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Sanges S, Tian W, Dubucquoi S, Chang JL, Collet A, Launay D, Nicolls MR. B-cells in pulmonary arterial hypertension: friend, foe or bystander? Eur Respir J 2024; 63:2301949. [PMID: 38485150 PMCID: PMC11043614 DOI: 10.1183/13993003.01949-2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 03/01/2024] [Indexed: 04/22/2024]
Abstract
There is an unmet need for new therapeutic strategies that target alternative pathways to improve the prognosis of patients with pulmonary arterial hypertension (PAH). As immunity has been involved in the development and progression of vascular lesions in PAH, we review the potential contribution of B-cells in its pathogenesis and evaluate the relevance of B-cell-targeted therapies. Circulating B-cell homeostasis is altered in PAH patients, with total B-cell lymphopenia, abnormal subset distribution (expansion of naïve and antibody-secreting cells, reduction of memory B-cells) and chronic activation. B-cells are recruited to the lungs through local chemokine secretion, and activated by several mechanisms: 1) interaction with lung vascular autoantigens through cognate B-cell receptors; 2) costimulatory signals provided by T follicular helper cells (interleukin (IL)-21), type 2 T helper cells and mast cells (IL-4, IL-6 and IL-13); and 3) increased survival signals provided by B-cell activating factor pathways. This activity results in the formation of germinal centres within perivascular tertiary lymphoid organs and in the local production of pathogenic autoantibodies that target the pulmonary vasculature and vascular stabilisation factors (including angiotensin-II/endothelin-1 receptors and bone morphogenetic protein receptors). B-cells also mediate their effects through enhanced production of pro-inflammatory cytokines, reduced anti-inflammatory properties by regulatory B-cells, immunoglobulin (Ig)G-induced complement activation, and IgE-induced mast cell activation. Precision-medicine approaches targeting B-cell immunity are a promising direction for select PAH conditions, as suggested by the efficacy of anti-CD20 therapy in experimental models and a trial of rituximab in systemic sclerosis-associated PAH.
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Affiliation(s)
- Sébastien Sanges
- Univ. Lille, U1286 - INFINITE - Institute for Translational Research in Inflammation, F-59000 Lille, France
- INSERM, F-59000 Lille, France
- CHU Lille, Département de Médecine Interne et Immunologie Clinique, F-59000 Lille, France
- Centre National de Référence Maladies Auto-immunes Systémiques Rares du Nord, Nord-Ouest, Méditerranée et Guadeloupe (CeRAINOM), F-59000 Lille, France
- Health Care Provider of the European Reference Network on Rare Connective Tissue and Musculoskeletal Diseases Network (ReCONNET), F-59000 Lille, France
- Veteran Affairs Palo Alto Health Care System, Palo Alto, CA, USA
- Division of Pulmonary, Allergy, and Critical Care Medicine, Stanford University, School of Medicine, Stanford, CA, USA
- Both authors contributed equally and share co-first authorship
| | - Wen Tian
- Veteran Affairs Palo Alto Health Care System, Palo Alto, CA, USA
- Division of Pulmonary, Allergy, and Critical Care Medicine, Stanford University, School of Medicine, Stanford, CA, USA
- Both authors contributed equally and share co-first authorship
| | - Sylvain Dubucquoi
- Univ. Lille, U1286 - INFINITE - Institute for Translational Research in Inflammation, F-59000 Lille, France
- INSERM, F-59000 Lille, France
- CHU Lille, Institut d'Immunologie, Pôle de Biologie Pathologie Génétique, F-59000 Lille, France
| | - Jason L Chang
- Veteran Affairs Palo Alto Health Care System, Palo Alto, CA, USA
- Division of Pulmonary, Allergy, and Critical Care Medicine, Stanford University, School of Medicine, Stanford, CA, USA
| | - Aurore Collet
- Univ. Lille, U1286 - INFINITE - Institute for Translational Research in Inflammation, F-59000 Lille, France
- INSERM, F-59000 Lille, France
- CHU Lille, Institut d'Immunologie, Pôle de Biologie Pathologie Génétique, F-59000 Lille, France
| | - David Launay
- Univ. Lille, U1286 - INFINITE - Institute for Translational Research in Inflammation, F-59000 Lille, France
- INSERM, F-59000 Lille, France
- CHU Lille, Département de Médecine Interne et Immunologie Clinique, F-59000 Lille, France
- Centre National de Référence Maladies Auto-immunes Systémiques Rares du Nord, Nord-Ouest, Méditerranée et Guadeloupe (CeRAINOM), F-59000 Lille, France
- Health Care Provider of the European Reference Network on Rare Connective Tissue and Musculoskeletal Diseases Network (ReCONNET), F-59000 Lille, France
- Veteran Affairs Palo Alto Health Care System, Palo Alto, CA, USA
- Division of Pulmonary, Allergy, and Critical Care Medicine, Stanford University, School of Medicine, Stanford, CA, USA
- Both authors contributed equally and share co-last authorship
| | - Mark R Nicolls
- Veteran Affairs Palo Alto Health Care System, Palo Alto, CA, USA
- Division of Pulmonary, Allergy, and Critical Care Medicine, Stanford University, School of Medicine, Stanford, CA, USA
- Both authors contributed equally and share co-last authorship
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2
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Chi W, Kang N, Sheng L, Liu S, Tao L, Cao X, Liu Y, Zhu C, Zhang Y, Wu B, Chen R, Cheng L, Wang J, Sun X, Liu X, Deng H, Yang J, Li Z, Liu W, Chen L. MCT1-governed pyruvate metabolism is essential for antibody class-switch recombination through H3K27 acetylation. Nat Commun 2024; 15:163. [PMID: 38167945 PMCID: PMC10762154 DOI: 10.1038/s41467-023-44540-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 12/18/2023] [Indexed: 01/05/2024] Open
Abstract
Monocarboxylate transporter 1 (MCT1) exhibits essential roles in cellular metabolism and energy supply. Although MCT1 is highly expressed in activated B cells, it is not clear how MCT1-governed monocarboxylates transportation is functionally coupled to antibody production during the glucose metabolism. Here, we report that B cell-lineage deficiency of MCT1 significantly influences the class-switch recombination (CSR), rendering impaired IgG antibody responses in Mct1f/fMb1Cre mice after immunization. Metabolic flux reveals that glucose metabolism is significantly reprogrammed from glycolysis to oxidative phosphorylation in Mct1-deficient B cells upon activation. Consistently, activation-induced cytidine deaminase (AID), is severely suppressed in Mct1-deficient B cells due to the decreased level of pyruvate metabolite. Mechanistically, MCT1 is required to maintain the optimal concentration of pyruvate to secure the sufficient acetylation of H3K27 for the elevated transcription of AID in activated B cells. Clinically, we found that MCT1 expression levels are significantly upregulated in systemic lupus erythematosus patients, and Mct1 deficiency can alleviate the symptoms of bm12-induced murine lupus model. Collectively, these results demonstrate that MCT1-mediated pyruvate metabolism is required for IgG antibody CSR through an epigenetic dependent AID transcription, revealing MCT1 as a potential target for vaccine development and SLE disease treatment.
