Toll-like receptors regulation of viral infection and disease☆

Abstract

In recent years, it has become increasingly evident that mammalian Toll-like receptors (TLRs) play a critical role in determining the outcome of virus infection. TLRs have evolved to recognize viral nucleic acids, and promote the stimulation of innate and adaptive immune responses. Interestingly, the study of mice harboring deficiencies in various TLR proteins and their adaptors suggests that TLR activation promotes protective anti-viral immunity in some cases, while exacerbating virusinduced disease in others. In this report we describe the interactions of viruses with both the TLR system and the intracellular recognition system and highlight the role of TLRs in shaping the outcome of virus infection in both a positive and negative manner.

Expression and function of toll-like receptors in peripheral blood mononuclear cells of patients with polymyalgia rheumatica and giant cell arteritis

“…It has been demonstrated that viral infections upregulate the expression of TLRs 33 34. TLR3, TLR7, TLR8 and TLR9 typically reside in the endosomes where they can gain access to viral nucleic acids 35. TLR7 recognises ssRNA in the cytoplasm of infected cells during viral replication 36.…”

“…Presumably, TLR7 senses a specific invariant feature present in the genomic RNA or viral replication intermediates of these viruses. However, little evidence exists regarding the particular viral ligand that serves as the authentic pathogen‑associated molecular pattern that binds to TLR7, or about the regulation of TLRs by viruses 35 37. It is also possible that microorganisms different from viruses or an endogenous TLR7 stimulus of non-infectious origin may induce a type I IFN response through the TLR7 pathway 38–41.…”

Hepatitis C and hepatocellular carcinoma: A review of natural history

“…Nuclear factor κB (NF-κB), interferon (IFN) regulatory factor (IRF)-3, IRF-5, and IRF-7 are the factors which mediate these responses. [32] NF-κB mediate the inflammatory response to HCV by inducing chemokines and proinflammatory cytokines in parallel with tumor necrosis factor-α (TNF-α).…”

Roles of PAR1 and PAR2 in viral myocarditis

“…Pathogen-associated molecular patterns (PAMPs) are detected by pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) [5]. Viral infections are mainly detected by the endosomal TLRs that are activated by nucleic acids, including TLR3, TLR7, TLR8 and TLR9.…”