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Massa C, Wang Y, Marr N, Seliger B. Interferons and Resistance Mechanisms in Tumors and Pathogen-Driven Diseases—Focus on the Major Histocompatibility Complex (MHC) Antigen Processing Pathway. Int J Mol Sci 2023; 24:ijms24076736. [PMID: 37047709 PMCID: PMC10095295 DOI: 10.3390/ijms24076736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 02/22/2023] [Accepted: 02/25/2023] [Indexed: 04/08/2023] Open
Abstract
Interferons (IFNs), divided into type I, type II, and type III IFNs represent proteins that are secreted from cells in response to various stimuli and provide important information for understanding the evolution, structure, and function of the immune system, as well as the signaling pathways of other cytokines and their receptors. They exert comparable, but also distinct physiologic and pathophysiologic activities accompanied by pleiotropic effects, such as the modulation of host responses against bacterial and viral infections, tumor surveillance, innate and adaptive immune responses. IFNs were the first cytokines used for the treatment of tumor patients including hairy leukemia, renal cell carcinoma, and melanoma. However, tumor cells often develop a transient or permanent resistance to IFNs, which has been linked to the escape of tumor cells and unresponsiveness to immunotherapies. In addition, loss-of-function mutations in IFN signaling components have been associated with susceptibility to infectious diseases, such as COVID-19 and mycobacterial infections. In this review, we summarize general features of the three IFN families and their function, the expression and activity of the different IFN signal transduction pathways, and their role in tumor immune evasion and pathogen clearance, with links to alterations in the major histocompatibility complex (MHC) class I and II antigen processing machinery (APM). In addition, we discuss insights regarding the clinical applications of IFNs alone or in combination with other therapeutic options including immunotherapies as well as strategies reversing the deficient IFN signaling. Therefore, this review provides an overview on the function and clinical relevance of the different IFN family members, with a specific focus on the MHC pathways in cancers and infections and their contribution to immune escape of tumors.
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Affiliation(s)
- Chiara Massa
- Medical Faculty, Martin Luther University Halle-Wittenberg, Magdeburger Str. 2, 06112 Halle, Germany
- Institute for Translational Immunology, Brandenburg Medical School Theodor Fontane, Hochstr. 29, 14770 Brandenburg an der Havel, Germany
| | - Yuan Wang
- Medical Faculty, Martin Luther University Halle-Wittenberg, Magdeburger Str. 2, 06112 Halle, Germany
| | - Nico Marr
- Institute for Translational Immunology, Brandenburg Medical School Theodor Fontane, Hochstr. 29, 14770 Brandenburg an der Havel, Germany
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha P.O. Box 34110, Qatar
| | - Barbara Seliger
- Medical Faculty, Martin Luther University Halle-Wittenberg, Magdeburger Str. 2, 06112 Halle, Germany
- Institute for Translational Immunology, Brandenburg Medical School Theodor Fontane, Hochstr. 29, 14770 Brandenburg an der Havel, Germany
- Fraunhofer Institute for Cell Therapy and Immunology, Perlickstr. 1, 04103 Leipzig, Germany
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2
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Ke X, Zhang R, Yao Q, Duan S, Hong W, Cao M, Zhou Q, Zhong X, Zhao H. Alternative splicing of medaka bcl6aa and its repression by Prdm1a and Prdm1b. FISH PHYSIOLOGY AND BIOCHEMISTRY 2021; 47:1229-1242. [PMID: 34218391 DOI: 10.1007/s10695-021-00980-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 06/24/2021] [Indexed: 06/13/2023]
Abstract
Bcl6 and Prdm1 (Blimp1) are a pair of transcriptional factors that repressing each other in mammals. Prdm1 represses the expression of bcl6 by binding a cis-element of the bcl6 gene in mammals. The homologs of Bcl6 and Prdm1 have been identified in teleost fish. However, whether these two factors regulate each other in the same way in fish like that in mammals is not clear. In this study, the regulation of bcl6aa by Prdm1 was investigated in medaka. The mRNA of bcl6aa has three variants (bcl6aaX1-X3) at the 5'-end by alternative splicing detected by RT-PCR. The three variants can be detected in adult tissues and developing embryos of medaka. Prdm1a and prdm1b are expressed in the tissues and embryos where and when bcl6aa is expressed. The expression of prdm1a was high while the expression of bcl6aa was low, and vice versa, detected in the spleen after stimulation with LPS or polyI:C. In vitro reporter assay indicated that bcl6aa could be directly repressed by both Prdm1a and Prdm1b in a dosage-dependent manner. After mutation of the key base, G, of all predicted binding sites in the core promoter region of bcl6aa, the repression by Prdm1a and/or Prdm1b disappeared. The binding site of Prdm1 in the bcl6aa gene is GAAAA(T/G). These results indicate that both Prdm1a and Prdm1b directly repress the expression of bcl6aa by binding their binding sites where the 5'-G is critical in medaka fish.
