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Bonnin M, Fares N, Testoni B, Estornes Y, Weber K, Vanbervliet B, Lefrançois L, Garcia A, Kfoury A, Pez F, Coste I, Saintigny P, Viari A, Lang K, Guey B, Petrilli V, Hervieu V, Bancel B, Bartosch B, Durantel D, Renno T, Merle P, Lebecque S. Corrigendum to "Toll-like receptor 3 downregulation is an escape mechanism from apoptosis during hepatocarcinogenesis" [J Hepatol 71 (2019) 763-772]. J Hepatol 2020; 72:594. [PMID: 31780083 DOI: 10.1016/j.jhep.2019.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Affiliation(s)
- Marc Bonnin
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Nadim Fares
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Barbara Testoni
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Yann Estornes
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Kathrin Weber
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Béatrice Vanbervliet
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Lydie Lefrançois
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Amandine Garcia
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Alain Kfoury
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Floriane Pez
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Isabelle Coste
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Pierre Saintigny
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France; Department of Translational Research and Innovation and Department of Medicine, Centre Léon Bérard, Lyon, France
| | - Alain Viari
- Synergie Lyon Cancer, Plateforme de Bioinformatique 'Gilles Thomas' Centre Léon Bérard, Lyon, France
| | - Kévin Lang
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Baptiste Guey
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Virginie Petrilli
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Valérie Hervieu
- Service d'Anatomopathologie, Groupement Hospitalier Est, Hospices Civils de Lyon, Lyon, France
| | - Brigitte Bancel
- Service d'Anatomopathologie, Groupement Hospitalier Est, Hospices Civils de Lyon, Lyon, France
| | - Birke Bartosch
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - David Durantel
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Toufic Renno
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Philippe Merle
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France; Groupement Hospitalier Lyon Nord, Hepatology Unit, Lyon, France.
| | - Serge Lebecque
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France; Hospices Civils de Lyon, Laboratoire d'Anatomie et Cytologie Pathologiques, Centre Hospitalier Lyon Sud, Pierre Bénite, France.
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Pez F, Gifu P, Degli-Esposti D, Fares N, Lopez A, Lefrançois L, Michelet M, Rivoire M, Bancel B, Sylla BS, Herceg Z, Merle P, Caron de Fromentel C. In vitro transformation of primary human hepatocytes: Epigenetic changes and stemness properties. Exp Cell Res 2019; 384:111643. [PMID: 31557464 DOI: 10.1016/j.yexcr.2019.111643] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 09/19/2019] [Accepted: 09/21/2019] [Indexed: 02/07/2023]
Abstract
Human hepatocarcinogenesis is a complex process with many unresolved issues, including the cell of origin (differentiated and/or progenitor/stem cells) and the initial steps leading to tumor development. With the aim of providing new tools for studying hepatocellular carcinoma initiation and progression, we developed an innovative model based on primary human hepatocytes (PHHs) lentivirus-transduced with SV40LT+ST, HRASV12 with or without hTERT. The differentiation status of these transduced-PHHs was characterized by RNA sequencing (including lncRNAs), and the expression of some differentiation markers confirmed by RT-qPCR and immunofluorescence. In addition, their transformation capacity was assessed by colony formation in soft agar and tumorigenicity evaluated in immune-deficient mice. The co-expression of SV40LT+ST and HRASV12 in PHHs, in association or not with hTERT, led to the emergence of transformed clones. These clones exhibited a poorly differentiated cell phenotype with expression of stemness and mesenchymal-epithelial transition markers and gave rise to cancer stem cell subpopulations. In vivo, they resulted in poorly differentiated hepatocellular carcinomas with a reactivation of endogenous hTERT. These experiments demonstrate for the first time that non-cycling human mature hepatocytes can be permissive to in vitro transformation. This cellular tool provides the first comprehensive in vitro model for identifying genetic/epigenetic changes driving human hepatocarcinogenesis.
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Affiliation(s)
- Floriane Pez
- INSERM U1052, CNRS 5286, Univ Lyon, Université Claude Bernard Lyon 1, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France
| | - Patricia Gifu
- INSERM U1052, CNRS 5286, Univ Lyon, Université Claude Bernard Lyon 1, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France
| | - Davide Degli-Esposti
- Epigenetics Group, International Agency for Research on Cancer (IARC), Lyon, France
| | - Nadim Fares
- INSERM U1052, CNRS 5286, Univ Lyon, Université Claude Bernard Lyon 1, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France
| | - Anaïs Lopez
- INSERM U1052, CNRS 5286, Univ Lyon, Université Claude Bernard Lyon 1, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France
| | - Lydie Lefrançois
- INSERM U1052, CNRS 5286, Univ Lyon, Université Claude Bernard Lyon 1, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France
| | - Maud Michelet
- INSERM U1052, CNRS 5286, Univ Lyon, Université Claude Bernard Lyon 1, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France
| | - Michel Rivoire
- Département de Chirurgie et Institut de Chirurgie Expérimentale, Centre Léon Bérard, Lyon, France
| | - Brigitte Bancel
- INSERM U1052, CNRS 5286, Univ Lyon, Université Claude Bernard Lyon 1, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France; Hospices Civils de Lyon, Service d'Anatomopathologie, Groupement Hospitalier Lyon Nord, France
| | - Bakary S Sylla
- Infections and Cancer Biology Group, International Agency for Research on Cancer (IARC), Lyon, France
| | - Zdenko Herceg
- Epigenetics Group, International Agency for Research on Cancer (IARC), Lyon, France
| | - Philippe Merle
- INSERM U1052, CNRS 5286, Univ Lyon, Université Claude Bernard Lyon 1, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France; Hospices Civils de Lyon, Service d'Hépatologie et Gastroentérologie, Groupement Hospitalier Lyon Nord, France
| | - Claude Caron de Fromentel
- INSERM U1052, CNRS 5286, Univ Lyon, Université Claude Bernard Lyon 1, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon, F-69000, Lyon, France.
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Bonnin M, Fares N, Testoni B, Estornes Y, Weber K, Vanbervliet B, Lefrançois L, Garcia A, Kfoury A, Pez F, Coste I, Saintigny P, Viari A, Lang K, Guey B, Hervieu V, Bancel B, Bartoch B, Durantel D, Renno T, Merle P, Lebecque S. Toll-like receptor 3 downregulation is an escape mechanism from apoptosis during hepatocarcinogenesis. J Hepatol 2019; 71:763-772. [PMID: 31220470 DOI: 10.1016/j.jhep.2019.05.031] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 05/17/2019] [Accepted: 05/21/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Low levels of toll-like receptor 3 (TLR3) in patients with hepatocellular carcinoma (HCC) are associated with poor prognosis, primarily owing to the loss of inflammatory signaling and subsequent lack of immune cell recruitment to the liver. Herein, we explore the role of TLR3-triggered apoptosis in HCC cells. METHODS Quantitative reverse transcription PCR, western blotting, immunohistochemistry and comparative genomic hybridization were used to analyze human and mouse HCC cell lines, as well as surgically resected primary human HCCs, and to study the impact of TLR3 expression on patient outcomes. Functional analyses were performed in HCC cells, following the restoration of TLR3 by lentiviral transduction. The role of TLR3-triggered apoptosis in HCC was analyzed in vivo in a transgenic mouse model of HCC. RESULTS Lower expression of TLR3 in tumor compared to non-tumor matched tissue was observed at both mRNA and protein levels in primary HCC, and was predictive of shorter recurrence-free survival after surgical resection in both univariate (hazard ratio [HR] 1.79; 95% CI 1.04-3.06; p = 0.03) and multivariate analyses (HR 1.73; CI 1.01-2.97; p = 0.04). Immunohistochemistry confirmed frequent downregulation of TLR3 in human and mouse primary HCC cells. None of the 6 human HCC cell lines analyzed expressed TLR3, and ectopic expression of TLR3 following lentiviral transduction not only restored the inflammatory response but also sensitized cells to TLR3-triggered apoptosis. Lastly, in the transgenic mouse model of HCC, absence of TLR3 expression was accompanied by a lower rate of preneoplastic hepatocyte apoptosis and accelerated hepatocarcinogenesis without altering the tumor immune infiltrate. CONCLUSION Downregulation of TLR3 protects transforming hepatocytes from direct TLR3-triggered apoptosis, thereby contributing to hepatocarcinogenesis and poor patient outcome. LAY SUMMARY Hepatocellular carcinoma (HCC) is a heterogeneous disease associated with a poor prognosis. In patients with HCC, TLR3 downregulation is associated with reduced survival. Herein, we show that the absence of TLR3 is associated with a lower rate of apoptosis, and subsequently more rapid hepatocarcinogenesis, without any change to the immune infiltrate in the liver. Therefore, the poor prognosis associated with low TLR3 expression in HCC is likely linked to tumors ability to escape apoptosis. TLR3 may become a promising therapeutic target in TLR3-positive HCC.
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Affiliation(s)
- Marc Bonnin
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Nadim Fares
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Barbara Testoni
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Yann Estornes
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Kathrin Weber
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Béatrice Vanbervliet
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Lydie Lefrançois
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Amandine Garcia
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Alain Kfoury
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Floriane Pez
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Isabelle Coste
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Pierre Saintigny
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France; Department of Translational Research and Innovation and Department of Medicine, Centre Léon Bérard, Lyon, France
| | - Alain Viari
- Synergie Lyon Cancer, Plateforme de Bioinformatique 'Gilles Thomas' Centre Léon Bérard, Lyon, France
| | - Kévin Lang
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Baptiste Guey
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Valérie Hervieu
- Service d'Anatomopathologie, Groupement Hospitalier Est, Hospices Civils de Lyon, Lyon, France
| | - Brigitte Bancel
- Service d'Anatomopathologie, Groupement Hospitalier Est, Hospices Civils de Lyon, Lyon, France
| | - Birke Bartoch
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - David Durantel
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Toufic Renno
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France
| | - Philippe Merle
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France; Groupement Hospitalier Lyon Nord, Hepatology Unit, Lyon, France.
| | - Serge Lebecque
- INSERM, U1052, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL1), CNRS UMR_5286, Centre Léon Bérard, Lyon, France; Hospices Civils de Lyon, Laboratoire d'Anatomie et Cytologie Pathologiques, Centre Hospitalier Lyon Sud, Pierre Bénite, France.
