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Magne B, Ferland K, Savard É, Barbier MA, Morissette A, Larouche D, Beaudoin-Cloutier C, Germain L. The Human Neonatal Skin Fibroblast, an Available Cell Source for Tissue Production and Transplantation, Exhibits Low Risk of Immunogenicity In Vitro. Int J Mol Sci 2024; 25:6965. [PMID: 39000078 PMCID: PMC11241615 DOI: 10.3390/ijms25136965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 06/19/2024] [Accepted: 06/20/2024] [Indexed: 07/16/2024] Open
Abstract
The immunogenicity of allogeneic skin fibroblasts in transplantation has been controversial. Whether this controversy comes from a natural heterogeneity among fibroblast subsets or species-specific differences between human and mouse remains to be addressed. In this study, we sought to investigate whether fibroblasts derived from either adult or neonatal human skin tissues could induce different immune responses toward phagocytosis and T cell activation using in vitro co-culture models. Our results indicate that both phagocytosis and T cell proliferation are reduced in the presence of neonatal skin fibroblasts compared to adult skin fibroblasts. We also show that neonatal skin fibroblasts secrete paracrine factors that are responsible for reduced T cell proliferation. In addition, we show that neonatal skin fibroblasts express less class II human leukocyte antigen (HLA) molecules than adult skin fibroblasts after interferon gamma priming, which might also contribute to reduced T cell proliferation. In conclusion, this study supports the use of allogeneic neonatal skin fibroblasts as a readily available cell source for tissue production and transplantation to treat patients with severe injuries.
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Affiliation(s)
- Brice Magne
- Department of Surgery, Faculty of Medicine, Université Laval, Québec City, QC G1V 0A6, Canada
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Quebec City, QC G1J 5B3, Canada
- CHU de Québec-Université Laval Research Centre, Québec City, QC G1E 6W2, Canada
| | - Karel Ferland
- Department of Surgery, Faculty of Medicine, Université Laval, Québec City, QC G1V 0A6, Canada
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Quebec City, QC G1J 5B3, Canada
- CHU de Québec-Université Laval Research Centre, Québec City, QC G1E 6W2, Canada
| | - Étienne Savard
- Department of Surgery, Faculty of Medicine, Université Laval, Québec City, QC G1V 0A6, Canada
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Quebec City, QC G1J 5B3, Canada
- CHU de Québec-Université Laval Research Centre, Québec City, QC G1E 6W2, Canada
| | - Martin A. Barbier
- Department of Surgery, Faculty of Medicine, Université Laval, Québec City, QC G1V 0A6, Canada
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Quebec City, QC G1J 5B3, Canada
- CHU de Québec-Université Laval Research Centre, Québec City, QC G1E 6W2, Canada
| | - Amélie Morissette
- Department of Surgery, Faculty of Medicine, Université Laval, Québec City, QC G1V 0A6, Canada
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Quebec City, QC G1J 5B3, Canada
- CHU de Québec-Université Laval Research Centre, Québec City, QC G1E 6W2, Canada
| | - Danielle Larouche
- Department of Surgery, Faculty of Medicine, Université Laval, Québec City, QC G1V 0A6, Canada
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Quebec City, QC G1J 5B3, Canada
- CHU de Québec-Université Laval Research Centre, Québec City, QC G1E 6W2, Canada
| | - Chanel Beaudoin-Cloutier
- Department of Surgery, Faculty of Medicine, Université Laval, Québec City, QC G1V 0A6, Canada
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Quebec City, QC G1J 5B3, Canada
- CHU de Québec-Université Laval Research Centre, Québec City, QC G1E 6W2, Canada
- Burn Care Unit, CHU de Québec-Université Laval Hospital, Québec City, QC G1J 1Z4, Canada
| | - Lucie Germain
- Department of Surgery, Faculty of Medicine, Université Laval, Québec City, QC G1V 0A6, Canada
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Quebec City, QC G1J 5B3, Canada
- CHU de Québec-Université Laval Research Centre, Québec City, QC G1E 6W2, Canada
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2
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Alvarez-Simon D, Ait Yahia S, de Nadai P, Audousset C, Chamaillard M, Boneca IG, Tsicopoulos A. NOD-like receptors in asthma. Front Immunol 2022; 13:928886. [PMID: 36189256 PMCID: PMC9515552 DOI: 10.3389/fimmu.2022.928886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 08/23/2022] [Indexed: 12/28/2022] Open
Abstract
Asthma is an extremely prevalent chronic inflammatory disease of the airway where innate and adaptive immune systems participate collectively with epithelial and other structural cells to cause airway hyperresponsiveness, mucus overproduction, airway narrowing, and remodeling. The nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) are a family of intracellular innate immune sensors that detect microbe-associated molecular patterns and damage-associated molecular patterns, well-recognized for their central roles in the maintenance of tissue homeostasis and host defense against bacteria, viruses and fungi. In recent times, NLRs have been increasingly acknowledged as much more than innate sensors and have emerged also as relevant players in diseases classically defined by their adaptive immune responses such as asthma. In this review article, we discuss the current knowledge and recent developments about NLR expression, activation and function in relation to asthma and examine the potential interventions in NLR signaling as asthma immunomodulatory therapies.
