentina de Inmunología.; 2015

We hypothesized that thecomponents of B. abortus involved inthe inhibition of MHC-I could be vita-PAMPssuch as B. abortus RNA, since theyare found exclusively in live bacteria and are actively expressed during earlystages of infection. Thus, theaim of this study was to characterize thecomponents, signalling pathways and mechanisms implicated in MHC-Idown-modulation. Overall, our results indicate that the vita-PAMP RNA as well as its degradation products constitute novelvirulence factors whereby B. abortus,by a TLR8-dependent mechanism and through the EGFRpathway, inhibits the IFN-g-inducedMHC-I surface expression on human monocytes/macrophages.