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Affiliation(s)
- Xiaomei Ke
- Hubei Key Laboratory of Gene Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, China
| | - Runshuai Zhang
- Hubei Key Laboratory of Gene Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, China
| | - Qiting Yao
- Hubei Key Laboratory of Gene Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, China
| | - Shi Duan
- Hubei Key Laboratory of Gene Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, China
| | - Wentao Hong
- Hubei Key Laboratory of Gene Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, China
| | - Mengxi Cao
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, 430056, China
| | - Qingchun Zhou
- Hubei Key Laboratory of Gene Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, China
| | - Xueping Zhong
- Hubei Key Laboratory of Gene Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, China
| | - Haobin Zhao
- Hubei Key Laboratory of Gene Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, China.
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3
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Anderson KJ, Ósvaldsdóttir ÁB, Atzinger B, Traustadóttir GÁ, Jensen KN, Lárusdóttir AE, Bergthórsson JT, Hardardóttir I, Magnúsdóttir E. The BLIMP1-EZH2 nexus in a non-Hodgkin lymphoma. Oncogene 2020; 39:5138-5151. [PMID: 32533097 DOI: 10.1038/s41388-020-1347-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 05/26/2020] [Accepted: 06/01/2020] [Indexed: 01/12/2023]
Abstract
Waldenström's macroglobulinemia (WM) is a non-Hodgkin lymphoma, resulting in antibody-secreting lymphoplasmacytic cells in the bone marrow and pathologies resulting from high levels of monoclonal immunoglobulin M (IgM) in the blood. Despite the key role for BLIMP1 in plasma cell maturation and antibody secretion, its potential effect on WM cell biology has not yet been explored. Here we provide evidence of a crucial role for BLIMP1 in the survival of cells from WM cell line models and further demonstrate that BLIMP1 is necessary for the expression of the histone methyltransferase EZH2 in both WM and multiple myeloma cell lines. The effect of BLIMP1 on EZH2 levels is post-translational, at least partially through the regulation of proteasomal targeting of EZH2. Chromatin immunoprecipitation analysis and transcriptome profiling suggest that the two factors co-operate in regulating genes involved in cancer cell immune evasion. Co-cultures of natural killer cells and cells from a WM cell line further suggest that both factors participate in immune evasion by promoting escape from natural killer cell-mediated cytotoxicity. Together, the interplay of BLIMP1 and EZH2 plays a vital role in promoting the survival of WM cell lines, suggesting a role for the two factors in Waldenström's macroglobulinaemia.
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Affiliation(s)
- Kimberley Jade Anderson
- Department of Anatomy, Faculty of Medicine, University of Iceland, Vatnsmýrarvegur 16, 101, Reykjavik, Iceland.,Department of Biomedical Science, Faculty of Medicine, University of Iceland, Vatnsmýrarvegur 16, 101, Reykjavík, Iceland.,The University of Iceland Biomedical Center, Vatnsmýrarvegur 16, 101, Reykjavík, Iceland
| | - Árný Björg Ósvaldsdóttir
- Department of Anatomy, Faculty of Medicine, University of Iceland, Vatnsmýrarvegur 16, 101, Reykjavik, Iceland.,Department of Biomedical Science, Faculty of Medicine, University of Iceland, Vatnsmýrarvegur 16, 101, Reykjavík, Iceland.,The University of Iceland Biomedical Center, Vatnsmýrarvegur 16, 101, Reykjavík, Iceland
| | - Birgit Atzinger
- Department of Anatomy, Faculty of Medicine, University of Iceland, Vatnsmýrarvegur 16, 101, Reykjavik, Iceland.,Department of Biomedical Science, Faculty of Medicine, University of Iceland, Vatnsmýrarvegur 16, 101, Reykjavík, Iceland.,The University of Iceland Biomedical Center, Vatnsmýrarvegur 16, 101, Reykjavík, Iceland
| | - Gunnhildur Ásta Traustadóttir
- Department of Anatomy, Faculty of Medicine, University of Iceland, Vatnsmýrarvegur 16, 101, Reykjavik, Iceland.,The University of Iceland Biomedical Center, Vatnsmýrarvegur 16, 101, Reykjavík, Iceland
| | - Kirstine Nolling Jensen
- The University of Iceland Biomedical Center, Vatnsmýrarvegur 16, 101, Reykjavík, Iceland.,Department of Biochemistry and Molecular Biology, Faculty of Medicine, Vatnsmýrarvegur 16, University of Iceland, 101, Reykjavík, Iceland.,Department of Immunology, Landspitali-The National University Hospital of Iceland, Hringbraut, 101, Reykjavík, Iceland
| | - Aðalheiður Elín Lárusdóttir
- Department of Anatomy, Faculty of Medicine, University of Iceland, Vatnsmýrarvegur 16, 101, Reykjavik, Iceland.,Department of Biomedical Science, Faculty of Medicine, University of Iceland, Vatnsmýrarvegur 16, 101, Reykjavík, Iceland.,The University of Iceland Biomedical Center, Vatnsmýrarvegur 16, 101, Reykjavík, Iceland
| | - Jón Thór Bergthórsson
- Department of Biomedical Science, Faculty of Medicine, University of Iceland, Vatnsmýrarvegur 16, 101, Reykjavík, Iceland.,The University of Iceland Biomedical Center, Vatnsmýrarvegur 16, 101, Reykjavík, Iceland.,Department of Laboratory Haematology, Landspitali-The National University Hospital of Iceland, Hringbraut, 101, Reykjavík, Iceland
| | - Ingibjörg Hardardóttir
- The University of Iceland Biomedical Center, Vatnsmýrarvegur 16, 101, Reykjavík, Iceland.,Department of Biochemistry and Molecular Biology, Faculty of Medicine, Vatnsmýrarvegur 16, University of Iceland, 101, Reykjavík, Iceland.,Department of Immunology, Landspitali-The National University Hospital of Iceland, Hringbraut, 101, Reykjavík, Iceland
| | - Erna Magnúsdóttir
- Department of Anatomy, Faculty of Medicine, University of Iceland, Vatnsmýrarvegur 16, 101, Reykjavik, Iceland. .,Department of Biomedical Science, Faculty of Medicine, University of Iceland, Vatnsmýrarvegur 16, 101, Reykjavík, Iceland. .,The University of Iceland Biomedical Center, Vatnsmýrarvegur 16, 101, Reykjavík, Iceland.
