Bacteria‑host transcriptional response during intestinal epithelial cells infection by Klebsiella pneumoniae

Notably, the host genes encoding REDD1, BHLHE40, ANKRD37 and NLRP3 exhibited significant upregulation upon infection. REDD1 expression was progressively induced during infection, both at the mRNA and protein levels (significantly at 2h and 4h infection). In addition, functional study showed that siRNA-mediated knock-down of REDD1 did not affect intestinal epithelial tight junction integrity.

However, REDD1 was critical for facilitating the intracellular invasion of K. pneumoniae. Finally, we found that molybdenum cofactor biosynthesis protein of K. pneumoniae encoded by mogA may promote bacterial invasion through host REDD1. This study for the first time demonstrated the potential interaction between K. pneumoniae and human intestinal epithelium.