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Kobayashi KS, van den Elsen PJ. NLRC5: a key regulator of MHC class I-dependent immune responses. Nat Rev Immunol 2013; 12:813-20. [PMID: 23175229 DOI: 10.1038/nri3339] [Citation(s) in RCA: 277] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The expression of MHC class I molecules is crucial for the initiation and regulation of adaptive immune responses against pathogens. NOD-, LRR- and CARD-containing 5 (NLRC5) was recently identified as a specific transactivator of MHC class I genes (CITA). NLRC5 and the master regulator for MHC class II genes, class II transactivator (CIITA), interact with similar MHC promoter-bound factors. Here, we provide a broad overview of the molecular mechanisms behind MHC class I transcription and the role of the class I transactivator NLRC5 in MHC class I-dependent immune responses.
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Affiliation(s)
- Koichi S Kobayashi
- Department of Microbial and Molecular Pathogenesis, College of Medicine, Texas A&M Health Science Center, College Station, Texas 77843, USA.
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52
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Class II, major histocompatibility complex, transactivator (CIITA) in channel catfish: identification and expression patterns responding to different pathogens. Mol Biol Rep 2012; 39:11041-50. [DOI: 10.1007/s11033-012-2007-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Accepted: 10/01/2012] [Indexed: 01/06/2023]
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53
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Pisapia L, Pozzo GD, Barba P, Citro A, Harris PE, Maffei A. Contrasting effects of IFNα on MHC class II expression in professional vs. nonprofessional APCs: Role of CIITA type IV promoter. RESULTS IN IMMUNOLOGY 2012; 2:174-83. [PMID: 24371581 DOI: 10.1016/j.rinim.2012.09.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 09/16/2012] [Accepted: 09/19/2012] [Indexed: 01/01/2023]
Abstract
We previously demonstrated that, in ex vivo cultures, IFNα downregulates the expression of MHC class II (MHCII) genes in human non-professional APCs associated with pancreatic islets. IFNα has an opposing effect on MHCII expression in professional APCs. In this study, we found that the mechanism responsible for the IFNα-mediated MHCII's downregulation in human MHCII-positive non-professional antigen presenting human non-hematopoietic cell lines is the result of the negative feedback system that regulates cytokine signal transduction, which eventually inhibits promoters III and IV of CIITA gene. Because the CIITA-PIV isoform is mostly responsible for the constitutive expression of MHCII genes in non-professional APCs, we pursued and achieved the specific knockdown of CIITA-PIV mRNA in our in vitro system, obtaining a partial silencing of MHCII molecules similar to that obtained by IFNα. We believe that our results offer a new understanding of the potential significance of CIITA-PIV as a therapeutic target for interventional strategies that can manage autoimmune disease and allograft rejection with little interference on the function of professional APCs of the immune system.
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Affiliation(s)
- Laura Pisapia
- Institute of Genetics and Biophysics A. Buzzati-Traverso, CNR, Naples, Italy
| | - Giovanna Del Pozzo
- Institute of Genetics and Biophysics A. Buzzati-Traverso, CNR, Naples, Italy
| | - Pasquale Barba
- Institute of Genetics and Biophysics A. Buzzati-Traverso, CNR, Naples, Italy
| | - Alessandra Citro
- Department of Medicine of Columbia University Medical Center, New York, NY, USA
| | - Paul E Harris
- Department of Medicine of Columbia University Medical Center, New York, NY, USA
| | - Antonella Maffei
- Institute of Genetics and Biophysics A. Buzzati-Traverso, CNR, Naples, Italy ; Department of Medicine of Columbia University Medical Center, New York, NY, USA
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54
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Kumar GSS, Venugopal AK, Kashyap MK, Raju R, Marimuthu A, Palapetta SM, Subbanayya Y, Goel R, Chawla A, Dikshit JB, Tata P, Harsha HC, Maharudraiah J, Ramachandra YL, Satishchandra P, Prasad TSK, Pandey A, Mahadevan A, Shankar SK. Gene Expression Profiling of Tuberculous Meningitis Co-infected with HIV. JOURNAL OF PROTEOMICS & BIOINFORMATICS 2012; 5:235-244. [PMID: 27053842 PMCID: PMC4820295 DOI: 10.4172/jpb.1000243] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Tuberculous meningitis (TBM) is a fatal form of Mycobacterium tuberculosis infection of the central nervous system (CNS). The similarities in the clinical and radiological findings in TBM cases with or without HIV make the diagnosis very challenging. Identification of genes, which are differentially expressed in brain tissues of HIV positive and HIV negative TBM patients, would enable better understanding of the molecular aspects of the infection and would also serve as an initial platform to evaluate potential biomarkers. Here, we report the identification of 796 differentially regulated genes in brain tissues of TBM patients co-infected with HIV using oligonucleotide DNA microarrays. We also performed immunohistochemical validation and confirmed the abundance of four gene products-glial fibrillary acidic protein (GFAP), serpin peptidase inhibitor, clade A member 3 (SERPINA3), thymidine phosphorylase (TYMP/ECGF1) and heat shock 70 kDa protein 8 (HSPA8). Our study paves the way for understanding the mechanism of TBM in HIV positive patients and for further validation of potential disease biomarkers.
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Affiliation(s)
- Ghantasala S. Sameer Kumar
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
- Department of Biotechnology, Kuvempu University, Shimoga 577451, India
| | - Abhilash K. Venugopal
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
- Department of Biotechnology, Kuvempu University, Shimoga 577451, India
- McKusick-Nathans Institute of Genetic Medicine; Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Manoj Kumar Kashyap
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
| | - Rajesh Raju
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
| | - Arivusudar Marimuthu
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
| | - Shyam Mohan Palapetta
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
- Centre of Excellence in Bioinformatics, School of Life Sciences, Pondicherry University, Pondicherry, 605014, India
| | - Yashwanth Subbanayya
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
- Rajiv Gandhi University of Health Sciences, Bangalore 560041, India
| | - Renu Goel
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
- Department of Biotechnology, Kuvempu University, Shimoga 577451, India
| | - Ankit Chawla
- Armed Forces Medical College, Pune-411040, India
| | | | - Pramila Tata
- Strand Life Sciences, Bangalore 560024, Karnataka, India
| | - H. C. Harsha
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
| | - Jagadeesha Maharudraiah
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
| | - Y. L. Ramachandra
- Department of Biotechnology, Kuvempu University, Shimoga 577451, India
| | | | - T. S. Keshava Prasad
- Institute of Bioinformatics, International Technology Park, Bangalore 560066, Karnataka, India
- Centre of Excellence in Bioinformatics, School of Life Sciences, Pondicherry University, Pondicherry, 605014, India
- Manipal University, Madhav Nagar, Manipal 576104, India
| | - Akhilesh Pandey
- McKusick-Nathans Institute of Genetic Medicine; Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Pathology and Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Corresponding authors: Akhilesh Pandey, McKusick-Nathans Institute of Genetic Medicine, 733 N. Broadway, BRB 527, Johns Hopkins University, Baltimore, USA, Tel: 410-502-6662; Fax: 410-502-7544; , S. K. Shankar, Department of Neuropathology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India, Tel: 91-080-26995001/5002; Fax: 91-080-26564830;
| | - Anita Mahadevan
- Department of Neuropathology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
| | - S. K. Shankar
- Department of Neuropathology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India
- Corresponding authors: Akhilesh Pandey, McKusick-Nathans Institute of Genetic Medicine, 733 N. Broadway, BRB 527, Johns Hopkins University, Baltimore, USA, Tel: 410-502-6662; Fax: 410-502-7544; , S. K. Shankar, Department of Neuropathology, National Institute of Mental Health and Neurosciences, Bangalore 560029, India, Tel: 91-080-26995001/5002; Fax: 91-080-26564830;
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55
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Truax AD, Thakkar M, Greer SF. Dysregulated recruitment of the histone methyltransferase EZH2 to the class II transactivator (CIITA) promoter IV in breast cancer cells. PLoS One 2012; 7:e36013. [PMID: 22563434 PMCID: PMC3338556 DOI: 10.1371/journal.pone.0036013] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 03/27/2012] [Indexed: 11/19/2022] Open
Abstract
One mechanism frequently utilized by tumor cells to escape immune system recognition and elimination is suppression of cell surface expression of Major Histocompatibility Class II (MHC II) molecules. Expression of MHC II is regulated primarily at the level of transcription by the Class II Transactivator, CIITA, and decreased CIITA expression is observed in multiple tumor types. We investigate here contributions of epigenetic modifications to transcriptional silencing of CIITA in variants of the human breast cancer cell line MDA MB 435. Significant increases in histone H3 lysine 27 trimethylation upon IFN-γ stimulation correlate with reductions in transcription factor recruitment to the interferon-γ inducible CIITA promoter, CIITApIV, and with significantly increased CIITApIV occupancy by the histone methyltransferase enhancer of zeste homolog 2 (EZH2). Most compelling is evidence that decreased expression of EZH2 in MDA MB 435 variants results in significant increases in CIITA and HLA-DRA mRNA expression, even in the absence of interferon-γ stimulation, as well as increased cell surface expression of MHC II. Together, these data add mechanistic insight to prior observations of increased EZH2 expression and decreased CIITA expression in multiple tumor types.
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Affiliation(s)
- Agnieszka D. Truax
- Division of Cellular and Molecular Biology and Physiology, Department of Biology, Georgia State University, Atlanta, Georgia, United States of America
| | - Meghna Thakkar
- Division of Cellular and Molecular Biology and Physiology, Department of Biology, Georgia State University, Atlanta, Georgia, United States of America
| | - Susanna F. Greer
- Division of Cellular and Molecular Biology and Physiology, Department of Biology, Georgia State University, Atlanta, Georgia, United States of America
- * E-mail:
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56
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Neerincx A, Rodriguez GM, Steimle V, Kufer TA. NLRC5 controls basal MHC class I gene expression in an MHC enhanceosome-dependent manner. THE JOURNAL OF IMMUNOLOGY 2012; 188:4940-50. [PMID: 22490867 DOI: 10.4049/jimmunol.1103136] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Nucleotide-binding domain and leucine-rich repeat (NLR) proteins play important roles in innate immune responses as pattern-recognition receptors. Although most NLR proteins act in cell autonomous immune pathways, some do not function as classical pattern-recognition receptors. One such NLR protein is the MHC class II transactivator, the master regulator of MHC class II gene transcription. In this article, we report that human NLRC5, which we recently showed to be involved in viral-mediated type I IFN responses, shuttles to the nucleus and activates MHC class I gene expression. Knockdown of NLRC5 in different human cell lines and primary dermal fibroblasts leads to reduced MHC class I expression, whereas introduction of NLRC5 into cell types with very low expression of MHC class I augments MHC class I expression to levels comparable to those found in lymphocytes. Expression of NLRC5 positively correlates with MHC class I expression in human tissues. Functionally, we show that both the N-terminal effector domain of NLRC5 and its C-terminal leucine-rich repeat domain are needed for activation of MHC class I expression. Moreover, nuclear shuttling and function depend on a functional Walker A motif. Finally, we identified a promoter sequence in the MHC class I promoter, the X1 box, to be involved in NLRC5-mediated MHC class I gene activation. Taken together, this suggested that NLRC5 acts in a manner similar to class II transactivator to drive MHC expression and revealed NLRC5 as an important regulator of basal MHC class I expression.
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Affiliation(s)
- Andreas Neerincx
- Institute for Medical Microbiology, Immunology, and Hygiene, University of Cologne, 50931 Cologne, Germany
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57
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Meissner TB, Li A, Kobayashi KS. NLRC5: a newly discovered MHC class I transactivator (CITA). Microbes Infect 2011; 14:477-84. [PMID: 22209772 DOI: 10.1016/j.micinf.2011.12.007] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Revised: 12/09/2011] [Accepted: 12/12/2011] [Indexed: 02/07/2023]
Abstract
Major histocompatibility complex (MHC) class I and class II are crucial for the function of the human adaptive immune system. An NLR protein, CIITA (MHC class II transactivator), is a master regulator of MHC class II gene expression as well as of some of the genes involved in MHC class II antigen presentation. It has recently been discovered that another member of the NLR protein family, NLRC5, transcriptionally activates MHC class I genes, and thus acts as "CITA" (MHC class I transactivator), a counterpart to CIITA. In addition to MHC class I genes, NLRC5 can induce the expression of β2M, TAP1 and LMP2, essential components of MHC class I antigen presentation. These findings indicate that NLRC5 and CIITA are transcriptional regulators that orchestrate the concerted expression of critical components in the MHC class I and MHC class II pathways, respectively.
