Potentiality of toll-like receptors (TLRS) in viral infections

Abstract

Living organisms exist in nature usually perceptible to infectious agents like viruses, bacteria, and many other pathogens. Immune system of host organism typically elicits both nonspecific innate and “specific” adaptive immune responses against foreign pathogens. Cells of innate immunity expresses a diversity of pattern recognition receptors (PRRs), which were developed during evolutionary process, recognizes conserved structures of distinct pathogens known as pathogen-associated molecular patterns (PAMPs). There are several classes of PRRs like Toll-like receptors (TLRS), RLRs, NLRs, and many DNA and RNA sensors. Among these PRRs, Toll-like receptors plays an important role in eliciting innate immunity, development of B and T cell responses and as well as pathogen-specific adaptive immune response. Immune responses in any viral infections are elicited by the recognition viral PAMPs like nucleic acids such as DNA and RNA, viral capsid proteins by the host PRR. TLRs sense these viral PAMPs and induce the antiviral response by inducing the immune active chemokines and cytokines. This chapter focuses on the responses of different TLRs with viral PAMPS, immune responses mediated by TLRS in viral infections, agonists of TLRs for treatment of viral infections.