Design and validation of HIV peptide pools for detection of HIV-specific CD4+ and CD8+ T cells

Reagents to monitor T cell responses to the entire HIV genome, based on well characterized epitopes, are missing. Evaluation of HIV-specific T cell responses is of importance to study natural infection, and therapeutic and vaccine interventions. Experimentally derived CD4(+) and CD8(+) HIV epitopes from the HIV molecular immunology database were developed into Class I and Class II HIV megapools (MPs). We assessed HIV responses in persons with HIV pre antiretroviral therapy (ART) (n = 17) and post-ART (n = 18) and compared these responses to 15 controls without HIV (matched by sex at birth, age, and ethnicity). Using the Activation Induced Marker (AIM) assay, we quantified HIV-specific total CD4(+), memory CD4(+), circulating T follicular helper, total CD8(+) and memory CD8(+) T cells. We also compared the Class I and Class II HIV MPs to commercially available HIV gag peptide pools. Overall, HIV Class II MP detected HIV-specific CD4(+) T cells in 21/35 (60%) HIV positive samples and 0/15 HIV negative samples. HIV Class I MP detected an HIV-specific CD8(+) T cells in 17/35 (48.6%) HIV positive samples and 0/15 HIV negative samples. Our innovative HIV MPs are reflective of the entire HIV genome, and its performance is comparable to other commercially available peptide pools. Here, we detected HIV-specific CD4(+) and CD8(+) T cell responses in people on and off ART, but not in people without HIV.

Automated summary

Reagents to monitor T cell responses to the entire HIV genome have been developed in this study, which are crucial for assessing HIV-specific T cell responses in natural infection and therapeutic and vaccine interventions. The results showed that the developed reagents can detect HIV-specific CD4(+) and CD8(+) T cell responses in individuals with HIV, but not in individuals without HIV.