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Affiliation(s)
- Torsten B Meissner
- Department of Cancer Immunology & AIDS, Dana-Farber Cancer Institute, Harvard Medical School, Dana 1420A, Boston, MA 02215, United States
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58
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Verweij FJ, van Eijndhoven MAJ, Hopmans ES, Vendrig T, Wurdinger T, Cahir-McFarland E, Kieff E, Geerts D, van der Kant R, Neefjes J, Middeldorp JM, Pegtel DM. LMP1 association with CD63 in endosomes and secretion via exosomes limits constitutive NF-κB activation. EMBO J 2011; 30:2115-29. [PMID: 21527913 DOI: 10.1038/emboj.2011.123] [Citation(s) in RCA: 188] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Accepted: 03/25/2011] [Indexed: 02/01/2023] Open
Abstract
The ubiquitous Epstein Barr virus (EBV) exploits human B-cell development to establish a persistent infection in ∼90% of the world population. Constitutive activation of NF-κB by the viral oncogene latent membrane protein 1 (LMP1) has an important role in persistence, but is a risk factor for EBV-associated lymphomas. Here, we demonstrate that endogenous LMP1 escapes degradation upon accumulation within intraluminal vesicles of multivesicular endosomes and secretion via exosomes. LMP1 associates and traffics with the intracellular tetraspanin CD63 into vesicles that lack MHC II and sustain low cholesterol levels, even in 'cholesterol-trapping' conditions. The lipid-raft anchoring sequence FWLY, nor ubiquitylation of the N-terminus, controls LMP1 sorting into exosomes. Rather, C-terminal modifications that retain LMP1 in Golgi compartments preclude assembly within CD63-enriched domains and/or exosomal discharge leading to NF-κB overstimulation. Interference through shRNAs further proved the antagonizing role of CD63 in LMP1-mediated signalling. Thus, LMP1 exploits CD63-enriched microdomains to restrain downstream NF-κB activation by promoting trafficking in the endosomal-exosomal pathway. CD63 is thus a critical mediator of LMP1 function in- and outside-infected (tumour) cells.
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Affiliation(s)
- Frederik J Verweij
- Department of Pathology, Cancer Center Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
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59
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Smith MA, Wright G, Wu J, Tailor P, Ozato K, Chen X, Wei S, Piskurich JF, Ting JPY, Wright KL. Positive regulatory domain I (PRDM1) and IRF8/PU.1 counter-regulate MHC class II transactivator (CIITA) expression during dendritic cell maturation. J Biol Chem 2011; 286:7893-7904. [PMID: 21216962 PMCID: PMC3048676 DOI: 10.1074/jbc.m110.165431] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Revised: 12/10/2010] [Indexed: 12/31/2022] Open
Abstract
Dendritic cells (DCs) are key mediators of immune function through robust and tightly regulated presentation of antigen in the context of the MHC Class II. MHC Class II expression is controlled by the transactivator CIITA. CIITA expression in conventional DCs is uniquely dependent on an uncharacterized myeloid cell-specific promoter, CIITApI. We now identify in vivo the promoter structure and factors regulating CIITApI. In immature DCs transcription requires binding of PU.1, IRF8, NFκB, and Sp1 to the promoter. PU.1 binds independently at one site and in a required heterodimer with IRF8 at a composite element. DCs from IRF8-null mice have an unoccupied CIITApI promoter that can be rescued by reconstitution with IRF8 in vitro. Furthermore, mutation of either PU.1 site or the IFR8 site inhibits transcriptional activation. In vivo footprinting and chromatin immunoprecipitation reveals that DC maturation induces complete disassociation of the bound activators paralleled by recruitment of PRDM1/Blimp-1 to the promoter. PRDM1 is a transcriptional repressor with essential roles in B cells, T cells, NK cells, and DCs. We show that PRDM1 co-repressors, G9a and HDAC2, are recruited to CIITApI, leading to a loss of histone acetylation and acquisition of histone H3K9 dimethylation and heterochromatin protein 1γ (HP1γ). PRDM1 binding also blocks IRF8-mediated activation dependent on the PU.1/IRF composite element. Together these findings reveal the mechanisms regulating CIITA and, thus, antigen presentation in DCs, demonstrating that PRDM1 and IRF8/PU.1 counter-regulate expression. The activity of PRDM1 in silencing all three cell type-specific CIITA promoters places it as a central regulator of antigen presentation.
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Affiliation(s)
- Matthew A Smith
- From the H. Lee Moffitt Cancer Center and Research Institute, Department of Molecular Medicine and Department of Oncologic Sciences, University of South Florida, Tampa, Florida 33612
| | - Gabriela Wright
- From the H. Lee Moffitt Cancer Center and Research Institute, Department of Molecular Medicine and Department of Oncologic Sciences, University of South Florida, Tampa, Florida 33612
| | - Jian Wu
- From the H. Lee Moffitt Cancer Center and Research Institute, Department of Molecular Medicine and Department of Oncologic Sciences, University of South Florida, Tampa, Florida 33612
| | - Prafullakumar Tailor
- the Laboratory of Molecular Growth Regulation, NICHD, National Institutes of Health, Bethesda, Maryland 20892
| | - Keiko Ozato
- the Laboratory of Molecular Growth Regulation, NICHD, National Institutes of Health, Bethesda, Maryland 20892
| | - Xianghong Chen
- From the H. Lee Moffitt Cancer Center and Research Institute, Department of Molecular Medicine and Department of Oncologic Sciences, University of South Florida, Tampa, Florida 33612
| | - Sheng Wei
- From the H. Lee Moffitt Cancer Center and Research Institute, Department of Molecular Medicine and Department of Oncologic Sciences, University of South Florida, Tampa, Florida 33612
| | - Janet F Piskurich
- the Department of Medical Education, Texas Tech University Health Sciences Center, Paul L. Foster School of Medicine, El Paso, Texas 79905, and
| | - Jenny P-Y Ting
- the Department of Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Kenneth L Wright
- From the H. Lee Moffitt Cancer Center and Research Institute, Department of Molecular Medicine and Department of Oncologic Sciences, University of South Florida, Tampa, Florida 33612,.
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60
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Nakano N, Nishiyama C, Yagita H, Koyanagi A, Ogawa H, Okumura K. Notch1-mediated signaling induces MHC class II expression through activation of class II transactivator promoter III in mast cells. J Biol Chem 2011; 286:12042-8. [PMID: 21321116 DOI: 10.1074/jbc.m110.138966] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Mast cells constitutively express Notch1 and Notch2 on the cell surface. Notch ligand Dll1 (Delta-like 1) stimulation induces MHC class II expression in mast cells and renders them as antigen-presenting cells. However, nothing is known about the mechanism by which Notch signaling induces MHC class II expression in mast cells. MHC class II genes are regulated by the class II transactivator (CIITA). In mice, transcription of the CIITA gene is controlled by three cell type-specific promoters (pI, pIII, and pIV). Here, we show that CIITA expression induced by Dll1 stimulation in mouse bone marrow-derived mast cells (BMMCs) depends critically on the signal mediated by Notch1 and that the most dominant promoter in Notch signaling-mediated CIITA expression in BMMCs is pIII, which is a lymphoid lineage-specific promoter. ChIP assays indicated that Notch signaling increased the binding of the transcription factor PU.1 to CIITA pIII in BMMCs. The knockdown of PU.1 expression using a specific siRNA suppressed Notch signaling-mediated CIITA expression, suggesting that PU.1 contributes to the expression of MHC class II induced by Notch signaling in mast cells. Furthermore, we show that a portion of freshly isolated splenic mast cells express MHC class II and that the most dominant promoter of CIITA in mast cells is pIII. These findings indicate that activation of CIITA pIII plays an important role in MHC class II expression in mast cells.
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Affiliation(s)
- Nobuhiro Nakano
- Atopy Allergy Research Center, Department of Immunology, Juntendo Univesity School of Medicine, Tokyo, Japan.
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61
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Meissner TB, Li A, Biswas A, Lee KH, Liu YJ, Bayir E, Iliopoulos D, van den Elsen PJ, Kobayashi KS. NLR family member NLRC5 is a transcriptional regulator of MHC class I genes. Proc Natl Acad Sci U S A 2010; 107:13794-9. [PMID: 20639463 PMCID: PMC2922274 DOI: 10.1073/pnas.1008684107] [Citation(s) in RCA: 338] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
MHC class I plays a critical role in the immune defense against viruses and tumors by presenting antigens to CD8 T cells. An NLR protein, class II transactivator (CIITA), is a key regulator of MHC class II gene expression that associates and cooperates with transcription factors in the MHC class II promoter. Although CIITA also transactivates MHC class I gene promoters, loss of CIITA in humans and mice results in the severe reduction of only MHC class II expression, suggesting that additional mechanisms regulate the expression of MHC class I. Here, we identify another member of the NLR protein family, NLRC5, as a transcriptional regulator of MHC class I genes. Similar to CIITA, NLRC5 is an IFN-gamma-inducible nuclear protein, and the expression of NLRC5 resulted in enhanced MHC class I expression in lymphoid as well as epithelial cell lines. Using chromatin immunoprecipitation and reporter gene assays, we show that NLRC5 associates with and activates the promoters of MHC class I genes. Furthermore, we show that the IFN-gamma-induced up-regulation of MHC class I requires NLRC5, because knockdown of NLRC5 specifically impaired the expression of MHC class I. In addition to MHC class I genes, NLRC5 also induced the expression of beta2-microglobulin, transporter associated with antigen processing, and large multifunctional protease, which are essential for MHC class I antigen presentation. Our results suggest that NLRC5 is a transcriptional regulator, orchestrating the concerted expression of critical components in the MHC class I pathway.
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Affiliation(s)
- Torsten B. Meissner
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA 02115
- Department of Pathology, Harvard Medical School, Boston, MA 02115
| | - Amy Li
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA 02115
| | - Amlan Biswas
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA 02115
- Department of Pathology, Harvard Medical School, Boston, MA 02115
| | - Kyoung-Hee Lee
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA 02115
- Department of Pathology, Harvard Medical School, Boston, MA 02115
| | - Yuen-Joyce Liu
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA 02115
| | - Erkan Bayir
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA 02115
| | - Dimitrios Iliopoulos
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115
| | - Peter J. van den Elsen
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; and
- Department of Pathology, VU University Medical Center, 1081 HV Amsterdam, The Netherlands
| | - Koichi S. Kobayashi
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA 02115
- Department of Pathology, Harvard Medical School, Boston, MA 02115
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62
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Mahmoud ME, Nikami H, Shiina T, Takewaki T, Shimizu Y. Capsaicin inhibits IFN-γ-induced MHC class II expression by suppressing transcription of class II transactivator gene in murine peritoneal macrophages. Int Immunopharmacol 2010; 10:86-90. [DOI: 10.1016/j.intimp.2009.10.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Revised: 08/26/2009] [Accepted: 10/02/2009] [Indexed: 11/16/2022]
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63
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The 19S ATPase S6a (S6'/TBP1) regulates the transcription initiation of class II transactivator. J Mol Biol 2009; 395:254-69. [PMID: 19853614 DOI: 10.1016/j.jmb.2009.10.035] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 10/13/2009] [Accepted: 10/14/2009] [Indexed: 01/24/2023]
Abstract
Class II transactivator (CIITA) is the master regulator of the major histocompatibility class II transcription complex (MHC-II) and is critical for initiation of adaptive immune responses. We have previously demonstrated that the 19S proteasome ATPase Sug1 plays a significant role in regulating CIITA activity and MHC-II expression. We now show that an additional component of the 19S complex, the 19S ATPase S6a (S6'/Tat-binding protein 1), is crucial for regulating cytokine-inducible transcription of CIITA. Lack of S6a negatively impacts CIITA activity and CIITA expression. Decreased expression of S6a significantly diminishes the recruitment of transcription factors to the CIITA interferon-gamma-inducible promoter [CIITA promoter IV (pIV)] and significantly decreases CIITApIV histone H3 and histone H4 acetylation, with a preferential loss of acetylation at H3 lysine 18 and H4 lysine 8. In addition, we provide evidence for the involvement of the 19S AAA (ATPases associated with diverse cellular activity) ATPase hexamer as the 19S ATPase S6b binds CIITApIV in an S6a-dependent fashion and has effects similar to S6a on CIITApIV histone acetylation. These analyses demonstrate the importance of 19S ATPases in the assembly of CIITApIV transcription machinery and provide additional insight into the regulatory mechanisms of the 19S proteasome in mammalian transcription.