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Mani SKK, Zhang H, Diab A, Pascuzzi PE, Lefrançois L, Fares N, Bancel B, Merle P, Andrisani O. EpCAM-regulated intramembrane proteolysis induces a cancer stem cell-like gene signature in hepatitis B virus-infected hepatocytes. J Hepatol 2016; 65:888-898. [PMID: 27238755 PMCID: PMC5289705 DOI: 10.1016/j.jhep.2016.05.022] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 05/02/2016] [Accepted: 05/17/2016] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Hepatocytes in which the hepatitis B virus (HBV) is replicating exhibit loss of the chromatin modifying polycomb repressive complex 2 (PRC2), resulting in re-expression of specific, cellular PRC2-repressed genes. Epithelial cell adhesion molecule (EpCAM) is a PRC2-repressed gene, normally expressed in hepatic progenitors, but re-expressed in hepatic cancer stem cells (hCSCs). Herein, we investigated the functional significance of EpCAM re-expression in HBV-mediated hepatocarcinogenesis. METHODS Employing molecular approaches (transfections, fluorescence-activated cell sorting, immunoblotting, qRT-PCR), we investigated the role of EpCAM-regulated intramembrane proteolysis (RIP) in HBV replicating cells in vitro, and in liver tumors from HBV X/c-myc mice and chronically HBV infected patients. RESULTS EpCAM undergoes RIP in HBV replicating cells, activating canonical Wnt signaling. Transfection of Wnt-responsive plasmid expressing green fluorescent protein (GFP) identified a GFP + population of HBV replicating cells. These GFP+/Wnt+ cells exhibited cisplatin- and sorafenib-resistant growth resembling hCSCs, and increased expression of pluripotency genes NANOG, OCT4, SOX2, and hCSC markers BAMBI, CD44 and CD133. These genes are referred as EpCAM RIP and Wnt-induced hCSC-like gene signature. Interestingly, this gene signature is also overexpressed in liver tumors of X/c-myc bitransgenic mice. Clinically, a group of HBV-associated hepatocellular carcinomas was identified, exhibiting elevated expression of the hCSC-like gene signature and associated with reduced overall survival post-surgical resection. CONCLUSIONS The hCSC-like gene signature offers promise as prognostic tool for classifying subtypes of HBV-induced HCCs. Since EpCAM RIP and Wnt signaling drive expression of this hCSC-like signature, inhibition of these pathways can be explored as therapeutic strategy for this subtype of HBV-associated HCCs. LAY SUMMARY In this study, we provide evidence for a molecular mechanism by which chronic infection by the hepatitis B virus results in the development of poor prognosis liver cancer. Based on this mechanism our results suggest possible therapeutic interventions.
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Affiliation(s)
- Saravana Kumar Kailasam Mani
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN 47907, United States,Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, United States
| | - Hao Zhang
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN 47907, United States,Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, United States
| | - Ahmed Diab
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN 47907, United States,Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, United States
| | - Pete E. Pascuzzi
- Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, United States,Purdue University Libraries, Purdue University, West Lafayette, IN 47907, United States
| | - Lydie Lefrançois
- Centre de Recherche en Cancérologie de Lyon, UMR INSERM 1052 – CNRS 5286, Lyon Cedex 03, France
| | - Nadim Fares
- Centre de Recherche en Cancérologie de Lyon, UMR INSERM 1052 – CNRS 5286, Lyon Cedex 03, France
| | - Brigitte Bancel
- Centre de Recherche en Cancérologie de Lyon, UMR INSERM 1052 – CNRS 5286, Lyon Cedex 03, France
| | - Philippe Merle
- Centre de Recherche en Cancérologie de Lyon, UMR INSERM 1052 – CNRS 5286, Lyon Cedex 03, France
| | - Ourania Andrisani
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN 47907, United States; Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907, United States.
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Studach LL, Menne S, Cairo S, Buendia MA, Hullinger RL, Lefrançois L, Merle P, Andrisani OM. Subset of Suz12/PRC2 target genes is activated during hepatitis B virus replication and liver carcinogenesis associated with HBV X protein. Hepatology 2012; 56:1240-51. [PMID: 22505317 PMCID: PMC3417088 DOI: 10.1002/hep.25781] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
UNLABELLED Chronic hepatitis B virus (HBV) infection is a major risk factor for developing liver cancer, and the HBV X protein (pX) has been implicated as a cofactor in hepatocyte transformation. We have shown that HBV replication as well as in vitro transformation by pX are associated with induction of the mitotic polo-like kinase 1 (Plk1) and down-regulation of the chromatin remodeling components Suz12 and Znf198. Herein, we demonstrate the same inverse relationship between Plk1 and Suz12/Znf198 in liver tumors from X/c-myc bitransgenic mice and woodchuck hepatitis virus (WHV)-infected woodchucks. Employing these animal models and the HBV replicating HepAD38 cells we examined the effect of Suz12/Znf198 down-regulation on gene expression. Genes analyzed include hepatic cancer stem cell markers BAMBI, DKK1,2, DLK1, EpCAM, MYC, and proliferation genes CCNA1, CCND2, IGFII, MCM4-6, PLK1, RPA2, and TYMS. Suz12 occupancy at the promoters of BAMBI, CCND2, DKK2, DLK1, EpCAM, and IGFII was demonstrated by chromatin immunoprecipitation in untransformed hepatocytes, but was markedly reduced in pX-transformed and Suz12 knockdown cells. Accordingly, we refer to these genes as "Suz12 repressed" genes in untransformed hepatocytes. The Suz12 repressed genes and proliferation genes were induced in HBV-replicating HepAD38 cells and, interestingly, they exhibited distinct expression profiles during hepatocellular carcinoma (HCC) progression in X/c-myc bitransgenics. Specifically, CCND2, EpCAM, and IGFII expression was elevated at the proliferative and preneoplastic stages in X/c-myc bitransgenic livers, whereas BAMBI and PLK1 were overexpressed in hepatic tumors from X/c-myc bitransgenics and WHV-infected woodchucks. Importantly, most of these genes were selectively up-regulated in HBV-induced HCCs. CONCLUSION The distinct expression profile of the identified Suz12 repressed genes in combination with the proliferation genes hold promise as biomarkers for progression of chronic HBV infection to HCC.
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MESH Headings
- Animals
- Carcinoma, Hepatocellular/genetics
- Carcinoma, Hepatocellular/virology
- Cell Cycle Proteins/genetics
- Cell Cycle Proteins/metabolism
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/pathology
- Cells, Cultured
- Disease Models, Animal
- Down-Regulation
- Gene Expression Regulation, Viral
- Hepatitis B virus/genetics
- Hepatitis B, Chronic/genetics
- Hepatitis B, Chronic/physiopathology
- Hepatocytes/pathology
- Liver Neoplasms/genetics
- Liver Neoplasms/virology
- Marmota
- Mice
- Mice, Transgenic
- Polycomb Repressive Complex 2/genetics
- Polycomb Repressive Complex 2/metabolism
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/metabolism
- Random Allocation
- Sensitivity and Specificity
- Trans-Activators/genetics
- Trans-Activators/metabolism
- Transcriptional Activation
- Viral Regulatory and Accessory Proteins
- Virus Replication/genetics
- Polo-Like Kinase 1
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Affiliation(s)
- Leo L. Studach
- Department of Basic Medical Sciences and Purdue University Center for Cancer Research, West Lafayette, IN, USA
| | - Stephan Menne
- Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC, USA
| | - Stefano Cairo
- XenTech, Research and Development Department, Genopole Campus 3 Evry, France
| | - Marie Annick Buendia
- Inserm U785 Unit, Hepatobiliary Center, Paul Brousse Hospital, Villejuif, France
| | - Ronald L. Hullinger
- Department of Basic Medical Sciences and Purdue University Center for Cancer Research, West Lafayette, IN, USA
| | - Lydie Lefrançois
- Inserm U1052, Centre de Recherche en Cancérologie de Lyon, Hepatocarcinogenesis and Viral Infection, Lyon Cedex 03 France
| | - Philippe Merle
- Inserm U1052, Centre de Recherche en Cancérologie de Lyon, Hepatocarcinogenesis and Viral Infection, Lyon Cedex 03 France
| | - Ourania M. Andrisani
- Department of Basic Medical Sciences and Purdue University Center for Cancer Research, West Lafayette, IN, USA
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Lefrançois L, Lycke N. Isolation of mouse small intestinal intraepithelial lymphocytes, Peyer's patch, and lamina propria cells. Curr Protoc Immunol 2008; Chapter 3:Unit 3.19. [PMID: 18432783 DOI: 10.1002/0471142735.im0319s17] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The intestinal mucosal immune system is composed of three major lymphoid areas: the lamina propria (LP), which lies just underneath the basement membrane in the intestinal villi; (2) the intraepithelial compartment, which contains the intraepithelial lymphocytes (IEL) and is located just above the basement membrane, between the columnar epithelial cells; and (3) Peyer's patches (PP), lymphoid nodules (akin to lymph nodes) embedded in the gut wall, separated from the LP and IEL. The LP, PP, and IEL lymphoid populations form a complex, interconnected network that responds to immunological insults in the intestine. Therefore, these lymphocyte populations should be analyzed when studying the immunological status of the intestine, for example in oral immunization or in intestinal disease (including infectious disease and tumors). This unit details techniques for isolation of IEL, PP cells, and LP cells from the small intestine of the mouse.
