AAV vector-meditated expression of HLA-G reduces injury-induced corneal vascularization, immune cell infiltration, and fibrosis

Sci Rep. 2017 Dec 19;7(1):17840. doi: 10.1038/s41598-017-18002-9.

Abstract

Over 1.5 million individuals suffer from cornea vascularization due to genetic and/or environmental factors, compromising visual acuity and often resulting in blindness. Current treatments of corneal vascularization are limited in efficacy and elicit undesirable effects including, ironically, vision loss. To develop a safe and effective therapy for corneal vascularization, adeno-associated virus (AAV) gene therapy, exploiting a natural immune tolerance mechanism induced by human leukocyte antigen G (HLA-G), was investigated. Self-complementary AAV cassettes containing codon optimized HLA-G1 (transmembrane) or HLA-G5 (soluble) isoforms were validated in vitro. Then, following a corneal intrastromal injection, AAV vector transduction kinetics, using a chimeric AAV capsid, were determined in rabbits. One week following corneal trauma, a single intrastromal injection of scAAV8G9-optHLA-G1 + G5 prevented corneal vascularization, inhibited trauma-induced T-lymphocyte infiltration (some of which were CD8+), and dramatically reduced myofibroblast formation compared to control treated eyes. Biodistribution analyses suggested AAV vectors persisted only in the trauma-induced corneas; however, a neutralizing antibody response to the vector capsid was observed inconsistently. The collective data demonstrate the clinical potential of scAAV8G9-optHLA-G to safely and effectively treat corneal vascularization and inhibit fibrosis while alluding to broader roles in ocular surface immunity and allogenic organ transplantation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Corneal Injuries* / genetics
  • Corneal Injuries* / metabolism
  • Corneal Injuries* / pathology
  • Corneal Injuries* / therapy
  • Corneal Neovascularization* / genetics
  • Corneal Neovascularization* / metabolism
  • Corneal Neovascularization* / pathology
  • Corneal Neovascularization* / therapy
  • Dependovirus*
  • Gene Expression*
  • Genetic Therapy*
  • HEK293 Cells
  • HLA-G Antigens* / biosynthesis
  • HLA-G Antigens* / genetics
  • Humans
  • Rabbits

Substances

  • HLA-G Antigens