1
|
Kubagawa H, Mahmoudi Aliabadi P, Al-Qaisi K, Jani PK, Honjo K, Izui S, Radbruch A, Melchers F. Functions of IgM fc receptor (FcµR) related to autoimmunity. Autoimmunity 2024; 57:2323563. [PMID: 38465789 DOI: 10.1080/08916934.2024.2323563] [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: 10/29/2023] [Accepted: 02/20/2024] [Indexed: 03/12/2024]
Abstract
Unlike Fc receptors for switched immunoglobulin (Ig) isotypes, Fc receptor for IgM (FcµR) is selectively expressed by lymphocytes. The ablation of the FcµR gene in mice impairs B cell tolerance as evidenced by concomitant production of autoantibodies of IgM and IgG isotypes. In this essay, we reiterate the autoimmune phenotypes observed in mutant mice, ie IgM homeostasis, dysregulated humoral immune responses including autoantibodies, and Mott cell formation. We also propose the potential phenotypes in individuals with FCMR deficiency and the model for FcµR-mediated regulation of self-reactive B cells.
Collapse
Affiliation(s)
| | | | | | - Peter K Jani
- Deutsches Rheuma-Forschungszentrum Berlin, Berlin, Germany
| | - Kazuhito Honjo
- Department of Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Shozo Izui
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | | | - Fritz Melchers
- Deutsches Rheuma-Forschungszentrum Berlin, Berlin, Germany
| |
Collapse
|
2
|
Ma K, Du W, Wang S, Xiao F, Li J, Tian J, Xing Y, Kong X, Rui K, Qin R, Zhu X, Wang J, Luo C, Wu H, Zhang Y, Wen C, He L, Liu D, Zou H, Lu Q, Wu L, Lu L. B1-cell-produced anti-phosphatidylserine antibodies contribute to lupus nephritis development via TLR-mediated Syk activation. Cell Mol Immunol 2023; 20:881-894. [PMID: 37291237 PMCID: PMC10250184 DOI: 10.1038/s41423-023-01049-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 05/22/2023] [Indexed: 06/10/2023] Open
Abstract
Autoantibodies produced by B cells play a pivotal role in the pathogenesis of systemic lupus erythematosus (SLE). However, both the cellular source of antiphospholipid antibodies and their contributions to the development of lupus nephritis (LN) remain largely unclear. Here, we report a pathogenic role of anti-phosphatidylserine (PS) autoantibodies in the development of LN. Elevated serum PS-specific IgG levels were measured in model mice and SLE patients, especially in those with LN. PS-specific IgG accumulation was found in the kidney biopsies of LN patients. Both transfer of SLE PS-specific IgG and PS immunization triggered lupus-like glomerular immune complex deposition in recipient mice. ELISPOT analysis identified B1a cells as the main cell type that secretes PS-specific IgG in both lupus model mice and patients. Adoptive transfer of PS-specific B1a cells accelerated the PS-specific autoimmune response and renal damage in recipient lupus model mice, whereas depletion of B1a cells attenuated lupus progression. In culture, PS-specific B1a cells were significantly expanded upon treatment with chromatin components, while blockade of TLR signal cascades by DNase I digestion and inhibitory ODN 2088 or R406 treatment profoundly abrogated chromatin-induced PS-specific IgG secretion by lupus B1a cells. Thus, our study has demonstrated that the anti-PS autoantibodies produced by B1 cells contribute to lupus nephritis development. Our findings that blockade of the TLR/Syk signaling cascade inhibits PS-specific B1-cell expansion provide new insights into lupus pathogenesis and may facilitate the development of novel therapeutic targets for the treatment of LN in SLE.