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Affiliation(s)
- L Lefrançois
- University of Connecticut Health Center, Farmington, Connecticut, USA
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8
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Abstract
Previous studies have identified mRNA three isoforms encoding interleukin-15 (IL-15) that are produced through differential splicing and encode for the same mature IL-15 protein with two different signal peptides. Our analysis of mouse intestinal epithelial cells revealed two new IL-15 mRNA isoforms generated by different alternative splicing events. In one form (IL-15DeltaE6), exon 6 is absent, and in the second form the first 48 nt of exon 7 are absent (IL-15DeltaE7) through usage of an alternative 5' splicing site within exon 7. These mRNA isoforms encoded in-frame IL-15 protein variants lacking either 15aa (IL-15DeltaE6) or 16aa (IL-15DeltaE7) both utilizing the normal long signal peptide. Significant structural changes were predicted for these new IL-15 isoforms. RNAse protection assays revealed the highest expression of isoform mRNA in the intestinal epithelium and functional analysis of recombinant IL-15 isoform proteins suggested possible regulatory functions.
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Affiliation(s)
- X Tan
- Department of Immunology, University of Connecticut Health Center, Farmington, CT 06030-1319, USA
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Bengochéa A, De Souza M, Lefrançois L, Trépo C, Kim M, Wands J, Hainaut P, Scoazec J, Vitvitski L, Merle P. O.085 Overexpression of the Wnt/Frizzled signal's memebers: A strikingly common and early event in human hepatocellular carcinoma (HCC). J Clin Virol 2006. [DOI: 10.1016/s1386-6532(06)80085-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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10
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De Souza M, Bengochéa A, Leroux E, Lefrançois L, Galy O, Chemin I, Trépo C, Vitvitski L, Scoazec J, Hainaut P, Merle P. P.434 Frizzled-7 is commonly expressed by cancerous hepatocytes in virus and non-virus related human hepatocellular carcinomas: correlations with pathological features and β-catenin/p53 mutation status. J Clin Virol 2006. [DOI: 10.1016/s1386-6532(06)80607-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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11
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Merle P, Kim M, Herrmann M, Gupte A, Lefrançois L, Califano S, Trépo C, Tanaka S, Vitvitski L, de la Monte S, Wands JR. Oncogenic role of the frizzled-7/beta-catenin pathway in hepatocellular carcinoma. J Hepatol 2005; 43:854-62. [PMID: 16098625 DOI: 10.1016/j.jhep.2005.05.018] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2004] [Revised: 05/13/2005] [Accepted: 05/16/2005] [Indexed: 12/04/2022]
Abstract
BACKGROUND/AIMS The molecular mechanisms of hepatocarcinogenesis remain largely unknown. Previous studies suggest that activation of the Wnt/beta-catenin pathway is important during hepatocyte transformation but the role of Frizzled receptor (FZD) in this process has not been defined. Here we investigate activation of this pathway by FZD using transgenic hepatocellular carcinoma (HCC) murine models. METHODS We employed single (c-myc, SV40-Tag) and established double [insulin receptor substrate-1 (IRS-1/c-myc) and hepatitis Bx protein (X/c-myc)] transgenic lines and all developed HCC. Expression of 9 FZD was measured by real time RT-PCR and Western blot analysis. Phosphorylation and cellular accumulation of beta-catenin were assessed in both dysplastic tissue and tumors. We investigated the effect of a dominant negative (DN) FZD7 on TCF transcriptional activity in a SV40 derived HCC cell line. RESULTS FZD7 was highly overexpressed at the mRNA and protein level(s) in HCC and occurred in dysplasia. Upregulation of FZD7 was associated with reduced phosphorylation of beta-catenin and led to nuclear accumulation in HCC tumors. Ectopic expression of a DN FZD7 construct decreased TCF transcriptional activity in tumor cells. CONCLUSIONS These observations suggest that upregulation of FZD7 receptors in association with activation of the canonical Wnt/beta-catenin pathway is a common molecular event in HCC.
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Affiliation(s)
- Philippe Merle
- Department of Medicine and Pathology, Brown Medical School, The Liver Research Center, Providence, 55 Claverick St., 4th Floor, Providence, RI 02903, Rhode Island 02903, USA
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12
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Barraud L, Merle P, Soma E, Lefrançois L, Guerret S, Chevallier M, Dubernet C, Couvreur P, Trépo C, Vitvitski L. Increase of doxorubicin sensitivity by doxorubicin-loading into nanoparticles for hepatocellular carcinoma cells in vitro and in vivo. J Hepatol 2005; 42:736-43. [PMID: 15826724 DOI: 10.1016/j.jhep.2004.12.035] [Citation(s) in RCA: 165] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2004] [Revised: 11/30/2004] [Accepted: 12/28/2004] [Indexed: 12/04/2022]
Abstract
BACKGROUND/AIMS Hepatocellular carcinoma (HCC) is known to be chemoresistant to anticancer drugs due to the multidrug resistant (MDR) transporters expression. Here, we compared in vitro and in vivo the anti-tumor efficacy of doxorubicin-loaded polyisohexylcyanoacrylate nanoparticles (PIHCA-Dox) versus free doxorubicin (Dox). These nanoparticles are known to overcome the MDR phenotype. METHODS We first determined in vitro the 50% inhibition concentration (IC(50)) of these drugs on different human hepatoma cell lines. Secondly, the efficacy of the drugs in vivo was determined on the X/myc transgenic murine model of HCC by histological counting of apoptotic tumorous hepatocytes and by TUNEL labeling. We characterized by semi-quantitative RT-PCR the MDR-related gene (mdr1, mdr3, mrp1) expression pattern in this model. RESULTS In vitro, IC(50) was reduced with PIHCA-Dox versus Dox for Huh7 (1.7-fold reduction; P<0.001), HepaRG (4.5-fold reduction; P<0.01), HepG2 (1.5-fold reduction; P<0.001), and HepG2.2.15 (1.5-fold reduction; P=0.059). In vivo, HCC in transgenic mice overexpressed the mdr1 and mdr3 genes and the antitumor drugs efficacy was greatly enhanced after injection of PIHCA-Dox (9.0+/-5.0%; n=15) versus Dox (4.6+/-3.3%; n=13; P=0.01) for apoptotic bodies count. CONCLUSIONS These promising data showing a higher anti-tumor efficacy on HCC of PIHCA-Dox versus Dox, warrant further studies in both animals and humans.
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Affiliation(s)
- Luc Barraud
- INSERM Unit 271, 151 Cours Albert Thomas, 69424 Lyon Cedex 03, France
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13
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Merle P, Barraud L, Lefrançois L, Chevallier M, Guerret S, Maisonnas M, Bordes I, Savre-Train I, Trepo C, Vitvitski-Trepo L. Long-term high-dose interferon-alpha therapy delays Hepadnavirus-related hepatocarcinogenesis in X/myc transgenic mice. Oncogene 2003; 22:2762-71. [PMID: 12743599 DOI: 10.1038/sj.onc.1206375] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The role of interferon-alpha (IFN-alpha) remains unclear in prevention of virus-induced hepatocellular carcinoma in humans. We have investigated it herewith in the X/myc transgenic mouse model of Hepadnavirus-related hepatocarcinogenesis because of upregulation of c-myc oncogene in the liver. We have demonstrated that IFN-alpha can downregulate dose-dependently hepatocyte proliferation and c-myc overexpression at early premalignant stages, while it does not affect either hepatocyte apoptosis or telomerase activity at these steps. However, continuous and long-term administration of IFN-alpha dose-dependently delays tumor onset in dysplastic livers and increases overall survival of animals, more efficiently whether started before the onset of dysplasia. The present study therefore highlights that early preventive administration of IFN-alpha can slow down evolution towards hepatocellular carcinoma via repression of c-myc and hepatocyte proliferation at premalignant steps in experimental c-myc-induced hepatocarcinogenesis. However, the transient effect observed in this study emphasizes a need to clarify the possible mechanisms of acquired resistance and subsequent therapeutic escape. Our experimental model may be a pertinent tool to explore antioncogenic properties of IFN-alpha in human cirrhotic livers showing c-myc upregulation.
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Affiliation(s)
- Philippe Merle
- INSERM U271, Virus des Hépatites et Pathologies Associées, 151 Cours Albert Thomas, 69424 Lyon Cedex 03, France
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14
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Abstract
Most studies of injury and repair to mucosal tissue have used nonspecific mediators to induce injury. Damage to the mucosal epithelium resulting from chemical or radiation treatment associated with cancer therapy may fall into this category of injury. When such treatments are applied, it is generally not possible to predict or control the extent of possible injury. This fact makes analysis of inductive and reparative processes difficult. In addition, the role of the immune system in the etiology and subsequent healing of mucosal tissue following cancer therapy with or without bone marrow transplantation remains unclear. To study tissue- and antigen-specific immune damage of intestinal mucosal tissue, we generated transgenic mice that express a nominal antigen exclusively in intestinal epithelial cells. The transfer of antigen-specific CD8 T cells with concomitant virus infection resulted in the destruction of intestinal epithelial cells and disease. The destructive phase in some cases was followed by complete recovery and tolerance induction. This model will provide a system that can be regulated for analysis of the mediators of mucosa-specific tissue damage and repair.
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Affiliation(s)
- L Lefrançois
- Division of Rheumatic Diseases, Department of Medicine, University of Connecticut Health Center, Farmington 06030, USA.
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15
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Abstract
Many intracellular pathogens infect a broad range of host tissues, but the importance of T cells for immunity in these sites is unclear because most of our understanding of antimicrobial T cell responses comes from analyses of lymphoid tissue. Here, we show that in response to viral or bacterial infection, antigen-specific CD8 T cells migrated to nonlymphoid tissues and were present as long-lived memory cells. Strikingly, CD8 memory T cells isolated from nonlymphoid tissues exhibited effector levels of lytic activity directly ex vivo, in contrast to their splenic counterparts. These results point to the existence of a population of extralymphoid effector memory T cells poised for immediate response to infection.