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64
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Sokol CL, Chu NQ, Yu S, Nish SA, Laufer TM, Medzhitov R. Basophils function as antigen-presenting cells for an allergen-induced T helper type 2 response. Nat Immunol 2009; 10:713-20. [PMID: 19465907 PMCID: PMC3252751 DOI: 10.1038/ni.1738] [Citation(s) in RCA: 463] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Accepted: 04/14/2009] [Indexed: 12/11/2022]
Abstract
T helper type 2 (T(H)2)-mediated immune responses are induced after infection with multicellular parasites and can be triggered by a variety of allergens. The mechanisms of induction and the antigen-presenting cells involved in the activation of T(H)2 responses remain poorly defined, and the innate immune sensing pathways activated by parasites and allergens are largely unknown. Basophils are required for the in vivo induction of T(H)2 responses by protease allergens. Here we show that basophils also function as antigen-presenting cells. We show that although dendritic cells were dispensable for allergen-induced activation of T(H)2 responses in vitro and in vivo, antigen presentation by basophils was necessary and sufficient for this. Thus, basophils function as antigen-presenting cells for T(H)2 differentiation in response to protease allergens.
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Affiliation(s)
- Caroline L Sokol
- Howard Hughes Medical Institute and Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA
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65
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Apps R, Murphy SP, Fernando R, Gardner L, Ahad T, Moffett A. Human leucocyte antigen (HLA) expression of primary trophoblast cells and placental cell lines, determined using single antigen beads to characterize allotype specificities of anti-HLA antibodies. Immunology 2009; 127:26-39. [PMID: 19368562 DOI: 10.1111/j.1365-2567.2008.03019.x] [Citation(s) in RCA: 277] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Human trophoblast cells express an unusual repertoire of human leucocyte antigen (HLA) molecules which has been difficult to define. Close homology between and extreme polymorphism at the classical HLA class-I (HLA-I) loci has made it difficult to generate locus-specific monoclonal antibodies (mAbs). The problem of defining an antibody's reactivity against the thousands of existing HLA-I allotypes has often made it impossible to determine the HLA bound by a mAb in biological samples from a normal outbred population. Here we have used commercially available beads coated with individual HLA-I to characterize experimentally the reactivity of nine mAb against 96 common HLA-I allotypes. In conjunction with donor HLA-I genotyping, we could then define the specific HLA molecules bound by these antibodies in normal individuals. We used this approach to analyse the HLA expression of primary trophoblast cells from normal pregnancies; the choriocarcinoma cells JEG-3 and JAR; and the placental cell lines HTR-8/SVneo, Swan-71 and TEV-1. We confirm that primary villous trophoblast cells are HLA null whereas extravillous trophoblast cells express HLA-C, HLA-G and HLA-E, but not HLA-A, HLA-B or HLA-DR molecules in normal pregnancy. Tumour-derived JEG-3 and JAR cells reflect extravillous and villous trophoblast HLA phenotypes, respectively, but the HLA repertoire of the in vitro derived placental cell lines is not representative of either in vivo trophoblast phenotype. This study raises questions regarding the validity of using the placental cell lines that are currently available as model systems for immunological interactions between fetal trophoblast and maternal leucocytes bearing receptors for HLA molecules.
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Affiliation(s)
- Richard Apps
- Department of Pathology, University of Cambridge, Cambridge, UK
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66
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Cycon KA, Clements JL, Holtz R, Fuji H, Murphy SP. The immunogenicity of L1210 lymphoma clones correlates with their ability to function as antigen-presenting cells. Immunology 2009; 128:e641-51. [PMID: 19740325 DOI: 10.1111/j.1365-2567.2009.03052.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Major histocompatibility complex class II (MHCII) antigen expression is directly correlated with immunogenicity, and inversely correlated with tumorigenicity, in clones of the L1210 murine B lymphoma. Moreover, loss of MHCII expression on human diffuse large B-cell lymphoma is associated with dramatic decreases in patient survival. Thus, the role that MHCII antigens play in the progression of B-cell lymphomas is clinically important. In this study, we investigated the basis for the immunogenicity of MHCII(+) L1210 clones. Immunogenic, but not tumorigenic L1210 clones stimulated the proliferation of naïve T cells and their interleukin (IL)-2 production, which indicates that the immunogenic clones can function as antigen-presenting cells (APCs). However, subclonal variants of the immunogenic L1210 clones, which form tumours slowly in mice, could not activate T cells. The costimulatory molecules B7-1, B7-2 and CD40 were expressed on the immunogenic L1210 clones, but not the tumorigenic clones. Importantly, the tumour-forming subclonal variants expressed MHCII and B7-1, but lacked B7-2 and CD40. These results suggest that MHCII and B7-1 expression on L1210 cells is insufficient to activate naïve T cells, and, furthermore, loss of B7-2 and/or CD40 expression contributes to the decreased immunogenicity of L1210 subclones. Blocking B7-1 or B7-2 function on immunogenic L1210 cells reduced their capacity to activate naïve T cells. Furthermore, incubation of immunogenic L1210 cells with CD40 antibodies significantly enhanced APC function. Therefore, the immunogenicity of L1210 cells directly correlates (i) with their ability to stimulate naïve T cells, and (ii) with the concomitant expression of MHCII, B7-1, B7-2, and CD40.
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Affiliation(s)
- Kelly A Cycon
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY, USA
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67
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Chan WK, Lau ASY, Li JCB, Law HKW, Lau YL, Chan GCF. MHC expression kinetics and immunogenicity of mesenchymal stromal cells after short-term IFN-gamma challenge. Exp Hematol 2008; 36:1545-55. [PMID: 18715686 DOI: 10.1016/j.exphem.2008.06.008] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2008] [Revised: 06/09/2008] [Accepted: 06/17/2008] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Under the influence of interferon-gamma (IFN-gamma), mesenchymal stromal cells (MSCs) are conditional antigen-presenting cells, which have immunosuppressive potential. Apart from IFN-gamma upregulation of major histocompatibility complexes class I and II (MHC-I and MHC-II) expression, the underlying kinetics and mechanisms have not been described previously. This information is helpful to delineate how human MSCs can be modulated by IFN-gamma in different clinical scenarios. MATERIALS AND METHODS Here, we demonstrated that IFN-gamma-treated MSCs underwent classical signal transduction pathway via phosphorylation of signal transducers and activators of transcription-1, activation of interferon regulatory factor-1, and class II transactivator comparable to that of primary human blood macrophages. RESULTS IFN-gamma markedly induced expression of MHC-I instantly, while its effects on MHC-II were less dramatic and delayed up to 4 days. This is due to a slower intracellular transport of the MHC-II antigen to the membrane surface. More important is that MSCs showed a reduction in their proliferation by 50% without evidence of cell death after prolonged IFN-gamma treatment for 8 days. High-dose IFN-gamma-treated MSCs (500 U/mL) could initiate T-cell activation as indicated by expression of CD25 and proliferation of allogeneic T cells. CONCLUSIONS The summative IFN-gamma effects will adversely affect the immunoprivilege status and lifespan of MSCs.
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Affiliation(s)
- Wing Keung Chan
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
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68
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Niazi KR, Ochoa MT, Sieling PA, Rooke NE, Peter AK, Mollahan P, Dickey M, Rabizadeh S, Rea TH, Modlin RL. Activation of human CD4+ T cells by targeting MHC class II epitopes to endosomal compartments using human CD1 tail sequences. Immunology 2007; 122:522-31. [PMID: 17635609 PMCID: PMC2266034 DOI: 10.1111/j.1365-2567.2007.02666.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Distinct CD4(+) T-cell epitopes within the same protein can be optimally processed and loaded into major histocompatibility complex (MHC) class II molecules in disparate endosomal compartments. The CD1 protein isoforms traffic to these same endosomal compartments as directed by unique cytoplasmic tail sequences, therefore we reasoned that antigen/CD1 chimeras containing the different CD1 cytoplasmic tail sequences could optimally target antigens to the MHC class II antigen presentation pathway. Evaluation of trafficking patterns revealed that all four human CD1-derived targeting sequences delivered antigen to the MHC class II antigen presentation pathway, to early/recycling, early/sorting and late endosomes/lysosomes. There was a preferential requirement for different CD1 targeting sequences for the optimal presentation of an MHC class II epitope in the following hierarchy: CD1b > CD1d = CD1c > > > CD1a or untargeted antigen. Therefore, the substitution of the CD1 ectodomain with heterologous proteins results in their traffic to distinct intracellular locations that intersect with MHC class II and this differential distribution leads to specific functional outcomes with respect to MHC class II antigen presentation. These findings may have implications in designing DNA vaccines, providing a greater variety of tools to generate T-cell responses against microbial pathogens or tumours.
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Affiliation(s)
- Kayvan R Niazi
- Discovery Translation Unit, Buck Institute, Novato, CA, USA
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69
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Bewry NN, Bolick SCE, Wright KL, Harton JA. GTP-dependent recruitment of CIITA to the class II major histocompatibility complex promoter. J Biol Chem 2007; 282:26178-84. [PMID: 17623662 DOI: 10.1074/jbc.m611747200] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We previously established that the class II transactivator CIITA binds GTP and disruption of the GTP binding ability of CIITA results in increased cytoplasmic CIITA, loss of nuclear CIITA, and thus diminished class II major histocompatibility complex transcription. Because of its role in facilitating nuclear localization, whether GTP binding is also required for CIITA-mediated transactivation of major histocompatibility class II genes remains unclear. We now show that recruitment of CIITA to the human leukocyte antigen (HLA)-DR promoter and activation of HLA-DR transcription is also GTP-dependent. After restoration of nuclear expression, CIITA mutants defective in GTP binding lack full transcriptional activation capacity. Although the availability of the activation domain of CIITA is unaltered, GTP mutants no longer cooperate with CREB-binding protein, p300, and pCAF and are defective in recruitment to the HLA-DR promoter.
