Vasoactive Intestinal Peptide: a Potential Target for Antiviral Therapy

Viral infection is clinically common and some viral diseases, such as the ongoing global outbreak of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), have high morbidity and mortality. However, most viral infections are currently lacking in specific therapeutic agents and effective prophylactic vaccines, due to inadequate response, increased rate of drug resistance and severe adverse side effects. Therefore, it is urgent to find new specific therapeutic targets for antiviral defense among which "peptide-based therapeutics" is an emerging field. Peptides may be promising antiviral drugs because of their high efficacy and low toxic side effects. Vasoactive intestinal peptide (VIP) is a prospective antiviral peptide. Since its successful isolation in 1970, VIP has been reported to be involved in infections of SARS-CoV-2, human immune deficiency virus (HIV), vesicular stomatitis virus (VSV), respiratory syncytial virus (RSV), Zika virus (ZIKV) and cytomegalovirus (CMV). Additionally, given that viral attacks sometimes cause severe complications due to overaction of inflammatory and immune responses, the potent anti-inflammatory and immunoregulator properties of VIP facilitate it to be a powerful and promising candidate. This review summarizes the role and mechanisms of VIP in all reported viral infections and suggests its clinical potential as an antiviral therapeutic target.