Analysis of the CD8+ T cell anti-HIV activity in heterologous cell co-cultures reveals the benefit of multiple HLA class I matches.

CD8+ T lymphocytes can reduce the production of human immunodeficiency virus 1 (HIV-1) by CD4+ T cells by cytotoxic and non-cytotoxic mechanisms. To investigate the involvement of human leukocyte antigen (HLA) class I compatibility in anti-HIV responses, we co-cultured primary CD8+ T cells, isolated from the peripheral blood of HIV-1-infected individuals, with panels of autologous and heterologous acutely HIV-1-infected primary CD4+ T cells. Altogether, CD8+ T cell anti-HIV activity was evaluated in more than 200 co-cultures. Marked heterogeneity in HIV-1 replication levels was observed among the co-cultures sharing a common CD8+ T cell source. The co-cultures that exhibited greater than 50% reduction in HIV production were found to have significantly increased numbers of matching HLA class I alleles (Yates chi-square = 54.21; p < 0.001). With CD8+ T cells from HIV controllers and asymptomatic viremic individuals, matching HLA-B and/or HLA-C alleles were more predictive of strong anti-HIV activity than matching HLA-A alleles. Overall, HLA class I genotype matches were more closely associated with CD8+ T cell anti-HIV activity than supertype pairings. Antibodies against HLA class I and CD3 reduced the CD8+ T cell anti-HIV activity. Stimulated CD8+ T cells exhibited increased anti-HIV activity and reduced dependency on HLA compatibility. These findings provide evidence that the maximal suppression of HIV replication by CD8+ T cells requires the recognition of multiple epitopes. These studies provide insight for HIV vaccine development, and the analytic approach can be useful for the functional characterization of HLA class I alleles and tentative HLA class I supertypes.