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Affiliation(s)
- Nadine N Bewry
- Department of Molecular Medicine, H. Lee Moffitt Cancer Center, University of South Florida, Tampa, Florida 33612, USA
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70
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He F, Guo R, Du X, Lu ZS, Weng JY, Lin W. Inhibitory effects of anti-CII TA M1-RNA on IFN-γ induced major histocompatibility complex class II antigens expression on cultured human chondrocytes. Transpl Immunol 2007; 17:231-6. [PMID: 17493524 DOI: 10.1016/j.trim.2006.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2006] [Revised: 11/23/2006] [Accepted: 12/04/2006] [Indexed: 10/23/2022]
Abstract
Major histocompatibility complex class II (MHC-II) trans-activator (CII TA) has been shown to be required for constitutive and IFN-gamma-induced MHC-II transcription. This study investigated the inhibitory effect of anti-CII TA M1-RNA on expression of MHC-II in chondrocytes in response to IFN-gamma. M1-RNAs with different guide sequence (GS) recognizing 452 or 3408 sites in CII TA (M1-452-GS and M1-3408-GS, respectively) were cloned into pUC19 vector. Target mRNA (3176-3560) in CII TA was obtained from Raji cell and inserted into pGEM-7zf(+) plasmid. The recombinant M1-RNAs and their target mRNA were incubated in a cell-free condition. It showed that only M1-3408-GS could cleave the target mRNA exclusively. M1-3408-GS was also cloned into psNAV vector (named pA3408). Chondrocytes was stably transfected with pA3408 and expressions of classical MHC-II (HLA-DR, -DP, -DQ) were analyzed by Flow Cytometry. The level of CII TA mRNA was measured by RT-PCR. Peripheral blood mono-nucleated cells (PBMNCs) were stimulated by pA3408-positive chondrocytes in mixed lymphocyte reaction, and proliferation of PBMNCs and IL-2 mRNA were detected. The expression of HLA-DR and HLA-DP on pA3408-positive chondrocytes in response to IFN-gamma decreased 73.00%+/-5.24%, 88.47%+/-2.02%, respectively (P<0.05); So did the content of CII TA mRNA (70.11%+/-5.79%, P<0.05). Proliferation of PBMNCs and production of IL-2 mRNA were both inhibited by pA3408 in mixed lymphocyte reaction. This is the first description that anti-CII TA M1-RNA could prevent IFN-gamma-induced CII TA transcription and results in a decreased MHC-II expression in chondrocytes.
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Affiliation(s)
- Fei He
- Department of Cardiology, Guangdong Provincial People's Hospital, Guangzhou, Guangdong Province, 510080, China
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71
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Carlo-Stella C, Guidetti A, Di Nicola M, Lavazza C, Cleris L, Sia D, Longoni P, Milanesi M, Magni M, Nagy Z, Corradini P, Carbone A, Formelli F, Gianni AM. IFN-gamma enhances the antimyeloma activity of the fully human anti-human leukocyte antigen-DR monoclonal antibody 1D09C3. Cancer Res 2007; 67:3269-75. [PMID: 17409435 DOI: 10.1158/0008-5472.can-06-3744] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To investigate the therapeutic activity of the fully human anti-HLA-DR antibody 1D09C3 in multiple myeloma (MM), we reevaluated HLA-DR expression on CD138(+) cells, analyzed the capacity of IFN-gamma to up-regulate HLA-DR expression on MM cell lines, and tested the in vitro and in vivo activity of 1D09C3 alone or in combination with IFN-gamma. CD138(+)HLA-DR(+) cells were detected in 31 of 60 patients, with 15 of 60 patients having >/=20% CD138(+)HLA-DR(+) cells (median, 50%; range, 23-100). Because primary plasma cells cannot be efficiently cultured in vitro, we used a panel of MM cell lines with a dim/negative to bright HLA-DR expression to evaluate 1D09C3-induced cell death. Annexin V/propidium iodide (PI) staining showed that 1D09C3-induced cell death correlated with constitutive HLA-DR expression. Induction of HLA-DR by IFN-gamma restored the sensitivity of HLA-DR dim cell lines to 1D09C3. In vivo, the combined IFN-gamma/1D09C3 treatment significantly increased the median survival of nonobese diabetic/severe combined immunodeficient mice xenografted with KMS-11 cell line, compared with controls (147 versus 48 days, P </= 0.0001) or mice receiving 1D09C3 alone (147 versus 92 days, P </= 0.03). The better therapeutic activity of IFN-gamma/1D09C3 treatment over 1D09C3 alone was further shown by a 2-fold increase of mice being disease-free at 150 days after xenograft (47% versus 25%). No mice experienced any apparent treatment-related toxicity. Our data show that (a) one fourth of MM patients express HLA-DR on CD138(+) cells and (b) IFN-gamma-induced up-regulation of HLA-DR results in a potent enhancement of the in vivo antimyeloma activity of 1D09C3.
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Affiliation(s)
- Carmelo Carlo-Stella
- "Cristina Gandini" Medical Oncology Unit, Medical Oncology, University of Milano, Milan, Italy
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72
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Yao Y, Li P, Singh P, Thiele AT, Wilkes DS, Renukaradhya GJ, Brutkiewicz RR, Travers JB, Luker GD, Hong SC, Blum JS, Chang CH. Vaccinia virus infection induces dendritic cell maturation but inhibits antigen presentation by MHC class II. Cell Immunol 2007; 246:92-102. [PMID: 17678637 PMCID: PMC2100387 DOI: 10.1016/j.cellimm.2007.06.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2007] [Revised: 06/15/2007] [Accepted: 06/16/2007] [Indexed: 11/19/2022]
Abstract
Vaccinia virus (VV) infection is known to inhibit dendritic cells (DC) functions in vitro. Paradoxically, VV is also highly immunogenic and thus has been used as a vaccine. In the present study, we investigated the effects of an in vivo VV infection on DC function by focusing on early innate immunity. Our data indicated that DC are activated upon in vivo VV infection of mice. Splenic DC from VV-infected mice expressed elevated levels of MHC class I and co-stimulatory molecules on their cell surface and exhibited the enhanced potential to produce cytokines upon LPS stimulation. DC from VV-infected mice also expressed a high level of interferon-beta. However, a VV infection resulted in the down-regulation of MHC class II expression and the impairment of antigen presentation to CD4 T cells by DC. Thus, during the early stage of a VV infection, although DC are impaired in some of the critical antigen presentation functions, they can promote innate immune defenses against viral infection.
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Affiliation(s)
- Yongxue Yao
- Department of Microbiology and Immunology and Walther Oncology Center, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Ping Li
- Department of Microbiology and Immunology and Walther Oncology Center, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Pratibha Singh
- Department of Microbiology and Immunology and Walther Oncology Center, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Allison T. Thiele
- Department of Microbiology and Immunology and Walther Oncology Center, Indiana University School of Medicine, Indianapolis, IN 46202
| | - David S. Wilkes
- Department of Microbiology and Immunology and Walther Oncology Center, Indiana University School of Medicine, Indianapolis, IN 46202
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Gourapura J. Renukaradhya
- Department of Microbiology and Immunology and Walther Oncology Center, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Randy R. Brutkiewicz
- Department of Microbiology and Immunology and Walther Oncology Center, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Jeffrey B. Travers
- Department of Dermatology and H.B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Gary D. Luker
- Departments of Radiology and Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109
| | - Soon-Cheol Hong
- Department of Microbiology and Immunology and Walther Oncology Center, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Janice S. Blum
- Department of Microbiology and Immunology and Walther Oncology Center, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Cheong-Hee Chang
- Department of Microbiology and Immunology and Walther Oncology Center, Indiana University School of Medicine, Indianapolis, IN 46202
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73
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Choi JC, Holtz R, Petroff MG, Alfaidy N, Murphy SP. Dampening of IFN-gamma-inducible gene expression in human choriocarcinoma cells is due to phosphatase-mediated inhibition of the JAK/STAT-1 pathway. THE JOURNAL OF IMMUNOLOGY 2007; 178:1598-607. [PMID: 17237409 DOI: 10.4049/jimmunol.178.3.1598] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Trophoblast cells (TBCs) form the blastocyst-derived component of the placenta and play essential roles in fetal maintenance. The proinflammatory cytokine IFN-gamma plays a central role in activating cellular immunity, controlling cell proliferation, and inducing apoptosis. IFN-gamma is secreted by uterine NK cells in the placenta during pregnancy and in mice is required for proper formation of the decidual layer and remodeling of the uterine vasculature. Despite the presence of IFN-gamma in the placenta, TBCs do not express either MHC class Ia or class II Ags, and are resistant to IFN-gamma-mediated apoptosis. In this study, we demonstrate that IFN-gamma-induced expression of multiple genes is significantly reduced in human trophoblast-derived choriocarcinoma cells relative to HeLa epithelial or fibroblast cells. These results prompted us to investigate the integrity of the JAK/STAT-1 pathway in these cells. Choriocarcinoma cells and HeLa cells express comparable levels of the IFN-gamma receptor. However, tyrosine phosphorylation of JAK-2 is compromised in IFN-gamma-treated choriocarcinoma cells. Moreover, phosphorylation of STAT-1 at tyrosine 701 is substantially reduced in both IFN-gamma-treated human choriocarcinoma and primary TBCs compared with HeLa cells or primary foreskin fibroblasts. A corresponding reduction of both IFN regulatory factor 1 mRNA and protein expression was observed in IFN-gamma-treated TBCs. Treatment of choriocarcinoma cells with the tyrosine phosphatase inhibitor pervanadate significantly enhanced IFN-gamma-inducible JAK and STAT-1 tyrosine phosphorylation and select IFN-gamma-inducible gene expression. We propose that phosphatase-mediated suppression of IFN-gamma signaling in TBCs contributes to fetal maintenance by inhibiting expression of genes that could be detrimental to successful pregnancy.
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Affiliation(s)
- Jason C Choi
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
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74
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Smith CM, Rosa GTL, May JS, Bennett NJ, Mount AM, Belz GT, Stevenson PG. CD4+ T cells specific for a model latency-associated antigen fail to control a gammaherpesvirus in vivo. Eur J Immunol 2006; 36:3186-97. [PMID: 17109468 DOI: 10.1002/eji.200636164] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
CD4(+) T cells play a major role in containing herpesvirus infections. However, their cellular targets remain poorly defined. In vitro CD4(+) T cells have been reported to kill B cells that harbor a latent gammaherpesvirus. We used the B cell-tropic murine gammaherpesvirus-68 (MHV-68) to test whether this also occurred in vivo. MHV-68 that expressed cytoplasmic ovalbumin (OVA) in tandem with its episome maintenance protein, ORF73, stimulated CD8(+) T cells specific for the H2-K(b)-restricted OVA epitope SIINFEKL and was rapidly eliminated from C57BL/6 (H2(b)) mice. However, the same virus failed to stimulate CD4(+) T cells specific for the I-A(d)/I-A(b)-restricted OVA(323-339) epitope. We overcame any barrier to the MHC class II-restricted presentation of an endogenous epitope by substituting OVA(323-339) for the CLIP peptide of the invariant chain (ORF73-IRES-Ii-OVA), again expressed in tandem with ORF73. This virus presented OVA(323-339) but showed little or no latency deficit in either BALB/c (H2(d)) or C57BL/6 mice. Latent antigen-specific CD4(+) T cells therefore either failed to recognize key virus-infected cell populations in vivo or lacked the effector functions required to control them.
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Affiliation(s)
- Christopher M Smith
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge, UK
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75
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van der Stoep N, Quinten E, Alblas G, Plancke A, van Eggermond MCJA, Holling TM, van den Elsen PJ. Constitutive and IFNgamma-induced activation of MHC2TA promoter type III in human melanoma cell lines is governed by separate regulatory elements within the PIII upstream regulatory region. Mol Immunol 2006; 44:2036-46. [PMID: 17067677 DOI: 10.1016/j.molimm.2006.09.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Revised: 09/11/2006] [Accepted: 09/12/2006] [Indexed: 11/28/2022]
Abstract
Cell lines established from tumor tissue of cutaneous melanoma biopsies often display constitutive and IFNgamma-inducible expression of MHC class II molecules. The expression of MHC class II molecules in melanoma is associated with an overall poor prognosis and unfavorable clinical outcome. We have analyzed the DNA elements and interacting transcription factors that control the constitutive and IFNgamma-inducible expression of the class II transactivator (CIITA), a co-activator essential for transcription of all MHC class II genes. Our studies reveal the activation of multiple CIITA promoter regions (CIITA-PII, -PIII and -PIV) in melanoma cell lines for both the constitutive and IFNgamma-inducible expression of MHC class II molecules. Furthermore, we show that constitutive and IFNgamma-inducible expression of the CIITA-PIII isoform is governed by separate regulatory elements within the PIII upstream regulatory region (PURR). Similarly constitutive activation in melanoma of CIITA-PII, CIITA-PIII, and CIITA-PIV does not require components of the IFNgamma signaling pathway. However, these components are readily recruited to the PURR and CIITA-PIV after exposure of cells to IFNgamma and account for the IFNgamma-induced expression of CIITA. Together, our data reveal the contribution of distinct elements and factors in the constitutive and IFNgamma-inducible expression of CIITA in melanoma cell lines of the skin.