Collapse
Affiliation(s)
- Kongyang Ma
- Centre for Infection and Immunity Studies, School of Medicine, The Sun Yat-sen University, Shenzhen, 518107, Guangdong, China
- Department of Pathology and Shenzhen Institute of Research and Innovation, The University of Hong Kong, Hong Kong, 999077, China
- Department of Rheumatology, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, Shenzhen, China
| | - Wenhan Du
- Department of Pathology and Shenzhen Institute of Research and Innovation, The University of Hong Kong, Hong Kong, 999077, China
- Chongqing International Institute for Immunology, Chongqing, 400038, China
| | - Shiyun Wang
- Department of Pathology and Shenzhen Institute of Research and Innovation, The University of Hong Kong, Hong Kong, 999077, China
| | - Fan Xiao
- Department of Pathology and Shenzhen Institute of Research and Innovation, The University of Hong Kong, Hong Kong, 999077, China
| | - Jingyi Li
- Department of Rheumatology and Immunology, Southwest Hospital, The First Hospital Affiliated to Army Medical University, Chongqing, 400038, China
| | - Jie Tian
- Department of Laboratory Medicine, Affiliated Hospital and Institute of Medical Immunology, Jiangsu University, Zhenjiang, China
| | - Yida Xing
- Department of Rheumatology, The Second Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Xiaodan Kong
- Department of Rheumatology, The Second Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Ke Rui
- Department of Laboratory Medicine, Affiliated Hospital and Institute of Medical Immunology, Jiangsu University, Zhenjiang, China
| | - Rencai Qin
- Centre for Infection and Immunity Studies, School of Medicine, The Sun Yat-sen University, Shenzhen, 518107, Guangdong, China
| | - Xiaoxia Zhu
- Department of Rheumatology, Huashan Hospital, Fudan University, Shanghai, China
| | - Jing Wang
- Department of Rheumatology and Immunology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Cainan Luo
- Department of Rheumatology and Immunology, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China
| | - Haijing Wu
- Department of Dermatology, Hunan Key Laboratory of Medical Epigenomics, Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yun Zhang
- Key Laboratory of Chinese Medicine Rheumatology of Zhejiang Province, Institute of Basic Research in Clinical Medicine, College of Basic Medical Science, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Chengping Wen
- Key Laboratory of Chinese Medicine Rheumatology of Zhejiang Province, Institute of Basic Research in Clinical Medicine, College of Basic Medical Science, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Lan He
- Department of Rheumatology and Immunology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, Shaanxi, China
| | - Dongzhou Liu
- Department of Rheumatology, Shenzhen People's Hospital, The Second Clinical Medical College, Jinan University, Shenzhen, China
| | - Hejian Zou
- Department of Rheumatology, Huashan Hospital, Fudan University, Shanghai, China
| | - Qianjin Lu
- Department of Dermatology, Hunan Key Laboratory of Medical Epigenomics, Second Xiangya Hospital, Central South University, Changsha, Hunan, China.
| | - Lijun Wu
- Department of Rheumatology and Immunology, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China.
| | - Liwei Lu
- Department of Pathology and Shenzhen Institute of Research and Innovation, The University of Hong Kong, Hong Kong, 999077, China.
- Chongqing International Institute for Immunology, Chongqing, 400038, China.
- Centre for Oncology and Immunology, Hong Kong Science Park, Hong Kong, China.
| |
Collapse
|
3
|
Wang Y, Qin WY, Wang Q, Liu XN, Li XH, Ye XQ, Bai Y, Zhang Y, Liu P, Wang XL, Zhou YH, Shao ZB, Yuan HP. Young Sca-1 + bone marrow stem cell-derived exosomes preserve visual function via the miR-150-5p/MEKK3/JNK/c-Jun pathway to reduce M1 microglial polarization. J Nanobiotechnology 2023; 21:194. [PMID: 37322478 DOI: 10.1186/s12951-023-01944-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 05/29/2023] [Indexed: 06/17/2023] Open
Abstract
BACKGROUND Polarization of microglia, the resident retinal immune cells, plays important roles in mediating both injury and repair responses post-retinal ischemia-reperfusion (I/R) injury, which is one of the main pathological mechanisms behind ganglion cell apoptosis. Aging could perturb microglial balances, resulting in lowered post-I/R retinal repair. Young bone marrow (BM) stem cell antigen 1-positive (Sca-1+) cells have been demonstrated to have higher reparative capabilities post-I/R retinal injury when transplanted into old mice, where they were able to home and differentiate into retinal microglia. METHODS Exosomes were enriched from young Sca-1+ or Sca-1- cells, and injected into the vitreous humor of old mice post-retinal I/R. Bioinformatics analyses, including miRNA sequencing, was used to analyze exosome contents, which was confirmed by RT-qPCR. Western blot was then performed to examine expression levels of inflammatory factors and underlying signaling pathway proteins, while immunofluorescence staining was used to examine the extent of pro-inflammatory M1 microglial polarization. Fluoro-Gold labelling was then utilized to identify viable ganglion cells, while H&E staining was used to examine retinal morphology post-I/R and exosome treatment. RESULTS Sca-1+ exosome-injected mice yielded better visual functional preservation and lowered inflammatory factors, compared to Sca-1-, at days 1, 3, and 7 days post-I/R. miRNA sequencing found that Sca-1+ exosomes had higher miR-150-5p levels, compared to Sca-1- exosomes, which was confirmed by RT-qPCR. Mechanistic analysis found that miR-150-5p from Sca-1+ exosomes repressed the mitogen-activated protein kinase kinase kinase 3 (MEKK3)/JNK/c-Jun axis, leading to IL-6 and TNF-α downregulation, and subsequently reduced microglial polarization, all of which contributes to reduced ganglion cell apoptosis and preservation of proper retinal morphology. CONCLUSION This study elucidates a potential new therapeutic approach for neuroprotection against I/R injury, via delivering miR-150-5p-enriched Sca-1+ exosomes, which targets the miR-150-5p/MEKK3/JNK/c-Jun axis, thereby serving as a cell-free remedy for treating retinal I/R injury and preserving visual functioning.
