Purpose: To evaluate the effect of vaccination with fusion protein(gD-IL-2) consisting of herpes simplex type1(HSV-1) glycoprotein D(gD) and human interleukin-2(IL-2), and the effect of plasmid DNA vaccine encoding gD-IL-2 against murine herpetic keratitis.
Methods: Plasmid containing gD-IL-2(pHDL-neol) was constructed, and gD-IL-2 peptide was purified. BALB/c mice were injected twice hypodermally or subconjunctivally with 1 microgram/0.1 ml of gD-IL-2 peptide, or twice subconjunctivally with 90 micrograms/0.05 ml of gD-IL-2 plasmid DNA. Neutralizing antibody titer and delayed-type hypersensitivity (DTH) against HSV-1 were measured. Immunized mice were challenged with CHR3 strain of HSV-1 via the cornea. The clinical picture of epithelial and stromal keratitis was scored.
Results: Stromal keratitis was inhibited in gD-IL-2 peptide- or gD-IL-2 DNA-immunized mice, but epithelial keratitis was not. It was confirmed that plasmid gD-IL-2 elicited significant serum virus neutralizing titer and DTH response.
Conclusion: Vaccination with gD-IL-2 was effective against herpetic keratitis.