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4
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Suzuki K, Luo Y. Histone Acetylation and the Regulation of Major Histocompatibility Class II Gene Expression. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2017; 106:71-111. [PMID: 28057216 DOI: 10.1016/bs.apcsb.2016.08.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Major histocompatibility complex (MHC) class II molecules are essential for processing and presenting exogenous pathogen antigens to activate CD4+ T cells. Given their central role in adaptive immune responses, MHC class II genes are tightly regulated in a tissue- and activation-specific manner. The regulation of MHC class II gene expression involves various transcription factors that interact with conserved proximal cis-acting regulatory promoter elements, as well as MHC class II transactivator that interacts with a variety of chromatin remodeling machineries. Recent studies also identified distal regulatory elements within MHC class II gene locus that provide enormous insight into the long-range coordination of MHC class II gene expression. Novel therapeutic modalities that can modify MHC class II genes at the epigenetic level are emerging and are currently in preclinical and clinical trials. This review will focus on the role of chromatin remodeling, particularly remodeling that involves histone acetylation, in the constitutive and inducible regulation of MHC class II gene expression.
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Affiliation(s)
- K Suzuki
- Faculty of Medical Technology, Teikyo University, Itabashi, Japan.
| | - Y Luo
- Faculty of Medical Technology, Teikyo University, Itabashi, Japan
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5
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Zhang SY, Lv Y, Zhang H, Gao S, Wang T, Feng J, Wang Y, Liu G, Xu MJ, Wang X, Jiang C. Adrenomedullin 2 Improves Early Obesity-Induced Adipose Insulin Resistance by Inhibiting the Class II MHC in Adipocytes. Diabetes 2016; 65:2342-55. [PMID: 27207558 DOI: 10.2337/db15-1626] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 04/26/2016] [Indexed: 11/13/2022]
Abstract
MHC class II (MHCII) antigen presentation in adipocytes was reported to trigger early adipose inflammation and insulin resistance. However, the benefits of MHCII inhibition in adipocytes remain largely unknown. Here, we showed that human plasma polypeptide adrenomedullin 2 (ADM2) levels were negatively correlated with HOMA of insulin resistance in obese human. Adipose-specific human ADM2 transgenic (aADM2-tg) mice were generated. The aADM2-tg mice displayed improvements in high-fat diet-induced early adipose insulin resistance. This was associated with increased insulin signaling and decreased systemic inflammation. ADM2 dose-dependently inhibited CIITA-induced MHCII expression by increasing Blimp1 expression in a CRLR/RAMP1-cAMP-dependent manner in cultured adipocytes. Furthermore, ADM2 treatment restored the high-fat diet-induced early insulin resistance in adipose tissue, mainly via inhibition of adipocyte MHCII antigen presentation and CD4(+) T-cell activation. This study demonstrates that ADM2 is a promising candidate for the treatment of early obesity-induced insulin resistance.
