Cathelicidin LL-37 and HSV-1 Corneal Infection: Peptide Versus Gene Therapy

Abstract

Purpose: To evaluate the potential utility of collagen-based corneal implants with anti-Herpes Simplex Virus (HSV)-1 activity achieved through sustained release of LL-37, from incorporated nanoparticles, as compared with cell-based delivery from model human corneal epithelial cells (HCECs) transfected to produce endogenous LL-37. Methods:We tested the ability of collagen-phosphorylcholine implants to tolerate the adverse microenvironment of herpetic murine corneas. Then, we investigated the efficacy of LL-37 peptides delivered through nanoparticles incorporated within the corneal implants to block HSV-1 viral activity. In addition, LL-37 complementary DNA (cDNA) was transferred into HCECs to confer viral resistance, and their response to HSV-1 infection was examined.Results: Our implants remained in herpetic murine corneas 7 days longer than allografts. LL-37 released from the implants blocked HSV-1 infection of HCECs by interfering with viral binding. However, in pre-infected HCECs, LL-37 delayed but could not prevent viral spreading nor clear viruses from the infected cells. HCECs transfected with the LL-37 expressed and secreted the peptide. Secreted LL-37 inhibited viral binding in vitro but was insufficient to protect cells completely from HSV-1 infection. Nevertheless, secreted LL-37 reduced both the incidence of plaque formation and plaque size.Conclusion: LL-37 released from composite nanoparticle-hydrogel corneal implants and HCEC-produced peptide, both showed anti-HSV-1 activity by blocking binding. However, while both slowed down virus spread, neither was able on its own to completely inhibit the viruses.Translational Relevance: LL-37 releasing hydrogels may have potential utility as corneal substitutes for grafting in HSV-1 infected corneas, possibly in combination with LL-37 producing therapeutic cells.

LL-37 disrupts the Kaposi's sarcoma-associated herpesvirus envelope and inhibits infection in oral epithelial cells

“…The activity of the native LL-37 was significantly greater than scrLL-37, leading us to conclude that LL-37 had a structure-dependent antiviral activity against KSHV. This ability of the native primary structure of LL-37 to inhibit viral infections as opposed to a scrambled version of the peptide has also been observed with a number of other viruses—including DENV (Alagarasu et al, 2017), HAdV19 (Gordon et al, 2005), HCV (Matsumura et al, 2016), HRV (Sousa et al, 2017), HSV-1 (Gordon et al, 2005; Lee et al, 2014), influenza A virus (Barlow et al, 2011; Tripathi et al, 2015a, 2013 White et al, 2017), and RSV (Currie et al, 2013; Harcourt et al, 2016)—suggesting the specific structure, and not simply the charge, of LL-37 is important in its antiviral activity.…”

“…While the antiviral activities of adrenomedullin have not been characterized, beta-defensins 1-3 and LL-37 were shown to exhibit antiviral activities (Barlow et al, 2014a; Klotman and Chang, 2006). Of these HDPs, LL-37, a 37-amino acid cationic peptide present in both saliva and gingival crevicular fluid (Murakami et al, 2002; Türkoğlu et al, 2009), has been the most widely studied in the context of antiviral activities, with defined mechanisms against dengue type 2 virus (DENV2) (Alagarasu et al, 2017), hepatitis C virus (HCV) (Matsumura et al, 2016), human immunodeficiency virus (HIV) (Wong et al, 2011), influenza A virus (Tripathi et al, 2015b, 2014, 2013), respiratory syncytial virus (RSV) (Currie et al, 2016, 2013), vaccinia virus (VV) (Dean et al, 2010; Ulaeto et al, 2016), and herpes simplex virus type 1 (HSV-1) (Lee et al, 2014; Takiguchi et al, 2014). In contrast, no HDP has been studied with respect to KSHV infection.…”

The interplay between vitamin D and viral infections

“…The potent anti‐viral activity of LL37 against HSV‐1 has also been reported in human corneal epithelial cells (HCECs) and appears to be mainly because of the blocking of virus binding to the cells as the peptide was ineffective once HSV‐1 was internalized . The anti‐viral effect of LL37 was also reported in a HCV cell culture system.…”

High Serum 25-Hydroxyvitamin D Levels Are Associated with Pediatric Sepsis

“…Both peptides are intracellular mediators of antiviral and antibacterial activity (Wang et al 2004). Cathelicidin, also known as LL-37, is one of endogenous antimicrobial peptides that have a defensive role against a wide spectrum of infectious agents including gram negative and positive bacteria, fungi and mycobacteria (Lee et al 2014). Liu et al (2006) showed that 1,25-dihydr oxy vitamin D 3 treatment of cultured macrophages infected with Myobacterium tuberculosis caused enhanced expression of cathelicidin.…”