Tailoring vascular phenotype through AAV therapy promotes anti-tumor immunity in glioma
Mohanraj Ramachandran, Alessandra Vaccaro, Tiarne van de Walle, Maria Georganaki, Roberta Lugano, Kalyani Vemuri, Despoina Kourougkiaouri, Konstantinos Vazaios, Marie Hedlund, Georgia Tsaridou, Lene Uhrbom, Ilkka Pietilä, Miika Martikainen, Luuk van Hooren, Thomas Olsson Bontell, Asgeir Store Jakola, Di Yu, Bengt Westermark, Magnus Essand, Anna Dimberg
Abstract
Glioblastomas are aggressive brain tumors that are largely immunotherapy resistant. This is associated with immunosuppression and a dysfunctional tumor vasculature, which hinder T cell infiltration. LIGHT/TNFSF14 can induce high endothelial venules (HEVs) and tertiary lymphoid structures (TLS), suggesting that its therapeutic expression could promote T cell recruitment. Here, we use a brain endothelial cell-targeted adeno-associated viral (AAV) vector to express LIGHT in the glioma vasculature (AAV-LIGHT). We found that systemic AAV-LIGHT treatment induces tumor-associated HEVs and T cell-rich TLS, prolonging survival in αPD-1-resistant murine glioma. AAV-LIGHT treatment reduces T cell exhaustion and promotes TCF1 + CD8 + stem-like T cells, which reside in TLS and intratumoral antigen-presenting niches. Tumor regression upon AAV-LIGHT therapy correlates with tumor-specific cytotoxic/memory T cell responses. Our work reveals that altering vascular phenotype through vessel-targeted expression of LIGHT promotes efficient anti-tumor T cell responses and prolongs survival in glioma. These findings have broader implications for treatment of other immunotherapy-resistant cancers.