Figure 2.

Illustration of peptide immunization regimen, HSV-1 challenge, T-cell immunogenicity, and protective efficacy studies in HLA-Tg rabbits. Three groups of age-matched HLA-A*02:01 rabbits (n = 10 each) were immunized subcutaneously twice (on days 0 and 15) with CD8⁺ peptide epitopes as outlined in Materials and Methods. As a negative control, a fourth group of HLA transgenic rabbits (n = 10) received adjuvant alone (mock-vaccinated). Two weeks after final immunization, HLA-Tg rabbits were ocularly challenged (both eyes, without scarification) with 2 × 10⁵ pfu of HSV-1 (strain McKrae) delivered as eye drops in 20 μL of tissue culture media. Rabbits were examined for ocular disease immediately before ocular challenge, and on days 1, 3, 5, 7, 10, 14, and 21 thereafter. Survival was determined in a window of 30 days after challenge. Tears from both eyes were collected by swabbing rabbit eyes with a Dacron swab on days 3, 5, and 7 after challenge for titration of viral load. Frequency and function of HSV-1 epitope-specific CD8⁺ T cells were analyzed on days −1, 9, and 21 post challenge.