Research progress on the role of toll-like receptor 4 in allergic rhinitis

Allergic rhinitis(AR) is the most common allergic diseases and the most common chronic nasal diseases worldwide, affecting up to 50% of the population in some countries. AR is a non-infectious chronic inflammatory disease of nasal mucosa mediated mainly by immunoglobulin E (IgE) in atopic individuals exposed to allergens. The recognition, presentation and immune response to allergens are the key factors in the pathogenesis of AR. Toll-like receptors(TLRs) is the oldest “gatekeeper” of human beings and the first line of defense against foreign invading pathogens. Among all of the TLRs, TLR4 is one of the TLRs that most closely related to AR. Since TLR4 was first discovered in 1997, our understanding of the immunological role of TLR4 in innate and adaptive immune has been greatly improved. In recent years, a large number of studies on the correlation between TLR4 and AR have emerged, including genetic polymorphism, pathogenesis and treatment. Therefore, this paper will review the immune role and potential mechanism of TLR4 in the pathogenesis and treatment of AR.