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Affiliation(s)
- Daniel Alvarez-Simon
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR9017-CIIL-Centre d’Infection et d’Immunité de Lille, Lille, France
| | - Saliha Ait Yahia
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR9017-CIIL-Centre d’Infection et d’Immunité de Lille, Lille, France
| | - Patricia de Nadai
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR9017-CIIL-Centre d’Infection et d’Immunité de Lille, Lille, France
| | - Camille Audousset
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR9017-CIIL-Centre d’Infection et d’Immunité de Lille, Lille, France
| | - Mathias Chamaillard
- Laboratory of Cell Physiology, INSERM U1003, University of Lille, Lille, France
| | - Ivo Gomperts Boneca
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, INSERM U1306, Unité Biologie et génétique de la paroi bactérienne, Paris, France
| | - Anne Tsicopoulos
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019-UMR9017-CIIL-Centre d’Infection et d’Immunité de Lille, Lille, France
- *Correspondence: Anne Tsicopoulos,
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3
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IFNγ and GM-CSF control complementary differentiation programs in the monocyte-to-phagocyte transition during neuroinflammation. Nat Immunol 2022; 23:217-228. [DOI: 10.1038/s41590-021-01117-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 12/10/2021] [Indexed: 02/06/2023]
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4
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Evasion of the Host Immune Response by Betaherpesviruses. Int J Mol Sci 2021; 22:ijms22147503. [PMID: 34299120 PMCID: PMC8306455 DOI: 10.3390/ijms22147503] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/11/2021] [Accepted: 07/12/2021] [Indexed: 02/07/2023] Open
Abstract
The human immune system boasts a diverse array of strategies for recognizing and eradicating invading pathogens. Human betaherpesviruses, a highly prevalent subfamily of viruses, include human cytomegalovirus (HCMV), human herpesvirus (HHV) 6A, HHV-6B, and HHV-7. These viruses have evolved numerous mechanisms for evading the host response. In this review, we will highlight the complex interplay between betaherpesviruses and the human immune response, focusing on protein function. We will explore methods by which the immune system first responds to betaherpesvirus infection as well as mechanisms by which viruses subvert normal cellular functions to evade the immune system and facilitate viral latency, persistence, and reactivation. Lastly, we will briefly discuss recent advances in vaccine technology targeting betaherpesviruses. This review aims to further elucidate the dynamic interactions between betaherpesviruses and the human immune system.
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5
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Reincke ME, Payne KJ, Harder I, Strohmeier V, Voll RE, Warnatz K, Keller B. The Antigen Presenting Potential of CD21 low B Cells. Front Immunol 2020; 11:535784. [PMID: 33193306 PMCID: PMC7609862 DOI: 10.3389/fimmu.2020.535784] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 09/22/2020] [Indexed: 12/13/2022] Open
Abstract
Human CD21low B cells are expanded in autoimmune (AI) diseases and display a unique phenotype with high expression of co-stimulatory molecules, compatible with a potential role as antigen-presenting cells (APCs). Thus, we addressed the co-stimulatory capacity of naïve-like, IgM-memory, switched memory and CD27negIgDneg memory CD21low B cells in allogenic co-cultures with CD4 T cells. CD21low B cells of patients with AI disorders expressed high levels of not only CD86, CD80, and HLA-DR (memory B cells) but also PD-L1 ex vivo and efficiently co-stimulated CD4 T cells of healthy donors (HD), as measured by upregulation of CD25, CD69, inducible co-stimulator (ICOS), and programmed cell death protein 1 (PD-1) and induction of cytokines. While the co-stimulatory capacity of the different CD21low B-cell populations was over all comparable to CD21pos counterparts of patients and HD, especially switched memory CD21low B cells lacked the increased capacity of CD21pos switched memory B-cells to induce high expression of ICOS, IL-2, IL-10, and IFN-γ. Acknowledging the limitation of the in vitro setting, CD21low B cells do not seem to preferentially support a specific Th effector response. In summary, our data implies that CD21low B cells of patients with AI diseases can become competent APCs and may, when enriched for autoreactive B-cell receptors (BCR), potentially contribute to AI reactions as cognate interaction partners of autoreactive T cells at sites of inflammation.
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Affiliation(s)
- Marlene E Reincke
- Department of Rheumatology and Clinical Immunology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Chronic Immunodeficiency, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Kathryn J Payne
- Department of Rheumatology and Clinical Immunology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Chronic Immunodeficiency, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Ina Harder
- Department of Rheumatology and Clinical Immunology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Chronic Immunodeficiency, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Valentina Strohmeier
- Department of Rheumatology and Clinical Immunology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Chronic Immunodeficiency, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Reinhard E Voll
- Department of Rheumatology and Clinical Immunology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Chronic Immunodeficiency, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Klaus Warnatz
- Department of Rheumatology and Clinical Immunology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Chronic Immunodeficiency, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Baerbel Keller
- Department of Rheumatology and Clinical Immunology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Chronic Immunodeficiency, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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6
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Hou J, Chen SN, Gan Z, Li N, Huang L, Huo HJ, Yang YC, Lu Y, Yin Z, Nie P. In Primitive Zebrafish, MHC Class II Expression Is Regulated by IFN-γ, IRF1, and Two Forms of CIITA. THE JOURNAL OF IMMUNOLOGY 2020; 204:2401-2415. [DOI: 10.4049/jimmunol.1801480] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 02/13/2020] [Indexed: 12/21/2022]
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7
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Mottok A, Woolcock B, Chan FC, Tong KM, Chong L, Farinha P, Telenius A, Chavez E, Ramchandani S, Drake M, Boyle M, Ben-Neriah S, Scott DW, Rimsza LM, Siebert R, Gascoyne RD, Steidl C. Genomic Alterations in CIITA Are Frequent in Primary Mediastinal Large B Cell Lymphoma and Are Associated with Diminished MHC Class II Expression. Cell Rep 2015; 13:1418-1431. [PMID: 26549456 DOI: 10.1016/j.celrep.2015.10.008] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 08/17/2015] [Accepted: 10/04/2015] [Indexed: 02/06/2023] Open
Abstract
Primary mediastinal large B cell lymphoma (PMBCL) is an aggressive non-Hodgkin's lymphoma, predominantly affecting young patients. We analyzed 45 primary PMBCL tumor biopsies and 3 PMBCL-derived cell lines for the presence of genetic alterations involving the major histocompatibility complex (MHC) class II transactivator CIITA and found frequent aberrations consisting of structural genomic rearrangements, missense, nonsense, and frame-shift mutations (53% of primary tumor biopsies and all cell lines). We also detected intron 1 mutations in 47% of the cases, and detailed sequence analysis strongly suggests AID-mediated aberrant somatic hypermutation as the mutational mechanism. Furthermore, we demonstrate that genomic lesions in CIITA result in decreased protein expression and reduction of MHC class II surface expression, creating an immune privilege phenotype in PMBCL. In summary, we establish CIITA alterations as a common mechanism of immune escape through reduction of MHC class II expression in PMBCL, with potential implications for future treatments targeting microenvironment-related biology.
