THE DOWN-MODULATION OF IFN-GAMMA-INDUCED MHC-I EXPRESSION BY BRUCELLA ABORTUS CAN BE EXTRAPOLATED TO CELLS OTHER THAN MONOCYTES

SERAFINO, AGUSTINA; MILILLO, M. AYELÉN; BARRIONUEVO, PAULA

Congreso; Reunión de Sociedades de Biociencias 2021; 2021

Brucella abortus (Ba) is an intracellular pathogen capable of survivinginside macrophages. Since the disease is presented in multipleforms, many different cells are susceptible to be infected by Ba. Thisbug is able to evade the host immune system. We have previouslydemonstrated that infection of human macrophages with Ba diminishesthe IFN-ϒ-induced MHC-I surface expression. One of thePAMPs that triggers this down-modulation is Ba RNA. MHC-I totalexpression is not altered, instead these proteins are retained withinthe Golgi Apparatus (GA). However, we acknowledged whether thisevent could be triggered in other cells able to be infected with Ba.So, we started by stimulating the lung epithelium cell line (Calu-6)and the endothelial microvasculature cell line (HMEC) with differentdoses of Ba RNA in the presence of IFN-ϒ. MHC-I expression wasassessed by flow cytometry. Ba RNA (10 ug/ml) diminished the IFN-ϒ-induced MHC-I surface expression (p