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Affiliation(s)
- Wenna Chi
- School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing, 100084, China
- Collaborative Innovation Center for Biotherapy, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, 610065, China
| | - Na Kang
- State Key Laboratory of Membrane Biology, School of Life Sciences, Institute for Immunology, China Ministry of Education Key Laboratory of Protein Sciences, Beijing Key Lab for Immunological Research on Chronic Diseases, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, China
| | - Linlin Sheng
- School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing, 100084, China
| | - Sichen Liu
- State Key Laboratory of Membrane Biology, School of Life Sciences, Institute for Immunology, China Ministry of Education Key Laboratory of Protein Sciences, Beijing Key Lab for Immunological Research on Chronic Diseases, Tsinghua University, Beijing, 100084, China
| | - Lei Tao
- School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing, 100084, China
- Collaborative Innovation Center for Biotherapy, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, 610065, China
| | - Xizhi Cao
- School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing, 100084, China
| | - Ye Liu
- School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing, 100084, China
| | - Can Zhu
- State Key Laboratory of Membrane Biology, School of Life Sciences, Institute for Immunology, China Ministry of Education Key Laboratory of Protein Sciences, Beijing Key Lab for Immunological Research on Chronic Diseases, Tsinghua University, Beijing, 100084, China
| | - Yuming Zhang
- School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing, 100084, China
| | - Bolong Wu
- School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing, 100084, China
| | - Ruiqun Chen
- School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing, 100084, China
| | - Lili Cheng
- School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing, 100084, China
| | - Jing Wang
- State Key Laboratory of Membrane Biology, School of Life Sciences, Institute for Immunology, China Ministry of Education Key Laboratory of Protein Sciences, Beijing Key Lab for Immunological Research on Chronic Diseases, Tsinghua University, Beijing, 100084, China
| | - Xiaolin Sun
- Department of Rheumatology and Immunology, Peking University People's Hospital, Beijing, 100044, China
- Beijing Key Laboratory for Rheumatism Mechanism and Immune Diagnosis (BZ0135), Beijing, 100044, China
| | - Xiaohui Liu
- National Center for Protein Science, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Haiteng Deng
- National Center for Protein Science, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Jinliang Yang
- Collaborative Innovation Center for Biotherapy, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, 610065, China
| | - Zhanguo Li
- Tsinghua-Peking Center for Life Sciences, Beijing, China
- Department of Rheumatology and Immunology, Peking University People's Hospital, Beijing, 100044, China
- Beijing Key Laboratory for Rheumatism Mechanism and Immune Diagnosis (BZ0135), Beijing, 100044, China
| | - Wanli Liu
- State Key Laboratory of Membrane Biology, School of Life Sciences, Institute for Immunology, China Ministry of Education Key Laboratory of Protein Sciences, Beijing Key Lab for Immunological Research on Chronic Diseases, Tsinghua University, Beijing, 100084, China.
- Tsinghua-Peking Center for Life Sciences, Beijing, China.
| | - Ligong Chen
- School of Pharmaceutical Sciences, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing, 100084, China.
- Collaborative Innovation Center for Biotherapy, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, 610065, China.
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Kiruthiga C, Niharika K, Devi KP. Phytol and α-Bisabolol Synergy Induces Autophagy and Apoptosis in A549 Cells and Additional Molecular Insights through Comprehensive Proteome Analysis via Nano LC-MS/MS. Anticancer Agents Med Chem 2024; 24:773-788. [PMID: 38415491 DOI: 10.2174/0118715206289038240214102951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/23/2024] [Accepted: 01/29/2024] [Indexed: 02/29/2024]
Abstract
BACKGROUND Non-Small Cell Lung Cancer (NSCLC) is a malignancy with a significant prevalence and aggressive nature, posing a considerable challenge in terms of therapeutic interventions. Autophagy and apoptosis, two intricate cellular processes, are integral to NSCLC pathophysiology, each affecting the other through shared signaling pathways. Phytol (Phy) and α-bisabolol (Bis) have shown promise as potential anticancer agents individually, but their combined effects in NSCLC have not been extensively investigated. OBJECTIVE The present study was to examine the synergistic impact of Phy and Bis on NSCLC cells, particularly in the context of autophagy modulation, and to elucidate the resulting differential protein expression using LCMS/ MS analysis. METHODS The A549 cell lines were subjected to the patented effective concentration of Phy and Bis, and subsequently, the viability of the cells was evaluated utilizing the MTT assay. The present study utilized real-time PCR analysis to assess the expression levels of crucial apoptotic genes, specifically Bcl-2, Bax, and Caspase-9, as well as autophagy-related genes, including Beclin-1, SQSTM1, Ulk1, and LC3B. The confirmation of autophagy marker expression (Beclin-1, LC3B) and the autophagy-regulating protein SQSTM1 was achieved through the utilization of Western blot analysis. Differentially expressed proteins were found using LC-MS/MS analysis. RESULTS The combination of Phy and Bis demonstrated significant inhibition of NSCLC cell growth, indicating their synergistic effect. Real-time PCR analysis revealed a shift towards apoptosis, with downregulation of Bcl-2 and upregulation of Bax and Caspase-9, suggesting a shift towards apoptosis. Genes associated with autophagy regulation, including Beclin-1, SQSTM1 (p62), Ulk1, and LC3B, showed significant upregulation, indicating potential induction of autophagy. Western blot analysis confirmed increased expression of autophagy markers, such as Beclin-1 and LC3B, while the autophagy-regulating protein SQSTM1 exhibited a significant decrease. LC-MS/MS analysis revealed differential expression of 861 proteins, reflecting the modulation of cellular processes. Protein-protein interaction network analysis highlighted key proteins involved in apoptotic and autophagic pathways, including STOML2, YWHAB, POX2, B2M, CDA, CAPN2, TXN, ECHS1, PEBP1, PFN1, CDC42, TUBB1, HSPB1, PXN, FGF2, and BAG3, emphasizing their crucial roles. Additionally, PANTHER pathway analysis uncovered enriched pathways associated with the differentially expressed proteins, revealing their involvement in a diverse range of biological processes, encompassing cell signaling, metabolism, and cellular stress responses. CONCLUSION The combined treatment of Phy and Bis exerts a synergistic inhibitory effect on NSCLC cell growth, mediated through the interplay of apoptosis and autophagy. The differential protein expression observed, along with the identified proteins and enriched pathways, provides valuable insights into the underlying molecular mechanisms. These findings offer a foundation for further exploration of the therapeutic potential of Phy and Bis in the management of NSCLC.
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Affiliation(s)
| | - Kambati Niharika
- Department of Biotechnology, Alagappa University, Karaikudi, 630 003, Tamil Nadu, India
| | - Kasi Pandima Devi
- Department of Biotechnology, Alagappa University, Karaikudi, 630 003, Tamil Nadu, India
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4
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King JJ, Borzooee F, Im J, Asgharpour M, Ghorbani A, Diamond CP, Fifield H, Berghuis L, Larijani M. Structure-Based Design of First-Generation Small Molecule Inhibitors Targeting the Catalytic Pockets of AID, APOBEC3A, and APOBEC3B. ACS Pharmacol Transl Sci 2021; 4:1390-1407. [PMID: 34423273 PMCID: PMC8369683 DOI: 10.1021/acsptsci.1c00091] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Indexed: 12/12/2022]
Abstract
![]()
Activation-induced
cytidine deaminase (AID) initiates antibody
diversification by mutating immunoglobulin loci in B lymphocytes.
AID and related APOBEC3 (A3) enzymes also induce genome-wide mutations
and lesions implicated in tumorigenesis and tumor progression. The
most prevalent mutation signatures across diverse tumor genomes are
attributable to the mistargeted mutagenic activities of AID/A3s. Thus,
inhibiting AID/A3s has been suggested to be of therapeutic benefit.
We previously used a computational-biochemical approach to gain insight
into the structure of AID’s catalytic pocket, which resulted
in the discovery of a novel type of regulatory catalytic pocket closure
that regulates AID/A3s that we termed the “Schrodinger’s
CATalytic pocket”. Our findings were subsequently confirmed
by direct structural studies. Here, we describe our search for small
molecules that target the catalytic pocket of AID. We identified small
molecules that inhibit purified AID, AID in cell extracts, and endogenous
AID of lymphoma cells. Analogue expansion yielded derivatives with
improved potencies. These were found to also inhibit A3A and A3B,
the two most tumorigenic siblings of AID. Two compounds exhibit low
micromolar IC50 inhibition of AID and A3A, exhibiting the
strongest potency for A3A. Docking suggests key interactions between
their warheads and residues lining the catalytic pockets of AID, A3A,
and A3B and between the tails and DNA-interacting residues on the
surface proximal to the catalytic pocket opening. Accordingly, mutants
of these residues decreased inhibition potency. The chemistry and
abundance of key stabilizing interactions between the small molecules
and residues within and immediately outside the catalytic pockets
are promising for therapeutic development.