Collapse
Affiliation(s)
- Yuan Wang
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
- Future Medical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Wan-Yun Qin
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
- Future Medical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Qi Wang
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
- Future Medical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
- The Key Laboratory of Myocardial Ischemia, Harbin Medical University, Ministry Education, Harbin, China
| | - Xin-Na Liu
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
- Future Medical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
- The Key Laboratory of Myocardial Ischemia, Harbin Medical University, Ministry Education, Harbin, China
| | - Xiang-Hui Li
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
- Future Medical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Xin-Qi Ye
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
- Future Medical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Ying Bai
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
- Future Medical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Yan Zhang
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
- Future Medical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Pan Liu
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Xin-Lin Wang
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
- Future Medical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Yu-Hang Zhou
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
- Future Medical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Zheng-Bo Shao
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China.
- Future Medical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin, China.
| | - Hui-Ping Yuan
- Department of Ophthalmology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China.
| |
Collapse
|
4
|
Sharma J, Collins TD, Roach T, Mishra S, Lam BK, Mohamed ZS, Veal AE, Polk TB, Jones A, Cornaby C, Haider MI, Zeumer-Spataro L, Johnson HM, Morel LM, Larkin J. Suppressor of cytokine signaling-1 mimetic peptides attenuate lymphocyte activation in the MRL/lpr mouse autoimmune model. Sci Rep 2021; 11:6354. [PMID: 33737712 PMCID: PMC7973732 DOI: 10.1038/s41598-021-86017-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 03/09/2021] [Indexed: 12/30/2022] Open
Abstract
Autoimmune diseases are driven largely by a pathogenic cytokine milieu produced by aberrantly activated lymphocytes. Many cytokines, including interferon gamma (IFN-γ), utilize the JAK/STAT pathway for signal propagation. Suppressor of Cytokine Signaling-1 (SOCS1) is an inducible, intracellular protein that regulates IFN-γ signaling by dampening JAK/STAT signaling. Using Fas deficient, MRL/MpJ-Faslpr/J (MRL/lpr) mice, which develop lupus-like disease spontaneously, we tested the hypothesis that a peptide mimic of the SOCS1 kinase inhibitory region (SOCS1-KIR) would inhibit lymphocyte activation and modulate lupus-associated pathologies. Consistent with in vitro studies, SOCS1-KIR intraperitoneal administration reduced the frequency, activation, and cytokine production of memory CD8+ and CD4+ T lymphocytes within the peripheral blood, spleen, and lymph nodes. In addition, SOCS1-KIR administration reduced lymphadenopathy, severity of skin lesions, autoantibody production, and modestly reduced kidney pathology. On a cellular level, peritoneal SOCS1-KIR administration enhanced Foxp3 expression in total splenic and follicular regulatory T cells, reduced the effector memory/naïve T lymphocyte ratio for both CD4+ and CD8+ cells, and reduced the frequency of GL7+ germinal center enriched B cells. Together, these data show that SOCS1-KIR treatment reduced auto-reactive lymphocyte effector functions and suggest that therapeutic targeting of the SOCS1 pathway through peptide administration may have efficacy in mitigating autoimmune pathologies.
