Enhancement of Antiviral Activity of Human Alpha-Defensin 5 against Herpes Simplex Virus 2 by Arginine Mutagenesis at Adaptive Evolution Sites

Abstract

bHerpes simplex virus 2 (HSV-2) infection is still one of the common causes of sexually transmitted diseases worldwide. The prevalence of HSV strains resistant to traditional nucleoside antiviral agents has led to the development of novel antiviral drugs. Human alpha-defensin 5 (HD5), a kind of endogenous antimicrobial peptide expressed in the epithelia of the small intestine and urogenital tract, displays natural antiviral activity. Based on arginine-rich features and adaptive evolution characteristics of vertebrate defensins, we conducted a screen for HD5 derivatives with enhanced anti-HSV-2 activity by a single arginine substitution at the adaptive evolution sites. Cell protection assay and temporal antiviral studies showed that HD5 and its mutants displayed affirmatory but differential anti-HSV-2 effects in vitro by inhibiting viral adhesion and entry. Inspiringly, the E21R-HD5 mutant had significantly higher antiviral activity than natural HD5, which is possibly attributed to the stronger binding affinity of the E21R-HD5 mutant with HSV-2 capsid protein gD, indicating that E21R mutation can increase the anti-HSV-2 potency of HD5. In a mouse model of lethal HSV-2 infection, prophylactic and/or therapeutic treatment with E21R-HD5 via intravaginal instillation remarkably alleviated the symptoms and delayed disease progress and resulted in about a 1.5-fold-higher survival rate than in the HD5 group. Furthermore, the E21R variant exhibited a 2-fold-higher antiviral potency against HIV-1 over parental HD5 in vitro. This study demonstrates that arginine mutagenesis at appropriate evolution sites may significantly enhance the antiviral activity of HD5, which also paves a facile way to search for potent antiviral drugs based on natural antimicrobial peptides.

Porcine β-defensin 2 inhibits proliferation of pseudorabies virus in vitro and in transgenic mice

“…HNP-4 and HD-6 were capable of block HSV binding by interacting with heparan sulfate, the primary receptor for HSV binding, while HBD-3 with enhanced inhibitory effect against HSV bound both heparan sulfate and gB [20]. HD-5 was able to prevent viral adhesion and entry of HSV by binding to both gB and gD [20,21,23]. Likewise, rabbit NP-1 and HNP-1, -2, -3 inactivated HSV by preventing viral entry [22,31,35].…”

“…The antiviral abilities of defensins against alphaherpesviruses have been described previously. Some αdefensins with antiviral ability against herpes simplex virus (HSV) infection were characterized, such as human neutrophil peptide (HNP) 1-4, human α-defensin (HD) 5 and 6, rabbit α-defensin NP-1 and NP-2 [19][20][21][22][23][24]. In terms of β-defensins, human β-defensin (HBD) 3 and a synthetic β-defensin analog constituted by domains of HBD-1 and HBD-3 have been confirmed to inactivate HSV [20,25,26].…”

A ntimicrobial peptides and gut microbiota in homeostasis and pathology

“…Mechanistic studies could also show that an artificial D-enantiomer version of HD5 shows significantly less activity than the native L-form isomer in killing Staphylococcus aureus, but equally bactericidal potential against Escherichia coli (Wei et al, 2009), revealing an unexpected functional complexity. Both Paneth cell a-defenins also seem to have antiviral activity (Doss et al, 2009;Klotman & Chang, 2006;Wang et al, 2013) but, depending on the setting, might also increase infectivity of certain viruses (Klotman et al, 2008). Furthermore, for HD5, anti-parasitic activity has been reported (Leitch & Ceballos, 2009).…”

Perspectives for clinical use of engineered human host defense antimicrobial peptides

“…2013). All the mice were pretreated with progesterone subcutaneously (2 mg) and 5 days later each mouse was inoculated with a lethal dose of HSV-2 (10 5 PFU).…”