Salmonella Enteritidis Rfbd Interferes with Autophagy Through Redd1 to Promote Bacterial Survival

Abstract

Salmonella enterica serovar Enteritidis is an important food-borne facultative intracellular pathogen, which seriously threatens the life and health of humans and animals. Autophagy can be exploited to eliminate intracellular pathogens. Previously, we reported that dTDP-4-dehydro-β-ւ-rhamnose reductase (RfbD) was able to enhance bacterial colonisation in vivo and in vitro by regulating autophagy. Through RNA sequencing, we found that REDD1 was affected by RfbD. The results of qRT-PCR and western blotting showed that the REDD1 RNA and protein levels were notably elevated in the Z11ΔrfbD infection group compared to both the Z11 and Z11ΔrfbD::rfbD infection groups. REDD1 knockdown decreased the autophagy levels induced by Z11ΔrfbD and strongly increased bacterial survival. In contrast, REDD1 overexpression increased the autophagy levels induced by Z11ΔrfbD and reduced bacterial survival. These findings indicate that REDD1 may be a key factor in the suppression of autophagy by RfbD. Our study provides new insights into the mechanism underlying the interaction between Salmonellaenterica and the host.

Keywords: Salmonella Enteritidis, autophagy, RfbD, REDD1, host-pathogen interaction