Collapse
Affiliation(s)
- Jatin Sharma
- Department of Microbiology & Cell Science, University of Florida, Museum Road Building 981, PO Box 110700, Gainesville, FL, 32611, USA
| | - Teresa D Collins
- Department of Microbiology & Cell Science, University of Florida, Museum Road Building 981, PO Box 110700, Gainesville, FL, 32611, USA
| | - Tracoyia Roach
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Shiwangi Mishra
- Department of Microbiology & Cell Science, University of Florida, Museum Road Building 981, PO Box 110700, Gainesville, FL, 32611, USA
| | - Brandon K Lam
- Department of Microbiology & Cell Science, University of Florida, Museum Road Building 981, PO Box 110700, Gainesville, FL, 32611, USA
| | - Zaynab Sidi Mohamed
- Department of Microbiology & Cell Science, University of Florida, Museum Road Building 981, PO Box 110700, Gainesville, FL, 32611, USA
| | - Antia E Veal
- Department of Microbiology & Cell Science, University of Florida, Museum Road Building 981, PO Box 110700, Gainesville, FL, 32611, USA
| | - Timothy B Polk
- Department of Microbiology & Cell Science, University of Florida, Museum Road Building 981, PO Box 110700, Gainesville, FL, 32611, USA
| | - Amari Jones
- Department of Microbiology & Cell Science, University of Florida, Museum Road Building 981, PO Box 110700, Gainesville, FL, 32611, USA
| | - Caleb Cornaby
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Mohammed I Haider
- Department of Microbiology & Cell Science, University of Florida, Museum Road Building 981, PO Box 110700, Gainesville, FL, 32611, USA
| | - Leilani Zeumer-Spataro
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Howard M Johnson
- Department of Microbiology & Cell Science, University of Florida, Museum Road Building 981, PO Box 110700, Gainesville, FL, 32611, USA
| | - Laurence M Morel
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Joseph Larkin
- Department of Microbiology & Cell Science, University of Florida, Museum Road Building 981, PO Box 110700, Gainesville, FL, 32611, USA.
| |
Collapse
|
5
|
Peripheral B Cell Subsets in Autoimmune Diseases: Clinical Implications and Effects of B Cell-Targeted Therapies. J Immunol Res 2020; 2020:9518137. [PMID: 32280720 PMCID: PMC7125470 DOI: 10.1155/2020/9518137] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 03/01/2020] [Accepted: 03/10/2020] [Indexed: 12/14/2022] Open
Abstract
Antibody-secreting cells (ASCs) play a fundamental role in humoral immunity. The aberrant function of ASCs is related to a number of disease states, including autoimmune diseases and cancer. Recent insights into activated B cell subsets, including naïve B cell to ASC stages and their resultant cellular disturbances, suggest that aberrant ASC differentiation occurs during autoimmune diseases and is closely related to disease severity. However, the mechanisms underlying highly active ASC differentiation and the B cell subsets in autoimmune patients remain undefined. Here, we first review the processes of ASC generation. From the perspective of novel therapeutic target discovery, prediction of disease progression, and current clinical challenges, we further summarize the aberrant activity of B cell subsets including specialized memory CD11chiT-bet+ B cells that participate in the maintenance of autoreactive ASC populations. An improved understanding of subgroups may also enhance the knowledge of antigen-specific B cell differentiation. We further discuss the influence of current B cell therapies on B cell subsets, specifically focusing on systemic lupus erythematosus, rheumatoid arthritis, and myasthenia gravis.
Collapse
|
6
|
Dieudé M, Cardinal H, Hébert MJ. Injury derived autoimmunity: Anti-perlecan/LG3 antibodies in transplantation. Hum Immunol 2019; 80:608-613. [PMID: 31029511 DOI: 10.1016/j.humimm.2019.04.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 04/08/2019] [Accepted: 04/13/2019] [Indexed: 01/02/2023]
Abstract
Ischemic, immunologic or pharmacological stressors can induce vascular injury and endothelial apoptosis in organ donors, in transplant candidates due to the impact of end stage organ failure on the vasculature, and in association with peri-transplantation events. Vascular injury may shape innate and adaptive immune responses, leading to dysregulation in the balance between tolerance and immunoreactivity to vascular-derived antigens. Mounting evidence shows that the early stages of apoptosis, characterized by the absence of membrane permeabilization, are prone to trigger various modes of intercellular communication allowing neoantigen production, exposure, or both. In this review, we present the evidence for the release of LG3, an immunogenic fragment of perlecan, as a consequence of caspase-3 dependent vascular apoptosis leading to the genesis of anti-LG3 autoantibodies and the consequences of these autoantibodies in native and transplanted kidneys.
