Peptide-MHC–targeted retroviruses enable in vivo expansion and gene delivery to tumor-specific T cells
- Ellen J. K. Xu
- Blake E. Smith
- Winiffer D. Conce Alberto
- Michael J. Walsh
- Birkley Lim
- Megan T. Hoffman
- Li Qiang
- Ariana Barreiro
- Emma N. Finburgh
- Jiayi Dong
- Andrea Garmilla
- Qingyang Henry Zhao
- Caleb R. Perez
- Stephanie A. Gaglione
- Connor S. Dobson
- Michael Dougan
- Stephanie K. Dougan
- Michael E. Birnbaum
2025-11-07
Tumor-infiltrating lymphocyte (TIL) therapy has demonstrated that endogenous T cells can be harnessed to initiate effective antitumor responses. Despite clinical promise, current TIL production protocols involve weeks-long ex vivo expansions that can affect treatment efficacy. Therefore, additional tools are needed to engineer TILs to have increased potency while mitigating manufacturing challenges. Here, we present a strategy for pseudotyping retroviruses with peptide–major histocompatibility complexes (pMHCs) for antigen-specific gene delivery to CD8 T cells and validate therapeutic impact in immunocompetent mouse models. We demonstrate that pMHC-targeted viruses specifically deliver function-enhancing cargos while simultaneously activating and expanding antitumor T cells. This targeting precision enables in vivo engineering of tumor-specific T cells, resulting in improved overall survival in B16F10-bearing mice. Together, we have established that pMHC-targeted viruses are efficient vectors for reprogramming and expanding tumor-specific T cells directly in vivo, with the potential to substantially streamline engineered cell therapy production.