Robust HIV-specific CD4+ and CD8+ T-cell responses distinguish the rare phenotype of elite control in adolescents living with HIV from viraemic non-progressors.

Background: Elite controllers (ECs) are therapy-naïve HIV-infected individuals capable of spontaneous control of plasma viraemia for at least a year. Although viraemic non-progressors are more common in vertical HIV-infection than in adults infection, elite control has been rarely characterised in the paediatric population.

Results: PECs T-cell populations had lower immune activation and exhaustion levels when compared to PP, reflected by a more sustained and preserved effector function. The HIV-specific T-cell responses among PECs were characterised by high-frequency Gag-specific CD4+ T-cell activity, and markedly more polyfunctional Gag-specific CD8+ activity, compared to PNPs and PPs. These findings were consistently observed even in the absence of protective HLA-I molecules such as HLA-B*27/57/81.

Conclusion: PECs T-cell populations had lower immune activation and exhaustion levels when compared to PP, reflected by a more sustained and preserved effector function. The HIV-specific T-cell responses among PECs were characterised by high-frequency Gag-specific CD4+ T-cell activity, and markedly more polyfunctional Gag-specific CD8+ activity, compared to PNPs and PPs. These findings were consistently observed even in the absence of protective HLA-I molecules such as HLA-B*27/57/81.