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Affiliation(s)
- D Masopust
- Division of Immunology, Department of Medicine, University of Connecticut Health Center, Farmington, CT 06030, USA
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16
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Lefrançois L, Delpuech JJ, Hébrant M, Chrisment J, Tondre C. Aggregation and Protonation Phenomena in Third Phase Formation: An NMR Study of the Quaternary Malonamide/Dodecane/Nitric Acid/Water System. J Phys Chem B 2001. [DOI: 10.1021/jp002465h] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Lydie Lefrançois
- Laboratoire de Chimie Physique Organique et Colloïdale, Unité Mixte de Recherche CNRS−UHP (UMR 7565), Université Henri Poincaré-Nancy I, B.P. 239, 54506 Nancy-Vandoeuvre Cedex, France
| | - Jean-Jacques Delpuech
- Laboratoire de Chimie Physique Organique et Colloïdale, Unité Mixte de Recherche CNRS−UHP (UMR 7565), Université Henri Poincaré-Nancy I, B.P. 239, 54506 Nancy-Vandoeuvre Cedex, France
| | - Marc Hébrant
- Laboratoire de Chimie Physique Organique et Colloïdale, Unité Mixte de Recherche CNRS−UHP (UMR 7565), Université Henri Poincaré-Nancy I, B.P. 239, 54506 Nancy-Vandoeuvre Cedex, France
| | - Jacques Chrisment
- Laboratoire de Chimie Physique Organique et Colloïdale, Unité Mixte de Recherche CNRS−UHP (UMR 7565), Université Henri Poincaré-Nancy I, B.P. 239, 54506 Nancy-Vandoeuvre Cedex, France
| | - Christian Tondre
- Laboratoire de Chimie Physique Organique et Colloïdale, Unité Mixte de Recherche CNRS−UHP (UMR 7565), Université Henri Poincaré-Nancy I, B.P. 239, 54506 Nancy-Vandoeuvre Cedex, France
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17
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Pope C, Kim SK, Marzo A, Masopust D, Williams K, Jiang J, Shen H, Lefrançois L. Organ-specific regulation of the CD8 T cell response to Listeria monocytogenes infection. J Immunol 2001; 166:3402-9. [PMID: 11207297 DOI: 10.4049/jimmunol.166.5.3402] [Citation(s) in RCA: 326] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The intestinal mucosal CD8 T cell response to infection with Listeria monocytogenes was measured using MHC class I tetramers and was compared with the response in peripheral blood, secondary lymphoid tissue, and liver. To assess the vaccination potential of Listeria and to analyze responses in C57BL/6 mouse strains, a recombinant Listeria expressing OVA (rLM-ova) was generated. The response peaked at 9 days postinfection with a much larger fraction of the intestinal mucosa and liver CD8 T cell pool OVA specific, as compared with the spleen. However, these differences were not linked to bacterial titers in each site. The higher responses in lamina propria and liver resulted in a larger CD8 memory population in these tissues. Furthermore, the level of memory induced was dependent on infectious dose and inversely correlated with the magnitude of the recall response after oral challenge. Recall responses in the tissues were most robust in the lamina propria and liver, and reactivated Ag-specific T cells produced IFN-gamma. Infection of CD40- or MHC class II-deficient mice induced poor CD8 T cell responses in the intestinal mucosa, but only partially reduced responses in the spleen and liver. Overall, the results point to novel pathways of tissue-specific regulation of primary and memory antimicrobial CD8 T cell responses.
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MESH Headings
- Administration, Oral
- Animals
- Bacterial Vaccines/administration & dosage
- Bacterial Vaccines/genetics
- Bacterial Vaccines/immunology
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- CD40 Antigens/biosynthesis
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/microbiology
- Dose-Response Relationship, Immunologic
- Egg Proteins/administration & dosage
- Egg Proteins/genetics
- Egg Proteins/immunology
- Epitopes, T-Lymphocyte/immunology
- Immunization, Secondary
- Immunodominant Epitopes/immunology
- Immunologic Memory/genetics
- Intestinal Mucosa/immunology
- Intestinal Mucosa/microbiology
- Listeria monocytogenes/genetics
- Listeria monocytogenes/immunology
- Listeriosis/blood
- Listeriosis/immunology
- Listeriosis/microbiology
- Liver/immunology
- Liver/microbiology
- Lymphocyte Activation/genetics
- Lymphoid Tissue/immunology
- Lymphoid Tissue/microbiology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Organ Specificity/immunology
- Ovalbumin/administration & dosage
- Ovalbumin/genetics
- Ovalbumin/immunology
- Peptide Fragments
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/genetics
- Vaccines, Synthetic/immunology
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Affiliation(s)
- C Pope
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington, CT 06030, USA
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18
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Masopust D, Jiang J, Shen H, Lefrançois L. Direct analysis of the dynamics of the intestinal mucosa CD8 T cell response to systemic virus infection. J Immunol 2001; 166:2348-56. [PMID: 11160292 DOI: 10.4049/jimmunol.166.4.2348] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The CD8 T cell response to vesicular stomatitis virus infection was characterized in the spleen and intestinal mucosa using MHC tetramers. Surprisingly, the primary response persisted in the lamina propria long after the splenic response had declined. Furthermore, the response was characterized by a protracted effector phase in which cytolytic activity in the lamina propria, but not in the spleen, was maintained. The appearance of Ag-specific cells in the intestinal mucosa was largely, though not exclusively, a result of beta(7) integrin-mediated migration. Infection with Listeria monocytogenes or with vaccinia virus also led to sustained mucosal responses. After reinfection of vesicular stomatitis virus-primed mice with a serotypically distinct virus, a sustained recall response was detected in all tissues. In CD40(-/-) mice, the mucosal, but not the splenic, response was compromised, resulting in diminished mucosal memory. The recall response was CD40 independent and correlated with memory levels, indicating that the mucosal and systemic responses operated independently. These findings illustrated the integrated yet distinct nature of systemic vs mucosal immune responses.
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Affiliation(s)
- D Masopust
- Division of Immunology, Department of Medicine, University of Connecticut Health Center, Farmington, CT 06030, USA
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19
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Abstract
The naïve and memory T lymphocyte pools are maintained through poorly understood homeostatic mechanisms that may include signaling via cytokine receptors. We show that interleukin-7 (IL-7) plays multiple roles in regulating homeostasis of CD8+ T cells. We found that IL-7 was required for homeostatic expansion of naïve CD8+ and CD4+ T cells in lymphopenic hosts and for CD8+ T cell survival in normal hosts. In contrast, IL-7 was not necessary for growth of CD8+ T cells in response to a virus infection but was critical for generating T cell memory. Up-regulation of Bcl-2 in the absence of IL-7 signaling was impaired after activation in vivo. Homeostatic proliferation of memory cells was also partially dependent on IL-7. These results point to IL-7 as a pivotal cytokine in T cell homeostasis.
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Affiliation(s)
- K S Schluns
- Department of Medicine, University of Connecticut Health Center, Farmington, CT 06030, USA
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20
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Boivin-Angele S, Pedron S, Bertrand S, Desmouliere A, Martel-Planche G, Lefrançois L, Bancel B, Trépo C, Marion MJ. Establishment and characterization of a spontaneously immortalized myofibroblast cell line derived from a human liver angiosarcoma. J Hepatol 2000; 33:290-300. [PMID: 10952247 DOI: 10.1016/s0168-8278(00)80370-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND/AIM Fibrosis and/or cirrhosis are present in the precursor stages of most liver cancers. However, little is known about the reciprocal interactions of fibroblasts, mainly responsible for fibrosis, and the other liver cells. We report here the isolation of a new liver myofibroblast cell line from a human liver angiosarcoma and its characterization. METHODS The cells were isolated by the explant technique and characterization was performed, on one hand, using immunohistochemical and ultrastructural analysis and, in the other hand, by determining their karyotype, ras and p53 status and their tumorigenic properties. RESULTS To date, the cells have undergone approximately 170 population doublings and are still proliferating. Immunohistochemically, they were negative for desmin, smooth muscle myosin, cytokeratin 19 and von Willebrand factor, positive for vimentin and alpha-smooth muscle actin, with an important deposition of fibronectin around the cells. Ultrastructure showed particularly cytoplasmic microfilament bundles. Their chromosome number ranged from 38 to 168 with a bimodal population, near diploid and hypotetraploid. No mutations were found in codons 12, 13 or 61 of Ha-, Ki- and N-ras genes but a homozygous missense mutation in codon 179 (CAT-->CTT) was detected in the p53 gene. They were unable to form foci in soft agar or tumors in nude mice. CONCLUSIONS Taken together, these results show that these cells, called BM 2.2.1, exhibited typical myofibroblast-like features. Although they contained a karyotype suggestive of tumoral cells and a homozygous mutated p53 gene, they were not tumorigenic. The nature of these cells and the abnormalities of the p53 gene and the karyotype, suggest that: i) they were a component of the tumor stroma, and ii) they could have been involved in angiosarcoma development. Thus, this cell line may be valuable for the study of cellular interactions in liver carcinogenesis.
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Affiliation(s)
- S Boivin-Angele
- Institut National de la Santé et de la Recherche Médicale, Unité 271, Lyon, France
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21
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Abstract
Reactivity to intestinal epithelium-specific antigen was studied by transgenic expression of cytosolic ovalbumin controlled by an enterocyte-specific promoter. Transferred OVA-specific CD8 cells (OT-I) preferentially expanded in mucosal lymphoid tissues and the epithelium but failed to cause tissue damage. In contrast, concomitant VSV-ova infection induced OT-I-mediated epithelial cell destruction that correlated with antigen density. OT-I cells retained in the epithelium exhibited high levels of lytic activity but were unable to produce cytokines. The mice were systemically tolerant to OVA since endogenous CD8 cells were nonresponsive to VSV-ova infection. Thus, intestinal antigen gained access to peripheral tissues via absorption from effete epithelial cells. This system demonstrated a requirement for inflammation to drive pathogenic autoreactivity against enterocytes and identified pathways of intestine-specific immunoregulation.