Collapse
Affiliation(s)
- Mélanie Dieudé
- Research Centre, Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, Canada; Canadian Donation and Transplantation Research Program, Canada; Université de Montréal, Canada.
| | - Héloïse Cardinal
- Research Centre, Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, Canada; Canadian Donation and Transplantation Research Program, Canada; Université de Montréal, Canada.
| | - Marie-Josée Hébert
- Research Centre, Centre hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, Canada; Canadian Donation and Transplantation Research Program, Canada; Université de Montréal, Canada.
| |
Collapse
|
7
|
Padet L, Dieudé M, Karakeussian‐Rimbaud A, Yang B, Turgeon J, Cailhier J, Cardinal H, Hébert M. New insights into immune mechanisms of antiperlecan/LG3 antibody production: Importance of T cells and innate B1 cells. Am J Transplant 2019; 19:699-712. [PMID: 30129231 PMCID: PMC6519043 DOI: 10.1111/ajt.15082] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 07/25/2018] [Accepted: 07/29/2018] [Indexed: 01/25/2023]
Abstract
Autoantibodies against perlecan/LG3 (anti-LG3) have been associated with increased risks of delayed graft function, acute rejection, and reduced long-term survival. High titers of anti-LG3 antibodies have been found in de novo renal transplants recipients in the absence of allosensitizing or autoimmune conditions. Here, we seek to understand the pathways controlling anti-LG3 production prior to transplantation. Mice immunized with recombinant LG3 produce concomitantly IgM and IgG anti-LG3 antibodies suggesting a memory response. ELISpot confirmed the presence of LG3-specific memory B cells in nonimmunized mice. Purification of B1 and B2 subtypes identified peritoneal B1 cells as the major source of memory B cells reactive to LG3. Although nonimmunized CD4-deficient mice were found to express LG3-specific memory B cells, depletion of CD4+ T cells in wild type mice during immunization significantly decreased anti-LG3 production. These results demonstrate that B cell memory to LG3 is T cell independent but that production of anti-LG3 antibodies requires T cell help. Further supporting an important role for T cells in controlling anti-LG3 levels, we found that human renal transplant recipients show a significant decrease in anti-LG3 titers upon the initiation of CNI-based immunosuppression. Collectively, these results identify T cell targeting interventions as a means of reducing anti-LG3 levels in renal transplant patients.
Collapse
Affiliation(s)
- Lauriane Padet
- Research CentreCentre Hospitalier de l'Université de Montréal (CRCHUM)MontrealQuebecCanada,Canadian National Transplant Research ProgramEdmontonAlbertaCanada,Université de MontréalMontrealQuebecCanada
| | - Mélanie Dieudé
- Research CentreCentre Hospitalier de l'Université de Montréal (CRCHUM)MontrealQuebecCanada,Canadian National Transplant Research ProgramEdmontonAlbertaCanada
| | - Annie Karakeussian‐Rimbaud
- Research CentreCentre Hospitalier de l'Université de Montréal (CRCHUM)MontrealQuebecCanada,Canadian National Transplant Research ProgramEdmontonAlbertaCanada
| | - Bing Yang
- Research CentreCentre Hospitalier de l'Université de Montréal (CRCHUM)MontrealQuebecCanada,Canadian National Transplant Research ProgramEdmontonAlbertaCanada,Université de MontréalMontrealQuebecCanada
| | - Julie Turgeon
- Research CentreCentre Hospitalier de l'Université de Montréal (CRCHUM)MontrealQuebecCanada,Canadian National Transplant Research ProgramEdmontonAlbertaCanada
| | - Jean‐François Cailhier
- Research CentreCentre Hospitalier de l'Université de Montréal (CRCHUM)MontrealQuebecCanada,Canadian National Transplant Research ProgramEdmontonAlbertaCanada
| | - Héloïse Cardinal
- Research CentreCentre Hospitalier de l'Université de Montréal (CRCHUM)MontrealQuebecCanada,Canadian National Transplant Research ProgramEdmontonAlbertaCanada
| | - Marie‐Josée Hébert
- Research CentreCentre Hospitalier de l'Université de Montréal (CRCHUM)MontrealQuebecCanada,Canadian National Transplant Research ProgramEdmontonAlbertaCanada,Université de MontréalMontrealQuebecCanada
| |
Collapse
|
8
|
Roles of B Cell-Intrinsic TLR Signals in Systemic Lupus Erythematosus. Int J Mol Sci 2015; 16:13084-105. [PMID: 26068236 PMCID: PMC4490487 DOI: 10.3390/ijms160613084] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 05/31/2015] [Accepted: 06/03/2015] [Indexed: 12/16/2022] Open
Abstract
Toll-like receptors (TLRs) are a large family of pattern recognition receptors. TLR signals are involved in the pathogenesis of systemic lupus erythematosus. Mouse and human B cells constitutively express most TLRs. Many B cell subpopulations are highly responsive to certain TLR ligation, including B-1 B cells, transitional B cells, marginal zone B cells, germinal center B cell and memory B cells. The B cell-intrinsic TLR signals play critical roles during lupus process. In this review, roles of B cell-intrinsic TLR2, 4, 7, 8 and 9 signals are discussed during lupus pathogenesis in both mouse model and patients. Moreover, mechanisms underlying TLR ligation-triggered B cell activation and signaling pathways are highlighted.