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Affiliation(s)
- Song-Yang Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Ying Lv
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Heng Zhang
- Department of Endocrinology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China
| | - Song Gao
- Department of General Surgery, Peking University First Hospital, Peking University, Beijing, China
| | - Ting Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Juan Feng
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Yuhui Wang
- Institute of Cardiovascular Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, China
| | - George Liu
- Institute of Cardiovascular Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, China
| | - Ming-Jiang Xu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Xian Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
| | - Changtao Jiang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education and Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, China
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6
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Liu JH, Bian YM, Xie Y, Lu DP. Epigenetic modification and preliminary investigation of the mechanism of the immune evasion of HL-60 cells. Mol Med Rep 2015; 12:1059-65. [PMID: 25815463 PMCID: PMC4438930 DOI: 10.3892/mmr.2015.3526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 02/24/2015] [Indexed: 11/05/2022] Open
Abstract
The aim of the present study was to explore the effect of epigenetic modification of class II transactivator (CIITA) methylation on histocompatibility complex (MHC) class II expression and the immune evasion of leukemia HL-60 cells. HL-60 cells were treated with various concentrations of 5-aza-2′deoxycytidine (5-Aza-CdR) and 0.5 μmol/l suberoyl-anilide hydroxamic acid (SAHA) for 24 h and then stimulated by interferon γ (IFN-γ) for 48 h. The mRNA levels of MHC class I, II and co-stimulatory molecules were quantified by reverse transcription polymerase chain reaction (RT-PCR). The levels of CIITA protein were determined by western blot analysis, and the CpG island methylation ratios in the CIITA promoter IV (CIITApIV) were analyzed by bisulfite-sequencing PCR (BSP). MHC I as well as the co-stimulatory molecules CD40 and CD80 were significantly increased following treatment with 5-Aza-CdR + SAHA + IFN-γ (epigenetic groups) compared with those in the control group and IFN-γ group (P<0.05). The expression of MHC class II and CIITA was restored and increased in an 5-Aza-CdR concentration-dependent manner in the three epigenetic groups. The results of the BSP assay showed that the methylation rate of CIITApIV CpG sites decreased with the treatment of epigenetic modification and negatively correlated to the 5-Aza-CdR concentration. This demonstrated that the negative expression of CIITA protein was the key reason for the loss of MHC II expression in HL-60 cells. The results of the present study may help to illustrate the mechanism of immune evasion in HL-60 cells.
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Affiliation(s)
- Jin Hong Liu
- Department of Hematology, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai 200240, P.R. China
| | - Yong Mei Bian
- Department of Pediatrics, Minhang District Maternal and Child Health Care Hospital of Shanghai, Shanghai 201102, P.R. China
| | - Yi Xie
- Department of Hematology, Huashan Hospital, Fudan University, Shanghai 200040, P.R. China
| | - Dao Pei Lu
- Department of Hematology, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai 200240, P.R. China
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7
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Yang H, Qiu Q, Gao B, Kong S, Lin Z, Fang D. Hrd1-mediated BLIMP-1 ubiquitination promotes dendritic cell MHCII expression for CD4 T cell priming during inflammation. ACTA ACUST UNITED AC 2014; 211:2467-79. [PMID: 25366967 PMCID: PMC4235642 DOI: 10.1084/jem.20140283] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The ubiquitin pathway plays critical roles in antigen presentation. However, the ubiquitin ligases that regulate MHC gene transcription remain unidentified. We showed that the ubiquitin ligase Hrd1, expression of which is induced by Toll-like receptor (TLR) stimulation, is required for MHC-II but not MHC-I transcription in dendritic cells (DCs). Targeted Hrd1 gene deletion in DCs diminished MHC-II expression. As a consequence, Hrd1-null DCs failed to prime CD4(+) T cells without affecting the activation of CD8(+) T cells. Hrd1 catalyzed ubiquitination and degradation of the transcriptional suppressor B lymphocyte-induced maturation protein 1 (BLIMP1) to promote MHC-II expression. Genetic suppression of Hrd1 function in DCs protected mice from myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE). We identified Hrd1-mediated BLIMP1 ubiquitination as a previously unknown mechanism in programming DC for CD4(+) T cell activation during inflammation.
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Affiliation(s)
- Heeyoung Yang
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Quan Qiu
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Beixue Gao
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Sinyi Kong
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Zhenghong Lin
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Deyu Fang
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
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8
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Cycon KA, Mulvaney K, Rimsza LM, Persky D, Murphy SP. Histone deacetylase inhibitors activate CIITA and MHC class II antigen expression in diffuse large B-cell lymphoma. Immunology 2013; 140:259-72. [PMID: 23789844 DOI: 10.1111/imm.12136] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 06/11/2013] [Accepted: 06/13/2013] [Indexed: 12/29/2022] Open
Abstract
Diffuse large B-cell lymphoma (DLBCL), the most common form of non-Hodgkin's lymphoma (NHL) diagnosed in the USA, consists of at least two distinct subtypes: germinal centre B (GCB) and activated B-cell (ABC). Decreased MHC class II (MHCII) expression on the tumours in both DLBCL subtypes directly correlates with significant decreases in patient survival. One common mechanism accounting for MHCII down-regulation in DLBCL is reduced expression of the MHC class II transactivator (CIITA), the master regulator of MHCII transcription. Furthermore, reduced CIITA expression in ABC DLBCL correlates with the presence of the transcriptional repressor positive regulatory domain-I-binding factor-1 (PRDI-BF1). However, the mechanisms underlying down-regulation of CIITA in GCB DLBCL are currently unclear. In this study, we demonstrate that neither PRDI-BF1 nor CpG hypermethylation at the CIITA promoters are responsible for decreased CIITA in GCB DLBCL. In contrast, histone modifications associated with an open chromatin conformation and active transcription were significantly lower at the CIITA promoters in CIITA(-) GCB cells compared with CIITA(+) B cells, which suggests that epigenetic mechanisms contribute to repression of CIITA transcription. Treatment of CIITA(-) or CIITA(low) GCB cells with several different histone deacetylase inhibitors (HDACi) activated modest CIITA and MHCII expression. However, CIITA and MHCII levels were significantly higher in these cells after exposure to the HDAC-1-specific inhibitor MS-275. These results suggest that CIITA transcription is repressed in GCB DLBCL cells through epigenetic mechanisms involving HDACs, and that HDACi treatment can alleviate repression. These observations may have important implications for patient therapy.