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Affiliation(s)
- Anja Mottok
- Centre for Lymphoid Cancer, Department of Lymphoid Cancer Research, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada; Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC V6T 2B5, Canada
| | - Bruce Woolcock
- Centre for Lymphoid Cancer, Department of Lymphoid Cancer Research, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada
| | - Fong Chun Chan
- Centre for Lymphoid Cancer, Department of Lymphoid Cancer Research, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada; Bioinformatics Training Program, University of British Columbia, Vancouver, BC V5Z 4S6, Canada
| | - King Mong Tong
- Centre for Lymphoid Cancer, Department of Lymphoid Cancer Research, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada
| | - Lauren Chong
- Centre for Lymphoid Cancer, Department of Lymphoid Cancer Research, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada; Bioinformatics Training Program, University of British Columbia, Vancouver, BC V5Z 4S6, Canada
| | - Pedro Farinha
- Centre for Lymphoid Cancer, Department of Lymphoid Cancer Research, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada
| | - Adèle Telenius
- Centre for Lymphoid Cancer, Department of Lymphoid Cancer Research, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada
| | - Elizabeth Chavez
- Centre for Lymphoid Cancer, Department of Lymphoid Cancer Research, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada
| | - Suvan Ramchandani
- Centre for Lymphoid Cancer, Department of Lymphoid Cancer Research, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada
| | - Marie Drake
- Centre for Lymphoid Cancer, Department of Lymphoid Cancer Research, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada
| | - Merrill Boyle
- Centre for Lymphoid Cancer, Department of Lymphoid Cancer Research, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada
| | - Susana Ben-Neriah
- Centre for Lymphoid Cancer, Department of Lymphoid Cancer Research, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada
| | - David W Scott
- Centre for Lymphoid Cancer, Department of Lymphoid Cancer Research, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada
| | - Lisa M Rimsza
- Department of Pathology, University of Arizona, Tucson, AZ 85724, USA
| | - Reiner Siebert
- Institute of Human Genetics, Christian-Albrechts-University Kiel and University Hospital Schleswig-Holstein, Campus Kiel, Kiel 24105, Germany
| | - Randy D Gascoyne
- Centre for Lymphoid Cancer, Department of Lymphoid Cancer Research, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada; Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC V6T 2B5, Canada
| | - Christian Steidl
- Centre for Lymphoid Cancer, Department of Lymphoid Cancer Research, BC Cancer Agency, Vancouver, BC V5Z 1L3, Canada; Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC V6T 2B5, Canada.
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8
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Wong D, Lee W, Humburg P, Makino S, Lau E, Naranbhai V, Fairfax BP, Chan K, Plant K, Knight JC. Genomic mapping of the MHC transactivator CIITA using an integrated ChIP-seq and genetical genomics approach. Genome Biol 2015; 15:494. [PMID: 25366989 PMCID: PMC4243378 DOI: 10.1186/s13059-014-0494-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Indexed: 12/30/2022] Open
Abstract
Background The master transactivator CIITA is essential to the regulation of Major Histocompatibility Complex (MHC) class II genes and an effective immune response. CIITA is known to modulate a small number of non-MHC genes involved in antigen presentation such as CD74 and B2M but its broader genome-wide function and relationship with underlying genetic diversity has not been resolved. Results We report the first genome-wide ChIP-seq map for CIITA and complement this by mapping inter-individual variation in CIITA expression as a quantitative trait. We analyse CIITA recruitment for pathophysiologically relevant primary human B cells and monocytes, resting and treated with interferon-gamma, in the context of the epigenomic regulatory landscape and DNA-binding proteins associated with the CIITA enhanceosome including RFX, CREB1/ATF1 and NFY. We confirm recruitment to proximal promoter sequences in MHC class II genes and more distally involving the canonical CIITA enhanceosome. Overall, we map 843 CIITA binding intervals involving 442 genes and find 95% of intervals are located outside the MHC and 60% not associated with RFX5 binding. Binding intervals are enriched for genes involved in immune function and infectious disease with novel loci including major histone gene clusters. We resolve differentially expressed genes associated in trans with a CIITA intronic sequence variant, integrate with CIITA recruitment and show how this is mediated by allele-specific recruitment of NF-kB. Conclusions Our results indicate a broader role for CIITA beyond the MHC involving immune-related genes. We provide new insights into allele-specific regulation of CIITA informative for understanding gene function and disease. Electronic supplementary material The online version of this article (doi:10.1186/s13059-014-0494-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Daniel Wong
- Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt, Drive, Oxford OX3 7BN, UK
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The class II transactivator (CIITA) is regulated by post-translational modification cross-talk between ERK1/2 phosphorylation, mono-ubiquitination and Lys63 ubiquitination. Biosci Rep 2015; 35:BSR20150091. [PMID: 26181363 PMCID: PMC4613680 DOI: 10.1042/bsr20150091] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 06/11/2015] [Indexed: 02/01/2023] Open
Abstract
The class II transactivator (CIITA) is known as the master regulator for the major histocompatibility class II (MHC II) molecules. CIITA is dynamically regulated through a series of intricate post-translational modifications (PTMs). CIITA's role is to initiate transcription of MHC II genes, which are responsible for presenting extracellular antigen to CD4(+) T-cells. In the present study, we identified extracellular signal-regulated kinase (ERK)1/2 as the kinase responsible for phosphorylating the regulatory site, Ser(280), which leads to increased levels of mono-ubiquitination and an overall increase in MHC II activity. Further, we identify that CIITA is also modified by Lys(63)-linked ubiquitination. Lys(63) ubiquitinated CIITA is concentrated in the cytoplasm and following activation of ERK1/2, CIITA phosphorylation occurs and Lys=ubiquitinated CIITA translocates to the nucleus. CIITA ubiquitination and phosphorylation perfectly demonstrates how CIITA location and activity is regulated through PTM cross-talk. Identifying CIITA PTMs and understanding how they mediate CIITA regulation is necessary due to the critical role CIITA has in the initiation of the adaptive immune response.