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Affiliation(s)
- V Vezys
- Department of Medicine, University of Connecticut Health Center, Farmington 06030, USA
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22
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Boivin-Angèle S, Lefrançois L, Froment O, Spiethoff A, Bogdanffy MS, Wegener K, Wesch H, Barbin A, Bancel B, Trépo C, Bartsch H, Swenberg J, Marion MJ. Ras gene mutations in vinyl chloride-induced liver tumours are carcinogen-specific but vary with cell type and species. Int J Cancer 2000. [PMID: 10629081 DOI: 10.1002/(sici)1097-0215(20000115)85:2<223::aid-ijc12>3.0.co;2-h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Previous studies have shown that a high proportion (5/6) of human liver angiosarcomas (ASL) associated with exposure to vinyl chloride (VC) contains a GC-->AT mutation at the Ki-ras codon 13. This mutation, however, has not been found in 5 ASL or 2 hepatocellular carcinomas (HCC) induced in rats by VC. These 2 HCC did contain a mutation at codon 61 of the Ha-ras gene. In order to extend this study and further explore the mechanisms of tumour induction, an additional 6 ASL and 6 HCC induced in rats by VC were analysed for ras gene point mutations, as well as 10 rat and 10 murine ASL induced by vinyl fluoride (VF), and 5 ASL, 6 Kupffer cell sarcomas, 4 HCC and 2 cholangiocellular carcinomas induced by Thorotrast in rats. Tumour DNA was analysed by PCR-SSCP and direct sequencing. None of the rodent ASL contained a mutation at codon 13 of the Ki-ras gene showing that the ras gene mutational pattern is species-specific. The CAA-->CTA mutation, previously found at codon 61 of the Ha-ras gene in rat HCC, was observed in 5 further VC-induced HCC but was not detected in the Thorotrast-induced HCC, suggesting carcinogen-specificity. This mutation was also absent in VC-induced ASL, which supports the cell-specificity of the ras mutational pattern in chemically induced tumours. No predominant mutation was detected in VF- and Thorotrast-induced tumours. Thus, a given mutation in a tumour may be carcinogen-specific but also depend on the species and the cell type.
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Affiliation(s)
- S Boivin-Angèle
- Institut National de la Santé et de la Recherche Médicale, Unité 271, Lyon, France
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23
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Boivin-Angèle S, Lefrançois L, Froment O, Spiethoff A, Bogdanffy MS, Wegener K, Wesch H, Barbin A, Bancel B, Trépo C, Bartsch H, Swenberg J, Marion MJ. ras gene mutations in vinyl chloride-induced liver tumours are carcinogen-specific but vary with cell type and species. Int J Cancer 2000. [DOI: 10.1002/(sici)1097-0215(20000115)85:2%3c223::aid-ijc12%3e3.0.co;2-h] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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24
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Boivin-Angèle S, Lefrançois L, Froment O, Spiethoff A, Bogdanffy MS, Wegener K, Wesch H, Barbin A, Bancel B, Trépo C, Bartsch H, Swenberg J, Marion MJ. Ras gene mutations in vinyl chloride-induced liver tumours are carcinogen-specific but vary with cell type and species. Int J Cancer 2000; 85:223-7. [PMID: 10629081 DOI: 10.1002/(sici)1097-0215(20000115)85:2<223::aid-ijc12>3.0.co;2-h] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Previous studies have shown that a high proportion (5/6) of human liver angiosarcomas (ASL) associated with exposure to vinyl chloride (VC) contains a GC-->AT mutation at the Ki-ras codon 13. This mutation, however, has not been found in 5 ASL or 2 hepatocellular carcinomas (HCC) induced in rats by VC. These 2 HCC did contain a mutation at codon 61 of the Ha-ras gene. In order to extend this study and further explore the mechanisms of tumour induction, an additional 6 ASL and 6 HCC induced in rats by VC were analysed for ras gene point mutations, as well as 10 rat and 10 murine ASL induced by vinyl fluoride (VF), and 5 ASL, 6 Kupffer cell sarcomas, 4 HCC and 2 cholangiocellular carcinomas induced by Thorotrast in rats. Tumour DNA was analysed by PCR-SSCP and direct sequencing. None of the rodent ASL contained a mutation at codon 13 of the Ki-ras gene showing that the ras gene mutational pattern is species-specific. The CAA-->CTA mutation, previously found at codon 61 of the Ha-ras gene in rat HCC, was observed in 5 further VC-induced HCC but was not detected in the Thorotrast-induced HCC, suggesting carcinogen-specificity. This mutation was also absent in VC-induced ASL, which supports the cell-specificity of the ras mutational pattern in chemically induced tumours. No predominant mutation was detected in VF- and Thorotrast-induced tumours. Thus, a given mutation in a tumour may be carcinogen-specific but also depend on the species and the cell type.
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Affiliation(s)
- S Boivin-Angèle
- Institut National de la Santé et de la Recherche Médicale, Unité 271, Lyon, France
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25
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Lefrançois L, Altman JD, Williams K, Olson S. Soluble antigen and CD40 triggering are sufficient to induce primary and memory cytotoxic T cells. J Immunol 2000; 164:725-32. [PMID: 10623816 DOI: 10.4049/jimmunol.164.2.725] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The signals directing induction of tolerance rather than immunity are largely unknown. The CD8 T cell response to soluble Ags generally results in deletional tolerance following transient, costimulation-dependent activation. We demonstrated that CD40 signaling reversed the outcome of this response. Adoptive transfer of OVA-specific CD8 T cells followed by soluble OVA immunization resulted in induction of lytic activity and optimal clonal expansion only when CD40 was triggered via an agonistic mAb. Activation of CD8 T cells by CD40 signaling was indirect, because CD40 expression by host cells was required. CD40 signaling along with soluble Ag immunization also induced expansion of secondary lymphoid and intestinal mucosal endogenous OVA-specific CD8 T cells as detected by MHC tetramer reactivity. When CD40 activation was included, long-lived secondary lymphoid and mucosal memory CD8 cells were generated from adoptively transferred and endogenous CD8 T cells. Mucosal and peripheral CD8 memory cells exhibited constitutive Ag-specific lytic activity, with mucosal memory cells being 10-fold more lytic than splenic or lymph node memory cells. These results demonstrated that CD40 signaling during a response to a poorly immunogenic soluble Ag was necessary and sufficient for CTL and memory T cell induction.
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Affiliation(s)
- L Lefrançois
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington, CT 06037, USA.
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26
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Lefrançois L, Olson S, Masopust D. A critical role for CD40-CD40 ligand interactions in amplification of the mucosal CD8 T cell response. J Exp Med 1999; 190:1275-84. [PMID: 10544199 PMCID: PMC2195681 DOI: 10.1084/jem.190.9.1275] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/1999] [Accepted: 08/25/1999] [Indexed: 11/25/2022] Open
Abstract
The role of CD40 ligand (CD40L) in CD8 T cell activation was assessed by tracking antigen-specific T cells in vivo using both adoptive transfer of T cell receptor transgenic T cells and major histocompatibility complex (MHC) class I tetramers. Soluble antigen immunization induced entry of CD8 cells into the intestinal mucosa and cytotoxic T lymphocyte (CTL) differentiation, whereas CD8 cells in secondary lymphoid tissue proliferated but were not cytolytic. Immunization concurrent with CD40L blockade or in the absence of CD40 demonstrated that accumulation of CD8 T cells in the mucosa was CD40L dependent. Furthermore, activation was mediated through CD40L expressed by the CD8 cells, since inhibition by anti-CD40L monoclonal antibodies occurred after adoptive transfer to CD40L-deficient mice. However, mucosal CD8 T cells in normal and CD40(-/-) mice were equivalent killers, indicating that CD40L was not required for CTL differentiation. Appearance of virus-specific mucosal, but not splenic, CD8 cells also relied heavily on CD40-CD40L interactions. The mucosal CTL response of transferred CD8 T cells was MHC class II and interleukin 12 independent. The results established a novel pathway of direct CD40L-mediated CD8 T cell activation.
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Affiliation(s)
- L Lefrançois
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington, Connecticut 06030, USA.
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Kim SK, Schluns KS, Lefrançois L. Induction and visualization of mucosal memory CD8 T cells following systemic virus infection. J Immunol 1999; 163:4125-32. [PMID: 10510347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Whether CD8 T cell memory exists outside secondary lymphoid organs is unclear. Using an adoptive transfer system that enables tracking of OVA-specific CD8 T cells, we explored the antigenic requirements for inducing CD8 T cell memory and identified intestinal mucosa memory cells. Although systemic immunization with soluble OVA induced clonal expansion, memory CD8 cells were not produced. In contrast, infection with virus-encoding OVA induced memory CD8 cells in the periphery and the lamina propria and intraepithelial compartments of the intestinal mucosa. Mucosal memory cells expressed a distinct array of adhesion molecules as compared with secondary lymphoid memory cells, suggesting that there may be separate mucosal and systemic memory pools. Mucosal CD8 memory cells rapidly produced IFN-gamma after Ag stimulation. Reactivation of memory cells by Ag feeding resulted in increased cell size and up-regulation of CD28 and CD11c. CD8 mucosal memory cells exhibited ex vivo lytic activity that was up-regulated dramatically following Ag reencounter in vivo. Interestingly, reactivation of memory cells did not require CD28-mediated costimulation. The ability of the intestinal mucosa to maintain CD8 memory cells provides a potential mechanism for effective mucosal vaccination.