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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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10
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Yoon HS, Scharer CD, Majumder P, Davis CW, Butler R, Zinzow-Kramer W, Skountzou I, Koutsonanos DG, Ahmed R, Boss JM. ZBTB32 is an early repressor of the CIITA and MHC class II gene expression during B cell differentiation to plasma cells. THE JOURNAL OF IMMUNOLOGY 2012; 189:2393-403. [PMID: 22851713 DOI: 10.4049/jimmunol.1103371] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
CIITA and MHC class II expression is silenced during the differentiation of B cells to plasma cells. When B cell differentiation is carried out ex vivo, CIITA silencing occurs rapidly, but the factors contributing to this event are not known. ZBTB32, also known as repressor of GATA3, was identified as an early repressor of CIITA in an ex vivo plasma cell differentiation model. ZBTB32 activity occurred at a time when B lymphocyte-induced maturation protein-1 (Blimp-1), the regulator of plasma cell fate and suppressor of CIITA, was minimally induced. Ectopic expression of ZBTB32 suppressed CIITA and I-A gene expression in B cells. Short hairpin RNA depletion of ZBTB32 in a plasma cell line resulted in re-expression of CIITA and I-A. Compared with conditional Blimp-1 knockout and wild-type B cells, B cells from ZBTB32/ROG-knockout mice displayed delayed kinetics in silencing CIITA during ex vivo plasma cell differentiation. ZBTB32 was found to bind to the CIITA gene, suggesting that ZBTB32 directly regulates CIITA. Lastly, ZBTB32 and Blimp-1 coimmunoprecipitated, suggesting that the two repressors may ultimately function together to silence CIITA expression. These results introduce ZBTB32 as a novel regulator of MHC-II gene expression and a potential regulatory partner of Blimp-1 in repressing gene expression.
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Affiliation(s)
- Hye Suk Yoon
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA
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van den Elsen PJ. Expression regulation of major histocompatibility complex class I and class II encoding genes. Front Immunol 2011; 2:48. [PMID: 22566838 PMCID: PMC3342053 DOI: 10.3389/fimmu.2011.00048] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Accepted: 09/14/2011] [Indexed: 12/26/2022] Open
Abstract
Major histocompatibility complex (MHC)-I and MHC-II molecules play an essential role in the immune response to pathogens by virtue of their ability to present peptides to CD8+ and CD4+ T cells, respectively. Given this critical role, MHC-I and MHC-II genes are regulated in a tight fashion at the transcriptional level by a variety of transcription factors that interact with conserved cis-acting regulatory promoter elements. In addition to the activities of these regulatory factors, modification of chromatin also plays an essential role in the efficient transcription of these genes to meet with local requirement for an effective immune response. The focus of this review is on the transcription factors that interact with conserved cis-acting promoter elements and the epigenetic mechanisms that modulate induced and constitutive expression of these MHC genes.
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Affiliation(s)
- Peter J van den Elsen
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center Leiden, Netherlands.
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12
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Montes-Moreno S, Montalbán C, Piris MA. Large B-cell lymphomas with plasmablastic differentiation: a biological and therapeutic challenge. Leuk Lymphoma 2011; 53:185-94. [PMID: 21812534 DOI: 10.3109/10428194.2011.608447] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Plasmablastic differentiation can be found in a variety of large B-cell lymphomas, including plasmablastic lymphoma, ALK-positive large B-cell lymphoma, primary effusion lymphoma, large B-cell lymphoma arising in human herpesvirus-8 (HHV-8)-associated multicentric Castleman disease and diffuse large B-cell lymphoma (DLBCL) with partial plasmablastic phenotype. These tumors are characterized by acquisition of the transcriptional profile of plasma cells (with overexpression of PRDM1/Blimp1 and XBP1s, in concert with extinction of the B-cell differentiation program) by proliferating immunoblasts. This particular biological entity, i.e. large B-cell lymphoma with plasmablastic differentiation, is almost always associated with an aggressive clinical behavior. This review summarizes the current knowledge of the biological basis of plasmablastic differentiation in large B-cell lymphomas, the diagnostic borders with DLBCL and multiple myeloma, the associated adverse molecular events (with concomitant MYC, p53 and ALK alterations) and the potential therapeutic targets so far identified (including the unfolded protein response pathway). The highly aggressive nature of these lymphomas and the relative paucity of molecular data available highlight the need for deeper insights into the molecular pathogenesis of large B-cell lymphomas with plasmablastic differentiation in order to identify new and effective alternative treatments.
