Synergistic induction of avian immune gene expression by sirtuin modulators and histone methyltransferase inhibitors

Abstract

With the parallel increase in the global demand for poultry production and rise in the threat of antimicrobial resistance, the development of novel antibiotic alternatives is integral to the security of the food-animal industry and public health. Recently, the induction of host defense peptides (HDPs) of the innate immune system has emerged as a host-directed therapeutic approach to simultaneously mitigate poultry infections and disease resistance. This study is focused on comparing the capacity for several epigenetic compounds, specifically four sirtuin modulators and a known histone methyltransferase inhibitor (BIX01294), to induce the avian innate immune response. To evaluate the in vitro response, chicken macrophage cells were treated with each compound (resveratrol, SRT2104, sirtinol, and EX527) with or without BIX01294 at variable timepoints (12, 24, 48 h). Following optimized treatment, RNA isolation, reverse transcription, and qPCR analysis of select innate immune genes (AvBD3, AvBD9, AvBD10, CLDN1, IL-1B, and MUC2) were performed to profile the avian immune response. Despite the hypothesized upregulation of the innate response strictly from sirtuin inhibitors, both the sirtuin inhibitors and activators synergized with BIX01294 to induce a significant avian HDP response with minimized inflammation. Although no further expression of mucosal or tight junction barrier protective genes was induced by any of the four modulators, this study furthers the need to understand sirtuin modulator epigenetic activity with future studies of histone profiling. Despite the unknown mechanisms of sirtuin modulators, the significant synergy response to these treatments validates the promising potential for these compounds to be actively explored as antibiotic alternatives.