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Affiliation(s)
- S K Kim
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030, USA
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Abstract
The requirement of beta7 integrins for lymphocyte migration was examined during an ongoing immune response in vivo. Transgenic mice (OT-I) expressing an ovalbumin-specific major histocompatibility complex class I-restricted T cell receptor for antigen were rendered deficient in expression of all beta7 integrins or only the alphaEbeta7 integrin. To quantitate the relative use of beta7 integrins in migration in vivo, equal numbers of OT-I and OT-I-beta7(-/-) or OT-I-alphaE-/- lymph node (LN) cells were adoptively transferred to normal mice. Although OT-I-beta7(-/-) LN cells migrated to mesenteric LN and peripheral LN as well as wild-type cells, beta7 integrins were required for naive CD8 T cell and B cell migration to Peyer's patch. After infection with a recombinant virus (vesicular stomatitis virus) encoding ovalbumin, beta7 integrins became critical for migration of activated CD8 T cells to the mesenteric LN and Peyer's patch. Naive CD8 T cells did not enter the lamina propria or the intestinal epithelium, and the majority of migration of activated CD8 T cells to the small and large intestinal mucosa, including the epithelium, was beta7 integrin-mediated. The alphaEbeta7 integrin appeared to play no role in migration during a primary CD8 T cell immune response in vivo. Furthermore, despite dramatic upregulation of alphaEbeta7 by CD8 T cells after entry into the epithelium, long-term retention of intestinal intraepithelial lymphocytes was also alphaEbeta7 independent.
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Affiliation(s)
- L Lefrançois
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington, Connecticut 06037, USA
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Lefrançois L, Hébrant M, Tondre C, Delpuech JJ, Berthon C, Madic C. Z,E Isomerism and hindered rotations in malonamides: an NMR study of N,N ′-dimethyl-N,N ′-dibutyl-2-tetradecylpropane-1,3-diamide. ACTA ACUST UNITED AC 1999. [DOI: 10.1039/a900766k] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Kim SK, Reed DS, Olson S, Schnell MJ, Rose JK, Morton PA, Lefrançois L. Generation of mucosal cytotoxic T cells against soluble protein by tissue-specific environmental and costimulatory signals. Proc Natl Acad Sci U S A 1998; 95:10814-9. [PMID: 9724787 PMCID: PMC27978 DOI: 10.1073/pnas.95.18.10814] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We compared peripheral and mucosal primary CD8 T cell responses to inflammatory and noninflammatory forms of antigen in a T cell-adoptive transfer system. Immunization with the soluble antigen, ovalbumin (ova), administered i.p. or orally without adjuvant, activated nonmucosal CD8 T cells but did not induce cytotoxic activity. However, after activation, the transferred cells entered the intestinal mucosa and became potent antigen-specific killers. Thus, exogenous intact soluble protein entered the major histocompatibility complex class I antigen presentation pathway and induced mucosal cytotoxic T lymphocytes. Moreover, distinct costimulatory requirements for activation of peripheral versus mucosal T cells were noted in that the CD28 ligand, B7-1, was critical for activated mucosal T cell generation but not for activation of peripheral CD8 T cells. The costimulator, B7-2, was required for optimum activation of both populations. Infection with a new recombinant vesicular stomatitis virus encoding ovalbumin induced lytic activity in mucosal as well as peripheral sites, demonstrating an adjuvant effect of inflammatory mediators produced during virus infection. Generation of antiviral cytotoxic T lymphocytes was also costimulation-dependent. The results indicated that induction of peripheral tolerance via antigen administration may not extend to mucosal sites because of distinct costimulatory and inflammatory signals in the mucosa.
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Affiliation(s)
- S K Kim
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington, CT 06030, USA
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Laky K, Lefrançois L, von Freeden-Jeffry U, Murray R, Puddington L. The role of IL-7 in thymic and extrathymic development of TCR gamma delta cells. J Immunol 1998; 161:707-13. [PMID: 9670946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
IL-7-deficient (IL-7(-/-)) mice have reduced numbers of B and TCR alpha beta cells, but lack mature TCR gamma delta cells. Although most T cell development occurs in the thymus, some intestinal intraepithelial lymphocytes (IEL), including TCR gamma delta cells, can develop extrathymically. Epithelial cells in both thymus and intestine synthesize IL-7, suggesting that TCR gamma delta cell development could occur in either site. To evaluate the role of thymic IL-7 in development of TCR gamma delta cells, newborn TCR beta-deficient (TCR beta(-/-)) thymi were grafted to IL-7(-/-) mice. Donor- and host-derived TCR gamma delta cells were recovered from thymus grafts, spleen, and IEL. However, when IL-7(-/-) thymi were grafted to TCR beta(-/-) mice, no development of graft-derived TCR gamma delta cells occurred, indicating that extrathymic IL-7 did not support TCR gamma delta IEL generation from newborn thymic precursors. In contrast, TCR gamma delta IEL development occurred efficiently in adult, thymectomized, irradiated C57BL/6J mice reconstituted with IL-7(-/-) bone marrow. This demonstrated that extrathymic development of TCR gamma delta IEL required extrathymic IL-7 production. Thus, intrathymic IL-7 was required for development of thymic TCR gamma delta cells, while peripheral IL-7 was sufficient for development of extrathymic TCR gamma delta IEL.
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Affiliation(s)
- K Laky
- Department of Medicine, University of Connecticut Health Center, Farmington 06030, USA
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Abstract
CT1 is a carbohydrate moiety of CD45 that is expressed on fetal thymocytes in vivo. Examination of CT1 expression on thymocyte subsets revealed that primarily pro-T cells (CD44+ CD25+) and pre-T cells (CD44- CD25+) expressed CT1. Interestingly, non-T-lineage committed lymphoid progenitors (CD44+ CD25-) lacked CT1 indicating temporal regulation of expression of this determinant in early T-lineage committed development. In addition, CT1 was expressed by the majority of thymocytes in RAG-2(-/-) mice where thymocyte development is blocked at the CD44- CD25+ stage. Since late pre-T cells (CD44- CD25-) lacked the CT1 epitope we tested whether pre-TCR triggering regulated CT1 expression. Injection of CD3epsilon-specific mAb into RAG-2(-/-) mice induces differentiation of immature thymocytes to the double-positive stage of thymocyte development. Using this system, we demonstrated that expression of CT1 by RAG-2(-/-) thymocytes was rapidly lost from pre-T cells following anti-CD3 mAb treatment. Furthermore, the decline in CT1 expression induced by CD3 signaling paralleled a loss of mRNA for the glycosyltransferase responsible for the addition of CT1 to CD45. Flow cytometric analysis also revealed that the loss of the CT1 epitope was inversely correlated with an increase in peanut agglutinin ligand expression, demonstrating a complex regulation of cell surface glycosylation at a critical juncture in thymocyte development.
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Affiliation(s)
- D S Reed
- Department of Medicine, University of Connecticut Health Center, Farmington 06030, USA
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Kim SK, Reed DS, Heath WR, Carbone F, Lefrançois L. Activation and migration of CD8 T cells in the intestinal mucosa. J Immunol 1997; 159:4295-306. [PMID: 9379025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The activation of CD8 T cells was studied using transgenic mice expressing an MHC class I-restricted OVA-specific TCR (OT-I). Immunization of OT-I mice resulted in activation of lymph node T cells and up-regulation of expression of B220, CD11a, and CD44 and caused a preferential loss of mucosal-type T cells from the periphery. Immunization induced dramatic changes in intestinal lymphocytes, including the appearance of a CD11a high population that resembled peripheral T cells and induced a primary cytolytic response. Activation of adoptively transferred OT-I cells induced migration of CD8 T cells into the lamina propria and intraepithelial lymphocyte compartments. The results suggest that Ag presentation in the intestinal epithelium occurs, and that CD8 cells activated in the periphery can readily enter the mucosa during an ongoing immune response.
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Affiliation(s)
- S K Kim
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030, USA
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Kim SK, Reed DS, Heath WR, Carbone F, Lefrançois L. Activation and migration of CD8 T cells in the intestinal mucosa. The Journal of Immunology 1997. [DOI: 10.4049/jimmunol.159.9.4295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
The activation of CD8 T cells was studied using transgenic mice expressing an MHC class I-restricted OVA-specific TCR (OT-I). Immunization of OT-I mice resulted in activation of lymph node T cells and up-regulation of expression of B220, CD11a, and CD44 and caused a preferential loss of mucosal-type T cells from the periphery. Immunization induced dramatic changes in intestinal lymphocytes, including the appearance of a CD11a high population that resembled peripheral T cells and induced a primary cytolytic response. Activation of adoptively transferred OT-I cells induced migration of CD8 T cells into the lamina propria and intraepithelial lymphocyte compartments. The results suggest that Ag presentation in the intestinal epithelium occurs, and that CD8 cells activated in the periphery can readily enter the mucosa during an ongoing immune response.
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Affiliation(s)
- S K Kim
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030, USA
| | - D S Reed
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030, USA
| | - W R Heath
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030, USA
| | - F Carbone
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030, USA
| | - L Lefrançois
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030, USA
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36
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Laky K, Lefrançois L, Puddington L. Age-dependent intestinal lymphoproliferative disorder due to stem cell factor receptor deficiency: parameters in small and large intestine. The Journal of Immunology 1997. [DOI: 10.4049/jimmunol.158.3.1417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Signaling through c-Kit/stem cell factor (SCF) is crucial for normal development of erythroid and myeloid hematopoietic precursors and of melanocytes and germ cells. While peripheral lymphoid populations of W/Wv and SI/SId mice appear normal, we demonstrated that the intraepithelial lymphocyte (IEL) populations of small (SI) and large (LI) intestine were significantly affected. IEL populations of young W/Wv animals were indistinguishable from those of their control littermates, but an age-dependent decrease in SI and LI TCRgamma delta IEL occurred in c-Kit mutant mice. In SI, but not in LI, this diminution was accompanied by gross expansion of TCRalpha beta IEL that resulted in significantly increased IEL:epithelial cell ratios in c-Kit mutant mice. Bromodeoxyuridine labeling studies revealed that the increase in cell numbers was due to lymphoproliferation that occurred in situ. Interestingly, TCRgamma delta IEL expressed cell surface c-Kit, while the expanding population of TCRalpha beta IEL did not. Analysis of radiation bone marrow chimeras demonstrated that the dysregulation required either disruption of stromal cell SCF or IEL c-Kit and showed that the effect on IEL or their precursors was not due to other changes in the intestinal microenvironment. Lamina propria T cell populations in these mice were unaffected, reinforcing the idea that the developmental requirements of these gut-resident lymphocyte populations are distinct. Overall, the results demonstrated that the development of intestinal TCRgamma delta IEL, regardless of location, shares common requirements for SCF, while SI and LI TCRalpha beta IEL may develop along distinct pathways. Possible mechanisms for the loss of proliferative regulation in gut T cells in c-Kit/SCF deficiency are discussed.