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13
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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 DOI: 10.1074/jbc.m110.165431] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [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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14
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Epigenetic Control in Immune Function. EPIGENETIC CONTRIBUTIONS IN AUTOIMMUNE DISEASE 2011; 711:36-49. [DOI: 10.1007/978-1-4419-8216-2_4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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15
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O'Gorman GM, Al Naib A, Naib AA, Ellis SA, Mamo S, O'Doherty AM, Lonergan P, Fair T. Regulation of a bovine nonclassical major histocompatibility complex class I gene promoter. Biol Reprod 2010; 83:296-306. [PMID: 20427761 DOI: 10.1095/biolreprod.109.082560] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Studies have shown in humans and other species that the major histocompatibility complex class I (MHC-I) region is involved at a number of levels in the establishment and maintenance of pregnancy. The aim of this study was to characterize how a bovine nonclassical MHC-I gene (NC1) is regulated. Initial serial deletion experiments of a 2-kb fragment of the NC1 promoter identified regions with positive regulatory elements in the proximal promoter and evidence for a silencer module(s) further upstream that cooperatively contributed to constitutive NC1 expression. The cytokines interferon tau (IFNT), interferon gamma (IFNG), and interleukin 4 (IL4) significantly increased luciferase expression in NC1 promoter reporter constructs and endogenous NC1 mRNA levels in a bovine endometrial cell line. In addition, IFNG, IL3, IL4, and progesterone significantly increased Day 7 bovine blastocyst NC1 mRNA expression when supplemented during in vitro embryo culture. Site-directed mutagenesis analysis identified a STAT6 binding site that conferred IL4 responsiveness in the NC1 proximal promoter. Furthermore, methylation treatment of the proximal promoter, which contains a CpG island, completely abrogated constitutive NC1 expression. Overall, the findings presented here suggest that constitutive NC1 expression is regulated positively by elements in the proximal promoter, which are further controlled by upstream silencer modules. The promoter is responsive to IFNT, IFNG, and IL4, suggesting possible roles for these cytokines in bovine preimplantation embryo survival and/or maternal-fetal tolerance. Our studies also suggest that methylation of the proximal promoter, in particular, could play a significant role in regulating NC1 expression.
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Affiliation(s)
- Grace M O'Gorman
- School of Agriculture, Food Science & Veterinary Medicine, University College Dublin, Belfield, Dublin, Ireland
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16
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Montes-Moreno S, Gonzalez-Medina AR, Rodriguez-Pinilla SM, Maestre L, Sanchez-Verde L, Roncador G, Mollejo M, García JF, Menarguez J, Montalbán C, Ruiz-Marcellan MC, Conde E, Piris MA. Aggressive large B-cell lymphoma with plasma cell differentiation: immunohistochemical characterization of plasmablastic lymphoma and diffuse large B-cell lymphoma with partial plasmablastic phenotype. Haematologica 2010; 95:1342-9. [PMID: 20418245 DOI: 10.3324/haematol.2009.016113] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Plasmablastic lymphoma has recently come to be considered a distinct entity among mature B cell neoplasms, although the limits with diffuse large B-cell lymphoma (DLBCL) need to be more accurately defined. DESIGN AND METHODS Here we show the results of an immunohistochemical study of 35 cases of plasmablastic lymphoma compared with a set of 111 conventional DLBCLs. RESULTS Our results demonstrate that the use of a limited combination of immunohistochemical markers (PAX5&CD20, PRDM1/BLIMP1 and XBP1s) enables the identification of a plasmablastic immunophenotype highly characteristic of plasmablastic lymphoma cases and associated with an aggressive clinical behavior. Additionally, the study shows that the acquisition of a partial plasmablastic phenotype (PRDM1/BLIMP1 expression) in DLBCL is associated with shorter survival in R-CHOP-treated patients. CONCLUSIONS The use of a restricted combination of immunohistochemical markers (PAX5&CD20, PRDM1/BLIMP1 and XBP1s) enables a more accurate definition of terminal differentiation for large B-cell lymphoma.
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Affiliation(s)
- Santiago Montes-Moreno
- Lymphoma Group, Molecular Pathology Programme Spanish National Cancer Research Centre, CNIO, Madrid, Spain.
