Expression of immune checkpoint ligands (ICLs) is necessary to trigger the inhibitory signal via immune checkpoint receptors (ICRs) in exhausted T cells under tumor immune microenvironment. Nevertheless,to our knowledge, ICL expression profile in cancer patients has not been investigated. Using previously reported RNA-seq data sets, we found that expression of ICLs was patient specific but their coexpression can be patterned in non–small-cell lung cancers (NSCLCs). Since the expression of PD-L1 and poliovirus receptor (PVR) among various ICLs was independently regulated, we could stratify the patients who were treated with anti–PD-1 later into 4 groups according to the expression level of PD-L1 and PVR. Of interest, high PVR and low PVR expressions in PD-L1–expressing patients enriched nonresponders and responders to PD-1 blockade, respectively, helping in further selection of responders. Using a genetically engineered cancer model, we also found that PVR-deficient and PD-L1–sufficient tumor-bearing mice were highly sensitive to anti–PD-1 therapy, whereas PVR-sufficient and PD-L1–deficient tumor-bearing mice were resistant to anti–PD-1 therapy. Taken together, our study provides a concept that combinatorial expression patterns of PVR and PD-L1 are key determinants for PD-1 blockade and furthermore suggest a better therapeutic usage of immune checkpoint blockades (ICBs).
Bo Ryeong Lee, Sehyun Chae, Jihyun Moon, Myeong Joon Kim, Hankyu Lee, Hyuk Wan Ko, Byoung Chul Cho, Hyo Sup Shim, Daehee Hwang, Hye Ryun Kim, Sang-Jun Ha