Ruud H. Wijdeven, Sietse J. Luk, Tom A. W. Schoufour, Sabina Y. van der Zanden, Marta Cabezuelo, Mirjam H. M. Heemskerk, Jacques Neefjes
{"title":"Balanced Epigenetic Regulation of MHC Class I Expression in Tumor Cells by the Histone Ubiquitin Modifiers BAP1 and PCGF1","authors":"Ruud H. Wijdeven, Sietse J. Luk, Tom A. W. Schoufour, Sabina Y. van der Zanden, Marta Cabezuelo, Mirjam H. M. Heemskerk, Jacques Neefjes","doi":"10.4049/jimmunol.2300263","DOIUrl":null,"url":null,"abstract":"<jats:title>Abstract</jats:title> MHC class I (MHC-I) molecules are critical for CD8+ T cell responses to viral infections and malignant cells, and tumors can downregulate MHC-I expression to promote immune evasion. In this study, using a genome-wide CRISPR screen on a human melanoma cell line, we identified the polycomb repressive complex 1 (PRC1) subunit PCGF1 and the deubiquitinating enzyme BAP1 as opposite regulators of MHC-I transcription. PCGF1 facilitates deposition of ubiquitin at H2AK119 at the MHC-I promoters to silence MHC-I, whereas BAP1 removes this modification to restore MHC-I expression. PCGF1 is widely expressed in tumors and its depletion increased MHC-I expression in multiple tumor lines, including MHC-Ilow tumors. In cells characterized by poor MHC-I expression, PRC1 and PRC2 act in parallel to impinge low transcription. However, PCGF1 depletion was sufficient to increase MHC-I expression and restore T cell–mediated killing of the tumor cells. Taken together, our data provide an additional layer of regulation of MHC-I expression in tumors: epigenetic silencing by PRC1 subunit PCGF1.","PeriodicalId":22698,"journal":{"name":"The Journal of Immunology","volume":"287 2 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Journal of Immunology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.4049/jimmunol.2300263","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract MHC class I (MHC-I) molecules are critical for CD8+ T cell responses to viral infections and malignant cells, and tumors can downregulate MHC-I expression to promote immune evasion. In this study, using a genome-wide CRISPR screen on a human melanoma cell line, we identified the polycomb repressive complex 1 (PRC1) subunit PCGF1 and the deubiquitinating enzyme BAP1 as opposite regulators of MHC-I transcription. PCGF1 facilitates deposition of ubiquitin at H2AK119 at the MHC-I promoters to silence MHC-I, whereas BAP1 removes this modification to restore MHC-I expression. PCGF1 is widely expressed in tumors and its depletion increased MHC-I expression in multiple tumor lines, including MHC-Ilow tumors. In cells characterized by poor MHC-I expression, PRC1 and PRC2 act in parallel to impinge low transcription. However, PCGF1 depletion was sufficient to increase MHC-I expression and restore T cell–mediated killing of the tumor cells. Taken together, our data provide an additional layer of regulation of MHC-I expression in tumors: epigenetic silencing by PRC1 subunit PCGF1.