Study of the autophagy pathway involvement in the Junin virus infection

J. S. ROLDÁN; L.R. DELGUI; M.I. COLOMBO; N.A. CANDURRA

Mendoza

Congreso; XLVII Reunión Anual de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular; 2012

Autophagy is a process whereby double membrane vesicles (autophagosomes) form around a portion of the cytoplasm and fuse with lysosomes where enzymatic degradation occurs. This process was described as a protection against viral invasion; however, viruses have been able to subvert this pathway in their own benefit. We analyzed the role of autophagy during Junin virus (JUNV) infection. We have observed that cells overexpressing EGFP-LC3 (a well-known autophagy marker), infected with JUNV showed an increased number of LC3 dots in the cells similar to starved- or BafilomycinA1 treated-cells which leads to autophagosome formation or accumulation, respectively. We analyzed the conversion of LC3-I (cytosolic) to LC3-II (associated to autophagosomes) by Western blot observing that the level of LC3-II in JUNV-infected cells was similar to that observed in starved-cells. Moreover, cells pre-treated with rapamycin, a pharmacological autophagy inductor, enhanced virus yield with respect to the control situation. In addition, we assayed the replication capacity of JUNV in Atg5 knock-out cells (a key molecular component of the autophagic pathway), but no differences were found. These results allowed us to conclude that JUNV infection leads to an autophagic response in the infected cells; however, a functional autophagy pathway does not seem to be required for efficient virus replication.