A Novel HLA (HLA-A*0201) Transgenic Rabbit Model for Preclinical Evaluation of Human CD8+ T Cell Epitope-Based Vaccines against Ocular Herpes

Laboratory of Cellular and Molecular Immunology, The Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA 92697, USA.
The Journal of Immunology (Impact Factor: 4.92). 03/2010; 184(5):2561-71. DOI: 10.4049/jimmunol.0902322
Source: PubMed


We introduced a novel humanized HLA-A*0201 transgenic (HLA Tg) rabbit model to assess the protective efficacy of a human CD8(+) T cell epitope-based vaccine against primary ocular herpes infection and disease. Each of the three immunodominant human CD8(+) T cell peptide epitopes from HSV-1 glycoprotein D (gD(53-61), gD(70-78), and gD(278-286)) were joined with a promiscuous human CD4(+) T cell peptide epitope (gD(49-82)) to construct three separate pairs of CD4-CD8 peptides. Each CD4-CD8 peptide pair was then covalently linked to an N(epsilon)-palmitoyl-lysine residue via a functional base lysine amino group to construct CD4-CD8 lipopeptides. HLA Tg rabbits were immunized s.c. with a mixture of the three CD4-CD8 HSV-1 gD lipopeptides. The HSV-gD-specific T cell responses induced by the mixture of CD4-CD8 lipopeptide vaccine and the protective efficacy against acute virus replication and ocular disease were determined. Immunization induced HSV-gD(49-82)-specific CD4(+) T cells in draining lymph node (DLN); induced HLA-restricted HSV-gD(53-61), gD(70-78), and gD(278-286)-specific CD8(+) T cells in DLN, conjunctiva, and trigeminal ganglia and reduced HSV-1 replication in tears and corneal eye disease after ocular HSV-1 challenge. In addition, the HSV-1 epitope-specific CD8(+) T cells induced in DLNs, conjunctiva, and the trigeminal ganglia were inversely proportional with corneal disease. The humanized HLA Tg rabbits appeared to be a useful preclinical animal model for investigating the immunogenicity and protective efficacy of human CD8(+) T cell epitope-based prophylactic vaccines against ocular herpes. The relevance of HLA Tg rabbits for future investigation of human CD4-CD8 epitope-based therapeutic vaccines against recurrent HSV-1 is discussed.

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    • "In this study, we tested long-peptide vaccines in our recently established CRPV/HLA-A2.1 transgenic rabbit model system [33]. The CRPV/HLA-A2.1 transgenic rabbit model has been used to test DNA and short peptide vaccines against HLA-A2.1 restricted epitopes from CRPV, HPV16 and HSV antigens [34] (and unpublished observations). We have verified HLA-A2.1 restricted targets from CRPV E1 for both prophylactic and therapeutic T-cell bases vaccines [35]. "
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    ABSTRACT: Long peptide immunization is a promising strategy to clear established tumors. In the current study, we investigated the therapeutic effect of a naturally existing long peptide that contained two HLA-A2.1 restricted epitopes (CRPVE1/149–157 and CRPVE1/161–169) from cottontail rabbit papillomavirus (CRPV) E1 using our CRPV/HLA-A2.1 transgenic rabbit model. A universal Tetanus Toxin helper motif (TT helper) was tagged at either the N-terminus or the carboxyl-terminus of this long peptide and designated as TT-E1 peptide and E1 peptide-TT, respectively. Four groups of HLA-A2.1 transgenic rabbits were infected with wild type CRPV DNA. Three weeks post-infection, the rabbits were immunized four times with TT-E1 peptide, E1 peptide only, E1 peptide-TT or TT-control peptide with two-week intervals between immunizations. Tumor outgrowth was monitored and recorded weekly. After the third booster immunization, tumors on two of the four E1 peptide-TT immunized rabbits began to shrink. One animal from this group was free of tumors at the termination of the study. The mean papilloma size of E1 peptide-TT immunized rabbits was significantly smaller when compared with that of the three other groups (P < 0.05, one way ANOVA analysis). It is interesting that E1 peptide-TT vaccination not only stimulated stronger T cell mediated immune responses but also stronger antibody generations. We conclude that the location of a TT helper motif tagged at the long peptide vaccine is critical for the outcome of therapeutic responses to persistent tumors in our HLA-A2.1 transgenic rabbit model.
    Full-text · Article · Dec 2014 · Trials in Vaccinology
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    • "The rabbit eye model has been used to investigate vaccines to prevent acute ocular herpes (prophylactically) or block recurrent ocular herpes (therapeutically) [86-90]. Many immunological and virological assays can be conducted to assess the efficiency of an HSV vaccine as to whether it is prophylactic and/or therapeutic. "
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    ABSTRACT: Background Rabbits latent with HSV-1 strain McKrae spontaneously shed infectious virus and viral DNA into their tears and develop recurrent herpetic-specific corneal lesions. The rabbit eye model has been used for many years to assess acute ocular infections and pathogenesis, antiviral efficacy, as well as latency, reactivation, and recurrent eye diseases. This study used real-time PCR to quantify HSV-1 DNA in the saliva and tears of rabbits latent with HSV-1 McKrae. Methods New Zealand white rabbits used were latent with HSV-1 strain McKrae and had no ocular or oral pathology. Scarified corneas were topically inoculated with HSV-1. Eye swabs and saliva were taken from post inoculation (PI) days 28 through 49 (22 consecutive days). Saliva samples were taken four times each day from each rabbit and the DNA extracted was pooled for each rabbit for each day; one swab was taken daily from each eye and DNA extracted. Real-time PCR was done on the purified DNA samples for quantification of HSV-1 DNA copy numbers. Data are presented as copy numbers for each individual sample, plus all the copy numbers designated as positive, for comparison between left eye (OS), right eye (OD), and saliva. Results The saliva and tears were taken from 9 rabbits and from 18 eyes and all tested positive at least once. Saliva was positive for HSV-1 DNA at 43.4% (86/198) and tears were positive at 28.0% (111/396). The saliva positives had 48 episodes and the tears had 75 episodes. The mean copy numbers ± the SEM for HSV-1 DNA in saliva were 3773 ± 2019 and 2294 ± 869 for tears (no statistical difference). Conclusion Rabbits latent with strain McKrae shed HSV-1 DNA into their saliva and tears. HSV-1 DNA shedding into the saliva was similar to humans. This is the first evidence that documents HSV-1 DNA in the saliva of latent rabbits.
    Full-text · Article · Sep 2012 · Virology Journal
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    • "Since HSV-1 and HSV-2 invade human mucosa, delivery of Ags through the IVAG route would induce better protection against these sexually transmitted infections [95, 96]. We previously demonstrated that intranasally administered lipopeptide epitopes induce both mucosal and systemic B- and CD4+ Th1-cell responses [2, 32–34, 97–100]. Similar results were obtained using the human cytomegalovirus pp65-derived CD8+ CTL lipopeptides in which higher levels of virus-specific CTL were obtained with lipopeptide delivered mucosally [2, 32–34, 97–101]. "
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    Full-text · Article · Mar 2012 · Clinical and Developmental Immunology
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