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Bovine leukemia virus: a major silent threat to proper immune responses in cattle. Vet Immunol Immunopathol 2014; 163:103-14. [PMID: 25554478 DOI: 10.1016/j.vetimm.2014.11.014] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 10/27/2014] [Accepted: 11/26/2014] [Indexed: 11/22/2022]
Abstract
Bovine leukemia virus (BLV) infection is widespread in the US dairy industry and the majority of producers do not actively try to manage or reduce BLV incidence within their herds. However, BLV is estimated to cost the dairy industry hundreds of millions of dollars annually and this is likely a conservative estimate. BLV is not thought to cause animal distress or serious pathology unless infection progresses to leukemia or lymphoma. However, a wealth of research supports the notion that BLV infection causes widespread abnormal immune function. BLV infection can impact cells of both the innate and adaptive immune system and alter proper functioning of uninfected cells. Despite strong evidence of abnormal immune signaling and functioning, little research has investigated the large-scale effects of BLV infection on host immunity and resistance to other infectious diseases. This review focuses on mechanisms of immune suppression associated with BLV infection, specifically aberrant signaling, proliferation and apoptosis, and the implications of switching from BLV latency to activation. In addition, this review will highlight underdeveloped areas of research relating to BLV infection and how it causes immune suppression.
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11
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Maganti N, Moody TD, Truax AD, Thakkar M, Spring AM, Germann MW, Greer SF. Nonproteolytic roles of 19S ATPases in transcription of CIITApIV genes. PLoS One 2014; 9:e91200. [PMID: 24625964 PMCID: PMC3953376 DOI: 10.1371/journal.pone.0091200] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 02/11/2014] [Indexed: 11/19/2022] Open
Abstract
Accumulating evidence shows the 26S proteasome is involved in the regulation of gene expression. We and others have demonstrated that proteasome components bind to sites of gene transcription, regulate covalent modifications to histones, and are involved in the assembly of activator complexes in mammalian cells. The mechanisms by which the proteasome influences transcription remain unclear, although prior observations suggest both proteolytic and non-proteolytic activities. Here, we define novel, non-proteolytic, roles for each of the three 19S heterodimers, represented by the 19S ATPases Sug1, S7, and S6a, in mammalian gene expression using the inflammatory gene CIITApIV. These 19S ATPases are recruited to induced CIITApIV promoters and also associate with CIITA coding regions. Additionally, these ATPases interact with elongation factor PTEFb complex members CDK9 and Hexim-1 and with Ser5 phosphorylated RNA Pol II. Both the generation of transcripts from CIITApIV and efficient recruitment of RNA Pol II to CIITApIV are negatively impacted by siRNA mediated knockdown of these 19S ATPases. Together, these results define novel roles for 19S ATPases in mammalian gene expression and indicate roles for these ATPases in promoting transcription processes.
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Affiliation(s)
- Nagini Maganti
- Graduate Program in Cell Biology and Immunology, Department of Biology, Georgia State University, Atlanta, Georgia, United States of America
| | - Tomika D. Moody
- Graduate Program in Cell Biology and Immunology, Department of Biology, Georgia State University, Atlanta, Georgia, United States of America
| | - Agnieszka D. Truax
- Graduate Program in Cell Biology and Immunology, Department of Biology, Georgia State University, Atlanta, Georgia, United States of America
| | - Meghna Thakkar
- Graduate Program in Cell Biology and Immunology, Department of Biology, Georgia State University, Atlanta, Georgia, United States of America
| | - Alexander M. Spring
- Department of Chemistry, Georgia State University, Atlanta, Georgia, United States of America
| | - Markus W. Germann
- Department of Chemistry, Georgia State University, Atlanta, Georgia, United States of America
| | - Susanna F. Greer
- Graduate Program in Cell Biology and Immunology, Department of Biology, Georgia State University, Atlanta, Georgia, United States of America
- * E-mail:
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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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Cai Q, Banerjee S, Cervini A, Lu J, Hislop AD, Dzeng R, Robertson ES. IRF-4-mediated CIITA transcription is blocked by KSHV encoded LANA to inhibit MHC II presentation. PLoS Pathog 2013; 9:e1003751. [PMID: 24204280 PMCID: PMC3814934 DOI: 10.1371/journal.ppat.1003751] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 09/23/2013] [Indexed: 01/18/2023] Open
Abstract
Peptides presentation to T cells by MHC class II molecules is of importance in initiation of immune response to a pathogen. The level of MHC II expression directly influences T lymphocyte activation and is often targeted by various viruses. Kaposi's sarcoma-associated herpesvirus (KSHV) encoded LANA is known to evade MHC class I peptide processing, however, the effect of LANA on MHC class II remains unclear. Here, we report that LANA down-regulates MHC II expression and presentation by inhibiting the transcription of MHC II transactivator (CIITA) promoter pIII and pIV in a dose-dependent manner. Strikingly, although LANA knockdown efficiently disrupts the inhibition of CIITA transcripts from its pIII and pIV promoter region, the expression of HLA-DQβ but no other MHC II molecules was significantly restored. Moreover, we revealed that the presentation of HLA-DQβ enhanced by LANA knockdown did not help LANA-specific CD4+ T cell recognition of PEL cells, and the inhibition of CIITA by LANA is independent of IL-4 or IFN-γ signaling but dependent on the direct interaction of LANA with IRF-4 (an activator of both the pIII and pIV CIITA promoters). This interaction dramatically blocked the DNA-binding ability of IRF-4 on both pIII and pIV promoters. Thus, our data implies that LANA can evade MHC II presentation and suppress CIITA transcription to provide a unique strategy of KSHV escape from immune surveillance by cytotoxic T cells.