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17
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Cycon KA, Rimsza LM, Murphy SP. Alterations in CIITA constitute a common mechanism accounting for downregulation of MHC class II expression in diffuse large B-cell lymphoma (DLBCL). Exp Hematol 2009; 37:184-194. [PMID: 19081173 DOI: 10.1016/j.exphem.2008.10.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Revised: 09/20/2008] [Accepted: 10/01/2008] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Significant decreases in patient survival are associated with downregulation of major histocompatibility complex class II (MHC-II) antigen expression in diffuse large B-cell lymphoma (DLBCL). However, the molecular mechanisms responsible for decreased MHC-II expression in DLBCL are poorly defined. We therefore examined these mechanisms in established DLBCL cell lines. MATERIALS AND METHODS Human leukocyte antigen (HLA)-DR surface expression was examined by flow cytometry. Expression of the MHC-II genes and the MHC-II transcriptional activators class II transactivator (CIITA) and RFX was investigated by reverse transcriptase polymerase chain reaction. The integrity of the MHC-II genes was examined by polymerase chain reaction. Stable transfection assays were utilized to reconstitute CIITA expression. RESULTS Dramatic variations in the levels of cell surface HLA-DR expression were observed on the DLBCL cell lines. OCI-Ly10 cells lack HLA-DR and HLA-DQ expression due to homozygous deletions within the MHC-II locus on chromosome 6. Dyscoordinate downregulation of MHC-II beta-chain expression in OCI-Ly3 cells mediates dramatic reductions of MHC-II surface expression. In SUDHL-4 and SUDHL-6 cells, expression of the MHC-II genes is coordinately reduced and quantitatively correlated with expression of the CIITA, the master regulator of MHC-II transcription. DB cells lack expression of CIITA and all of the MHC-II genes. Stable transfection of DB cells with CIITA expression vectors resulted in coordinate upregulation of MHC-II gene expression, which demonstrates the causal relationship between the lack of CIITA and MHC-II loss. CONCLUSIONS These data demonstrate that downregulation of MHC-II expression occurs by multiple distinct mechanisms in DLBCL. However, decreases in CIITA expression appear to be the most prevalent mechanism.
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MESH Headings
- Cell Line, Tumor
- Chromosomes, Human, Pair 6/genetics
- Chromosomes, Human, Pair 6/metabolism
- Gene Expression Regulation, Leukemic/genetics
- HLA-DQ Antigens/biosynthesis
- HLA-DQ Antigens/genetics
- HLA-DR Antigens/biosynthesis
- HLA-DR Antigens/genetics
- Humans
- Lymphoma, Large B-Cell, Diffuse/genetics
- Lymphoma, Large B-Cell, Diffuse/metabolism
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Nuclear Proteins/biosynthesis
- Nuclear Proteins/genetics
- Quantitative Trait Loci/genetics
- Trans-Activators/biosynthesis
- Trans-Activators/genetics
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Affiliation(s)
- Kelly A Cycon
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY, USA
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18
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Abstract
Interferons represent a protein family with pleiotropic functions including immunomodulatory, cytostatic, and cytotoxic activities. Based on these effects, interferons are involved in innate as well as adaptive immunity, thereby shaping the tumor host immune responses. These cytokines, alone or in combination, have been successfully implemented for the treatment of some malignancies. However, it has been recently demonstrated that tumor cells could be resistant to interferon treatment, which may be associated with an escape of tumor cells from immune surveillance. Therefore, the aim of this chapter is to summarize the frequency of impaired interferon signal transduction, their underlying molecular mechanisms, and their clinical relevance.
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Affiliation(s)
- Barbara Seliger
- Martin Luther University Halle-Wittenberg, Institute of Medical Immunology, Halle, Germany
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19
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Boyce BF, Xing L. Functions of RANKL/RANK/OPG in bone modeling and remodeling. Arch Biochem Biophys 2008; 473:139-46. [PMID: 18395508 DOI: 10.1016/j.abb.2008.03.018] [Citation(s) in RCA: 1170] [Impact Index Per Article: 73.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2008] [Revised: 03/18/2008] [Accepted: 03/19/2008] [Indexed: 12/11/2022]
Abstract
The discovery of the RANKL/RANK/OPG system in the mid 1990s for the regulation of bone resorption has led to major advances in our understanding of how bone modeling and remodeling are regulated. It had been known for many years before this discovery that osteoblastic stromal cells regulated osteoclast formation, but it had not been anticipated that they would do this through expression of members of the TNF superfamily: receptor activator of NF-kappaB ligand (RANKL) and osteoprotegerin (OPG), or that these cytokines and signaling through receptor activator of NF-kappaB (RANK) would have extensive functions beyond regulation of bone remodeling. RANKL/RANK signaling regulates osteoclast formation, activation and survival in normal bone modeling and remodeling and in a variety of pathologic conditions characterized by increased bone turnover. OPG protects bone from excessive resorption by binding to RANKL and preventing it from binding to RANK. Thus, the relative concentration of RANKL and OPG in bone is a major determinant of bone mass and strength. Here, we review our current understanding of the role of the RANKL/RANK/OPG system in bone modeling and remodeling.
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Affiliation(s)
- Brendan F Boyce
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, 601 Elmwood Avenue, Box 626, Rochester, NY 14642, USA.