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Affiliation(s)
- Justin J King
- Department of Molecular Biology and Biochemistry, Faculty of Science, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.,Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3 V6, Canada
| | - Faezeh Borzooee
- Department of Molecular Biology and Biochemistry, Faculty of Science, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.,Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3 V6, Canada
| | - Junbum Im
- Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3 V6, Canada.,BC Cancer Research/Terry Fox Labs, University of British Columbia, Vancouver, British Columbia BC V5Z 1L3, Canada
| | - Mahdi Asgharpour
- Department of Molecular Biology and Biochemistry, Faculty of Science, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.,Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3 V6, Canada
| | - Atefeh Ghorbani
- Department of Molecular Biology and Biochemistry, Faculty of Science, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.,Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3 V6, Canada
| | - Cody P Diamond
- Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3 V6, Canada
| | - Heather Fifield
- Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3 V6, Canada
| | - Lesley Berghuis
- Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3 V6, Canada
| | - Mani Larijani
- Department of Molecular Biology and Biochemistry, Faculty of Science, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.,Program in immunology and Infectious Diseases, Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3 V6, Canada
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5
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Hong H, Gao M, Wu Q, Yang P, Liu S, Li H, Burrows PD, Cua D, Chen JY, Hsu HC, Mountz JD. IL-23 Promotes a Coordinated B Cell Germinal Center Program for Class-Switch Recombination to IgG2b in BXD2 Mice. THE JOURNAL OF IMMUNOLOGY 2020; 205:346-358. [PMID: 32554431 DOI: 10.4049/jimmunol.2000280] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 05/14/2020] [Indexed: 12/12/2022]
Abstract
IL-23 promotes autoimmune disease, including Th17 CD4 T cell development and autoantibody production. In this study, we show that a deficiency of the p19 component of IL-23 in the autoimmune BXD2 (BXD2-p19-/- ) mouse leads to a shift of the follicular T helper cell program from follicular T helper (Tfh)-IL-17 to Tfh-IFN-γ. Although the germinal center (GC) size and the number of GC B cells remained the same, BXD2-p19-/- mice exhibited a lower class-switch recombination (CSR) in the GC B cells, leading to lower serum levels of IgG2b. Single-cell transcriptomics analysis of GC B cells revealed that whereas Ifngr1, Il21r, and Il4r genes exhibited a synchronized expression pattern with Cxcr5 and plasma cell program genes, Il17ra exhibited a synchronized expression pattern with Cxcr4 and GC program genes. Downregulation of Ighg2b in BXD2-p19-/- GC B cells was associated with decreased expression of CSR-related novel base excision repair genes that were otherwise predominantly expressed by Il17ra + GC B cells in BXD2 mice. Together, these results suggest that although IL-23 is dispensable for GC formation, it is essential to promote a population of Tfh-IL-17 cells. IL-23 acts indirectly on Il17ra + GC B cells to facilitate CSR-related base excision repair genes during the dark zone phase of GC B cell development.
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Affiliation(s)
- Huixian Hong
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Min Gao
- Informatics Institute, the University of Alabama at Birmingham, Birmingham, AL
| | - Qi Wu
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - PingAr Yang
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Shanrun Liu
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - Hao Li
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
| | - Peter D Burrows
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL
| | - Daniel Cua
- Discovery Research, Merck Research Laboratory, Boston, MA; and
| | - Jake Y Chen
- Informatics Institute, the University of Alabama at Birmingham, Birmingham, AL
| | - Hui-Chen Hsu
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL
| | - John D Mountz
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL; .,Department of Medicine, Birmingham VA Medical center, Birmingham, AL
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6
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Hamilton JA, Hsu HC, Mountz JD. Autoreactive B cells in SLE, villains or innocent bystanders? Immunol Rev 2019; 292:120-138. [PMID: 31631359 PMCID: PMC6935412 DOI: 10.1111/imr.12815] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 09/12/2019] [Accepted: 09/23/2019] [Indexed: 12/14/2022]
Abstract
The current concepts for development of autoreactive B cells in SLE (systemic lupus erythematosus) focus on extrinsic stimuli and factors that provoke B cells into tolerance loss. Traditionally, major tolerance loss pathways are thought to be regulated by factors outside the B cell including autoantigen engagement of the B-cell receptor (BCR) with simultaneous type I interferon (IFN) produced by dendritic cells, especially plasmacytoid dendritic cells (pDCs). Later, in autoreactive follicles, B-cells encounter T-follicular helper cells (Tfh) that produce interleukin (IL)-21, IL-4 and pathogenic cytokines, IL-17 and IFN gamma (IFNɣ). This review discusses these mechanisms and also highlights recent advances pointing to the peripheral transitional B-cell stage as a major juncture where transient autocrine IFNβ expression by developing B-cells imprints a heightened susceptibility to external factors favoring differentiation into autoantibody-producing plasmablasts. Recent studies highlight transitional B-cell heterogeneity as a determinant of intrinsic resistance or susceptibility to tolerance loss through the shaping of B-cell responsiveness to cytokines and other environment factors.
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Affiliation(s)
| | - Hui-Chen Hsu
- University of Alabama at Birmingham, Birmingham, AL, USA
| | - John D Mountz
- University of Alabama at Birmingham, Birmingham, AL, USA
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8
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McDonald G, Medina CO, Pilichowska M, Kearney JF, Shinkura R, Selsing E, Wortis HH, Honjo T, Imanishi-Kari T. Accelerated Systemic Autoimmunity in the Absence of Somatic Hypermutation in 564Igi: A Mouse Model of Systemic Lupus with Knocked-In Heavy and Light Chain Genes. Front Immunol 2017; 8:1094. [PMID: 28955333 PMCID: PMC5601273 DOI: 10.3389/fimmu.2017.01094] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 08/22/2017] [Indexed: 11/18/2022] Open
Abstract
564Igi mice have knocked-in immunoglobulin (Ig) heavy (H) and light (L) chain genes that encode an autoantibody recognizing RNA. Previously, we showed that these mice produce pathogenic IgG autoantibodies when activation-induced deaminase (AID) is expressed in pre-B and immature B cells but not when it is expressed only in mature B cells. AID has two functions; it is necessary for somatic hypermutation (SHM) and class switch recombination (CSR). To determine the role of each of these functions in the generation of pathogenic autoantibodies, we generated 564Igi mice that carry a mutant AID-encoding gene, Aicda (AicdaG23S), which is capable of promoting CSR but not SHM. We found that 564Igi AicdaG23S mice secreted class-switched antibodies (Abs) at levels approximately equal to 564Igi mice. However, compared to 564Igi mice, 564Igi AicdaG23S mice had increased pathogenic IgG Abs and severe systemic lupus erythematosus-like disease, including, glomerulonephritis, and early death. We suggest that in 564Igi mice SHM by AID changes Ig receptors away from self reactivity, thereby mitigating the production of autoantibody, providing a novel mechanism of tolerance.
