IDH status dictates oHSV mediated metabolic reprogramming affecting anti-tumor immunity

Identification of IDH mutations has uncovered the crucial role played by metabolism in glioma-genesis. Oncolytic herpes virus (oHSV) therapy initiates direct tumor debulking by tumor lysis and also activates antitumor immunity however little is known about the role of glioma metabolism in determining oHSV efficacy. Here we identified that oHSV therapy rewired central carbon metabolism with increased glucose utilization towards oxidative phosphorylation and shuttled glutamine towards reductive carboxylation in IDH wildtype (wt) glioma. The switch in metabolism resulted in increased lipid synthesis, and cellular ROS. PKC induced ACSL4 in oHSV treated cells led to lipid peroxidation and ferroptosis. Ferroptosis was critical to launch an antitumor immune response important for efficacy. Mutant IDH (IDHR132H) gliomas are incapable of reductive carboxylation and hence ferroptosis. Pharmacological blockade of IDHR132H induced ferroptosis and antitumor immunity. This study provides a rationale to treat high grade IDHR132H glioma patients under oHSV treatment with IDHR132H inhibitor. Overall design: CD45+ immune cells isolated from 005 GSC tumor bearing hemisphere of C57BL/6 mice 5 days post oHSV treatment with or without Ferrostatin-1 and analyzed using sc-seq.