T cell immunogen design

T cell immunogens are key components of vaccines to trigger helper T cell support for antibody development and cytotoxic T cells to eliminate infected cells. The T cell Immunology and Vaccines (TIV) group at IrsiCaixa has extensive experience in developing this type of immunogen. We have been mapping T cell epitopes and measuring their avidity for almost 20 years, mainly for HIV. We are close collaborators with the HIV immune database in Los Alamos, where we maintain the optimally defined HIV epitope list. We have translated this knowledge into the development of a T cell vaccine immunogen based on HIV epitopes, the HIVACAT T cell Immunogen (HTI). The HTI immunogen was inserted in different vaccine vector (DNA plasmid, ChAdOx1, and MVA) to perform pre-clinical (Olvera et al. Vaccines (Basel). 2024 Mar 7;12(3):279; J Transl Med. 2015 Feb 15;13:60) and clinical studies (Bailon et al Nat Med. 2022 Dec;28(12):2611-2621; Bailon et al. Nat Commun. 2025 Mar 4;16(1):2146). The HTI asset was acquired by Gilead Sciences in late 2024.