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Affiliation(s)
- Gabrielle McDonald
- Department of Integrative Physiology and Pathobiology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, United States
| | - Carlos O Medina
- Department of Integrative Physiology and Pathobiology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, United States
| | - Monika Pilichowska
- Department of Pathology and Laboratory Medicine, Tufts Medical Center, Boston, MA, United States
| | - John F Kearney
- Department of Microbiology, University of Alabama, Birmingham, AL, United States
| | - Reiko Shinkura
- Department of Immunology, Nagahama Institute of Bioscience and Technology, Nagahama, Japan
| | - Erik Selsing
- Department of Integrative Physiology and Pathobiology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, United States
| | - Henry H Wortis
- Department of Integrative Physiology and Pathobiology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, United States
| | - Tasuku Honjo
- Department of Immunology and Genomic Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Thereza Imanishi-Kari
- Department of Integrative Physiology and Pathobiology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, United States
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9
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Regev K, Healy BC, Khalid F, Paul A, Chu R, Tauhid S, Tummala S, Diaz-Cruz C, Raheja R, Mazzola MA, von Glehn F, Kivisakk P, Dupuy SL, Kim G, Chitnis T, Weiner HL, Gandhi R, Bakshi R. Association Between Serum MicroRNAs and Magnetic Resonance Imaging Measures of Multiple Sclerosis Severity. JAMA Neurol 2017; 74:275-285. [PMID: 28114622 DOI: 10.1001/jamaneurol.2016.5197] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Importance MicroRNAs (miRNAs) are promising multiple sclerosis (MS) biomarkers. Establishing the association between miRNAs and magnetic resonance imaging (MRI) measures of disease severity will help define their significance and potential impact. Objective To correlate circulating miRNAs in the serum of patients with MS to brain and spinal MRI. Design, Setting, and Participants A cross-sectional study comparing serum miRNA samples with MRI metrics was conducted at a tertiary MS referral center. Two independent cohorts (41 and 79 patients) were retrospectively identified from the Comprehensive Longitudinal Investigation of Multiple Sclerosis at the Brigham and Women's Hospital. Expression of miRNA was determined by locked nucleic acid-based quantitative real-time polymerase chain reaction. Spearman correlation coefficients were used to test the association between miRNA and brain lesions (T2 hyperintense lesion volume [T2LV]), the ratio of T1 hypointense lesion volume [T1LV] to T2LV [T1:T2]), brain atrophy (whole brain and gray matter), and cervical spinal cord lesions (T2LV) and atrophy. The study was conducted from December 2013 to April 2016. Main Outcomes and Measures miRNA expression. Results Of the 120 patients included in the study, cohort 1 included 41 participants (7 [17.1%] men), with mean (SD) age of 47.7 (9.5) years; cohort 2 had 79 participants (26 [32.9%] men) with a mean (SD) age of 43.0 (7.5) years. Associations between miRNAs and MRIs were both protective and pathogenic. Regarding miRNA signatures, a topographic specificity differed for the brain vs the spinal cord, and the signature differed between T2LV and atrophy/destructive measures. Four miRNAs showed similar significant protective correlations with T1:T2 in both cohorts, with the highest for hsa.miR.143.3p (cohort 1: Spearman correlation coefficient rs = -0.452, P = .003; cohort 2: rs = -0.225, P = .046); the others included hsa.miR.142.5p (cohort 1: rs = -0.424, P = .006; cohort 2: rs = -0.226, P = .045), hsa.miR.181c.3p (cohort 1: rs = -0.383, P = .01; cohort 2: rs = -0.222, P = .049), and hsa.miR.181c.5p (cohort 1: rs = -0.433, P = .005; cohort 2: rs = -0.231, P = .04). In the 2 cohorts, hsa.miR.486.5p (cohort 1: rs = 0.348, P = .03; cohort 2: rs = 0.254, P = .02) and hsa.miR.92a.3p (cohort 1: rs = 0.392, P = .01; cohort 2: rs = 0.222, P = .049) showed similar significant pathogenic correlations with T1:T2; hsa.miR.375 (cohort 1: rs = -0.345, P = .03; cohort 2: rs = -0.257, P = .022) and hsa.miR.629.5p (cohort 1: rs = -0.350, P = .03; cohort 2: rs = -0.269, P = .02) showed significant pathogenic correlations with brain atrophy. Although we found several miRNAs associated with MRI outcomes, none of these associations remained significant when correcting for multiple comparisons, suggesting that further validation of our findings is needed. Conclusions and Relevance Serum miRNAs may serve as MS biomarkers for monitoring disease progression and act as surrogate markers to identify underlying disease processes.
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Affiliation(s)
- Keren Regev
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Brian C Healy
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts2Biostatistics Center, Massachusetts General Hospital, Boston
| | - Fariha Khalid
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts3Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Anu Paul
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Renxin Chu
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts3Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Shahamat Tauhid
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts3Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Subhash Tummala
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts3Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Camilo Diaz-Cruz
- Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Radhika Raheja
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Maria A Mazzola
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Felipe von Glehn
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Pia Kivisakk
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Sheena L Dupuy
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts3Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Gloria Kim
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts3Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Tanuja Chitnis
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts3Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Howard L Weiner
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts3Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Roopali Gandhi
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Rohit Bakshi
- Ann Romney Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts3Partners Multiple Sclerosis Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts4Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
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10
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Li H, Fu YX, Wu Q, Zhou Y, Crossman DK, Yang P, Li J, Luo B, Morel LM, Kabarowski JH, Yagita H, Ware CF, Hsu HC, Mountz JD. Interferon-induced mechanosensing defects impede apoptotic cell clearance in lupus. J Clin Invest 2015; 125:2877-90. [PMID: 26098211 DOI: 10.1172/jci81059] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 04/16/2015] [Indexed: 12/13/2022] Open
Abstract
Systemic lupus erythematosus (SLE) is a severe autoimmune disease that is associated with increased circulating apoptotic cell autoantigens (AC-Ags) as well as increased type I IFN signaling. Here, we describe a pathogenic mechanism in which follicular translocation of marginal zone (MZ) B cells in the spleens of BXD2 lupus mice disrupts marginal zone macrophages (MZMs), which normally clear AC debris and prevent follicular entry of AC-Ags. Phagocytosis of ACs by splenic MZMs required the megakaryoblastic leukemia 1 (MKL1) transcriptional coactivator-mediated mechanosensing pathway, which was maintained by MZ B cells through expression of membrane lymphotoxin-α1β2 (mLT). Specifically, type I IFN-induced follicular shuttling of mLT-expressing MZ B cells disengaged interactions between these MZ B cells and LTβ receptor-expressing MZMs, thereby downregulating MKL1 in MZMs. Loss of MKL1 expression in MZMs led to defective F-actin polymerization, inability to clear ACs, and, eventually, MZM dissipation. Aggregation of plasmacytoid DCs in the splenic perifollicular region, follicular translocation of MZ B cells, and loss of MKL1 and MZMs were also observed in an additional murine lupus model and in the spleens of patients with SLE. Collectively, the results suggest that lupus might be interrupted by strategies that maintain or enhance mechanosensing signaling in the MZM barrier to prevent follicular entry of AC-Ags.