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Affiliation(s)
- Nienke van der Stoep
- Division of Molecular Biology, Department of Immunohematology and Blood Transfusion, Building 1, E3-Q, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
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76
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Abstract
The MHC class II transactivator (CIITA) is the master transcriptional regulator of genes involved in MHC class II restricted antigen presentation. Previously we suggested another role of CIITA in Th1/Th2 balance by demonstrating that forced expression of CIITA in murine T cells repressed Th1 immunity both in vitro and in vivo. However, the results were contradictory to the report that CIITA functioned to suppress the production of Th2 cytokine by CD4+ T cells in CIITA deficient mice. In this study, we investigated the influence of constitutive expression of CIITA in T cells on Th2 immune response in vivo using murine experimental colitis model. In the dextran sodium sulfate-induced acute colitis, a disease involving innate immunity, CIITA transgenic mice and wild type control mice showed similar progression of the disease. However, the development of oxazolone-induced colitis, a colitis mediated by predominantly Th2 immune response, was aggravated in CIITA-transgenic mice. And, CD4+ T cells from the mesenteric lymph node of CIITA-transgenic mice treated with oxazolone exhibited a high level of IL-4 secretion. Together, these data demonstrate that constitutive expression of CIITA in T cells skews immune response to Th2, resulting in aggravation of Th2-mediated colitis in vivo.
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Affiliation(s)
- Tae Woon Kim
- Department of Pathology, Hallym University College of Medicine, Chuncheon, Korea
| | - Hyo Jin Park
- Department of Pathology, Seoul National University College of Medicine, Seoul, Korea
| | - Eun Young Choi
- Graduate Program of Immunology, Seoul National University College of Medicine, Seoul, Korea
- Center for Animal Resource Development, Seoul National University College of Medicine, Seoul, Korea
| | - Kyeong Cheon Jung
- Department of Pathology, Seoul National University College of Medicine, Seoul, Korea
- Graduate Program of Immunology, Seoul National University College of Medicine, Seoul, Korea
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77
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Malone CS, Kuraishy AI, Fike FM, Loya RG, Mikkili MR, Teitell MA, Wall R. B29 gene silencing in pituitary cells is regulated by its 3' enhancer. J Mol Biol 2006; 362:173-83. [PMID: 16920149 PMCID: PMC2104784 DOI: 10.1016/j.jmb.2006.07.046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2006] [Accepted: 07/21/2006] [Indexed: 12/26/2022]
Abstract
B cell-specific B29 (Igbeta, CD79b) genes in rat, mouse, and human are situated between the 5' growth hormone (GH) locus control region and the 3' GH gene cluster. The entire GH genomic region is DNase 1 hypersensitive in GH-expressing pituitary cells, which predicts an "open" chromatin configuration, and yet B29 is not expressed. The B29 promoter and enhancers exhibit histone deacetylation in pituitary cells, but histone deacetylase inhibition failed to activate B29 expression. The B29 promoter and a 3' enhancer showed local dense DNA methylation in both pituitary and non-lymphoid cells consistent with gene silencing. However, DNA methyltransferase inhibition did not activate B29 expression either. B29 promoter constructs were minimally activated in transfected pituitary cells. Co-transfection of the B cell-specific octamer transcriptional co-activator Bob1 with the B29 promoter construct resulted in high level promoter activity in pituitary cells comparable to B29 promoter activity in transfected B cells. Unexpectedly, inclusion of the B29 3' enhancer in B29 promoter constructs strongly inhibited B29 transcriptional activity even when pituitary cells were co-transfected with Bob1. Both Oct-1 and Pit-1 bind the B29 3' enhancer in in vitro electrophoretic mobility shift assay and in in vivo chromatin immunoprecipitation analyses. These data indicate that the GH locus-embedded, tissue-specific B29 gene is silenced in GH-expressing pituitary cells by epigenetic mechanisms, the lack of a B cell-specific transcription factor, and likely by the B29 3' enhancer acting as a powerful silencer in a context and tissue-specific manner.
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Affiliation(s)
- Cindy S Malone
- Department of Biology, California State University Northridge, Northridge, CA 91330, USA.
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78
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Kwon MJ, Soh JW, Chang CH. Protein kinase C delta is essential to maintain CIITA gene expression in B cells. THE JOURNAL OF IMMUNOLOGY 2006; 177:950-6. [PMID: 16818750 DOI: 10.4049/jimmunol.177.2.950] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Expression of MHC class II genes requires CIITA. Although the transactivation function of CIITA is well characterized, the signaling events that regulate CIITA expression are less understood. In this study, we report that CIITA expression in B cells depends on protein kinase Cdelta (PKCdelta). PKCdelta controls CIITA gene transcription mainly via modulating CREB recruitment to the CIITA promoter without affecting CIITA mRNA stability. Inhibition of PKCdelta by a pharmacological inhibitor or knocking down of endogenous PKCdelta expression by small interfering RNA reduced CREB binding to the CIITA promoter. The decrease of CIITA gene expression in the presence of the PKCdelta inhibitor was prevented by ectopically expressing a constitutively active form of CREB. In addition, histone acetylation of the CIITA promoter is regulated by PKCdelta since the PKCdelta inhibitor treatment or PKCdelta small interfering RNA resulted in decreased histone acetylation. Taken together, our study reveals that PKCdelta is an important signaling molecule necessary to maintain CIITA and MHC class II expression in B cells.
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Affiliation(s)
- Myung-Ja Kwon
- Department of Microbiology and Immunology, and Walther Oncology Center, Indiana University School of Medicine, 950 West Walnut Street, Indianapolis, IN 46202, USA
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79
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Yao Y, Xu Q, Kwon MJ, Matta R, Liu Y, Hong SC, Chang CH. ERK and p38 MAPK Signaling Pathways Negatively Regulate CIITA Gene Expression in Dendritic Cells and Macrophages. THE JOURNAL OF IMMUNOLOGY 2006; 177:70-6. [PMID: 16785500 DOI: 10.4049/jimmunol.177.1.70] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The CIITA is a master regulator for MHC class II expression, but the signaling events that control CIITA expression remain poorly understood. In this study, we report that both constitutive and IFN-gamma-inducible expression of CIITA in mouse bone marrow-derived dendritic cells (DC) and macrophages, respectively, are regulated by MAPK signals. In DC, the inhibitory effect of LPS on CIITA expression was prevented by MyD88 deficiency or pharmacological MAPK inhibitors specific for MEK (U0126) and p38 (SB203580), but not JNK (SP600125). In macrophages, LPS inhibited IFN-gamma-inducible CIITA and MHC class II expression without affecting expression of IFN regulatory factor-1 and MHC class I. Blocking ERK and p38 by MAPK inhibitors not only rescued LPS-mediated inhibition, but also augmented IFN-gamma induction of CIITA. Moreover, the induction of CIITA by IFN-gamma was enhanced by overexpressing MAPK phosphatase-1 that inactivates MAPK. Conversely, CIITA expression was attenuated in the absence of MAPK phosphatase-1. The down-regulation of CIITA gene expression by ERK and p38 was at least partly due to decreased histone acetylation of the CIITA promoter. Our study indicates that both MAPK and phosphatase play an important role for CIITA regulation in DC and macrophages.
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Affiliation(s)
- Yongxue Yao
- Department of Microbiology and Immunology, Walther Oncology Center, Indiana University School of Medicine, 950 West Walnut Street R2-302, Indianapolis, IN 46202, USA
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80
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Chen H, Gilbert CA, Hudson JA, Bolick SC, Wright KL, Piskurich JF. Positive regulatory domain I-binding factor 1 mediates repression of the MHC class II transactivator (CIITA) type IV promoter. Mol Immunol 2006; 44:1461-70. [PMID: 16765445 PMCID: PMC1987354 DOI: 10.1016/j.molimm.2006.04.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2006] [Revised: 04/24/2006] [Accepted: 04/25/2006] [Indexed: 02/06/2023]
Abstract
MHC class II transactivator (CIITA), a co-activator that controls MHC class II (MHC II) transcription, functions as the master regulator of MHC II expression. Persistent activity of the CIITA type III promoter (pIII), one of the four potential promoters of this gene, is responsible for constitutive expression of MHC II by B lymphocytes. In addition, IFN-gamma induces expression of CIITA in these cells through the type IV promoter (pIV). Positive regulatory domain 1-binding factor 1 (PRDI-BF1), called B lymphocyte-induced maturation protein 1 (Blimp-1) in mice, represses the expression of CIITA pIII in plasma and multiple myeloma cells. To investigate regulation of CIITA pIV expression by PRDI-BF1 in the B lymphocyte lineage, protein/DNA-binding studies, and functional promoter analyses were performed. PRDI-BF1 bound to the IFN regulatory factor-element (IRF-E) site in CIITA pIV. Ectopic expression of either PRDI-BF1 or Blimp-1 repressed this promoter in B lymphocytes. In vitro binding and functional analyses of CIITA pIV demonstrated that the IRF-E is the target of this repression. In vivo genomic footprint analysis demonstrated protein binding at the IRF-E site of CIITA pIV in U266 myeloma cells, which express PRDI-BF1. PRDI-BF1beta, a truncated form of PRDI-BF1 that is co-expressed in myeloma cells, also bound to the IRF-E site and repressed CIITA pIV. These findings demonstrate for the first time that, in addition to silencing expression of CIITA pIII in B lymphocytes, PRDI-BF1 is capable of binding and suppressing CIITA pIV.
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Affiliation(s)
- Han Chen
- Division of Basic Medical Sciences, Mercer University School of Medicine, 1550 College St., Macon, GA 31207, USA
| | - Carolyn A. Gilbert
- Division of Basic Medical Sciences, Mercer University School of Medicine, 1550 College St., Macon, GA 31207, USA
| | - John A. Hudson
- Department of Internal Medicine, Mercer University School of Medicine, 1550 College St., Macon, GA 31207, USA
| | - Sophia C. Bolick
- H. Lee Moffitt Cancer Center, Departments of Interdisciplinary Oncology and Molecular Medicine, University of South Florida, Tampa, FL 33612, USA
| | - Kenneth L. Wright
- H. Lee Moffitt Cancer Center, Departments of Interdisciplinary Oncology and Molecular Medicine, University of South Florida, Tampa, FL 33612, USA
| | - Janet F. Piskurich
- Division of Basic Medical Sciences, Mercer University School of Medicine, 1550 College St., Macon, GA 31207, USA
- * Corresponding author. Tel.: +1 478 301 4035; fax: +1 478 301 5489. E-mail address: (J.F. Piskurich)
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81
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Radosevich M, Jager M, Ono SJ. Inhibition of MHC class II gene expression in uveal melanoma cells is due to methylation of the CIITA gene or an upstream activator. Exp Mol Pathol 2006; 82:68-76. [PMID: 16650406 DOI: 10.1016/j.yexmp.2006.03.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2006] [Accepted: 03/09/2006] [Indexed: 11/18/2022]
Abstract
Most cells with an intact interferon-gamma receptor and signaling pathway are able to express MHC class II molecules when treated with cytokines such as interferon-gamma and tumor necrosis factor-a. Interestingly, primary uveal melanocytes and most ocular melanoma cells are resistant to interferon-gamma mediated induction of class II MHC genes. This unusual phenotype is hypothesized to be germane to the immune-privileged status to the eye. Via a series of experiments, we have probed the molecular basis of this class II MHC resistant phenotype. We have analyzed the methylation status of the gene encoding the class II transactivator (CIITA), and asked whether treatment of class II MHC resistant ocular melanoma cells with the demethylating agent 5'-azacytidine can restore interferon-gamma inducibility of these class II MHC genes in these cells. The data obtained suggest that the specific blockade in cytokine-induced class II MHC gene expression is due to a suppression of the gene encoding the class II transactivator (CIITA). Treatment with 5' azacytidine restores the ability of these cells to express class II MHC genes upon interferon-gamma treatment. Whilst this is reminiscent of what occurs in another immune-privileged tissue--the placental trophoblast--we show here that silencing of the CIITA gene in uveal melanocytes either involves methylation of distinct nucleotides from those detected in trophoblasts, or involves an upstream activator of CIITA gene expression.
