heparitin-sulfate and Eye-Infections--Viral

To prolong the release of a heparan sulfate binding peptide, G2-C, using a commercially available contact lens as a delivery vehicle and to demonstrate the ability of the released peptide to block herpes simplex virus-1 (HSV-1) infection using in vitro, ex vivo, and in vivo models of corneal HSV-1 infection.. Commercially available contact lenses were immersed in peptide solution for 5 days prior to determining the release of the peptide at various time points. Cytotoxicity of the released samples was determined by MTT and cell cycle analysis, and the functional activity of the released samples were assessed by viral entry, and viral spread assay using human corneal epithelial cells (HCE). The ability to suppress infection in human and pig cornea ex vivo and mouse in vivo models were also assessed.. Peptide G2-C was released through the contact lens. Following release for 3 days, the peptide showed significant activity by inhibiting HSV-1 viral entry and spread in HCE cells. Significant suppression of infection was also observed in the ex vivo and in vivo experiments involving corneas.. Extended release of an anti-HS peptide through a commercially available contact lens can generate significant anti-HSV-1 activity and provides a new and effective way to control corneal herpes.

Topics: Animals; Contact Lenses; Cornea; Delayed-Action Preparations; Disease Models, Animal; Eye Infections, Viral; Female; Heparitin Sulfate; Herpesvirus 1, Human; Humans; Keratitis, Herpetic; Male; Mice; Mice, Inbred BALB C; Swine

Heparan sulfate (HS) and its highly modified form, 3-O-sulfated heparan sulfate (3-OS HS), contribute strongly to herpes simplex virus type-1 (HSV-1) infection in vitro. Here we report results from a random M13-phage display library screening to isolate 12-mer peptides that bind specifically to HS, 3-OS HS, and block HSV-1 entry. The screening identified representative candidates from two-different groups of anti-HS peptides with high positive charge densities. Group 1, represented by G1 peptide (LRSRTKIIRIRH), belongs to a class with alternating charges (XRXRXKXXRXRX), and group 2, represented by G2 peptide (MPRRRRIRRRQK), shows repetitive charges (XXRRRRXRRRXK). Viral entry and glycoprotein D binding assays together with fluorescent microscopy data indicated that both G1 and G2 were potent in blocking HSV-1 entry into primary cultures of human corneal fibroblasts and CHO-K1 cells transiently expressing different glycoprotein D receptors. Interestingly, G2 peptide isolated against 3-OS HS displayed wider ability to inhibit entry of clinically relevant strains of HSV-1 and some divergent members of herpesvirus family including cytomegalovirus and human herpesvirus-8. To identify functional residues within G1 and G2, we performed point mutations and alanine-scanning mutagenesis. Several arginine and a lysine residues were needed for anti-HSV-1 activity, suggesting the importance of the positively charged residues in virus-cell binding and virus-induced membrane fusion. In vivo administration of G1 or G2 peptide as a prophylactic eye drop completely blocked HSV-1 spread in the mouse cornea as evident by immunohistochemistry. This result also highlights an in vivo significance of HS and 3-OS HS during ocular herpes infection.

Topics: Amino Acid Substitution; Animals; Antiviral Agents; Chlorocebus aethiops; CHO Cells; Cricetinae; Cricetulus; Eye Infections, Viral; HeLa Cells; Heparitin Sulfate; Herpes Simplex; Herpesvirus 1, Human; Humans; Mice; Mice, Inbred BALB C; Peptides; Point Mutation; Vero Cells; Viral Envelope Proteins; Virus Internalization