{'fraction_non_alphanumeric': 0.043773119605425403, 'fraction_numerical': 0.01911220715166461, 'mean_word_length': 5.194656488549619, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Phenotypic and Functional Characterization of HIV-1-Specific CD4+CD8+ Double-Positive T Cells in Early and Chronic HIV-1 Infection

Objective:CD4+CD8+ double-positive (DP) T cells represent a poorly characterized population of effector T cells found at low frequencies in the peripheral blood. Virus-specific DP T cells have been identified in HIV-1-infected patients but their origin, relationship to conventional CD4+ and CD8+ single-positive (SP) T cells, and role in disease pathogenesis are unclear. Methods:In this study, peripheral blood T cells were analyzed for cytokine production, maturation, and cytolytic marker expression by polychromatic flow cytometry in subjects with both early (n = 27) and chronic (n = 21) HIV-1 infection. Results and Conclusions:HIV-1-specific interferon gamma (IFN-γ)-producing DP T cells were identified at a median frequency of 0.48% compared with 1.08% and 0.02% for CD8 and CD4 SP cells, respectively, in response to pooled HIV-1 peptides. HIV-1-specific DP T cells exhibited polyfunctionality with characteristics of both CD4 and CD8 SP T cells, including coproduction of IFN-γ and IL-2 and expression of cytolytic-associated lysosomal-associated membrane protein. No differences in frequencies of unstimulated DP T cells were observed in early compared with chronic infection. However, chronic infection was associated with higher frequencies of HIV-specific, IFN-γ-producing DP T cells and higher fractions of effector memory and lysosomal-associated membrane protein expression among these cells, suggesting an effect of cumulative viral antigen burden on DP T-cell function.