Bing Xin1, Meixiang Yang1, Panyisha Wu1, Li Du1, Xingyu Deng1, Enfu Hui2, Gen-Sheng Feng1. 1. Department of Pathology, Division of Biological Sciences and Moores Cancer Center, University of California at San Diego, La Jolla, California, USA. 2. Section of Cell & Developmental Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, California, USA.
Abstract
BACKGROUND AND AIMS: Immunotherapy with programmed cell death 1 (PD-1)/programmed death ligand 1 (PD-L1) blockade has shown low response rates in liver cancer patients, with the underlying mechanisms unclear. To decipher a specific impact of the liver microenvironment, we compared the effects of anti-PD-L1 antibody (αPD-L1) blockade on the same tumor grown s.c. or in the liver. APPROACH AND RESULTS: We generated s.c. tumors in mice by inoculating MC38 colorectal cancer (CRC) cells under the skin and metastatic liver tumors by portal vein or splenic injection of CRC cells. Tumor-bearing mice were treated by i.p. injection of αPD-L1, polyinosinic:polycytidylic acid (poly[I:C]), or both. αPD-L1 monotherapy significantly suppressed s.c. tumor growth, but showed no effect on metastatic liver tumors. However, the combination of αPD-L1 with poly(I:C), an innate immunity-stimulating reagent, robustly inhibited tumor progression in liver. The combination therapy effectively down-regulated myeloid-derived suppressor cells (MDSCs), but up-regulated ratios of M1/M2 macrophages, CD8/CD4, and CD8/regulatory T (Treg) cells infiltrated into liver tumors and whole liver. A group of long-lasting T-bet+ Eomes- PD-1- cytotoxic T cells was maintained in the combo-treated liver, leading to resistance to tumor recurrence. Depleting macrophages or blocking type Ⅰ interferon signaling abrogated the synergistic antitumor effect of αPD-L1 and poly(I:C), indicating a requirement of boosting innate immunity for optimized activation of cytotoxic T cells by PD-1/PD-L1 blockade. CONCLUSIONS: The poor response of liver cancers to αPD-L1 therapy is largely attributable to a unique hepatic immunotolerant microenvironment, independent of tumor origins or types. The success of a combinatorial immunotherapy relies on coordinated inhibition or activation of various innate and adaptive immune cell activities.
BACKGROUND AND AIMS: Immunotherapy with programmed cell death 1 (PD-1)/programmed death ligand 1 (PD-L1) blockade has shown low response rates in liver cancer patients, with the underlying mechanisms unclear. To decipher a specific impact of the liver microenvironment, we compared the effects of anti-PD-L1 antibody (αPD-L1) blockade on the same tumor grown s.c. or in the liver. APPROACH AND RESULTS: We generated s.c. tumors in mice by inoculating MC38 colorectal cancer (CRC) cells under the skin and metastatic liver tumors by portal vein or splenic injection of CRC cells. Tumor-bearing mice were treated by i.p. injection of αPD-L1, polyinosinic:polycytidylic acid (poly[I:C]), or both. αPD-L1 monotherapy significantly suppressed s.c. tumor growth, but showed no effect on metastatic liver tumors. However, the combination of αPD-L1 with poly(I:C), an innate immunity-stimulating reagent, robustly inhibited tumor progression in liver. The combination therapy effectively down-regulated myeloid-derived suppressor cells (MDSCs), but up-regulated ratios of M1/M2 macrophages, CD8/CD4, and CD8/regulatory T (Treg) cells infiltrated into liver tumors and whole liver. A group of long-lasting T-bet+ Eomes- PD-1- cytotoxic T cells was maintained in the combo-treated liver, leading to resistance to tumor recurrence. Depleting macrophages or blocking type Ⅰ interferon signaling abrogated the synergistic antitumor effect of αPD-L1 and poly(I:C), indicating a requirement of boosting innate immunity for optimized activation of cytotoxic T cells by PD-1/PD-L1 blockade. CONCLUSIONS: The poor response of liver cancers to αPD-L1 therapy is largely attributable to a unique hepatic immunotolerant microenvironment, independent of tumor origins or types. The success of a combinatorial immunotherapy relies on coordinated inhibition or activation of various innate and adaptive immune cell activities.
Authors: Suzanne Ostrand-Rosenberg; Pratima Sinha; Daniel W Beury; Virginia K Clements Journal: Semin Cancer Biol Date: 2012-02-01 Impact factor: 15.707
Authors: Justin A Kenkel; William W Tseng; Matthew G Davidson; Lorna L Tolentino; Okmi Choi; Nupur Bhattacharya; E Scott Seeley; Daniel A Winer; Nathan E Reticker-Flynn; Edgar G Engleman Journal: Cancer Res Date: 2017-06-13 Impact factor: 12.701
Authors: Andrew X Zhu; Richard S Finn; Julien Edeline; Stephane Cattan; Sadahisa Ogasawara; Daniel Palmer; Chris Verslype; Vittorina Zagonel; Laetitia Fartoux; Arndt Vogel; Debashis Sarker; Gontran Verset; Stephen L Chan; Jennifer Knox; Bruno Daniele; Andrea L Webber; Scot W Ebbinghaus; Junshui Ma; Abby B Siegel; Ann-Lii Cheng; Masatoshi Kudo Journal: Lancet Oncol Date: 2018-06-03 Impact factor: 41.316
Authors: Christina Hackl; Peter Neumann; Michael Gerken; Martin Loss; Monika Klinkhammer-Schalke; Hans J Schlitt Journal: BMC Cancer Date: 2014-11-04 Impact factor: 4.430