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Affiliation(s)
- K Laky
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030, USA
| | - L Lefrançois
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030, USA
| | - L Puddington
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030, USA
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Laky K, Lefrançois L, Puddington L. Age-dependent intestinal lymphoproliferative disorder due to stem cell factor receptor deficiency: parameters in small and large intestine. J Immunol 1997; 158:1417-27. [PMID: 9013987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Signaling through c-Kit/stem cell factor (SCF) is crucial for normal development of erythroid and myeloid hematopoietic precursors and of melanocytes and germ cells. While peripheral lymphoid populations of W/Wv and SI/SId mice appear normal, we demonstrated that the intraepithelial lymphocyte (IEL) populations of small (SI) and large (LI) intestine were significantly affected. IEL populations of young W/Wv animals were indistinguishable from those of their control littermates, but an age-dependent decrease in SI and LI TCRgamma delta IEL occurred in c-Kit mutant mice. In SI, but not in LI, this diminution was accompanied by gross expansion of TCRalpha beta IEL that resulted in significantly increased IEL:epithelial cell ratios in c-Kit mutant mice. Bromodeoxyuridine labeling studies revealed that the increase in cell numbers was due to lymphoproliferation that occurred in situ. Interestingly, TCRgamma delta IEL expressed cell surface c-Kit, while the expanding population of TCRalpha beta IEL did not. Analysis of radiation bone marrow chimeras demonstrated that the dysregulation required either disruption of stromal cell SCF or IEL c-Kit and showed that the effect on IEL or their precursors was not due to other changes in the intestinal microenvironment. Lamina propria T cell populations in these mice were unaffected, reinforcing the idea that the developmental requirements of these gut-resident lymphocyte populations are distinct. Overall, the results demonstrated that the development of intestinal TCRgamma delta IEL, regardless of location, shares common requirements for SCF, while SI and LI TCRalpha beta IEL may develop along distinct pathways. Possible mechanisms for the loss of proliferative regulation in gut T cells in c-Kit/SCF deficiency are discussed.
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Affiliation(s)
- K Laky
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030, USA
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Lefrançois L, Fuller B, Huleatt JW, Olson S, Puddington L. On the front lines: intraepithelial lymphocytes as primary effectors of intestinal immunity. Springer Semin Immunopathol 1997; 18:463-75. [PMID: 9144865 DOI: 10.1007/bf00824053] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- L Lefrançois
- University of Connecticut Health Center, Division of Rheumatic Diseases, Farmington 06030, USA
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Abstract
Development of the mucosal immune system was examined in mice with partial loss of expression of ICAM-1 or CD18. Profound effects on Peyer's patch (PP), lamina propria (LP), and intraepithelial lymphocyte (IEL) T cell populations were observed in mutant mice. Normal expression of CD18 integrins and ICAM-1 was essential for development of the CD8(alpha beta) TCR(alpha beta)LP and IEL compartment and for the generation of normal PP lymphocyte populations. The partial loss of CD8(alpha beta) IEL correlated with the loss of TCR(alpha beta) IEL-mediated lytic activity. The presence of a subset of Thy1+TCR(gamma delta)IEL was also dependent on CD18 integrins and ICAM-1. Both the lytic activity and the expression of CD11c by TCR(gamma delta)IEL were up-regulated in the presence of TCR(alpha beta) T cells. Analysis of bone marrow chimeras demonstrated that a bone marrow-derived ICAM-1+ accessory cell was involved in the generation of some TCR(alpha beta) IEL. These results demonstrated that ICAM-1 and beta2 integrins were required for establishment of a normal intestinal immune system.
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Affiliation(s)
- J W Huleatt
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030, USA
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MESH Headings
- Animals
- Animals, Newborn
- Antibodies, Monoclonal
- CD4 Antigens/analysis
- CD8 Antigens/analysis
- Epithelium/immunology
- Immunity, Mucosal
- Intestinal Mucosa/immunology
- Lymph Nodes/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Inbred Strains
- Mice, Nude
- Mice, SCID
- Receptors, Antigen, T-Cell, gamma-delta/analysis
- T-Lymphocytes/immunology
- Thymectomy
- Thymus Gland/immunology
- Thymus Gland/transplantation
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Affiliation(s)
- L Lefrançois
- Department of Medicine, University of Connecticut Health Center, Farmington 06030, USA
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Fuller B, Lefrançois L. Requirement for extrathymic class I histocompatibility antigens for positive selection of thymus-derived T lymphocytes. The Journal of Immunology 1995. [DOI: 10.4049/jimmunol.155.6.2808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Abstract
We have examined whether the thymus can produce immature T cell precursors for subsequent positive selection in the periphery. Using the intestine as a model system, we demonstrate that extrathymic MHC class I molecules positively select thymus-derived TCR-alpha beta CD8+ intestinal intraepithelial lymphocytes. Grafting of MHC class I+ thymus onto MHC class I- hosts resulted in the generation of donor and host-derived CD4-CD8+ T cells in lymph node, but few TCR-alpha beta CD4-CD8+ intraepithelial lymphocytes. The results indicate that the intestine can act as a site of positive selection for thymus-derived T cells. Bone marrow reconstitution studies demonstrated that non-hematopoietic, radiation-resistant cells, perhaps intestinal epithelial cells, were responsible for extrathymic positive selection of thymus-derived T cells. These findings demonstrate that the thymus can support organ-specific immunity via provision of targeted precursor populations.
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Affiliation(s)
- B Fuller
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030, USA
| | - L Lefrançois
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030, USA
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Fuller B, Lefrançois L. Requirement for extrathymic class I histocompatibility antigens for positive selection of thymus-derived T lymphocytes. J Immunol 1995; 155:2808-11. [PMID: 7673696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We have examined whether the thymus can produce immature T cell precursors for subsequent positive selection in the periphery. Using the intestine as a model system, we demonstrate that extrathymic MHC class I molecules positively select thymus-derived TCR-alpha beta CD8+ intestinal intraepithelial lymphocytes. Grafting of MHC class I+ thymus onto MHC class I- hosts resulted in the generation of donor and host-derived CD4-CD8+ T cells in lymph node, but few TCR-alpha beta CD4-CD8+ intraepithelial lymphocytes. The results indicate that the intestine can act as a site of positive selection for thymus-derived T cells. Bone marrow reconstitution studies demonstrated that non-hematopoietic, radiation-resistant cells, perhaps intestinal epithelial cells, were responsible for extrathymic positive selection of thymus-derived T cells. These findings demonstrate that the thymus can support organ-specific immunity via provision of targeted precursor populations.
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Affiliation(s)
- B Fuller
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030, USA
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43
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Huleatt JW, Lefrançois L. Antigen-driven induction of CD11c on intestinal intraepithelial lymphocytes and CD8+ T cells in vivo. J Immunol 1995; 154:5684-93. [PMID: 7751620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Intraepithelial lymphocytes (IEL) of the intestinal epithelium represent a phenotypically and functionally distinct subpopulation of peripheral T cells. In this study, we report the production of a mAb, designated HL3, which exhibits reactivity with a subset of IEL. In differential screening assays HL3 reacted with 30 to 50% of IEL, but not with T cells of the thymus, spleen, or lymph nodes. Biochemical characterization revealed that the HL3 mAb recognized p150,95 (CD11c/CD18; CR4), a member of the beta 2-integrin family. Fluorescence flow cytometric analyses showed that p150,95 was expressed by TCR-alpha beta or TCR-gamma delta CD4-8+ IEL but not by CD4+8- IEL. Induction of graft-vs-host (GVH) disease resulted in up-regulation of p150,95 expression on donor-derived CD8+ T cells in the intestinal epithelium, as well as in the spleen and lymph nodes. GVH also induced MAC-1 (CD11b) expression on a subset of CD8+ lymph node T cells, but MAC-1 was not up-regulated on CD8+ IEL in this situation. In contrast, activation of identical T cell responders in vitro resulted in weak induction of p150,95 and MAC-1 expression. This result suggested that activation alone was insufficient for p150,95 up-regulation and that additional factors available in vivo were essential in this process. In the intestine, induction of p150,95 required the presence of intestinal flora as IEL from germfree mice lacked p150,95. Interestingly, gamma delta IEL expressing a non-IEL type transgenic TCR were also p150,95-, but exposure to Ag in vivo, but not in vitro, resulted in p150,95 induction. This result indicated that the constitutive expression of p150,95 on IEL is likely due to Ag stimulation via the TCR and not a bystander phenomenon. Overall, the results demonstrated p150,95 to be a hallmark of T cell activation in vivo and an indicator of ongoing antigen-specific T cell activation in the intestinal epithelium.
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Affiliation(s)
- J W Huleatt
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030, USA
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Huleatt JW, Lefrançois L. Antigen-driven induction of CD11c on intestinal intraepithelial lymphocytes and CD8+ T cells in vivo. The Journal of Immunology 1995. [DOI: 10.4049/jimmunol.154.11.5684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Intraepithelial lymphocytes (IEL) of the intestinal epithelium represent a phenotypically and functionally distinct subpopulation of peripheral T cells. In this study, we report the production of a mAb, designated HL3, which exhibits reactivity with a subset of IEL. In differential screening assays HL3 reacted with 30 to 50% of IEL, but not with T cells of the thymus, spleen, or lymph nodes. Biochemical characterization revealed that the HL3 mAb recognized p150,95 (CD11c/CD18; CR4), a member of the beta 2-integrin family. Fluorescence flow cytometric analyses showed that p150,95 was expressed by TCR-alpha beta or TCR-gamma delta CD4-8+ IEL but not by CD4+8- IEL. Induction of graft-vs-host (GVH) disease resulted in up-regulation of p150,95 expression on donor-derived CD8+ T cells in the intestinal epithelium, as well as in the spleen and lymph nodes. GVH also induced MAC-1 (CD11b) expression on a subset of CD8+ lymph node T cells, but MAC-1 was not up-regulated on CD8+ IEL in this situation. In contrast, activation of identical T cell responders in vitro resulted in weak induction of p150,95 and MAC-1 expression. This result suggested that activation alone was insufficient for p150,95 up-regulation and that additional factors available in vivo were essential in this process. In the intestine, induction of p150,95 required the presence of intestinal flora as IEL from germfree mice lacked p150,95. Interestingly, gamma delta IEL expressing a non-IEL type transgenic TCR were also p150,95-, but exposure to Ag in vivo, but not in vitro, resulted in p150,95 induction. This result indicated that the constitutive expression of p150,95 on IEL is likely due to Ag stimulation via the TCR and not a bystander phenomenon. Overall, the results demonstrated p150,95 to be a hallmark of T cell activation in vivo and an indicator of ongoing antigen-specific T cell activation in the intestinal epithelium.