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MESH Headings
- Animals
- Apoptosis/immunology
- Autoantibodies/biosynthesis
- B-Lymphocytes/immunology
- B-Lymphocytes/pathology
- Dendritic Cells/immunology
- Dendritic Cells/pathology
- Disease Models, Animal
- Female
- Humans
- Interferon Type I/immunology
- Lupus Erythematosus, Systemic/genetics
- Lupus Erythematosus, Systemic/immunology
- Lupus Erythematosus, Systemic/pathology
- Lymphotoxin beta Receptor/deficiency
- Lymphotoxin beta Receptor/genetics
- Macrophages/immunology
- Macrophages/pathology
- Mechanotransduction, Cellular/genetics
- Mechanotransduction, Cellular/immunology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Receptors, Immunologic/metabolism
- Serum Response Factor/deficiency
- Serum Response Factor/genetics
- Spleen/immunology
- Spleen/pathology
- Trans-Activators/deficiency
- Trans-Activators/genetics
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11
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Hamilton JA, Li J, Wu Q, Yang P, Luo B, Li H, Bradley JE, Taylor JJ, Randall TD, Mountz JD, Hsu HC. General Approach for Tetramer-Based Identification of Autoantigen-Reactive B Cells: Characterization of La- and snRNP-Reactive B Cells in Autoimmune BXD2 Mice. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2015; 194:5022-34. [PMID: 25888644 PMCID: PMC4417409 DOI: 10.4049/jimmunol.1402335] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 03/15/2015] [Indexed: 11/19/2022]
Abstract
Autoreactive B cells are associated with the development of several autoimmune diseases, including systemic lupus erythematosus and rheumatoid arthritis. The low frequency of these cells represents a major barrier to their analysis. Ag tetramers prepared from linear epitopes represent a promising strategy for the identification of small subsets of Ag-reactive immune cells. This is challenging given the requirement for identification and validation of linear epitopes and the complexity of autoantibody responses, including the broad spectrum of autoantibody specificities and the contribution of isotype to pathogenicity. Therefore, we tested a two-tiered peptide microarray approach, coupled with epitope mapping of known autoantigens, to identify and characterize autoepitopes using the BXD2 autoimmune mouse model. Microarray results were verified through comparison with established age-associated profiles of autoantigen specificities and autoantibody class switching in BXD2 and control (C57BL/6) mice and high-throughput ELISA and ELISPOT analyses of synthetic peptides. Tetramers were prepared from two linear peptides derived from two RNA-binding proteins (RBPs): lupus La and 70-kDa U1 small nuclear ribonucleoprotein. Flow cytometric analysis of tetramer-reactive B cell subsets revealed a significantly higher frequency and greater numbers of RBP-reactive marginal zone precursor, transitional T3, and PDL-2(+)CD80(+) memory B cells, with significantly elevated CD69 and CD86 observed in RBP(+) marginal zone precursor B cells in the spleens of BXD2 mice compared with C57BL/6 mice, suggesting a regulatory defect. This study establishes a feasible strategy for the characterization of autoantigen-specific B cell subsets in different models of autoimmunity and, potentially, in humans.
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Affiliation(s)
- Jennie A Hamilton
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Jun Li
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Qi Wu
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
| | - PingAr Yang
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Bao Luo
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Hao Li
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
| | - John E Bradley
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Justin J Taylor
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109; and
| | - Troy D Randall
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
| | - John D Mountz
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294; Department of Medicine, Birmingham, Alabama VA Medical Center, Birmingham, AL 35233
| | - Hui-Chen Hsu
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294;
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12
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Kim YU, Lim H, Jung HE, Wetsel RA, Chung Y. Regulation of autoimmune germinal center reactions in lupus-prone BXD2 mice by follicular helper T cells. PLoS One 2015; 10:e0120294. [PMID: 25768299 PMCID: PMC4358919 DOI: 10.1371/journal.pone.0120294] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 01/20/2015] [Indexed: 12/22/2022] Open
Abstract
BXD2 mice spontaneously develop autoantibodies and subsequent glomerulonephritis, offering a useful animal model to study autoimmune lupus. Although initial studies showed a critical contribution of IL-17 and Th17 cells in mediating autoimmune B cell responses in BXD2 mice, the role of follicular helper T (Tfh) cells remains incompletely understood. We found that both the frequency of Th17 cells and the levels of IL-17 in circulation in BXD2 mice were comparable to those of wild-type. By contrast, the frequency of PD-1+ CXCR5+ Tfh cells was significantly increased in BXD2 mice compared with wild-type mice, while the frequency of PD-1+ CXCR5+ Foxp3+ follicular regulatory T (Tfr) cells was reduced in the former group. The frequency of Tfh cells rather than that of Th17 cells was positively correlated with the frequency of germinal center B cells as well as the levels of autoantibodies to dsDNA. More importantly, CXCR5+ CD4+ T cells isolated from BXD2 mice induced the production of IgG from naïve B cells in an IL-21-dependent manner, while CCR6+ CD4+ T cells failed to do so. These results together demonstrate that Tfh cells rather than Th17 cells contribute to the autoimmune germinal center reactions in BXD2 mice.
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Affiliation(s)
- Young Uk Kim
- Center for Immunology and Autoimmune Diseases, Institute of Molecular Medicine, the University of Texas Medical School at Houston, Houston, Texas, United States of America; Graduate School of Biomedical Sciences, the University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Hoyong Lim
- Laboratory of Immunobiology, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul, Republic of Korea; Division of AIDS, Korea National Institute of Health, Cheongwon, Chungbuk, Republic of Korea
| | - Ha Eun Jung
- Center for Immunology and Autoimmune Diseases, Institute of Molecular Medicine, the University of Texas Medical School at Houston, Houston, Texas, United States of America
| | - Rick A Wetsel
- Center for Immunology and Autoimmune Diseases, Institute of Molecular Medicine, the University of Texas Medical School at Houston, Houston, Texas, United States of America; Graduate School of Biomedical Sciences, the University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Yeonseok Chung
- Laboratory of Immunobiology, Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul, Republic of Korea
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13
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Ding Y, Li J, Yang P, Luo B, Wu Q, Zajac AJ, Wildner O, Hsu HC, Mountz JD. Interleukin-21 promotes germinal center reaction by skewing the follicular regulatory T cell to follicular helper T cell balance in autoimmune BXD2 mice. Arthritis Rheumatol 2014; 66:2601-12. [PMID: 24909430 DOI: 10.1002/art.38735] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 05/29/2014] [Indexed: 12/23/2022]
Abstract
OBJECTIVE Follicular regulatory T (Tfr) cells act as the regulatory counterpart of follicular helper T (Tfh) cells to suppress germinal center (GC) B cell differentiation. We recently showed that interleukin-21 (IL-21) promoted Tfh cell differentiation in autoimmune BXD2 mice that develop spontaneous GCs. This study was undertaken to determine the modulatory effects of IL-21 on Tfr cells and the Tfr cell to Tfh cell balance in BXD2 mice. METHODS The percentage and phenotype of Tfr cells were determined in BXD2 and BXD2-IL21(-/-) mice. The effects of IL-21 on Tfr cells and the Tfr cell:Tfh cell ratio were evaluated. Sorted Tfr cells from BXD2-IL21(-/-) mice were cocultured with Tfh cells and B cells, or transferred into BXD2 mice to determine their function. RESULTS The percentages and numbers of GC B cells and Tfh cells were significantly reduced, but the percentage of Tfr cells was 2-fold higher in BXD2-IL21(-/-) mice than in wild-type BXD2 mice. Administration of AdIL-21 to BXD2-IL21(-/-) mice decreased the percentages and numbers of Tfr cells and the Tfr cell:Tfh cell ratio but increased the number of GC B cells in the spleen. Recombinant murine IL-21 suppressed FoxP3 and significantly reduced Tgfb1, Il2, and Gitr but enhanced Il21, Il6, Pd1, Cxcr5, and Icos expression in Tfr cells. IL-21 also counteracted Tfr cell-mediated inhibition of antibody secretion in the Tfh cell-B cell coculture system. Transfer of Tfr cells into young BXD2 mice reduced GC size and decreased the numbers of autoantibody-producing B cells. CONCLUSION Our findings indicate that high levels of IL-21 selectively enhance Tfh cell differentiation but inhibit Tfr cell commitment and the suppressive function of Tfr cells on Tfh cells and B cells, suggesting that IL-21 skews the balance from Tfr cells to Tfh cells to promote autoreactive GC reactions in BXD2 mice.
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14
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Li H, Hsu HC, Wu Q, Yang P, Li J, Luo B, Oukka M, Steele CH, Cua DJ, Grizzle WE, Mountz JD. IL-23 promotes TCR-mediated negative selection of thymocytes through the upregulation of IL-23 receptor and RORγt. Nat Commun 2014; 5:4259. [PMID: 25001511 PMCID: PMC4136447 DOI: 10.1038/ncomms5259] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 05/30/2014] [Indexed: 01/06/2023] Open
Abstract
Transient thymic involution is frequently found during inflammation, yet the mode of action of inflammatory cytokines is not well defined. Here we report that interleukin-23 (IL-23) production by the thymic dendritic cells (DCs) promotes apoptosis of the CD4hiCD8hi double positive (DP) thymocytes. A deficiency in IL-23 signaling interferes with negative selection in the male Db/H-Y T-cell receptor (TCR) transgenic mice. IL-23 plus TCR signaling results in significant up-regulation of IL-23 receptor (IL-23R) expressed predominantly on CD4hiCD8hiCD3+αβTCR+ DP thymocytes, and leads to RORγt dependent apoptosis. These results extend the action of IL-23 beyond its peripheral effects to a unique role in TCR mediated negative selection including elimination of natural T regulatory cells in the thymus.