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Affiliation(s)
- Qiliang Cai
- MOE&MOH Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China
| | - Shuvomoy Banerjee
- Department of Microbiology and the Tumor Virology Program of Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States of America
| | - Amanda Cervini
- Department of Microbiology and the Tumor Virology Program of Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States of America
| | - Jie Lu
- Department of Microbiology and the Tumor Virology Program of Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States of America
| | - Andrew D. Hislop
- School of Cancer Sciences and Medical Research Council Centre for Immune Regulation, The University of Birmingham, Birmingham, United Kingdom
| | - Richard Dzeng
- Department of Microbiology and the Tumor Virology Program of Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States of America
| | - Erle S. Robertson
- Department of Microbiology and the Tumor Virology Program of Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, United States of America
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14
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Park HL, Kim YJ, Na HN, Park MY, Kim JY, Yun CW, Nam JH. IK induced by coxsackievirus B3 infection transiently downregulates expression of MHC class II through increasing cAMP. Viral Immunol 2013; 26:13-24. [PMID: 23409929 DOI: 10.1089/vim.2012.0054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Major histocompatibility complex (MHC) class II expression is critical for the presentation of antigens in the immune response to viral infection. Consequently, some viruses regulate the MHC class II-mediated presentation of viral antigens as a mechanism of immune escape. In this study, we found that Coxsackievirus B3 (CVB3) infection transiently increased IK expression, which reduced the expression of MHC class II (I-A/I-E) on splenic B cells. Interestingly, CVB3-induced IK elevated cAMP, a downstream molecule of the G protein-coupled receptors, which inhibited MHC class II presentation on B cells. Transgenic mice expressing truncated IK showed lower expression of MHC class II on B cells than did wild-type mice after CVB3 infection. Taken together, these results imply that IK plays a role in downregulating MHC class II expression on B cells during CVB3 infection through the induction of cAMP.
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Affiliation(s)
- Hye-Lim Park
- Department of Biotechnology, The Catholic University of Korea, Bucheon, Gyeonggi-do, Republic of Korea
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15
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Cravens PD, Kieseier BC, Hussain R, Herndon E, Arellano B, Ben LH, Timmons BC, Castro-Rojas C, Hartung HP, Hemmer B, Weber MS, Zamvil SS, Stüve O. The neonatal CNS is not conducive for encephalitogenic Th1 T cells and B cells during experimental autoimmune encephalomyelitis. J Neuroinflammation 2013; 10:67. [PMID: 23705890 PMCID: PMC3679999 DOI: 10.1186/1742-2094-10-67] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Accepted: 05/06/2013] [Indexed: 01/07/2023] Open
Abstract
Multiple sclerosis (MS) is thought to be a CD4+ T cell mediated autoimmune demyelinating disease of the central nervous system (CNS) that is rarely diagnosed during infancy. Cellular and molecular mechanisms that confer disease resistance in this age group are unknown. We tested the hypothesis that a differential composition of immune cells within the CNS modulates age-associated susceptibility to CNS autoimmune disease. C57BL/6 mice younger than eight weeks were resistant to experimental autoimmune encephalomyelitis (EAE) following active immunization with myelin oligodendrocyte glycoprotein (MOG) peptide (p) 35-55. Neonates also developed milder EAE after transfer of adult encephalitogenic T cells primed by adult or neonate antigen presenting cells (APC). There was a significant increase in CD45+ hematopoietic immune cells and CD45+ high side scatter granulocytes in the CNS of adults, but not in neonates. Within the CD45+ immune cell compartment of adults, the accumulation of CD4+ T cells, Gr-1+ and Gr-1- monocytes and CD11c+ dendritic cells (DC) was identified. A significantly greater percentage of CD19+ B cells in the adult CNS expressed MHC II than neonate CNS B cells. Only in the adult CNS could IFNγ transcripts be detected 10 days post immunization for EAE. IFNγ is highly expressed by adult donor CD4+ T cells that are adoptively transferred but not by transferred neonate donor cells. In contrast, IL-17 transcripts could not be detected in adult or neonate CNS in this EAE model, and neither adult nor neonate donor CD4+ T cells expressed IL-17 at the time of adoptive transfer.
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Affiliation(s)
- Petra D Cravens
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, 75390-9036, USA
| | - Bernd C Kieseier
- Department of Neurology, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany
| | - Rehana Hussain
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, 75390-9036, USA
| | - Emily Herndon
- Department of Pathology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, 75390, USA
| | - Benjamine Arellano
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, 75390-9036, USA
| | - Li-Hong Ben
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, 75390-9036, USA
| | - Brenda C Timmons
- Hamon Center for Therapeutic Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, 75390, USA
| | - Cyd Castro-Rojas
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, 75390-9036, USA
| | - Hans-Peter Hartung
- Department of Neurology, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany
| | - Bernhard Hemmer
- Department of Neurology, Klinikum rechts der Isar, Technische Universität München, München, 81675, Germany
| | - Martin S Weber
- Department of Neurology, Klinikum rechts der Isar, Technische Universität München, München, 81675, Germany
- Department of Neurology, University Medical Center, Georg August University, Göttingen, 37075, Germany
- Department of Neuropathology, University Medical Center, Georg August University, Göttingen, 37975, Germany
| | - Scott S Zamvil
- Department of Neurology, University of California, San Francisco, CA, 94143, USA
- Program in Immunology, University of California, San Francisco, CA, 94143, USA
| | - Olaf Stüve
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, 75390-9036, USA
- Department of Neurology, Heinrich Heine University Düsseldorf, Düsseldorf, 40225, Germany
- Department of Neurology, Klinikum rechts der Isar, Technische Universität München, München, 81675, Germany
- Neurology Section, VA North Texas Health Care System, Medical Service, 4500 South Lancaster Rd, Dallas, TX, 75216, USA
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16
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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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17
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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: 34] [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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18
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Feng X, Liu T, Wang F, Cao R, Zhou B, Zhang Y, Mao X, Chen P, Zhang H. Isolation, antiproliferation on tumor cell and immunomodulatory activity of BSP-I, a novel bursal peptide from chicken humoral immune system. Peptides 2011; 32:1103-9. [PMID: 21550370 DOI: 10.1016/j.peptides.2011.04.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2011] [Revised: 04/19/2011] [Accepted: 04/21/2011] [Indexed: 01/12/2023]
Abstract
The bursa of Fabricius (BF) is acknowledged as central humoral immune organ unique to birds. Our purpose was to identify the potential function of a novel bursal-derived bioactive peptide. A bursal septpeptide (BSP-I), EPASGMM, first isolated from BF, reduced MCF and Hela tumor cells proliferation, and enhanced antitumor factor p53 luciferase activity and protein expression. Further, we found the significantly immune inducing function of BSP-I on antigen-specific immune response in BALB/c mice intraperitoneally immunized with inactivated avian influence virus (AIV, H(9)N(2) subtype) vaccine, including of enhancing the antibody (IgG, the isotypes IgG1 and IgG2a) production, and stimulating cytokines IL-4 and IFN-γ level, and inducing T cell immunophenotyping and lymphocyte proliferation. These results suggested that as the bioactive peptide from avian humoral immune system, various biological function of BSP-I may have far-reaching implication on immune system significance, which might provide novel insight on linking between humoral immune system and development of effective immunotherapeutic strategies for treating human cancers diseases.