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20
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Zhao M, Flynt FL, Hong M, Chen H, Gilbert CA, Briley NT, Bolick SC, Wright KL, Piskurich JF. MHC class II transactivator (CIITA) expression is upregulated in multiple myeloma cells by IFN-gamma. Mol Immunol 2007; 44:2923-32. [PMID: 17300840 PMCID: PMC1892219 DOI: 10.1016/j.molimm.2007.01.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2006] [Revised: 01/05/2007] [Accepted: 01/09/2007] [Indexed: 10/23/2022]
Abstract
The MHC class II transactivator (CIITA) acts in the cell nucleus as the master regulator of MHC class II (MHC II) gene expression. It is important to study CIITA regulation in multiple myeloma since MHC expression is central to ability of myeloma cells to present antigen and to the ability of the immune system to recognize and destroy this malignancy. Regulation of CIITA by IFN-gamma in B lymphocytes occurs through the CIITA type IV promoter (pIV), one of the four potential promoters (pI-pIV) of this gene. To investigate regulation of CIITA by IFN-gamma in multiple myeloma cells, first the ability of these cells to respond to IFN-gamma was examined. RT-PCR analyses show that IFN-gammaR1, the IFN-gamma-binding chain of the IFN-gamma receptor, is expressed in myeloma cells and IRF-1 expression increases in response to IFN-gamma treatment. Western blotting demonstrates that STAT1 is activated by phosphorylation in response to IFN-gamma. RT-PCR and functional promoter analyses show that IFN-gamma upregulates the activity of CIITA pIV, as does ectopic expression of IRF-1 or IRF-2. In vivo protein/DNA binding studies demonstrate protein binding at the GAS, E box and IRF-E sites. In vitro studies confirm the binding of IRF-1 and IRF-2 to CIITA pIV. Although multiple myeloma cells express PRDI-BF1/Blimp-1, a factor that represses both the CIITA type III and IV promoters, they retain the capability to upregulate CIITA pIV and MHC II expression in response to IFN-gamma treatment. These findings are the first to demonstrate that although PRDI-BF1/Blimp-1 diminishes the constitutive ability of these cells to present antigen by limiting CIITA and MHC II expression, it is possible to enhance this expression through the use of cytokines, like IFN-gamma.
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Affiliation(s)
- Mojun Zhao
- Division of Basic Medical Sciences, Mercer University School of Medicine, 1550 College Street, Macon, GA 31207, USA
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21
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Gao Y, Grassi F, Ryan MR, Terauchi M, Page K, Yang X, Weitzmann MN, Pacifici R. IFN-gamma stimulates osteoclast formation and bone loss in vivo via antigen-driven T cell activation. J Clin Invest 2006; 117:122-32. [PMID: 17173138 PMCID: PMC1697800 DOI: 10.1172/jci30074] [Citation(s) in RCA: 334] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2006] [Accepted: 10/31/2006] [Indexed: 12/18/2022] Open
Abstract
T cell-produced cytokines play a pivotal role in the bone loss caused by inflammation, infection, and estrogen deficiency. IFN-gamma is a major product of activated T helper cells that can function as a pro- or antiresorptive cytokine, but the reason why IFN-gamma has variable effects in bone is unknown. Here we show that IFN-gamma blunts osteoclast formation through direct targeting of osteoclast precursors but indirectly stimulates osteoclast formation and promotes bone resorption by stimulating antigen-dependent T cell activation and T cell secretion of the osteoclastogenic factors RANKL and TNF-alpha. Analysis of the in vivo effects of IFN-gamma in 3 mouse models of bone loss - ovariectomy, LPS injection, and inflammation via silencing of TGF-beta signaling in T cells - reveals that the net effect of IFN-gamma in these conditions is that of stimulating bone resorption and bone loss. In summary, IFN-gamma has both direct anti-osteoclastogenic and indirect pro-osteoclastogenic properties in vivo. Under conditions of estrogen deficiency, infection, and inflammation, the net balance of these 2 opposing forces is biased toward bone resorption. Inhibition of IFN-gamma signaling may thus represent a novel strategy to simultaneously reduce inflammation and bone loss in common forms of osteoporosis.
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Affiliation(s)
- Yuhao Gao
- Division of Endocrinology, Metabolism and Lipids, Department of Medicine, and
Immunology and Molecular Pathogenesis Program, Emory University, Atlanta, Georgia, USA
| | - Francesco Grassi
- Division of Endocrinology, Metabolism and Lipids, Department of Medicine, and
Immunology and Molecular Pathogenesis Program, Emory University, Atlanta, Georgia, USA
| | - Michaela Robbie Ryan
- Division of Endocrinology, Metabolism and Lipids, Department of Medicine, and
Immunology and Molecular Pathogenesis Program, Emory University, Atlanta, Georgia, USA
| | - Masakazu Terauchi
- Division of Endocrinology, Metabolism and Lipids, Department of Medicine, and
Immunology and Molecular Pathogenesis Program, Emory University, Atlanta, Georgia, USA
| | - Karen Page
- Division of Endocrinology, Metabolism and Lipids, Department of Medicine, and
Immunology and Molecular Pathogenesis Program, Emory University, Atlanta, Georgia, USA
| | - Xiaoying Yang
- Division of Endocrinology, Metabolism and Lipids, Department of Medicine, and
Immunology and Molecular Pathogenesis Program, Emory University, Atlanta, Georgia, USA
| | - M. Neale Weitzmann
- Division of Endocrinology, Metabolism and Lipids, Department of Medicine, and
Immunology and Molecular Pathogenesis Program, Emory University, Atlanta, Georgia, USA
| | - Roberto Pacifici
- Division of Endocrinology, Metabolism and Lipids, Department of Medicine, and
Immunology and Molecular Pathogenesis Program, Emory University, Atlanta, Georgia, USA
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