In vitro Insights into the Transcriptomic Response of Chicken Cells to Stressors

In genomic studies, scales of investigation can range from small (molecular and cellular) to large (organ, organism, population and system-biology), with each type uniquely contributing toward a more comprehensive understanding of response plasticity in the face of environmental perturbations. We used isolated cells to characterize transcriptomic responses to the single or multiple stressors of high environmental temperature and lipopolysaccharide (LPS)-induced endotoxemia, in vitro. Endotoxemia in animals can result from heat stress-induced “leaky gut”. Cell types included the chicken HD11 macrophage-like cell line, and bone marrow derived antigen presenting cells (BM-APC) of highly inbred Fayoumi and Leghorn chicken lines. Gene expression analysis was conducted using a panel of heat shock protein (HSP), stress-related, signaling molecule and immune-response genes. The HD11 cell line responded to high temperature with increased mRNA levels of several HSP and co-chaperone genes. Up-regulation of effector cytokine genes in response to LPS was greater in HD11 cells in the heat-stress environment than in thermoneutral conditions. In BM-APC of Fayoumi and Leghorn, several HSPs were strongly induced with heat treatment, with few differences between lines. Many immune-related genes in BM-APC responded strongly to one or more treatments with either up- or down-regulation, and most were significantly different between Leghorn and Fayoumi. Fayoumi BM-APC produced more nitric oxide and had higher phagocytic ability and MHC-II surface expression in most treatments. This research contributes toward understanding the genomic basis of cellular response differences to environmental stressors, demonstrates heat-LPS interaction, and genetic line-specific expression differences. Support: USDA-NIFA-AFRI grant and Hatch project 5358.