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Affiliation(s)
- Xiuli Feng
- Division of Key Lab of Animal Disease Diagnosis and Immunology of China's Department of Agriculture, Nanjing Agriculture University, Nanjing, China
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19
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Lee AW, Wang N, Hornell TMC, Harding JJ, Deshpande C, Hertel L, Lacaille V, Pashine A, Macaubas C, Mocarski ES, Mellins ED. Human cytomegalovirus decreases constitutive transcription of MHC class II genes in mature Langerhans cells by reducing CIITA transcript levels. Mol Immunol 2011; 48:1160-7. [PMID: 21458073 DOI: 10.1016/j.molimm.2011.02.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2010] [Revised: 02/20/2011] [Accepted: 02/21/2011] [Indexed: 11/29/2022]
Abstract
Human cytomegalovirus (HCMV) productively infects CD34(+) progenitor-derived, mature Langerhans-type dendritic cells (matLC) and reduces surface expression of MHC class II complexes (MHC II) by increasing intracellular retention of these molecules. To determine whether HCMV also inhibits MHC II expression by other mechanisms, we assessed mRNA levels of the class II transcriptional regulator, CIITA, and several of its target genes in infected matLC. Levels of CIITA, HLA-DRA (DRA) and DRB transcripts, and new DR protein synthesis were compared in mock-infected and HCMV-infected cells by quantitative PCR and pulse-chase immunoprecipitation analyses, respectively. CIITA mRNA levels were significantly lower in HCMV-infected matLC as compared to mock-infected cells. When assessed in the presence of Actinomycin D, the stability of CIITA transcripts was not diminished by HCMV. Analysis of promoter-specific CIITA isoforms revealed that types I, III and IV all were decreased by HCMV, a result that differs from changes after incubation of these cells with lipopolysaccharide (LPS). Exposure to UV-inactivated virus failed to reduce CIITA mRNA levels, implicating de novo viral gene expression in this effect. HCMV-infected matLC also expressed lower levels of DR transcripts and reduced DR protein synthesis rates compared to mock-infected matLC. In summary, we demonstrate that HCMV infection of a human dendritic cell subset inhibits constitutive CIITA expression, most likely at the transcriptional level, resulting in reduced MHC II biosynthesis. We suggest this represents a new mechanism of modulation of mature LC by HCMV.
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Affiliation(s)
- Andrew W Lee
- Department of Pediatrics, Program in Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
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20
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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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21
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Guo SQ, Xu JZ, Zou QM, Jiang DM. Immunological study of allogeneic mesenchymal stem cells during bone formation. J Int Med Res 2010; 37:1750-9. [PMID: 20146873 DOI: 10.1177/147323000903700611] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Autologous mesenchymal stem cells (MSCs) are limited in their clinical application because tissue-engineered bone cannot be pre-fabricated. Allogeneic MSCs are readily available but carry the risk of transplant rejection. It is not yet clear whether allogeneic MSCs can induce a rejection response during bone formation. In this study, two strains of genetically unmatched mini-pigs were used as experimental animals to study the immunological changes in MSCs in vitro and in vivo when generating bone. Mini-pig MSCs showed low immunogenicity during osteogenesis both in vitro and in vivo, indicating that allogeneic MSCs had little or no immunogenicity in osteosis. In conclusion, allogeneic MSCs are an important source of seed cells for the tissue engineering of bone. This favours the clinical application of pre-constructed tissue-engineered bone.
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Affiliation(s)
- S Q Guo
- Department of Orthopaedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
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22
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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: 1.6] [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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23
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Souwer Y, Chamuleau MED, van de Loosdrecht AA, Tolosa E, Jorritsma T, Muris JJF, Dinnissen-van Poppel MJ, Snel SN, van de Corput L, Ossenkoppele GJ, Meijer CJLM, Neefjes JJ, Marieke van Ham S. Detection of aberrant transcription of major histocompatibility complex class II antigen presentation genes in chronic lymphocytic leukaemia identifies HLA-DOA mRNA as a prognostic factor for survival. Br J Haematol 2009; 145:334-43. [PMID: 19245431 DOI: 10.1111/j.1365-2141.2009.07625.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In human B cells, effective major histocompatibility complex (MHC) class II-antigen presentation depends not only on MHC class II, but also on the invariant chain (CD74 or Ii), HLA-DM (DM) and HLA-DO (DO), the chaperones regulating the antigen loading process of MHC class II molecules. We analysed immediate ex vivo expression of HLA-DR (DR), CD74, DM and DO in B cell chronic lymphocytic leukaemia (B-CLL). Real-time reverse transcription polymerase chain reaction demonstrated a highly significant upregulation of DRA, CD74, DMB, DOA and DOB mRNA in purified malignant cells compared to B cells from healthy donors. The increased mRNA levels were not translated into enhanced protein levels but could reflect aberrant transcriptional regulation. Indeed, upregulation of DRA, DMB, DOA and DOB mRNA correlated with enhanced expression of class II transactivator (CIITA). In-depth analysis of the various CIITA transcripts demonstrated a significant increased activity of the interferon-gamma-inducible promoter CIITA-PIV in B-CLL. Comparison of the aberrant mRNA levels with clinical outcome identified DOA mRNA as a prognostic indicator for survival. Multivariate analysis revealed that the prognostic value of DOA mRNA was independent of the mutational status of the IGHV genes. Thus, aberrant transcription of DOA forms a novel and additional prognostic indicator for survival in B-CLL.
