T cell–based immunotherapies are a promising therapeutic approach for multiple malignancies, but their efficacy is limited by tumor hypoxia arising from dysfunctional blood vessels. Here, we report that cell-intrinsic properties of a single vascular component, namely the pericyte, contribute to the control of tumor oxygenation, macrophage polarization, vessel inflammation, and T cell infiltration. Switching pericyte phenotype from a synthetic to a differentiated state reverses immune suppression and sensitizes tumors to adoptive T cell therapy, leading to regression of melanoma in mice. In melanoma patients, improved survival is correlated with enhanced pericyte maturity. Importantly, pericyte plasticity is regulated by signaling pathways converging on Rho kinase activity, with pericyte maturity being inducible by selective low-dose therapeutics that suppress pericyte MEK, AKT, or notch signaling. We also show that low-dose targeted anticancer therapy can durably change the tumor microenvironment without inducing adaptive resistance, creating a highly translatable pathway for redosing anticancer targeted therapies in combination with immunotherapy to improve outcome.
Zhi-Jie Li, Bo He, Alice Domenichini, Jiulia Satiaputra, Kira H. Wood, Devina D. Lakhiani, Abate A. Bashaw, Lisa M. Nilsson, Ji Li, Edward R. Bastow, Anna Johansson-Percival, Elena Denisenko, Alistair R.R. Forrest, Suraj Sakaram, Rafael Carretero, Günter J. Hämmerling, Jonas A. Nilsson, Gabriel Y.F. Lee, Ruth Ganss
Intratumoral RGS5 expression determines pericyte phenotype in vivo and blood vessel functionality.