Dataset Information

PD-L1 promotes myofibroblastic activation of hepatic stellate cells by distinct mechanisms selective for TGF-β receptor I versus II.

ABSTRACT: Intrahepatic cholangiocarcinoma (ICC) contains abundant myofibroblasts derived from hepatic stellate cells (HSCs) through an activation process mediated by TGF-β. To determine the role of programmed death-ligand 1 (PD-L1) in myofibroblastic activation of HSCs, we disrupted PD-L1 of HSCs by shRNA or anti-PD-L1 antibody. We find that PD-L1, produced by HSCs, is required for HSC activation by stabilizing TGF-β receptors I (TβRI) and II (TβRII). While the extracellular domain of PD-L1 (amino acids 19-238) targets TβRII protein to the plasma membrane and protects it from lysosomal degradation, a C-terminal 260-RLRKGR-265 motif on PD-L1 protects TβRI mRNA from degradation by the RNA exosome complex. PD-L1 is required for HSC expression of tumor-promoting factors, and targeting HSC PD-L1 by shRNA or Cre/loxP recombination suppresses HSC activation and ICC growth in mice. Thus, myofibroblast PD-L1 can modulate the tumor microenvironment and tumor growth by a mechanism independent of immune suppression.

SUBMITTER: Sun L

PROVIDER: S-EPMC8903892 | biostudies-literature | 2022 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

PD-L1 promotes myofibroblastic activation of hepatic stellate cells by distinct mechanisms selective for TGF-β receptor I versus II.

Sun Liankang L Wang Yuanguo Y Wang Xianghu X Navarro-Corcuera Amaia A Ilyas Sumera S Jalan-Sakrikar Nidhi N Gan Can C Tu Xinyi X Shi Yu Y Tu Kangsheng K Liu Qingguang Q Lou Zhenkun Z Dong Haidong H Sharpe Arlene H AH Shah Vijay H VH Kang Ningling N

Cell reports 20220201 6

Intrahepatic cholangiocarcinoma (ICC) contains abundant myofibroblasts derived from hepatic stellate cells (HSCs) through an activation process mediated by TGF-β. To determine the role of programmed death-ligand 1 (PD-L1) in myofibroblastic activation of HSCs, we disrupted PD-L1 of HSCs by shRNA or anti-PD-L1 antibody. We find that PD-L1, produced by HSCs, is required for HSC activation by stabilizing TGF-β receptors I (TβRI) and II (TβRII). While the extracellular domain of PD-L1 (amino acids 1 ...[more]

PMID: 35139382

Similar Datasets

Project description:Inflammatory myofibroblastic tumor is a rare mesenchymal tumor occurring at many anatomic sites, with a predilection for children and young adults. Often indolent, they can be locally aggressive and can metastasize, resulting in significant morbidity and mortality. Therapeutic options are often limited. The identification of underlying kinase mutations has allowed the use of targeted therapy in a subset of patients. Unfortunately, not all tumors harbor mutations and resistance to tyrosine kinase inhibitor therapy is a potential problem. We hypothesized that these tumors may be amenable to PD-L1 therapy given the immune nature of the tumor. PD-L1 expression in inflammatory myofibroblastic tumors has not yet been defined. The purpose of this study was to explore PD-L1 expression in inflammatory myofibroblastic tumors, as adaptive PD-L1 expression is known to enrich for response to anti-PD-1/PD-L1 therapies. Expression of PD-L1 (clone SP142) was assessed in 35 specimens from 28 patients. Positivity was defined as membranous expression in ≥5% of cells and evaluated separately in tumor and immune cells. Adaptive vs. constitutive patterns of tumor cell PD-L1 expression were assessed. PD-L1 status was correlated with clinicopathologic features. CD8+ T cell infiltrates were quantified by digital image analysis. ALK status was assessed by immunohistochemistry and/or FISH. Twenty-four (69%) tumors had PD-L1(+) tumor cells and 28 (80%) showed PD-L1(+) immune cells. Most recurrent and metastatic tumors (80%) and ALK(-) tumors (88%) were PD-L1(+). Adaptive PD-L1 expression was present in 23 (96%) of PD-L1(+) tumors, which also showed a three-four fold increase in CD8+ T cell infiltration relative to PD-L1(-) tumors. Constitutive PD-L1 expression was associated with larger tumor size (p = 0.002). Inflammatory myofibroblastic tumors show frequent constitutive and adaptive PD-L1 expression, the latter of which is thought to be predictive of response to anti-PD-1. These data support further investigation into PD-1/PD-L1 blockade in this tumor type.

Project description:BackgroundBintrafusp alfa (BA) is a bifunctional fusion protein designed for colocalized, simultaneous inhibition of two immunosuppressive pathways, transforming growth factor-β (TGF-β) and programmed death-ligand 1 (PD-L1), within the tumor microenvironment (TME). We hypothesized that targeting PD-L1 to the tumor by BA colocalizes the TGF-β trap (TGF-βRII) to the TME, enabling it to sequester TGF-β in the tumor more effectively than systemic TGF-β blockade, thereby enhancing antitumor activity.MethodsMultiple technologies were used to characterize the TGF-β trap binding avidity. BA versus combinations of anti-PD-L1 and TGF-β trap or the pan-TGF-β antibody fresolimumab were compared in proliferation and two-way mixed lymphocyte reaction assays. Immunophenotyping of tumor-infiltrating lymphocytes (TILs) and RNA sequencing (RNAseq) analysis assessing stromal and immune landscape following BA or the combination therapy were performed in MC38 tumors. TGF-β and PD-L1 co-expression and their associated gene signatures in MC38 tumors and human lung carcinoma tissue were studied with single-cell RNAseq (scRNAseq) and immunostaining. BA-induced internalization, degradation, and depletion of TGF-β were investigated in vitro.ResultsBA and fresolimumab had comparable intrinsic binding to TGF-β1, but there was an ~80× avidity-based increase in binding affinity with BA. BA inhibited cell proliferation in TGF-β-dependent and PD-L1-expressing cells more potently than TGF-β trap or fresolimumab. Compared with the combination of anti-PD-L1 and TGF-β trap or fresolimumab, BA enhanced T cell activation in vitro and increased TILs in MC38 tumors, which correlated with efficacy. BA induced distinct gene expression in the TME compared with the combination therapy, including upregulation of immune-related gene signatures and reduced activities in TGF-β-regulated pathways, such as epithelial-mesenchymal transition, extracellular matrix deposition, and fibrosis. Regulatory T cells, macrophages, immune cells of myeloid lineage, and fibroblasts were key PD-L1/TGF-β1 co-expressing cells in the TME. scRNAseq analysis suggested BA modulation of the macrophage phenotype, which was confirmed by histological assessment. PD-L1/TGF-β1 co-expression was also seen in human tumors. Finally, BA induced TGF-β1 internalization and degradation in the lysosomes.ConclusionBA more effectively blocks TGF-β by targeting TGF-β trap to the tumor via PD-L1 binding. Such colocalized targeting elicits distinct and superior antitumor responses relative to single agent combination therapy.

Dataset Information

PD-L1 promotes myofibroblastic activation of hepatic stellate cells by distinct mechanisms selective for TGF-β receptor I versus II.

Publications

PD-L1 promotes myofibroblastic activation of hepatic stellate cells by distinct mechanisms selective for TGF-β receptor I versus II.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets