Expression pattern of toll like receptors in macrophages and heterophils of chickens induced by TLR agonists

Present work was carried out to study the induced TLR gene expression kinetics on various innate immune cells like macrophages and heterophils of White leghorn chicks after inoculation with two TLR agonist's viz., LPS and Poly I: C. After isolation of cDNA from these cells, expression of different TLRs was analyzed by using gene specific primers in real time PCR. Macrophages showed early response to LPS with transient increased TLR-4 and TLR-15 expression at 4 hr interval and down regulation in the subsequent intervals. TLR-3 expression, induced by Poly I: C was maximum at 12 hr interval in macrophages. Heterophils showed significantly higher expression of TLR-4 at 4 hr interval but TLR15 expression was higher at 12 hr interval, which is contrast to macrophages both in terms of time and magnitude of expression. Thus these TLR agonists could induce TLR expression in innate immune cells and can be used as immunomodulators for enhancing immune responses.