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Affiliation(s)
- Hao Li
- 1] Division of Clinical Immunology & Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA [2] Department Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Hui-Chen Hsu
- Division of Clinical Immunology & Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Qi Wu
- Division of Clinical Immunology & Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - PingAr Yang
- Division of Clinical Immunology & Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Jun Li
- Division of Clinical Immunology & Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Bao Luo
- Division of Clinical Immunology & Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Mohamed Oukka
- Department of Pediatrics, University of Washington, Seattle, Washington 98195, USA
| | - Claude H Steele
- Division of Pulmonary, Allergy & Critical Care, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Daniel J Cua
- Merck Research Laboratories, Palo Alto, California 94304, USA
| | - William E Grizzle
- Clinical Pathology & Anatomic Pathology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - John D Mountz
- 1] Division of Clinical Immunology & Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA [2] Birmingham VA Medical Center, Birmingham, Alabama 35233, USA
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15
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Li J, Yang P, Wu Q, Li H, Ding Y, Hsu HC, Spalding DM, Mountz JD. Death receptor 5-targeted depletion of interleukin-23-producing macrophages, Th17, and Th1/17 associated with defective tyrosine phosphatase in mice and patients with rheumatoid arthritis. ACTA ACUST UNITED AC 2014; 65:2594-605. [PMID: 23818173 DOI: 10.1002/art.38057] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 06/10/2013] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Bidirectional interactions between granulocyte-macrophage colony-stimulating factor-positive (GM-CSF+) T cells and interferon regulatory factor 5-positive (IRF-5+) macrophages play a major role in autoimmunity. In the absence of SH2 domain-containing phosphatase 1 (SHP-1), GM-CSF-stimulated cells are resistant to death receptor (DR)-mediated apoptosis. The objective of this study was to determine whether TRA-8, an anti-DR5 agonistic antibody, can eliminate inflammatory macrophages and CD4 T cells in the SHP-1-deficient condition. METHODS Ubiquitous Cre (Ubc.Cre) human/mouse-chimeric DR5-transgenic mice were crossed with viable SHP-1-defective motheaten (mev/mev) mice. TRA-8 was administered weekly for up to 4 weeks. The clinical scores, histopathologic severity, and macrophage and CD4 T cell phenotypes were evaluated. The role of TRA-8 in depleting inflammatory macrophages and CD4 T cells was also evaluated, using synovial fluid obtained from patients with rheumatoid arthritis (RA). RESULTS The levels of inflammatory macrophages (interleukin-23-positive [IL-23+] IRF-5+) and CD4 T cells (IL-17+ GM-CSF+) were elevated in mev/mev mice. In DR5-transgenic mev/mev mice, DR5 expression was up-regulated in these 2 cell populations. TRA-8 treatment depleted these cell populations and resulted in a significant reduction in inflammation and in the titers of autoantibodies. In synovial cells from patients with RA, the expression of IRF5 and DR5 was negatively correlated with the expression of PTPN6. TRA-8, but not TRAIL, suppressed RA inflammatory macrophages and Th17 cells under conditions in which the expression of SHP-1 is low. CONCLUSION In contrast to TRAIL, which lacks the capability to counteract the survival signal in the absence of SHP-1, TRA-8 eliminated both IRF-5+ IL-23+ M1 macrophages and pathogenic GM-CSF+ IL-17+ CD4 T cells in a SHP-1-independent manner. The results of the current study suggest that TRA-8 can deplete inflammatory cell populations that result from a hyperactive GM-CSF/IRF-5 axis.
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Affiliation(s)
- Jun Li
- University of Alabama at, Birmingham
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16
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Wang JH, New JS, Xie S, Yang P, Wu Q, Li J, Luo B, Ding Y, Druey KM, Hsu HC, Mountz JD. Extension of the germinal center stage of B cell development promotes autoantibodies in BXD2 mice. ARTHRITIS AND RHEUMATISM 2013; 65:2703-12. [PMID: 23818250 PMCID: PMC3979745 DOI: 10.1002/art.38059] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2013] [Accepted: 06/10/2013] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Regulator of G protein signaling (RGS) proteins inhibit chemokine signaling by desensitizing G protein-coupled receptor signals. This study was undertaken to determine the mechanisms by which RGS13 promotes the generation of pathogenic autoantibodies in germinal centers (GCs), using BXD2-Rgs13-/- mice. METHODS Confocal and light microscopy imaging techniques were used to determine the location of cells that express RGS13 and activation-induced cytidine deaminase (AID) in the mouse spleen, and the number of plasmablasts. The levels of GC and plasma cell program transcripts in GC B cells were determined by real-time quantitative polymerase chain reaction (qPCR). Differential interleukin-17 (IL-17)-mediated expression of RGS13 in GC versus non-GC B cells was analyzed using A20 and 70Z/3 B cells. RESULTS In the spleens of BXD2 mice, RGS13 was mainly expressed by GC B cells and was stimulated by IL-17 but not IL-21. IL-17 up-regulated RGS13 in A20 GC cells but not 70Z/3 non-GC B cells. BXD2- Rgs13-/- mice exhibited smaller GCs and lower AID levels, suggesting lower somatic hypermutation and affinity maturation. However, GC B cells from BXD2- Rgs13-/- mice showed increased levels of IgMbright plasmablasts, up-regulation of the genes encoding plasma program, including interferon regulatory factor 4, B lymphocyte-induced maturation protein 1, and X-box binding protein 1 and the p-CREB target genes Fosb and Obf1, and down-regulation of the GC program genes Aid, Pax5, and Bach2 compared to BXD2 mice. BXD2-Rgs13-/- mice had lower titers of IgG autoantibodies and IgG deposits in the glomeruli, suggesting reduced autoantibody pathogenicity. CONCLUSION RGS13 deficiency is associated with a reduction in GC program genes and the exit of fewer pathogenic IgM plasmablasts in BXD2 mice. Our findings indicate that prolonged GC program, mediated by up-regulation of RGS13, enhances AID expression and enables the generation of pathogenic autoantibodies in autoreactive GCs.
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Ding Y, Li J, Wu Q, Yang P, Luo B, Xie S, Druey KM, Zajac AJ, Hsu HC, Mountz JD. IL-17RA is essential for optimal localization of follicular Th cells in the germinal center light zone to promote autoantibody-producing B cells. THE JOURNAL OF IMMUNOLOGY 2013; 191:1614-24. [PMID: 23858031 DOI: 10.4049/jimmunol.1300479] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Germinal centers (GCs) provide a microenvironment that promotes and regulates the interactions of B cells with follicular Th (TFH) cells. In this study, we show that there are significantly higher frequencies of CXCR5(+)ICOS(+) TFH cells in autoimmune BXD2 mice, and these cells express both IL-21R and IL-17RA. Although IL-17 and IL-21 are both important for the formation of spontaneous GCs and development of pathogenic autoantibodies, IL-21, but not IL-17, is required for the proper development of TFH cells in BXD2 mice. The total numbers of TFH cells and their ability to induce B cell responses in vitro were not affected by a deficiency of IL-17RA in BXD2-Il17ra(-/-) mice, the majority of CXCR5(+) TFH cells from BXD2-Il17ra(-/-) mice were, however, not localized in the GC light zone (LZ). Interruption of IL-17 signaling, either acutely by AdIL-17R:Fc or chronically by Il17ra(-/-), disrupted TFH-B interactions and abrogated the generation of autoantibody-forming B cells in BXD2 mice. IL-17 upregulated the expression of regulator of G-protein signaling 16 (RGS16) to promote the ability of TFH to form conjugates with B cells, which was abolished in TFH cells from BXD2-Rgs16(-/-) mice. The results suggests that IL-17 is an extrinsic stop signal that it acts on postdifferentiated IL-17RA(+) TFH to enable its interaction with responder B cells in the LZ niche. These data suggest a novel concept that TFH differentiation and its stabilization in the LZ are two separate checkpoints and that IL-21 and IL-17 act at each checkpoint to enable pathogenic GC development.
