Lack of inflammatory gene expression in bats: a unique role for a transcription repressor

Sci Rep. 2017 May 22;7(1):2232. doi: 10.1038/s41598-017-01513-w.

Abstract

In recent years viruses similar to those that appear to cause no overt disease in bats have spilled-over to humans and other species causing serious disease. Since pathology in such diseases is often attributed to an over-active inflammatory response, we tested the hypothesis that bat cells respond to stimulation of their receptors for viral ligands with a strong antiviral response, but unlike in human cells, the inflammatory response is not overtly activated. We compared the response of human and bat cells to poly(I:C), a viral double-stranded RNA surrogate. We measured transcripts for several inflammatory, interferon and interferon stimulated genes using quantitative real-time PCR and observed that human and bat cells both, when stimulated with poly(I:C), contained higher levels of transcripts for interferon beta than unstimulated cells. In contrast, only human cells expressed robust amount of RNA for TNFα, a cell signaling protein involved in systemic inflammation. We examined the bat TNFα promoter and found a potential repressor (c-Rel) binding motif. We demonstrated that c-Rel binds to the putative c-Rel motif in the promoter and knocking down c-Rel transcripts significantly increased basal levels of TNFα transcripts. Our results suggest bats may have a unique mechanism to suppress inflammatory pathology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue, Brown / metabolism
  • Animals
  • Base Sequence
  • Binding Sites
  • Chiroptera / genetics*
  • Chiroptera / metabolism
  • Gene Expression*
  • Genetic Predisposition to Disease*
  • Inflammation / genetics*
  • Interferon-beta / metabolism
  • Models, Biological
  • Poly I-C / pharmacology
  • Promoter Regions, Genetic
  • Protein Binding
  • Proto-Oncogene Proteins c-rel / metabolism
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism
  • Toll-Like Receptor 3 / metabolism

Substances

  • Proto-Oncogene Proteins c-rel
  • Repressor Proteins
  • Toll-Like Receptor 3
  • Interferon-beta
  • Poly I-C