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Affiliation(s)
- Michael Radosevich
- Department of Immunology, University College London, Institute of Ophthalmology and Child Health and Moorfields Eye Hospital, 11-43 Bath Street, London, EC1V 9EL, UK
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82
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Naves R, Reyes LI, Rosemblatt M, Jacobelli S, González A, Bono MR. Lymphoid B cells induce NF-κB activation in high endothelial cells from human tonsils. Int Immunol 2005; 18:259-67. [PMID: 16373365 DOI: 10.1093/intimm/dxh365] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Immune surveillance depends on still poorly understood lymphocyte-endothelium interactions required for lymphocyte transendothelial migration into secondary lymphoid organs. The nuclear factor kappaB (NF-kappaB) regulatory system and its inhibitory IkappaB proteins control the inducible expression of adhesion molecules, cytokines and chemokines involved in endothelial activation and lymphocyte transmigration. Here we present results showing the activation of this system in response to the interaction of high endothelial cells from human tonsils (HUTEC) with human B and T lymphoid cell lines and primary tonsillar lymphocytes. Western blot and electrophoretic mobility shift assays show that adhesion of different lymphoid cells induce varying levels of NF-kappaB activation in HUTEC, with Daudi cells, tonsil-derived B cell line 10 (TBCL-10) and primary tonsillar B lymphocytes causing the strongest activation. The main NF-kappaB protein complexes translocated to the nucleus were p65/p50 and p50/p50. Results from reverse transcription-PCR and flow cytometry analysis of HUTEC indicate that the interaction with Daudi cells induce an increased expression of IL-6 and IL-8 mRNA and cell-surface expression of intercellular adhesion molecule-1, all of which were prevented by sodium salicylate, an inhibitor of NF-kappaB activation. Transwell experiments show that NF-kappaB activation and the response of HUTEC to the interaction of Daudi cells does not depend on direct cell-cell contact but rather on the production of soluble factors that require the presence of both cell types. These results suggest that lymphocytes and high endothelium establish a cross talk leading to NF-kappaB-mediated expression of cytokines and adhesion molecules, inducing endothelial cell activation.
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Affiliation(s)
- Rodrigo Naves
- Departamento de Inmunología Clínica y Reumatología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Casilla, Santiago 1365, Chile
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83
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Sendide K, Deghmane AE, Pechkovsky D, Av-Gay Y, Talal A, Hmama Z. Mycobacterium bovis BCG attenuates surface expression of mature class II molecules through IL-10-dependent inhibition of cathepsin S. THE JOURNAL OF IMMUNOLOGY 2005; 175:5324-32. [PMID: 16210638 DOI: 10.4049/jimmunol.175.8.5324] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We have previously shown that macrophage infection with Mycobacterium tuberculosis and M. bovis bacillus Calmette-Guérin (BCG) partially inhibits MHC class II surface expression in response to IFN-gamma. The present study examined the nature of class II molecules that do in fact reach the surface of infected cells. Immunostaining with specific Abs that discriminate between mature and immature class II populations showed a predominance of invariant chain (Ii)-associated class II molecules at the surface of BCG-infected cells suggesting that mycobacteria specifically block the surface export of peptide-loaded class II molecules. This phenotype was due to inhibition of IFN-gamma-induced cathepsin S (Cat S) expression in infected cells and the subsequent intracellular accumulation of alphabeta class II dimers associated with the Cat S substrate Ii p10 fragment. In contrast, infection with BCG was shown to induce secretion of IL-10, and addition of blocking anti-IL-10 Abs to cell cultures restored both expression of active Cat S and export of mature class II molecules to the surface of infected cells. Consistent with these findings, expression of mature class II molecules was also restored in cells infected with BCG and transfected with active recombinant Cat S. Thus, M. bovis BCG exploits IL-10 induction to inhibit Cat S-dependent processing of Ii in human macrophages. This effect results in inhibition of peptide loading of class II molecules and in reduced presentation of mycobacterial peptides to CD4(+) T cells. This ability may represent an effective mycobacterial strategy for eluding immune surveillance and persisting in the host.
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Affiliation(s)
- Khalid Sendide
- Department of Medicine, University of British Columbia and Vancouver Coastal Health Research Institute, Vancouver, British Columbia, Canada
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84
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von Delwig A, Musson JA, Shim HK, Lee JJ, Walker N, Harding CV, Williamson ED, Robinson JH. Distribution of productive antigen-processing activity for MHC class II presentation in macrophages. Scand J Immunol 2005; 62:243-50. [PMID: 16179011 DOI: 10.1111/j.1365-3083.2005.01664.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
We demonstrated that an epitope from the recombinant protective antigen (rPA) of Bacillus anthracis was presented by mature major histocompatibility complex class II (MHC-II) molecules, whereas an epitope from the recombinant virulent (rV) antigen of Yersinia pestis was presented by newly synthesized MHC-II. We addressed which endosomal compartments were involved in the antigen processing of each epitope. Bone-marrow-derived macrophages were subjected to subcellular fractionation; fractions were analysed for the expression of endosomal markers and used as a source of enzyme activity for the processing of rPA and rV antigens. The rPA epitope was productively processed by dense lysosomal fractions and light membrane fractions expressing early endosomal markers Rab5 and early endosomal antigen-1 as well as markers of antigen-presenting compartments (MHC-II, DM, DO and Ii chain). In contrast, the rV epitope was productively processed only by dense fractions with lysosomal activity. No productive antigen-processing activity was associated with fractions of intermediate density expressing Rab7 and Rab9, characteristic of late endosomes. The data suggest that endosomal compartments expressing Rab5 guanosine triphosphatase can productively process protein antigens for presentation by mature MHC class II molecules.
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Affiliation(s)
- A von Delwig
- Musculoskeletal Research Group, Clinical Medical Sciences, University of Newcastle upon Tyne, Framlington Place, Newcastle upon Tyne, UK.
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85
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Choi EY, Jung KC, Park HJ, Chung DH, Song JS, Yang SD, Simpson E, Park SH. Thymocyte-Thymocyte Interaction for Efficient Positive Selection and Maturation of CD4 T Cells. Immunity 2005; 23:387-96. [PMID: 16226504 DOI: 10.1016/j.immuni.2005.09.005] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2005] [Revised: 08/25/2005] [Accepted: 09/02/2005] [Indexed: 01/20/2023]
Abstract
Despite numerous reports on MHC class II expression by T cells from a wide spectrum of mammalian species including humans, the biological relevance of this phenomenon has never been tested with appropriately designed animal models. To address this issue, we developed mouse models in which immature thymocytes are the only positively selecting antigen-presenting cells in the thymus. In these mice, CD4+ T cells were generated with the appropriate maturation phenotype and showed a diverse repertoire of TCR Vbetas. The CD4+ T cells were functionally competent, mediating effective allogeneic responses that involved polyclonal TCR Vbetas. These results suggest that the thymocyte-thymocyte (T-T) interaction operates as an independent pathway for CD4+ T cell selection in the thymi of species with MHC II-positive thymocytes. This T-T interaction appears to be the basis for the generation of donor MHC-restricted CD4+ T cells in xenogeneic hosts.
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Affiliation(s)
- Eun Young Choi
- Graduate Program of Immunology, Seoul National University College of Medicine, Seoul 110-799, Korea
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86
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Yao Y, Li W, Kaplan MH, Chang CH. Interleukin (IL)-4 inhibits IL-10 to promote IL-12 production by dendritic cells. ACTA ACUST UNITED AC 2005; 201:1899-903. [PMID: 15967820 PMCID: PMC2212025 DOI: 10.1084/jem.20050324] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Interleukin (IL)-4 is known to be the most potent cytokine that can initiate Th2 cell differentiation. Paradoxically, IL-4 instructs dendritic cells (DCs) to promote Th1 cell differentiation. We investigated the mechanisms by which IL-4 directs CD4 T cells toward the Th1 cell lineage. Our study demonstrates that the IL-4–mediated induction of Th1 cell differentiation requires IL-10 production by DCs. IL-4 treatment of DCs in the presence of lipopolysaccharide or CpG resulted in decreased production of IL-10, which was accompanied by enhanced IL-12 production. In IL-10–deficient DCs, the level of IL-12 was greatly elevated and, more importantly, the ability of IL-4 to up-regulate IL-12 was abrogated. Interestingly, IL-4 inhibited IL-10 production by DCs but not by B cells. The down-regulation of IL-10 gene expression by IL-4 depended on Stat6 and was at least partly caused by decreased histone acetylation of the IL-10 promoter. These data indicate that IL-4 plays a key role in inducing Th1 cell differentiation by instructing DCs to produce less IL-10.
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Affiliation(s)
- Yongxue Yao
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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87
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Nagasaki M, Zhang J, Morikawa S, Harada T, Nabika T, Tanaka Y. Human leukocyte antigen-class II-negative long-term cultured human T-cell leukemia virus type-I-infected T-cell lines with progressed cytological properties significantly induce superantigen-dependent normal T-cell proliferation. Pathol Int 2005; 55:264-72. [PMID: 15871724 DOI: 10.1111/j.1440-1827.2005.01823.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
While most human T-cell leukemia virus type-I (HTLV-I)-infected T cells express abundant class II antigens, some aggressive-type adult T-cell leukemia (ATL) cells lose their expression. To investigate the significance of the class II antigen of HTLV-I infected cells, the progressiveness of HTLV-I-infected long-term cultured T-cell lines was evaluated, and then their antigen-presenting capacity was examined using a superantigen, staphylococcus enterotoxin B (SEB). Among the cell lines derived from peripheral blood, HPB-ATL-T (ATL-T), HPB-ATL-2 (ATL-2) and HPB-ATL-O were more progressed than Tax exclusively expressing HPB-CTL-I (CTL-I), because the former deleted p16 gene (polymerase chain reaction (PCR)) and strongly transcribed survivin (reverse transcriptase-PCR). Notably, interferon gamma-independent loss of class II expression of ATL-T and ATL-2 was found. In antigen-presenting experiments, however, both cell lines induced SEB-dependent significant T-cell proliferation estimated by [(3)H] thymidine uptake. No class II-re-expressed ATL-2 cells were observed in the SEB-presenting cultures by indirect immunofluorescence, and only minimum inhibition of SEB-dependent T-cell response by anti-human leukocyte antigen (HLA)-DR monoclonal antibody was observed. These findings suggest that both ATL-T and ATL-2 very effectively present SEB to T cells less dependently on class II molecules. These less immunogenic leukemic cells of aggressive ATL may contribute to disease aggression.
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88
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Kupfer TM, Crawford ML, Pham K, Gill RG. MHC-Mismatched Islet Allografts Are Vulnerable to Autoimmune Recognition In Vivo. THE JOURNAL OF IMMUNOLOGY 2005; 175:2309-16. [PMID: 16081800 DOI: 10.4049/jimmunol.175.4.2309] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
When transplanted into type 1a diabetic recipients, islet allografts are subject both to conventional allograft immunity and, presumably, to recurrent autoimmune (islet-specific) pathogenesis. Importantly, CD4 T cells play a central role both in islet allograft rejection and in autoimmune disease recurrence leading to the destruction of syngeneic islet transplants in diabetic NOD mice. However, it is unclear how NOD host MHC class II (I-A(g7))-restricted, autoreactive CD4 T cells may also contribute to the recognition of allogeneic islet grafts that express disparate MHC class II molecules. We hypothesized that islet-specific CD4 T cells can target MHC-mismatched islet allografts for destruction via the "indirect" (host APC-dependent) pathway of Ag recognition. To test this hypothesis, we determined whether NOD-derived, islet-specific CD4 T cells (BDC-2.5 TCR transgenic cells) could damage MHC-mismatched islets in vivo independent of conventional allograft immunity. Results demonstrate that BDC-2.5 CD4 T cells can vigorously destroy MHC class II-disparate islet allografts established in NOD.scid recipients. Tissue injury is tissue-specific in that BDC-2.5 T cells destroy donor-type islet, but not thyroid allografts established in the same NOD.scid recipient. Furthermore, BDC-2.5 CD4 T cells acutely destroy MHC class II-deficient islet allografts in vivo, indicating that autoimmune pathogenesis can be completely independent of donor MHC class II expression. Taken together, these findings indicate that MHC-mismatched islet allografts can be vulnerable to autoimmune pathogenesis triggered by autoreactive CD4 T cells, presumably through indirect autoantigen recognition in vivo.