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Affiliation(s)
- Yanna Ding
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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Zahn A, Daugan M, Safavi S, Godin D, Cheong C, Lamarre A, Di Noia JM. Separation of function between isotype switching and affinity maturation in vivo during acute immune responses and circulating autoantibodies in UNG-deficient mice. THE JOURNAL OF IMMUNOLOGY 2013; 190:5949-60. [PMID: 23667108 DOI: 10.4049/jimmunol.1202711] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Activation-induced deaminase converts deoxycytidine to deoxyuridine at the Ig loci. Complementary pathways, initiated by the uracil-DNA glycosylase (UNG) or the mismatch repair factor MSH2/MSH6, must process the deoxyuridine to initiate class-switch recombination (CSR) and somatic hypermutation. UNG deficiency most severely reduces CSR efficiency and only modestly affects the somatic hypermutation spectrum in vitro. This would predict isotype-switching deficiency but normal affinity maturation in Ung(-/-) mice in vivo, but this has not been tested. Moreover, puzzling differences in the amount of circulating Ig between UNG-deficient humans and mice make it unclear to what extent MSH2/MSH6 can complement for UNG in vivo. We find that Ab affinity maturation is indeed unaffected in Ung(-/-) mice, even allowing IgM responses with higher than normal affinity. Ung(-/-) mice display normal to only moderately reduced basal levels of most circulating Ig subclasses and gut-associated IgA, which are elicited in response to chronically available environmental Ag. In contrast, their ability to produce switched Ig in response to immunization or vesicular stomatitis virus infection is strongly impaired. Our results uncover a specific need for UNG in CSR for timely and efficient acute Ab responses in vivo. Furthermore, Ung(-/-) mice provide a novel model for separating isotype switching and affinity maturation during acute (but not chronic) Ab responses, which could be useful for dissecting their relative contribution to some infections. Interestingly, Ung(-/-) mice present with circulating autoantibodies, suggesting that UNG may impinge on tolerance.
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Affiliation(s)
- Astrid Zahn
- Institut de Recherches Cliniques de Montréal, Montréal, Québec H2W 1R7, Canada
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Li H, Wu Q, Li J, Yang P, Zhu Z, Luo B, Hsu HC, Mountz JD. Cutting Edge: defective follicular exclusion of apoptotic antigens due to marginal zone macrophage defects in autoimmune BXD2 mice. THE JOURNAL OF IMMUNOLOGY 2013; 190:4465-9. [PMID: 23543760 DOI: 10.4049/jimmunol.1300041] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Marginal zone macrophages (MZMs) act as a barrier to entry of circulating apoptotic debris into the follicles of secondary lymphoid organs. In autoimmune BXD2 mice, there is a progressive reduction in the function and numbers of MZMs. Absence of MZMs results in retention of apoptotic cell (AC) debris within the marginal zone (MZ) and increased loading of AC Ags on MZ B cells and MZ-precursor (MZ-P) B cells. The MZ-P B cells are capable of translocating the AC Ags to the follicular zone and stimulating T cells. Both MZMs and MZ-P B cells from BXD2 mice express low levels of tolerogenic signals and high levels of inflammatory signals. Thus, the current study suggests a multifaceted mechanism in which MZMs maintain tolerance to apoptotic autoantigens and suppress their translocation to follicles. Lack of clearance of apoptotic debris by MZMs drives follicular Ag-transportation by MZ-P B cells to stimulate an autoimmune response.
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Affiliation(s)
- Hao Li
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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20
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Abstract
Activation-induced cytidine deaminase (AID) is expressed in a B cell differentiation stage-specific fashion and is essential for immunoglobulin (Ig) gene class switch DNA recombination (CSR) and somatic hypermutation (SHM). CSR and SHM play a central role in the maturation of antibody and autoantibody responses. AID displays a mutagenic activity by catalyzing targeted deamination of deoxycytidine (dC) residues in DNA resulting in dU:dG mismatches, which are processed into point-mutations in SHM or double-strand breaks (DSBs) in CSR. Although AID specifically targets the Ig gene loci (IgH, Igκ and Igλ), it can also home into a wide array of non-Ig genes in B-and non-B-cell backgrounds. Aberrant expression of AID is associated with multiple diseases such as allergy, inflammation, autoimmunity and cancer. In autoimmune systemic lupus erythematosus, dysregulated AID expression underpins increased CSR, SHM and autoantibody production. As a potent mutator, AID is under stringent transcriptional, post-transcriptional and post-translational regulation. AID is also regulated in its targeting and enzymatic function. In resting naïve or memory B cells, AID transcripts and protein are undetectable. These, however, are readily and significantly up-regulated in B cells induced to undergo CSR and/or SHM. Transcription factors, such as HoxC4 and NF-κB, which are up-regulated in a B cell lineage-and/or differentiation stage-specific manner, regulate the induction of AID. HoxC4 induces AID expression by directly binding to the AID gene promoter through an evolutionarily conserved 5'-ATTT-3' motif. HoxC4 is induced by the same stimuli that induce AID and CSR. It is further up-regulated by estrogen through three estrogen responsive elements in its promoter region. The targeting of AID to switch (S) regions is mediated by 14-3-3 adaptor proteins, which specifically bind to 5'-AGCT-3' repeats that are exist at high frequency in S region cores. Like HoxC4, 14-3-3 adaptors are induced by the same stimuli that induce AID. These include "primary" inducing stimuli, that is, those that play a major role in inducing AID, i.e., engagement of CD40 by CD154, engagement of Toll-like receptors (TLRs) by microbial-associated molecular patterns (MAMPs) and cross-linking of the BCR, as synergized by "secondary" inducing stimuli, that is, those that synergize for AID induction and specify CSR to different isotypes, i.e., switch-directing cytokines IL-4, TGF-β or IFN-γ. In this review, we focus on the multi-levels regulation of AID expression and activity. We also discuss the dysregulation or misexpression of AID in autoimmunity and tumorigenesis.
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Affiliation(s)
- Hong Zan
- Institute for Immunology and School of Medicine, University of California, Irvine, CA 92697-4120, USA.
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Richter K, Burch L, Chao F, Henke D, Jiang C, Daly J, Zhao ML, Kissling G, Diaz M. Altered pattern of immunoglobulin hypermutation in mice deficient in Slip-GC protein. J Biol Chem 2012; 287:31856-65. [PMID: 22833677 DOI: 10.1074/jbc.m112.340661] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We recently identified a novel germinal center GTPase, SLIP-GC, that localizes to replication factories in B cells and that, when reduced, induces DNA breaks in lymphoma B cell lines in an activation-induced deaminase (AID)-dependent manner. Herein, we generated mice deficient in SLIP-GC and examined the impact of SLIP-GC deficiency in immunoglobulin hypermutation and class switch recombination, both AID-dependent mechanisms. SLIP-GC-deficient mice experienced a substantial increase in mutations at G:C base pairs at the region downstream of JH4 in the immunoglobulin heavy chain locus. This change was reflected in the overall mutation frequency, and it was associated with an increase in transitions from G:C base pairs, a hallmark of AID-mediated deamination during replication. In addition, G:C transitions at non-immunoglobulin loci also increased in these mice. Given the intracellular localization of SLIP-GC to sites of replicating DNA, these results suggest that SLIP-GC protects replicating DNA from AID-mediated deamination of cytosines in both strands.
