Acute retinal necrosis (ARN) is a rare, potentially blinding retinal disease resulting from ocular infections with herpes simplex virus (HSV) or varicella-zoster virus (VZV). To determine the antigen specificity and functional characteristics of ocular infiltrating T cells in ARN, T cells were isolated and expanded nonspecifically from intraocular fluid (IOF) samples from 2 patients with HSV-1- and 3 with VZV-mediated ARN. HSV-specific T cell reactivity could be detected only in the IOF-derived T cell lines (TCLs) of the 2 patients with HSV-mediated ARN. These TCLs consisted of both HSV type-common and type-specific CD4+ and CD8+ T cell clones (TCCs) with differential T cell receptor usage. Irrespective of their phenotype, the TCCs were cytolytic and secreted interferon-gamma, tumor necrosis factor-alpha, interleukin-4, and interleukin-5. In both patients, the antigen specificity of a substantial number of HSV-1-specific TCCs could be mapped to approximately 0.67-0.73 HSV-1 map units. The data presented suggest the contribution of T cells, specific for the triggering virus, to the pathogenesis of ARN.

Sllml-nal'yTo evaluate the effectiveness of vaccine protection from infected cells from another individual of the same species, vaccinated rhesus macaques (Macaca mulatta) were challenged with peripheral blood mononuclear cells from another animal diagnosed with acquired immune deficiency syndrome (AIDS). Half of the simian immunodeficiency virus (SIV)-vaccinated animals challenged were protected, whereas unprotected vaccinates progressed as rapidly to AIDS. Protection was unrelated to either total antibody titers to human cells, used in the production of the vaccine, to HLA antibodies or to virus neutralizing activity. However, analysis of the serotype of each animal revealed that all animals protected against cell-associated virus challenge were those which were SIV vaccinated and which shared a particular major histocompatibility complex (MHC) class I allele (Mamu-A26) with the donor of the infected cells. Cytotoxic T lymphocytes (CTL) specific for SIV envelope protein were detected in three of four protected animals vs. one of four unprotected animals, suggesting a possible role of MHC class I-restricted CTL in protection from infected blood cells. These findings have possible implications for the design of vaccines for intracellular pathogens such as human immunodeficiency virus (HIV).

It has previously been shown that T cells specific for the triggering virus infiltrate the eye of patients with herpes simplex virus type 1 (HSV-1)-induced acute retinal necrosis (ARN). The T cells were mainly directed against 0.67-0.73 HSV-1 map region encoded antigens. The fine specificities of genetically different T cell clones (TCC), obtained from affected eyes of 3 patients with HSV-induced ARN and reactive toward this genomic region of HSV-1, were analyzed with recombinant HSV viruses and synthetic peptides. For 1 patient, the HSV-1 UL46 gene encoded tegument protein VP11/12 was identified as the target antigen. Two separate CD4(+) T cell epitopes were defined in VP11/12. TCC from the other 2 patients recognized the HSV-1 UL47 gene encoded tegument protein VP13/14. Two separate CD4(+) VP13/14 T cell epitopes were identified in these patients. Analysis of the data indicates that HSV-1 VP11/12 and VP13/14 are major target antigens for T cells obtained from vitreous fluid samples of the HSV-induced ARN patients studied.

The immunogenicity and e~'cacy of an inactivated whole SIVmac (32H) preparation adjuvanted with muramyl dipeptide (SIV-MDP) and a gpl20-enriched SIVmac (32H) ISCOM preparation ( SIV-ISCOM), were compared by immunizing four rhesus macaques (Macaca mulatta)./bur times with SIV-MDP and four others in the same way with SIV-ISCOM. Two monkeys immunized with whole inactivated measles virus (MV) adjuvanted with MDP ( M V-MDP) and two monkeys immunized with M V-ISCOM served as controls. In the SIV-ISCOM.immunized monkeys higher SIV-specific serum antibody titres were ./ound than in the SIV-MDP-immunized monkeys. In contrast to the MV-immunized monkeys all SIV-MDP-and SIV-ISCOM-immunized monkeys were protected against intravenous challenge 2 weeks q[ier the last immunization with 10 median monkey il~fectious doses ( MIDso) of a cell-free SIVmac (32H) challenge stock propagated in the human T-cell line C8166. After 43 weeks the protected monkeys were reboosted and 2 weeks later rechallenged with 10 MIDso o[ the same virus produced in peripheral blood mononuclear cells ( PBMC) from a rhesus macaque, None of these animals proved

The frequencies of human immunodeficiency virus type 1 (HIV-1) Gag- and Epstein-Barr virus (EBV)-specific cytotoxic T lymphocyte precursors (CTLp) were studied longitudinally in peripheral blood mononuclear cells from 9 HIV-1-infected persons. By antigen-specific stimulation, HIV-1 Gag-specific CTLp were detected in vitro throughout the course of HIV-1 infection, even after the onset of overt disease. In 4 patients, however, HIV-1 Gag-specific CTLp frequencies declined over time in the presence of maintained EBV-specific CTLp. This decline was correlated with decreasing CD4 (r = .38; P < .05) and CD8 (r = .75; P < .001) cell numbers. The maintenance of EBV-specific CTLp in patients with low CD4 cell numbers indicated that EBV-specific CTL-mediated immunity may remain longer unaffected by HIV-1-induced immune dysfunction. Consistent with this observation, the growth of EBV-specific CTL could be supported in vitro by EBV-infected lymphoblastoid B cell lines, independent of both CD4 cells and exogenous cytokines.