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Affiliation(s)
- Yuri Souwer
- Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Academical Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
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24
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Tang KC, Trzaska KA, Smirnov SV, Kotenko SV, Schwander SK, Ellner JJ, Rameshwar P. Down-regulation of MHC II in mesenchymal stem cells at high IFN-gamma can be partly explained by cytoplasmic retention of CIITA. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2008; 180:1826-33. [PMID: 18209080 DOI: 10.4049/jimmunol.180.3.1826] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Mesenchymal stem cells (MSCs) are located in postnatal bone marrow, show plasticity, are linked to various bone marrow disorders, exhibit phagocytosis, exert Ag-presenting properties (APC), and are immune suppressive. Unlike professional APCs, MSCs respond bimodally to IFN-gamma in MHC-II expression, with expression at 10 U/ml and baseline, and down-regulation at 100 U/ml. The effects at high IFN-gamma could not be explained by down-regulation of its receptor, IFN-gammaRI. In this study, we report on the mechanisms by which IFN-gamma regulates MHC-II expression in MSCs. Gel shift assay and Western blot analyses showed dose-dependent increases in activated STAT-1, indicating responsiveness by IFN-gammaRI. Western blots showed decreased intracellular MHC-II, which could not be explained by decreased transcription of the master regulator CIITA, based on RT-PCR and in situ immunofluorescence. Reporter gene assays with PIII and PIV CIITA promoters indicate constitutive expression of PIII in MSCs and a switch to PIV by IFN-gamma, indicating the presence of factors for effect promoter responses. We explained decreased MHC-II at the level of transcription because CIITA protein was observed in the cytosol and not in nuclei at high IFN-gamma level. The proline/serine/threonine region of CIITA showed significant decrease in phosphorylation at high IFN-gamma levels. An understanding of the bimodal effects could provide insights on bone marrow homeostasis, which could be extrapolated to MSC dysfunction in hematological disorders.
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Affiliation(s)
- Katherine C Tang
- Graduate School of Biomedical Sciences, University of Medicine and Dentistry of New Jersey, 185 South Orange Avenue, Newark, NJ 07103, USA
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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: 1.0] [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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26
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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: 30] [Impact Index Per Article: 1.8] [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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27
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Hastings KT, Lackman RL, Cresswell P. Functional Requirements for the Lysosomal Thiol Reductase GILT in MHC Class II-Restricted Antigen Processing. THE JOURNAL OF IMMUNOLOGY 2006; 177:8569-77. [PMID: 17142755 DOI: 10.4049/jimmunol.177.12.8569] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ag processing and presentation via MHC class II is essential for activation of CD4(+) T lymphocytes. gamma-IFN-inducible lysosomal thiol reductase (GILT) is present in the MHC class II loading compartment and has been shown to facilitate class II Ag processing and recall responses to Ags containing disulfide bonds such as hen egg lysozyme (HEL). Reduction of proteins within the MHC class II loading compartment is hypothesized to expose residues for class II binding and protease trimming. In vitro analysis has shown that the active site of GILT involves Cys(46) and Cys(49), present in a CXXC motif that shares similarity with the thioredoxin family. To define the functional requirements for GILT in MHC class II Ag processing, a GILT-deficient murine B cell lymphoma line was generated and stably transduced with wild-type and cysteine mutants of GILT. Intracellular flow cytometric, immunoblotting, and immunofluorescence analyses demonstrated that wild-type and mutant GILT were expressed and maintained lysosomal localization. Transduction with wild-type GILT reconstituted MHC class II processing of a GILT-dependent HEL epitope. Mutation of either Cys(46) or Cys(49) abrogated MHC class II processing of a GILT-dependent HEL epitope. In addition, biochemical analysis of these mutants suggested that the active site facilitates processing of precursor GILT to the mature form. Precursor forms of GILT-bearing mutations in Cys(200) or Cys(211), previously found to display thiol reductase activity in vitro, could not mediate Ag processing. These studies demonstrate that the thiol reductase activity of GILT is its essential function in MHC class II-restricted Ag processing.
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Affiliation(s)
- K Taraszka Hastings
- Department of Dermatology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06520, USA
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28
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Tooze RM, Stephenson S, Doody GM. Repression of IFN-γ Induction of Class II Transactivator: A Role for PRDM1/Blimp-1 in Regulation of Cytokine Signaling. THE JOURNAL OF IMMUNOLOGY 2006; 177:4584-93. [PMID: 16982896 DOI: 10.4049/jimmunol.177.7.4584] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
MHC class II is expressed in restricted lineages and is modulated in response to pathogens and inflammatory stimuli. This expression is controlled by MHC CIITA, which is transcribed from multiple promoters. Although factors required for induction of CIITA are well characterized, less is known about the mechanisms leading to repression of this gene. During plasma cell differentiation, B lymphocyte-induced maturation protein-1 (PRDM1/Blimp-1) represses promoter (p)III of CIITA, responsible for constitutive expression in B cells. pIV is inducible by IFN-gamma in epithelia, macrophages and B cells. An IFN regulatory factor-element (IRF-E) in CIITA-pIV, which is bound by IRF-1 and IRF-2, is necessary for this response. This site matches the PRDM1/Blimp-1 consensus binding site, and PRDM1/Blimp-1 is expressed in cell lineages in which this promoter is operative. We, therefore, investigated whether PRDM1 regulates CIITA-pIV and found that PRDM1 bound to CIITA-pIV in vivo and the IRF-E in vitro. PRDM1 repressed IFN-gamma-mediated induction of a CIITA-pIV luciferase reporter in a fashion dependent on an intact consensus sequence and competes with IRF-1/IRF-2 for binding to the IRF-E and promoter activation. In human myeloma cell lines that express IRFs, PRDM1 occupancy of CIITA-pIV was associated with resistance to IFN-gamma stimulation, while short interfering RNA knockdown of PRDM1 led to up-regulation of CIITA. Our data indicate that PRDM1 is a repressor of CIITA-pIV, identifying a target of particular relevance to macrophages and epithelia. These findings support a model in which PRDM1/Blimp-1 can modulate the cellular response to IFN-gamma by competing with IRF-1/IRF-2 dependent activation of target promoters.
