Expression profiles of genes in Toll-like receptor-mediated signaling of broilers infected with Clostridium perfringens.

Toll-like receptors (TLRs) participate in detecting microbial pattern molecules for activation of the host immune response. We investigated possible roles of TLRs in the chicken response to Clostridium perfringens infection by examining the expression of TLR genes and other genes involved in TLR-mediated signaling within the spleens and ilea of C. perfringens-challenged broilers. Upregulation of a tumor necrosis factor alpha-inducing factor homolog in challenged chickens compared to naïve chickens was observed, regardless of the incidence of necrotic enteritis. In addition, the members of the TLR2 subfamily were found to be most strongly involved in the host response to C. perfringens challenge, although the expression of TLR4 and TLR7 was also upregulated in spleen tissues. While the combination of TLR1.2, TLR2.1, and TLR15 appeared to play a major role in the splenic response, the expression of TLR2.2 and TLR1.1 was positively correlated to the expression of adaptor molecules MyD88, TRAF6, TRIF, and receptor interacting protein 1 in the ileal tissues, demonstrating a dynamic spatial and temporal innate host response to C. perfringens.