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Affiliation(s)
- J W Huleatt
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030, USA
| | - L Lefrançois
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030, USA
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Lefrançois L, Boulanger L, Gaudreau P. Effects of aging on pituitary growth hormone-releasing factor receptor binding sites: in vitro mimicry by guanyl nucleotides and reducing agents. Brain Res 1995; 673:39-46. [PMID: 7757477 DOI: 10.1016/0006-8993(94)01392-u] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have investigated the effect of 5'-guanylylimidodiphosphate (Gpp(NH)p) and two disulfide bond reducing agents, reduced glutathione (GSH) and dithiothreitol (DTT), on the modulation of [125I-Tyr10]hGRF(1-44)NH2 binding to GRF receptor binding sites, in pituitaries of young and aging rats. In pituitaries from 2-month-old rats, Gpp(NH)p (0.1-1.0 mM), GSH and DTT (1-50 mM) exhibited a partial but concentration-dependent inhibitory effect on GRF specific binding. These effects were associated with a conversion of the high affinity GRF binding sites to lower affinity sites and to a reduction of the apparent number of total binding sites (high and low). No potentiation of these effects was observed when Gpp(NH)p (1 mM) and DTT (1 mM) were combined. In pituitaries from 14-month-old rats, Gpp(NH)p (1 mM) was capable of modulating GRF binding parameters in a similar fashion to that in pituitaries from 2-month-old rats. In pituitaries from 18-month-old rats, the high affinity GRF binding sites were already blunted and neither Gpp(NH)p nor Gpp(NH)p plus DTT significantly altered GRF binding parameters. In addition, in 20-month-old rats, the affinity of hGRF(1-29)NH2 and that of the full antagonist N alpha-Ac-[D-Arg2,Ala15]rGRF(1-29)NH2 were respectively decreased 9.3- and 9.9-fold. Our results suggest that in aging, alterations of GRF receptor binding sites could involve disulfide bond reduction or other structural modifications leading to conformational changes, similar to those induced by GSH or DTT. Such structural changes may prevent an efficient coupling of the GRF receptor with its ligands and G-protein, leading to a loss of somatotroph responsiveness.
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Affiliation(s)
- L Lefrançois
- Neuroendocrinology Laboratory, Notre-Dame Hospital Research Center, Montreal, Que., Canada
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Abstract
Extrathymic T-cell development is a topic of considerable interest and debate, with important implications for the mechanisms of T-cell maturation and repertoire selection. Recent evidence has suggested that intraepithelial T lymphocytes (IELs) of the small intestine can mature and undergo selection in the absence of a thymus. However, IEL precursors are present in the thymus and IEL development is known to be influenced by the thymus. Here, Leo Lefrançois and Lynn Puddington discuss these data and suggest that the differentiation pathway of IEL precursors is dependent on whether or not a thymus is present.
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Affiliation(s)
- L Lefrançois
- Division of Rheumatic Diseases, University of Connecticut Health Center, Farmington 06030
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Abstract
Interactions between stem cell factor (SCF) and its receptor, c-Kit, are important for development of hematopoietic, melanocytes, and germ cells. T lymphocytes appeared normal in c-Kit (W/Wv) or SCF (SI/SId) mutant mice, except for those residing within the intestinal epithelium, the intraepithelial lymphocytes (IEL). Normally, IEL are composed of equal numbers of cells with alpha beta or gamma delta T cell receptors. In mutant mice, beginning at 6-8 weeks of age, the number of gamma delta IEL decreased, whereas alpha beta IEL increased. The latter was due largely to an increased CD4+ CD8+ TCR alpha beta subset, suggesting that these cells may be intermediates in the alpha beta IEL lineage. c-Kit or SCF was expressed by IEL or intestinal epithelial cells, respectively, indicating a potential for direct intercellular interaction. This possibility was supported by reconstitution studies that demonstrated that c-Kit mutations directly affected IEL. Thus, SCF-c-Kit interactions are important for homeostasis of the intestinal immune compartment.
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Affiliation(s)
- L Puddington
- Department of Medicine, University of Connecticut Health Center, Farmington 06030
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Lefrançois L, Olson S. A novel pathway of thymus-directed T lymphocyte maturation. J Immunol 1994; 153:987-95. [PMID: 8027568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Recent evidence has indicated that the intestinal epithelium may be a major extrathymic site of T cell production. However, which of the multiple intestinal intraepithelial lymphocyte (IEL) subsets are extrathymic in origin has been controversial. We now report that the thymus is an integral component of IEL maturation and is required for a novel two-stage process of T cell production. Thus, in neonatally thymectomized mice TCR-gamma delta IELs were depleted and some TCR-alpha beta IELs were of an immature phenotype. Thymus grafting experiments revealed that all TCR-gamma delta and TCR-alpha beta IEL subsets could be thymus-derived, including TCR-alpha beta cells lacking Thy1 and CD8 beta. In utero anti-TCR-gamma delta mAb treatments resulted in depletion of gamma delta IEL without subsequent re-emergence of this subset in adulthood, whereas anti-TCR-alpha beta mAb treatment only marginally reduced the alpha beta IEL subset. These findings suggest that TCR-alpha beta and TCR-gamma delta IELs arose at distinct developmental stages. Overall, the results indicate that some IEL precursors are thymus-derived but require further thymic influence to mature in the periphery.
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MESH Headings
- Age Factors
- Animals
- Animals, Newborn/immunology
- Cell Differentiation
- Female
- Intestinal Mucosa/immunology
- Intestine, Small/immunology
- Male
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
- Receptors, Antigen, T-Cell, gamma-delta/metabolism
- T-Lymphocyte Subsets/cytology
- Thymectomy
- Thymus Gland/cytology
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Affiliation(s)
- L Lefrançois
- Department of Medicine, University of Connecticut Health Center, Farmington 06030
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49
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Abstract
Abstract
Recent evidence has indicated that the intestinal epithelium may be a major extrathymic site of T cell production. However, which of the multiple intestinal intraepithelial lymphocyte (IEL) subsets are extrathymic in origin has been controversial. We now report that the thymus is an integral component of IEL maturation and is required for a novel two-stage process of T cell production. Thus, in neonatally thymectomized mice TCR-gamma delta IELs were depleted and some TCR-alpha beta IELs were of an immature phenotype. Thymus grafting experiments revealed that all TCR-gamma delta and TCR-alpha beta IEL subsets could be thymus-derived, including TCR-alpha beta cells lacking Thy1 and CD8 beta. In utero anti-TCR-gamma delta mAb treatments resulted in depletion of gamma delta IEL without subsequent re-emergence of this subset in adulthood, whereas anti-TCR-alpha beta mAb treatment only marginally reduced the alpha beta IEL subset. These findings suggest that TCR-alpha beta and TCR-gamma delta IELs arose at distinct developmental stages. Overall, the results indicate that some IEL precursors are thymus-derived but require further thymic influence to mature in the periphery.
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Affiliation(s)
- L Lefrançois
- Department of Medicine, University of Connecticut Health Center, Farmington 06030
| | - S Olson
- Department of Medicine, University of Connecticut Health Center, Farmington 06030
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Abstract
Previous structure-activity studies on growth-hormone-releasing factor (GRF) have mainly been carried out in pituitary cell culture assays. In such systems, the molecular features necessary to increase GRF receptor affinity cannot be fully distinguished from those that improve proteolytic resistance. To assess the affinity of GRF analogues, we have recently characterized [125I-Tyr10]hGRF(1-44)NH2 binding to rat adenopituitary, developing a reliable binding assay in which GRF-carboxamide-related peptides are stable. In the present study, we have determined the binding affinity of two series of analogues in which the entire sequence of hGRF(1-29)NH2 was scanned with D-amino acid and alanine substitutions. To further document their potency, we have evaluated the ability of representative candidates of each series to stimulate cAMP production. In the first series, a D-amino acid substitution at Ala4, Ile5, Phe6, Thr7, Val13, Gln16, Leu17, Ala19, Arg20 and Ile26 decreased drastically the binding affinity of hGRF(1-29)NH2 while it induced a smaller decrease at Tyr1, Asp3, Ser9, Tyr10, Arg11, Lys12, Leu14, Ala15, Ser18, Lys21, Leu22, Leu23, Gln24, Met27 and Ser28. Interestingly, a D-substitution in position 8 generated an analogue exhibiting a significantly greater binding affinity than hGRF(1-29)NH2, while it had no influence on hGRF(1-29)NH2 affinity at Ala2, Asp25 and Arg29. Adenylate cyclase activities of [D-Tyr1], [D-Tyr10] and [D-Arg20]hGRF(1-29)NH2 correlate with their binding affinity. In the second series, the largest decrease of binding affinity was observed with an alanine substitution at Tyr1, Asp3, Ile5, Phe6, Tyr10, Arg11, Lys12, Leu14, Leu17, Arg20 and Lys21.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- L Lefrançois
- Neuroendocrinology Laboratory, Notre-Dame Hospital Research Center, University of Montreal, Canada
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