Role of toll‐like receptors in the pathogenesis of COVID‐19: Current and future perspectives

Abstract

AbstractThe coronavirus disease 2019 (COVID‐19) pandemic underlines a persistent threat of respiratory tract infectious diseases and warrants preparedness for a rapid response. At present, COVID‐19 has had a serious social impact and imposed a heavy global burden on public health. The exact pathogenesis of COVID‐19 has not been fully elucidated. Since the outbreak of COVID‐19, a renewed attention has been brought to Toll‐like receptors (TLRs). Available data and new findings have demonstrated that the interaction of human TLRs and SARS‐CoV‐2 is a vital mediator of COVID‐19 immunopathogenesis. TLRs such as TLR2, 4, 7 and 8 are potentially important in viral combat and activation of immunity in patients with COVID‐19. Therapeutics targeting TLRs are currently considered promising options against the pandemic. A number of TLR‐targeting immunotherapeutics are now being investigated in preclinical studies and different phases of clinical trials. In addition, innovative vaccines based on TLRs under development could be a promising approach for building a new generation of vaccines to solve the current challenges. In this review, we summarize recent progress in the role of TLRs in COVID‐19, focusing the new candidate drugs targeting TLRs, the current technology and potential paths forward for employing TLR agonists as vaccine adjuvants.