With the advancement in knowledge of innate immune functioning, toll-like receptors (TLRs) have emerged as potential adjuvant candidates. TLRs are one of the types of pattern recognition receptors (PRRs) that sense conserved signature molecules on invading pathogens. Detection of the pathogens via TLRs alerts the immune system of the host and helps in mounting a quick immune response against the invading pathogens. This property of TLR ligands may be exploited for the development of effective prophylactic agents against infectious chicken diseases. In this review the immunostimulatory effects of various TLRs will be discussed as well as their use as adjuvants in combination.