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Affiliation(s)
- Kathleen Richter
- Somatic Hypermutation Group, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA
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22
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Li G, Pone EJ, Tran DC, Patel PJ, Dao L, Xu Z, Casali P. Iron inhibits activation-induced cytidine deaminase enzymatic activity and modulates immunoglobulin class switch DNA recombination. J Biol Chem 2012; 287:21520-9. [PMID: 22556412 PMCID: PMC3375573 DOI: 10.1074/jbc.m112.366732] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 04/26/2012] [Indexed: 12/31/2022] Open
Abstract
Immunoglobulin (Ig) class switch DNA recombination (CSR) and somatic hypermutation (SHM) are critical for the maturation of the antibody response. Activation-induced cytidine deaminase (AID) initiates CSR and SHM by deaminating deoxycytidines (dCs) in switch (S) and V(D)J region DNA, respectively, to generate deoxyuracils (dUs). Processing of dUs by uracil DNA glycosylase (UNG) yields abasic sites, which are excised by apurinic/apyrimidinic endonucleases, eventually generating double strand DNA breaks, the obligatory intermediates of CSR. Here, we found that the bivalent iron ion (Fe(2+), ferrous) suppressed CSR, leading to decreased number of switched B cells, decreased postrecombination Iμ-C(H) transcripts, and reduced titers of secreted class-switched IgG1, IgG3, and IgA antibodies, without alterations in critical CSR factors, such as AID, 14-3-3γ, or PTIP, or in general germline I(H)-S-C(H) transcription. Fe(2+) did not affect B cell proliferation or plasmacytoid differentiation. Rather, it inhibited AID-mediated dC deamination in a dose-dependent fashion. The inhibition of intrinsic AID enzymatic activity by Fe(2+) was specific, as shown by lack of inhibition of AID-mediated dC deamination by other bivalent metal ions, such as Zn(2+), Mn(2+), Mg(2+), or Ni(2+), and the inability of Fe(2+) to inhibit UNG-mediated dU excision. Overall, our findings have outlined a novel role of iron in modulating a B cell differentiation process that is critical to the generation of effective antibody responses to microbial pathogens and tumoral cells. They also suggest a possible role of iron in dampening AID-dependent autoimmunity and neoplastic transformation.
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Affiliation(s)
- Guideng Li
- From the Institute for Immunology and Department of Medicine, School of Medicine, University of California, Irvine, California 92697-4120
| | - Egest J. Pone
- From the Institute for Immunology and Department of Medicine, School of Medicine, University of California, Irvine, California 92697-4120
| | - Daniel C. Tran
- From the Institute for Immunology and Department of Medicine, School of Medicine, University of California, Irvine, California 92697-4120
| | - Pina J. Patel
- From the Institute for Immunology and Department of Medicine, School of Medicine, University of California, Irvine, California 92697-4120
| | - Lisa Dao
- From the Institute for Immunology and Department of Medicine, School of Medicine, University of California, Irvine, California 92697-4120
| | - Zhenming Xu
- From the Institute for Immunology and Department of Medicine, School of Medicine, University of California, Irvine, California 92697-4120
| | - Paolo Casali
- From the Institute for Immunology and Department of Medicine, School of Medicine, University of California, Irvine, California 92697-4120
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Orthwein A, Di Noia JM. Activation induced deaminase: how much and where? Semin Immunol 2012; 24:246-54. [PMID: 22687198 DOI: 10.1016/j.smim.2012.05.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 05/18/2012] [Indexed: 11/28/2022]
Abstract
Activation induced deaminase (AID) plays a central role in adaptive immunity by initiating the processes of somatic hypermutation (SHM) and class switch recombination (CSR). On the other hand, AID also predisposes to lymphoma and plays a role in some autoimmune diseases, for which reasons AID expression and activity are regulated at various levels. Post-translational mechanisms regulating the amount and subcellular localization of AID are prominent in balancing AID physiological and pathological functions in B cells. Mechanisms regulating AID protein levels include stabilizing chaperones in the cytoplasm and proteins efficiently targeting AID to the proteasome within the nucleus. Nuclear export and cytoplasmic retention contribute to limit the amount of AID accessing the genome. Additionally, a number of factors have been implicated in AID active nuclear import. We review these intertwined mechanisms proposing two scenarios in which they could interact as a network or as a cycle for defining the optimal amount of AID protein. We also comparatively review the expression levels of AID necessary for its function during the immune response, present in different cancers as well as in those tissues in which AID has been implicated in epigenetic remodeling of the genome by demethylating DNA.
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Affiliation(s)
- Alexandre Orthwein
- Institut de Recherches Cliniques de Montréal, Montréal, Québec, H2W 1R7, Canada
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Li J, Hsu HC, Yang P, Wu Q, Li H, Edgington LE, Bogyo M, Kimberly RP, Mountz JD. Treatment of arthritis by macrophage depletion and immunomodulation: testing an apoptosis-mediated therapy in a humanized death receptor mouse model. ACTA ACUST UNITED AC 2011; 64:1098-109. [PMID: 22006294 DOI: 10.1002/art.33423] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To determine the therapeutic efficacy and immunomodulatory effect of an anti-human death receptor 5 (DR5) antibody, TRA-8, in eliminating macrophage subsets in a mouse model of type II collagen-induced arthritis (CIA). METHODS A human/mouse-chimeric DR5-transgenic mouse, under the regulation of a mouse 3-kb promoter and a loxP-flanked STOP cassette, was generated and crossed with an ubiquitous Cre (Ubc.Cre) mouse and a lysozyme M-Cre (LysM.Cre)-transgenic mouse to achieve inducible or macrophage-specific expression. Chicken type II collagen was used to induce CIA in mice, which were then treated with an anti-human DR5 antibody, TRA-8. Clinical scores, histopathologic severity, macrophage apoptosis and depletion, and T cell subset development were evaluated. RESULTS In human/mouse DR5-transgenic Ubc.Cre mice with CIA, transgenic DR5 was most highly expressed on CD11b+ macrophages, with lower expression on CD4+ T cells. In human/mouse DR5-transgenic LysM.Cre mice, transgenic DR5 was restrictively expressed on macrophages. Both in vivo near-infrared imaging of caspase activity and TUNEL staining demonstrated that TRA-8 rapidly induced apoptosis of macrophages in inflamed synovium. Depletion of pathogenic macrophages by TRA-8 led to significantly reduced clinical scores for arthritis; decreased macrophage infiltration, synovial hyperplasia, osteoclast formation, joint destruction, cathepsin activity, and inflammatory cytokine expression in joints; reduced numbers of Th17 cells; and an increased number of Treg cells in draining lymph nodes. CONCLUSION The anti-human DR5 antibody TRA-8 was efficacious in reducing the severity of arthritis via targeted depletion of macrophages and immunomodulation. Our data provide preclinical evidence that TRA-8 is a potential novel biologic agent for rheumatoid arthritis therapy.
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Affiliation(s)
- Jun Li
- University of Alabama at Birmingham, AL, USA
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25
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Morel L. Activation-induced cytidine deaminase catalytic domain as a target to eliminate pathogenic autoantibodies. ARTHRITIS AND RHEUMATISM 2011; 63:1776-1778. [PMID: 21305518 DOI: 10.1002/art.30256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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26
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Dimitrova P, Vassilev T, Shivarov V. Inhibition or overactivation of AICDA to eliminate pathologic B cell clones? Comment on the article by Hsu et al. ACTA ACUST UNITED AC 2011; 63:3174-5; author reply 3175-7. [PMID: 21656511 DOI: 10.1002/art.30491] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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27
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Autoimmunity: Engineered AICDA balances B cells. Nat Rev Rheumatol 2011; 7:131. [PMID: 21491649 DOI: 10.1038/nrrheum.2011.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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