Microbiota-associated immunotherapy resistance caused by deficient PD-L2 - RGMb signaling.

In a recent paper in Nature, Park et al. propose a mechanism through which intestinal dysbiosis compromises the efficacy of immunotherapy targeting the PD-L1/PD-1 interaction. Dysbiosis may upregulate a pair of checkpoint molecules, i.e. PD-L2 interacting with RGMb. Antibodies targeting PD-L2/RGMb can restore responses to PD-1 blockade in the context of dysbiosis.