HIV-1 HIVACAT T-cell Immunogen (HTI) epitopes (HTI)

HIV-1 Pol-derived HTI (HIVACAT T-cell Immunogen) epitopes are a specific set of highly conserved and subdominant viral peptide sequences derived from the HIV-1 polymerase (Pol) protein, integrated into a synthetic immunogen design (Mothe et al., 2015, Journal of Virology). These epitopes were selected based on their frequent recognition by T-cells in HIV controllers—individuals who naturally maintain low viral loads without antiretroviral therapy (Bailon et al., 2022, Nature Medicine). The HTI design aims to redirect the host's immune response toward vulnerable regions of the viral proteome where mutations typically result in a significant fitness cost to the virus. By including these Pol-derived segments alongside Gag, Vif, and Nef sequences, HTI-based vaccines (such as DNA-HTI, MVA-HTI, and ChAdOx1-HTI) seek to induce robust CD4+ and CD8+ T-cell responses. In clinical settings, these epitopes serve as the functional components of therapeutic vaccines intended to achieve a functional cure or prolonged viral suppression during analytical treatment interruptions (AELIX Therapeutics, 2023). The Pol-derived portion is particularly critical because the polymerase enzyme is essential for viral replication, and its high conservation limits the virus's ability to escape immune pressure.

Other names

HIVACAT T-cell ImmunogenHTI immunogenHIV-1 conserved epitopesHTI-derived peptides

Vaccine-mediated induction of cytotoxic T-lymphocyte (CTL) responses targeting conserved viral regions to control HIV-1 replication.