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MESH Headings
- Animals
- Antigen Presentation
- Autoantigens/immunology
- Autoantigens/metabolism
- CD4-Positive T-Lymphocytes/immunology
- Diabetes Mellitus, Type 1/genetics
- Diabetes Mellitus, Type 1/immunology
- Diabetes Mellitus, Type 1/pathology
- Disease Models, Animal
- Female
- Histocompatibility Antigens Class II/biosynthesis
- Histocompatibility Antigens Class II/immunology
- Histocompatibility Testing
- Islets of Langerhans Transplantation/immunology
- Islets of Langerhans Transplantation/pathology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred NOD
- Mice, Knockout
- Mice, SCID
- Mice, Transgenic
- Receptors, Antigen, T-Cell/genetics
- Recurrence
- Spleen/cytology
- Spleen/immunology
- Spleen/transplantation
- Transplantation, Isogeneic
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Affiliation(s)
- Tinalyn M Kupfer
- Barbara Davis Center for Childhood Diabetes, University of Colorado Health Sciences Center, Denver, CO 80262, USA
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89
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Wang Y, Curry HM, Zwilling BS, Lafuse WP. Mycobacteria inhibition of IFN-gamma induced HLA-DR gene expression by up-regulating histone deacetylation at the promoter region in human THP-1 monocytic cells. THE JOURNAL OF IMMUNOLOGY 2005; 174:5687-94. [PMID: 15843570 DOI: 10.4049/jimmunol.174.9.5687] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Infection of macrophages with mycobacteria has been shown to inhibit the macrophage response to IFN-gamma. In the current study, we examined the effect of Mycobacteria avium, Mycobacteria tuberculosis, and TLR2 stimulation on IFN-gamma-induced gene expression in human PMA-differentiated THP-1 monocytic cells. Mycobacterial infection inhibited IFN-gamma-induced expression of HLA-DRalpha and HLA-DRbeta mRNA and partially inhibited CIITA expression but did not affect expression of IFN regulatory factor-1 mRNA. To determine whether inhibition of histone deacetylase (HDAC) activity could rescue HLA-DR gene expression, butyric acid and MS-275, inhibitors of HDAC activity, were added at the time of M. avium or M. tuberculosis infection or TLR2 stimulation. HDAC inhibition restored the ability of these cells to express HLA-DRalpha and HLA-DRbeta mRNA in response to IFN-gamma. Histone acetylation induced by IFN-gamma at the HLA-DRalpha promoter was repressed upon mycobacteria infection or TLR2 stimulation. HDAC gene expression was not affected by mycobacterial infection. However, mycobacterial infection or TLR2 stimulation up-regulated expression of mammalian Sin3A, a corepressor that is required for MHC class II repression by HDAC. Furthermore, we show that the mammalian Sin3A corepressor is associated with the HLA-DRalpha promoter in M. avium-infected THP-1 cells stimulated with IFN-gamma. Thus, mycobacterial infection of human THP-1 cells specifically inhibits HLA-DR gene expression by a novel pathway that involves HDAC complex formation at the HLA-DR promoter, resulting in histone deacetylation and gene silencing.
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Affiliation(s)
- Yue Wang
- Department of Molecular Virology, Ohio State University, Columbus, OH 43210, USA
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90
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Piskurich JF, Gilbert CA, Ashley BD, Zhao M, Chen H, Wu J, Bolick SC, Wright KL. Expression of the MHC class II transactivator (CIITA) type IV promoter in B lymphocytes and regulation by IFN-gamma. Mol Immunol 2005; 43:519-28. [PMID: 15950283 PMCID: PMC1482792 DOI: 10.1016/j.molimm.2005.05.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2004] [Indexed: 10/25/2022]
Abstract
The MHC class II transactivator (CIITA), the master regulator of MHC class II (MHC II) expression, is a co-activator that controls MHC II transcription. Human B lymphocytes express MHC II constitutively due to persistent activity of CIITA promoter III (pIII), one of the four potential promoters (pI-pIV) of this gene. Although increases in MHC II expression in B cells in response to cytokines have been observed and induction of MHC II and CIITA by IFN-gamma has been studied in a number of different cell types, the specific effects of IFN-gamma on CIITA expression in B cells have not been studied. To investigate the regulation of CIITA expression by IFN-gamma in B cells, RT-PCR, in vivo and in vitro protein/DNA binding studies, and functional promoter analyses were performed. Both MHC II and CIITA type IV-specific RNAs increased in human B lymphocytes in response to IFN-gamma treatment. CIITA promoter analysis confirmed that pIV is IFN-gamma inducible in B cells and that the GAS and IRF-E sites are necessary for full induction. DNA binding of IRF-1 and IRF-2, members of the IFN regulatory factor family, was up-regulated in B cells in response to IFN-gamma and increased the activity of CIITA pIV. In vivo genomic footprint analysis demonstrated proteins binding at the GAS, IRF-E and E box sites of CIITA pIV. Although CIITA pIII is considered to be the hematopoietic-specific promoter of CIITA, these findings demonstrate that pIV is active in B lymphocytes and potentially contributes to the expression of CIITA and MHC II in these cells.
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Affiliation(s)
- Janet F Piskurich
- Division of Basic Sciences, Mercer University School of Medicine, 1550 College St., Macon, GA 31207, USA.
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91
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Yee CSK, Yao Y, Xu Q, McCarthy B, Sun-Lin D, Tone M, Waldmann H, Chang CH. Enhanced Production of IL-10 by Dendritic Cells Deficient in CIITA. THE JOURNAL OF IMMUNOLOGY 2005; 174:1222-9. [PMID: 15661876 DOI: 10.4049/jimmunol.174.3.1222] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Dendritic cells (DC) are professional APCs that play a critical role in regulating immunity. In DC, maturation-induced changes in MHC class II expression and Ag presentation require transcriptional regulation by CIITA. To study the role of CIITA in DC, we evaluated key cell functions in DC from CIITA-deficient (CIITA(-/-)) mice. The ability to take up Ag, measured by fluid phase endocytosis, was comparable between CIITA(-/-) and control DC. Although CIITA(-/-) DC lack MHC class II, they maintained normal expression of costimulatory molecules CD80, CD86, and CD40. In contrast, CIITA(-/-) DC activated with LPS or CpG expressed increased IL-10 levels, but normal levels of TNF-alpha and IL-12 relative to control. Enhanced IL-10 was due to greater IL-10 mRNA in CIITA(-/-) DC. Abeta(-/-) DC, which lack MHC class II but express CIITA normally, had exhibited no difference in IL-10 compared with control. When CIITA was cotransfected with an IL-10 promoter-reporter into a mouse monocyte cell line, RAW 264.7, IL-10 promoter activity was decreased. In addition, reintroducing CIITA into CIITA(-/-) DC reduced production of IL-10. In all, these data suggest that CIITA negatively regulates expression of IL-10, and that CIITA may direct DC function in ways that extend beyond control of MHC class II.
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Affiliation(s)
- Christina S K Yee
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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92
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Yang WS, Han NJ, Kim CS, Ahn H, Lee SK, Lee KU, Park SK. STAT1-Independent Down-Regulation of Interferon-Gamma-Induced Class II Transactivator and HLA-DR Expression by Transforming Growth Factor Beta-1 in Human Glomerular Endothelial Cells. ACTA ACUST UNITED AC 2005; 100:e124-31. [PMID: 15824515 DOI: 10.1159/000085058] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2004] [Accepted: 12/12/2004] [Indexed: 11/19/2022]
Abstract
BACKGROUND The competition between STAT1 and Smad3 for a limiting amount of the nuclear protein p300, a transcriptional coactivator, was suggested to be a mechanism for the antagonism between interferon-gamma (IFN-gamma) and transforming growth factor-beta1 (TGF-beta1). We investigated the effect of TGF-beta1 on IFN-gamma-induced HLA-DR production in cultured human glomerular endothelial cells (HGECs), and the involvement of p300 in this process. METHODS Cell surface expression of HLA-DR and mRNA levels of HLA-DR and class II transactivator (CIITA), the master regulator of HLA-DR gene transcription, were measured by cellular ELISA and Northern blot, respectively. The levels of STAT1 and Smad3 protein were analyzed by Western blot. Nuclear binding activity of STAT1 was assessed by electrophoretic mobility shift assay. RESULTS IFN-gamma increased the cell surface expression of HLA-DR along with increases in the mRNA levels of CIITA and HLA-DR, while these stimulatory effects of IFN-gamma were down-regulated by TGF-beta1. IFN-gamma increased phosphorylation of STAT1 and this activation was not inhibited by TGF-beta1. IFN-gamma increased binding of p-STAT1 to p300, while TGF-beta1 increased binding of Smad3 to p300. TGF-beta1-induced Smad3 binding to p300 was inhibited by IFN-gamma, whereas IFN-gamma-induced p-STAT1 binding to p300 was not inhibited by TGF-beta1. IFN-gamma increased DNA binding activity of STAT1. Inhibition of interaction between STAT1 and p300 by addition of anti-p300 antibody to nuclear extract down-regulated DNA binding activity of STAT1. In contrast, TGF-beta1 did not inhibit IFN-gamma-induced STAT1 binding to DNA. CONCLUSIONS TGF-beta1 down-regulated IFN-gamma-induced CIITA and HLA-DR expression in HGECs. Though there was an antagonism between IFN-gamma and TGF-beta1, the competition for p300 between p-STAT1 and Smad3 was not the mechanism for it.
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Affiliation(s)
- Won Seok Yang
- Department of Internal Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Korea
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93
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van der Stoep N, Quinten E, Marcondes Rezende M, van den Elsen PJ. E47, IRF-4, and PU.1 synergize to induce B-cell-specific activation of the class II transactivator promoter III (CIITA-PIII). Blood 2004; 104:2849-57. [PMID: 15242870 DOI: 10.1182/blood-2004-03-0790] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractIn B cells, expression of CIITA and resulting major histocompatibility complex II (MHCII) is mediated exclusively by promoter III (CIITA-PIII) activation. Recent studies have established that CIITA-PIII also participates in the expression of CIITA in activated human T cells, dendritic cells, and monocytes. In this study we characterized the various regulatory elements and interacting factors of CIITA-PIII that account for specific activation in B lymphocytes. We identified 2 E-box motifs and an Ets/ISRE-consensus element (EICE) in CIITA-PIII as playing a crucial role in the B-cell-specific transcriptional regulation of CIITA. Abolishment of factor binding to these elements resulted in a strong reduction of CIITA-PIII activation in B cells only, whereas it did scarcely affect or not affect the activity of CIITA-PIII in activated T cells and monocytes. We show that in B cells, E47 and PU.1/IRF-4 interact with the E-box motifs and the EICE, respectively, and act synergistically in the activation of CIITA-PIII. Moreover, functional inhibition of either E47 or IRF-4 resulted in strong reduction of CIITA-PIII activity in B lymphocytes only. The finding that PU.1, IRF-4, and E47 play an important role in the B-cell-mediated activation of CIITA-PIII provides a link between antigen presentation functions and activation and differentiation events in B lymphocytes.
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Affiliation(s)
- Nienke van der Stoep
- Division of Molecular Biology, Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, E3-Q, PO Box 9600, 2300 RC Leiden, the Netherlands.
