HIV-1 Virion infectivity factor-derived HIVACAT T-cell Immunogen epitopes (HIV-1 Vif HTI epitopes)

HIV-1 Vif-derived HTI epitopes are specific peptide sequences derived from the Virion infectivity factor (Vif) protein of HIV-1, integrated into the HIVACAT T-cell Immunogen (HTI) (Mothe et al., 2015, PubMed: 25653442). The Vif protein plays a critical role in viral evasion by neutralizing the host's APOBEC3G restriction factor, which normally induces lethal hypermutations in the viral DNA (UniProt: P03402). The HTI immunogen was designed to include 16 segments of the HIV-1 genome, including Vif, that are preferentially targeted by T-cells in individuals who naturally control HIV infection, known as HIV controllers (Bailon et al., 2022, Nature Communications). These specific Vif epitopes are highly conserved, meaning the virus cannot easily mutate them without losing significant biological fitness. Therapeutic vaccines utilizing these epitopes, such as MVA-HTI and DNA-HTI, aim to stimulate a potent CD8+ T-cell response capable of recognizing and killing infected cells (Mothe et al., 2019, Journal of Translational Medicine). By focusing the immune response on these Vif-derived regions, researchers hope to achieve a functional cure where the virus is suppressed without the need for lifelong antiretroviral therapy. Clinical studies have demonstrated that these epitopes are immunogenic and can shift the breadth of T-cell responses toward the desired targets in patients. However, challenges remain regarding the durability of these responses and the potential for viral rebound during analytical treatment interruptions.

Other names

Vif-derived HTI segmentsHIVACAT T-cell Immunogen Vif epitopesVif HTIHTI-Vif

Induction of HIV-specific CD4+ and CD8+ T-cell responses targeting conserved viral regions to suppress viral replication and overcome Vif-mediated immune evasion (Mothe et al., 2015).