Autophagy increases the survival rate of Macrobrachium rosenbergiiin after Aeromonas hydrophila infection

Autophagy is known as crucial components of crustacean innate immunity against pathogens. The dynamic changes of autophagy level during infectious disease is apparently related to disease severity, which needs to deeply understand for a health development and management of aquaculture. In this study, the role of autophagy during A. hydrophila infection was elucidated in M. rosenbergii. Adult freshwater prawn was firstly administered A. hydrophila to assess the virulence of the isolated strain. Pathological analysis of hepatopancreas and intestine tissues of moribund prawn showed significantly pathological changes, including cellular swelling and vacuolation, contraction or karyorrhexis of nuclei, dissolution and necrosis of villi, structural destruction of the striate border. A significant apoptosis and autophagy was observed in hepatopancreas tissues of the infected shrimp. Moreover, the rapamycin-pretreated groups showed high survival rate in contrast with drastic high mortality in autophagy-suppressed groups. Further analysis showed that the elevated autophagy levels restricted apoptosis signals. We conclude that autophagy plays a positive role during A. hydrophila infection and may be is a new therapeutic target for bacterial disease.