Survival of parvovirus B19-infected cells by cellular autophagy.

Human parvovirus B19 (B19) is a well-known pathogenic agent which causes apoptosis in erythrocyte lineage cells. Here, we provide the first evidence that mitochondrial autophagy is specifically found in the B19-infected cells. The protein expression ratio for LC3-II/LC3-I increased significantly in infected cells, indicating possible involvement of cellular autophagy in the infection process. Immunofluorescence confocal microscopy analyses revealed that B19 infection induced an intracellular autophagosome as judged by endogenous LC3 staining. Moreover, inhibition of autophagy by 3-MA significantly facilitated B19-infection-mediated cell death. These results suggest a novel mechanism by which B19-infected cells survive by cellular autophagy.