Activating systemic immunity through engineered lymph node-homing T cells 2335174

Abstract

Abstract Introduction Lymph nodes (LNs) serve as the critical education centers of adaptive immunity to combat pathogens while simultaneously protecting host tissues through peripheral tolerance induction. LNs are often co-opted by tumors to induce tumor-specific immune tolerance yet are also key sites of immunotherapy response. Here, we aim to develop a cell therapy capable of reeducating systemic anti-tumor immunity within LNs. Methods Naïve T cells continuously circulate between blood and LNs through a process that is dynamically regulated by multiple cell surface receptors. We have harnessed these mechanisms by engineering T cells to constitutively express the cell surface protein responsible for initiating the LN-homing cascade, L-selectin. We transduce T cells using viral vectors encoding a wild-type (WT L-sel) or engineered L-selectin variant (L-sel mut). To assess selective LN-homing capacity, we adoptively transfer our engineered cells into mice and subsequently quantify tissue accumulation by flow cytometry. Results Flow cytometry of cell surface L-selectin expression reveals a 6-fold increase on our engineered T cells compared to control cells. Upon PMA/Ionomycin stimulation, 91.2% of L-sel mut cells maintain cell surface expression of L-selectin in comparison to 28.9% of WT L-sel and 7.8% of control T cells. Furthermore, adoptive transfer of equal proportions of control, WT L-sel, and L-sel mut T cells yielded selective accumulation of the engineered cells within LNs. Conclusion By harnessing the intrinsic mechanisms that govern T cell LN-homing, we have engineered T cells that maintain expression of L-selectin on the cell surface, endowing them with a propensity for LN-homing. By combining these technologies with tumor recognition domains and armoring approaches, these therapies have the potential to elicit anti-tumor immunity within LNs and systemically. Funding Source NIAID DP2 Topic Categories Tumor Immunology: Checkpoints, Prevention, and Treatment (TIPT)