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Affiliation(s)
- Reuben M Tooze
- Section of Experimental Hematology, Leeds Institute of Molecular Medicine, St James's University Hospital, University of Leeds, Leeds LS9 7TF, U.K
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29
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Green MR, Yoon H, Boss JM. Epigenetic Regulation during B Cell Differentiation Controls CIITA Promoter Accessibility. THE JOURNAL OF IMMUNOLOGY 2006; 177:3865-73. [PMID: 16951349 DOI: 10.4049/jimmunol.177.6.3865] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
B cell to plasma cell maturation is marked by the loss of MHC class II expression. This loss is due to the silencing of the MHC class II transcriptional coactivator CIITA. In this study, experiments to identify the molecular mechanism responsible for CIITA silencing were conducted. CIITA is expressed from four promoters in humans, of which promoter III (pIII) controls the majority of B cell-mediated expression. Chromatin immunoprecipitation assays were used to establish the histone code for pIII and determine the differences between B cells and plasma cells. Specific histone modifications associated with accessible promoters and transcriptionally active genes were observed at pIII in B cells but not in plasma cells. A reciprocal exchange of histone H3 lysine 9 acetylation to methylation was also observed between B cells and plasma cells. The lack of histone acetylation correlated with an absence of transcription factor binding to pIII, particularly that of Sp1, PU.1, CREB, and E47. Intriguingly, changes in chromatin architecture of the 13-kb region encompassing all CIITA promoters showed a remarkable deficit in histone H3 and H4 acetylation in plasma cells, suggesting that the mechanism of silencing is global. When primary B cells were differentiated ex vivo, most of the histone marks associated with pIII activation and expression were lost within 24 h. The results demonstrate that CIITA silencing occurs by controlling chromatin accessibility through a multistep mechanism that includes the loss of histone acetylation and transcription factor binding, and the acquisition of repressive histone methylation marks.
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Affiliation(s)
- Myesha R Green
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA
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30
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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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31
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Harris PE, Malanga D, Liu Z, Hardy MA, Souza F, Del Pozzo G, Winchester RJ, Maffei A. Effect of interferon alpha on MHC class II gene expression in ex vivo human islet tissue. Biochim Biophys Acta Mol Basis Dis 2006; 1762:627-35. [PMID: 16782520 DOI: 10.1016/j.bbadis.2006.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2006] [Revised: 05/05/2006] [Accepted: 05/09/2006] [Indexed: 10/24/2022]
Abstract
Type 1 diabetes (T1D) is caused by autoimmune destruction of the insulin-producing beta-cells of the islets of Langerhans. One still open question is where naive islet-reactive T cells encounter antigens and become stimulated. In this report we have re-examined the expression of MHC class II (MHCII) genes in human islets to further explore the possibility that non-professional antigen presenting cells (APCs) within islets contribute to autoimmunity. Since development of T1D has been linked to viral infections, we also studied ex-vivo MHCII expression in response to interferon-alpha (IFNalpha) in islet tissue and in different APCs. The findings are: first, MHCII genes expression in human islets is linked with the expression of the class II transactivator isoform transcribed from the promoter IV, similar to that described in non-professional APCs. Second, there is IFNalpha-mediated lineage-specific regulation of MHCII genes expression, seen as a decrease in the accumulation of MHCII transcripts in pancreatic islets opposite to an increase in dendritic cells and B-lymphoblastoid cell lines. Third, there is allele-specific regulation of the HLA-DQA1 gene by IFNalpha in islet tissue. These findings may begin to explain the molecular events that create favorable conditions for organ-specific autoimmunity and explain the incomplete penetrance of T1D susceptibility alleles.
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Affiliation(s)
- Paul E Harris
- Institute of Genetics and Biophysics Adriano Buzzati-Traverso, Consiglio Nazionale delle Ricerche, Naples, Italy
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32
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Butticè G, Miller J, Wang L, Smith BD. Interferon-gamma induces major histocompatibility class II transactivator (CIITA), which mediates collagen repression and major histocompatibility class II activation by human aortic smooth muscle cells. Circ Res 2006; 98:472-9. [PMID: 16439692 PMCID: PMC1388256 DOI: 10.1161/01.res.0000204725.46332.97] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Chronic inflammation in atherosclerosis is responsible for plaque instability through alterations in extracellular matrix. Previously, we demonstrated that major histocompatibility class II (MHC II) transactivator (CIITA) in a complex with regulatory factor for X box 5 (RFX5) is a crucial protein mediating interferon (IFN)-gamma-induced repression of collagen type I gene transcription in fibroblasts. This article demonstrates that, in smooth muscle cells (SMCs), IFN-gamma dramatically increases the expression of CIITA isoforms III and IV, with no increase in expression of CIITA isoform I. Expression of CIITA III and IV correlates with decreased collagen type I and increased MHC II gene expression. Exogenous expression of CIITA I, III, and IV, in transiently transfected SMCs, represses collagen type I promoters (COL1A1 and COL1A2) and activates MHC II promoter. Levels of CIITA and RFX5 increase in the nucleus of cells treated with IFN-gamma. Moreover, simvastatin lowers the IFN-gamma-induced expression of RFX5 and MHC II in addition to repressing collagen expression. However, simvastatin does not block the IFN-gamma-induced expression of CIITA III and IV, suggesting a CIITA-independent mechanism. This first demonstration that RFX5 and CIITA isoforms are expressed in SMCs after IFN-gamma stimulation suggest that CIITA could be a key factor in plaque stability in atherosclerosis.
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Affiliation(s)
- Giovanna Butticè
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118, USA
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