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94
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Burd AL, Ingraham RH, Goldrick SE, Kroe RR, Crute JJ, Grygon CA. Assembly of Major Histocompatability Complex (MHC) Class II Transcription Factors: Association and Promoter Recognition of RFX Proteins. Biochemistry 2004; 43:12750-60. [PMID: 15461447 DOI: 10.1021/bi030262o] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Major histocompatibility complex (MHC) class II genes are regulated at the transcriptional level by coordinate action of a limited number of transcription factors that include regulatory factor X (RFX), class II transcriptional activator (CIITA), nuclear factor Y (NF-Y), and cyclic AMP-response element binding protein (CREB). Here, the MHC class-II-specific transcription factors and CREB were expressed in insect cells with recombinant baculoviruses, isolated, and characterized by biochemical and biophysical methods. Analytical ultracentrifugation (AUC) has demonstrated that RFX is a heterotrimer. A heterodimer of RFX5 and RFX-AP was also observed. A high-affinity interaction (K(d) = 25 nM) between RFX5 and RFX-AP was measured by isothermal titration calorimetry (ITC), while the interaction between RFX-AP and RFX-ANK is at least an order of magnitude weaker. The biophysical data show that the interaction between RFX-AP and RFX5 is a key event in the assembly of the heterotrimer. Fluorescence anisotropy was used to determine protein-nucleic acid binding affinities for the RFX subunits and complexes binding to duplex DNA. The RFX5 subunit was found to drive recognition of the promoter, while the auxiliary RFX-AP and RFX-ANK subunits were shown to contribute to the specificity of binding for the overall complex. AUC experiments demonstrate that in the absence of additional subunits, monomeric RFX5 binds to X-box DNA with a 1:1 stoichiometry. Interactions between CREB, CIITA, and RFX in the absence of DNA were demonstrated using bead-based immunoprecipitation assays, confirming that preassociation with DNA is not required for forming the macromolecular assemblies that drive MHC class II gene expression.
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Affiliation(s)
- Amy L Burd
- Department of Immunology and Inflammation, Boehringer Ingelheim Pharmaceuticals, Inc., 900 Ridgebury Road, Post Office Box 368, Ridgefield, Connecticut 06877-0368, USA
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95
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Young HY, Zucker P, Flavell RA, Jevnikar AM, Singh B. Characterization of the Role of Major Histocompatibility Complex in Type 1 Diabetes Recurrence after Islet Transplantation. Transplantation 2004; 78:509-15. [PMID: 15446308 DOI: 10.1097/01.tp.0000128907.83111.c6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Major histocompatibility complex (MHC) molecules are essential determinants of beta-cell destruction in type 1 diabetes (T1D). MHC class I- or class II-null nonobese diabetic (NOD) mice do not spontaneously develop autoimmune diabetes and are resistant to adoptive transfer of disease. Both CD4+ and CD8+ T cells are associated with graft destruction after syngeneic islet transplantation. MHC molecules within the graft (i.e., on beta-cells or donor lymphocytes) may influence the interactions between antigen presenting cells and effector T cells and, therefore, the survival outcome of the graft. METHODS Donor islets from NOD mice deficient in one or both of beta2-microglobulin and class II transactivator genes were transplanted into diabetic NOD mice. Immunohistochemistry was performed to identify the phenotype of infiltrating cells and to assess graft insulin production. The presence of cytokines in the grafts was assayed by reverse transcription polymerase chain reaction. RESULTS MHC class II-null islets demonstrated rates of rejection comparable with control wild-type (wt) islets. In contrast, MHC class I- and II-null islets demonstrated indefinite survival (over 100 days). Infiltrates of both failed and surviving grafts were comprised of cytotoxic lymphocytes (CTL), helper T cells, and macrophages. Grafts also showed the presence of both Th1- and Th2-type cytokines (interleukin [IL]-2, IL-4, IL-10, and interferon-gamma), independent of graft status. CONCLUSIONS These results demonstrate the primary importance of MHC class I molecules in the pathogenesis of diabetes recurrence postislet transplantation. Conversely, MHC class II expression is not a necessary mechanistic component of transplant destruction. In addition, these results implicate MHC class I-restricted CTLs but not MHC class II-restricted T cells in disease recurrence.
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Affiliation(s)
- Holly Y Young
- Department of Microbiology and Immunology, University of Western Ontario, London, ON, Canada
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96
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Murphy SP, Choi JC, Holtz R. Regulation of major histocompatibility complex class II gene expression in trophoblast cells. Reprod Biol Endocrinol 2004; 2:52. [PMID: 15236650 PMCID: PMC479700 DOI: 10.1186/1477-7827-2-52] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2004] [Accepted: 07/05/2004] [Indexed: 11/18/2022] Open
Abstract
Trophoblast cells are unique because they are one of the few mammalian cell types that do not express major histocompatibility complex (MHC) class II antigens, either constitutively or after exposure to IFN-gamma. The absence of MHC class II antigen expression on trophoblast cells has been postulated to be one of the essential mechanisms by which the semi-allogeneic fetus evades immune rejection reactions by the maternal immune system. Consistent with this hypothesis, trophoblast cells from the placentas of women suffering from chronic inflammation of unknown etiology and spontaneous recurrent miscarriages have been reported to aberrantly express MHC class II antigens. The lack of MHC class II antigen expression on trophoblast cells is due to silencing of expression of the class II transactivator (CIITA), a transacting factor that is essential for constitutive and IFN-gamma-inducible MHC class II gene transcription. Transfection of trophoblast cells with CIITA expression vectors activates both MHC class II and class Ia antigen expression, which confers on trophoblast cells both the ability to activate helper T cells, and sensitivity to lysis by cytotoxic T lymphocytes. Collectively, these studies strongly suggest that stringent silencing of CIITA (and therefore MHC class II) gene expression in trophoblast cells is critical for the prevention of immune rejection responses against the fetus by the maternal immune system. The focus of this review is to summarize studies examining the novel mechanisms by which CIITA is silenced in trophoblast cells. The elucidation of the silencing of CIITA in trophoblast cells may shed light on how the semi-allogeneic fetus evades immune rejection by the maternal immune system during pregnancy.
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Affiliation(s)
- Shawn P Murphy
- Department of Immunology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14263, USA
| | - Jason C Choi
- Department of Immunology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14263, USA
| | - Renae Holtz
- Department of Immunology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14263, USA
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97
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Sendide K, Deghmane AE, Reyrat JM, Talal A, Hmama Z. Mycobacterium bovis BCG urease attenuates major histocompatibility complex class II trafficking to the macrophage cell surface. Infect Immun 2004; 72:4200-9. [PMID: 15213164 PMCID: PMC427455 DOI: 10.1128/iai.72.7.4200-4209.2004] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2003] [Revised: 01/12/2004] [Accepted: 03/12/2004] [Indexed: 11/20/2022] Open
Abstract
We have previously shown that Mycobacterium tuberculosis attenuates cell surface expression of major histocompatibility complex class II molecules in response to gamma interferon (IFN-gamma) by a mechanism dependent on intracellular sequestration of alpha,beta dimers. In this study we examined whether intracellular alkalinization due to mycobacterial urease could account for the defect in intracellular trafficking of class II molecules. Phagocytosis of wild-type Mycobacterium bovis BCG was associated with secretion of ammonia intracellularly, which increased substantially upon addition of exogenous urea to the culture medium. Increased intracellular ammonia, due to urea degradation by the bacterium, correlated with inhibition of class II surface expression. Conversely, no ammonia was detected in cells infected with a urease-negative mutant strain of M. bovis BCG, which also displayed a reduced effect on surface expression of class II molecules. A direct cause-effect relationship between urease and class II molecule trafficking was established with experiments where cells ingesting beads coated with purified urease showed an increased ammonia level and decreased surface expression of class II in response to IFN-gamma. In contrast to BCG, infection of macrophages with Mycobacterium smegmatis, which expresses relatively greater urease activity in cell-free culture, had a marginal effect on both the intracellular level of ammonia and class II expression. The limited effect of M. smegmatis was consistent with a failure to resist intracellular killing, suggesting that urease alone is not sufficient to resist macrophage microbicidal mechanisms and that this is required for a more distal effect on cell regulation. Our results demonstrate that alkalinization of critical intracellular organelles by pathogenic mycobacteria expressing urease contributes significantly to the intracellular retention of class II dimers.
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Affiliation(s)
- Khalid Sendide
- Division of Infectious Diseases, Department of Medicine, University of British Columbia, Rm. 452D, 2733 Heather Street, Vancouver, BC, Canada V5Z 3J5
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98
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Yee CSK, Yao Y, Li P, Klemsz MJ, Blum JS, Chang CH. Cathepsin E: A Novel Target for Regulation by Class II Transactivator. THE JOURNAL OF IMMUNOLOGY 2004; 172:5528-34. [PMID: 15100295 DOI: 10.4049/jimmunol.172.9.5528] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The aspartic proteinase cathepsin E (CatE) has been implicated in Ag processing. In this study we report that CatE expression is negatively regulated by the MHC class II transactivator (CIITA). CIITA-deficient murine and human B cells expressed greater CatE than wild-type B cells, whereas overexpression of CIITA in a human gastric carcinoma cell line, AGS, resulted in decreased CatE mRNA and protein. AGS cells expressing CIITA also exhibited decreased processing of OVA Ag. Inhibition of CatE expression is specific to the type III CIITA isoform and maps to the acidic and proline/serine/threonine-rich (PST) protein domains of CIITA. We found that CatE expression is inducible by PU.1 and p300, and that this induction can be reversed by CIITA. These findings demonstrate a novel phenomenon: regulation of CatE Ag processing by CIITA in an isoform-dependent manner.
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Affiliation(s)
- Christina S K Yee
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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99
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Abstract
More than a half a century ago, interferons (IFN) were identified as antiviral cytokines. Since that discovery, IFN have been in the forefront of basic and clinical cytokine research. The pleiotropic nature of these cytokines continues to engage a large number of investigators to define their actions further. IFN paved the way for discovery of Janus tyrosine kinase (JAK)-signal transducing activators of transcription (STAT) pathways. A number of important tumor suppressive pathways are controlled by IFN. Several infectious pathogens counteract IFN-induced signaling pathways. Recent studies indicate that IFN activate several new protein kinases, including the MAP kinase family, and downstream transcription factors. This review not only details the established IFN signaling paradigms but also provides insights into emerging alternate signaling pathways and mechanisms of pathogen-induced signaling interference.
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Affiliation(s)
- Dhananjaya V Kalvakolanu
- Molecular and Cellular Biology Graduate Program, Greenebaum Cancer Center, Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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100
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Prod'homme T, Drénou B, De Ruyffelaere C, Barbieri G, Wiszniewski W, Bastard C, Charron D, Alcaide-Loridan C. Defective class II transactivator expression in a B lymphoma cell line. Leukemia 2004; 18:832-40. [PMID: 14973505 DOI: 10.1038/sj.leu.2403315] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Loss of MHC class II expression in B-cell lymphoma has been associated with a higher tumorigenicity resulting from lower titers of tumor-infiltrating lymphocytes. This report aims towards the identification of the molecular mechanism leading to defective MHC class II expression in a B-cell lymphoma cell line, Rec-1. We evidenced a coordinated alteration of HLA-D gene transcription, reminiscent of B lymphoblastoid cell lines from patients with MHC class II deficiency. Genetic complementation performed between these cell lines and the lymphoma cells indicated that Rec-1 is altered in the MHC2TA gene. MHC2TA encodes the class II transactivator (CIITA), the master regulator of HLA-D gene expression. However, the coding sequence of the Rec-1 CIITA transcript did not reveal any mutation that could hamper the activity of the encoded protein. In agreement with the genetic complementation analysis, we evidenced a highly residual CIITA protein expression in the Rec-1 cell line resulting from a transcriptional defect affecting MHC2TA expression. Anti-HLA-DR monoclonal antibody treatment has proved efficient in the destruction of B lymphoma cells. Our data indicate that the appearance of variants losing CIITA, and thereby HLA-DR, expression will require a thorough monitoring during such immunotherapy protocols.
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Affiliation(s)
- T Prod'homme
- INSERM U396, Centre de Recherches Biomédicales des Cordeliers, Paris, France
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