CTLA4 is a cell surface receptor on T cells that functions as an immune checkpoint molecule to enforce tolerance to cognate antigens. Anti-CTLA4 immunotherapy is highly effective at reactivating T-cell responses against melanoma, which is postulated to be due to targeting CTLA4 on T cells. Here, we report that CTLA4 is also highly expressed by most human melanoma cell lines, as well as in normal human melanocytes. Interferon-γ (IFNG) signaling activated the expression of the human CTLA4 gene in a melanocyte and melanoma cell-specific manner. Mechanistically, IFNG activated CTLA4 expression through JAK1/2-dependent phosphorylation of STAT1, which bound a specific gamma-activated sequence site on the CTLA4 promoter, thereby licensing CBP/p300-mediated histone acetylation and local chromatin opening. In melanoma cell lines, elevated baseline expression relied upon constitutive activation of the MAPK pathway. Notably, RNA-seq analyses of melanoma specimens obtained from patients who had received anti-CTLA4 immunotherapy (ipilimumab) showed upregulation of an IFNG-response gene expression signature, including CTLA4 itself, which correlated significantly with durable response. Taken together, our results raise the possibility that CTLA4 targeting on melanoma cells may contribute to the clinical immunobiology of anti-CTLA4 responses. These findings show that human melanoma cells express high levels of the immune checkpoint molecule CTLA4, with important possible implications for understanding how anti-CTLA4 immunotherapy mediates its therapeutic effects. .

BackgroundCurrent angiogenic therapies for cancers and cardiovascular diseases have not yet achieved expected benefits, which reflects the need for improved understanding of angiogenesis. In this study, we focused on solving the problem of whether tissues have different angiogenic potentials (APs) in physiological conditions and how angiogenesis is regulated in various disease conditions.MethodsIn healthy and diseased human and mouse tissues, we profiled the expression of 163 angiogenic genes, including transcription regulators (TRs), growth factors and receptors (GF/Rs), cytokines and chemokines (C/Cs), and proteases and inhibitors (P/Is). TRs were categorized as inflammatory, homeostatic, and endothelial cell-specific TRs, and C/Cs were categorized as pro-angiogenic, anti-angiogenic, and bi-functional C/Cs.ResultsWe made the following findings: (1) the human heart, muscle, eye, pancreas, and lymph node are among the tissues with the highest APs; (2) tissues with high APs have more active angiogenic pathways and angiogenic C/C responses; (3) inflammatory TRs dominate regulation of all angiogenic C/Cs; homeostatic TRs regulate all to a lower extent, while endothelial cell-specific TRs mainly regulate pro-angiogenic and bi-functional C/Cs; (4) tissue AP is positively correlated with the expression of oxygen sensors PHD2 and HIF1B, VEGF pathway gene VEGFB, and stem cell gene SOX2; (5) cancers of the digestive system tend to have increased angiogenesis dominated by endothelial cell-specific pro-angiogenic pathways, while lung cancer and prostate cancer have significantly decreased angiogenesis; and (6) endothelial cell-specific pro-angiogenic pathways are significantly increased in thrombus-derived leukocytes in patients with acute coronary artery disease.ConclusionsOur results demonstrate that thrombus-derived leukocytes express more endothelial cell-specific angiogenic markers to directly promote angiogenesis after myocardial infarction and that certain solid tumors may be more sensitive to anti-angiogenic therapies than others.Electronic supplementary materialThe online version of this article (doi:10.1186/s13045-017-0440-0) contains supplementary material, which is available to authorized users.

Folliculotropic mycosis fungoides (FMF) is an aggressive variant of mycosis fungoides (MF) characterized by infiltration of the hair follicle epithelium by neoplastic T cells. FMF demonstrates poor response rates to standard skin-directed therapies such as phototherapy and topical corticosteroids. Imiquimod, an immunomodulatory agent that stimulates the antitumor immune response, has been used successfully in treatment of early-stage MF. We report a 21-year-old patient with unilesional FMF who achieved clinical remission with imiquimod application. This case highlights a potential for use of imiquimod as a treatment option for patients with FMF and limited skin involvement.

<p>Supplementary Figure S1: CTLA4 mRNA expression in human tumor cell lines. Supplementary Figure S2: CTLA4 promoter analysis. Supplementary Figure S3: UCSC genome browser view of human CTLA4 locus. Supplementary Figure S4: Recruitment of STAT1 and POL II to CTLA4 promoter by IFNG treatment. Supplementary Figure S5: The effects of CBP inhibitors on CTLA4 expression. Supplementary Figure S6: Quantification of western blotting in Fig. 5H. Supplementary Figure S7: The effects of Ruxolitinib on expression of genes of IFNG signaling pathway.</p>

<div>Abstract<p>CTLA4 is a cell surface receptor on T cells that functions as an immune checkpoint molecule to enforce tolerance to cognate antigens. Anti–CTLA4 immunotherapy is highly effective at reactivating T-cell responses against melanoma, which is postulated to be due to targeting CTLA4 on T cells. Here, we report that CTLA4 is also highly expressed by most human melanoma cell lines, as well as in normal human melanocytes. Interferon-γ (IFNG) signaling activated the expression of the human CTLA4 gene in a melanocyte and melanoma cell–specific manner. Mechanistically, IFNG activated CTLA4 expression through JAK1/2-dependent phosphorylation of STAT1, which bound a specific gamma-activated sequence site on the CTLA4 promoter, thereby licensing CBP/p300-mediated histone acetylation and local chromatin opening. In melanoma cell lines, elevated baseline expression relied upon constitutive activation of the MAPK pathway. Notably, RNA-seq analyses of melanoma specimens obtained from patients who had received anti–CTLA4 immunotherapy (ipilimumab) showed upregulation of an IFNG-response gene expression signature, including CTLA4 itself, which correlated significantly with durable response. Taken together, our results raise the possibility that CTLA4 targeting on melanoma cells may contribute to the clinical immunobiology of anti–CTLA4 responses.</p><p><b>Significance:</b> These findings show that human melanoma cells express high levels of the immune checkpoint molecule CTLA4, with important possible implications for understanding how anti-CTLA4 immunotherapy mediates its therapeutic effects. <i>Cancer Res; 78(2); 436–50. ©2017 AACR</i>.</p></div>