Collapse
|
9
|
Self DNA from lymphocytes that have undergone activation-induced cell death enhances murine B cell proliferation and antibody production. PLoS One 2014; 9:e109095. [PMID: 25296026 PMCID: PMC4189923 DOI: 10.1371/journal.pone.0109095] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 09/02/2014] [Indexed: 11/23/2022] Open
Abstract
Systemic lupus erythematosus (SLE) is characterized by prominent autoinflammatory tissue damage associated with impaired removal of dying cells and DNA. Self DNA-containing immune complexes are able to activate both innate and adaptive immune responses and play an important role in the maintenance and exacerbation of autoimmunity in SLE. In this study, we used DNA from lymphocytes that have undergone activation-induced cell death (ALD-DNA) and analyzed its role on the activation and differentiation of B cells from normal BALB/c mice as well as lupus-prone MRL+/+ and MRL/lpr mice. We found that ALD-DNA directly increased the expression of costimulatory molecules and the survival of naïve B cells in vitro. Although ALD-DNA alone had little effect on the proliferation of naïve B cells, it enhanced LPS-activated B cell proliferation in vitro and in vivo. In addition, ALD-DNA increased plasma cell numbers and IgG production in LPS-stimulated cultures of naïve B cells, in part via enhancing IL-6 production. Importantly, B cells from lupus mice were hyperresponsive to ALD-DNA and/or LPS relative to normal control B cells in terminal plasma cell differentiation, as evidenced by increases in CD138+ cell numbers, IgM production, and mRNA levels of B lymphocyte-induced maturation protein-1 (Blimp-1) and the X-box binding protein 1 (XBP1). Furthermore, ALD-DNA enhanced CD40-activated naïve B cell proliferation. Collectively, these data indicate that self DNA can serve as a DAMP (damage-associated molecular pattern) that cooperates with signals from both innate and adaptive immunity to promote polyclonal B cell activation, a common characteristic of autoimmune diseases.
Collapse
|
10
|
Mao X, Wu Y, Diao H, Hao J, Tian G, Jia Z, Li Z, Xiong S, Wu Z, Wang P, Zhao L, Yin Z. Interleukin-6 promotes systemic lupus erythematosus progression with Treg suppression approach in a murine systemic lupus erythematosus model. Clin Rheumatol 2014; 33:1585-93. [PMID: 24928344 DOI: 10.1007/s10067-014-2717-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 05/10/2014] [Accepted: 06/04/2014] [Indexed: 12/29/2022]
Abstract
Our aim is to reveal the role of interleukin 6 (IL-6) in the pathogenesis of systemic lupus erythematosus (SLE) in a murine model of SLE. Normal female C57BL/6 mice were immunized with syngeneic-activated lymphocyte-derived DNA (ALD-DNA) to induce SLE. Non-immunized mice were used as control. SLE-associated markers, including anti-double-stranded DNA (anti-dsDNA) Abs, urine protein, and kidney histopathology, were assayed to ensure the induction of the disease. Compared with control mice, ALD-DNA immunized mice exhibited high levels of anti-dsDNA Abs, IL-6 expression in vivo and in vitro. We also found that IL-6 knockout (IL-6KO) mice were resistant to ALD-DNA-induced SLE. The activation of CD4(+) T cells in immunized IL-6KO mice was lower than in immunized wild-type (Wt) mice. Intracellular cytokine staining showed that Foxp3 expression in immunized IL-6KO mice was higher than in immunized Wt mice, which might be associated with the disease severity. We further discovered that ALD-DNA-stimulated dendritic cells supernatants could result in higher IL-6 and TNF-α expression and could suppress Foxp3 expression. In addition, blocking IL-6 could up-regulate Foxp3 expression. Therefore, our findings show that IL-6 promotes the progression of SLE via suppressing Treg differentiation.
Collapse
Affiliation(s)
- Xiaoli Mao
- Department of Immunology, School of Basic Medical Science, Wuhan University, Wuhan, 430200, China
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Shao WH, Cohen PL. The role of tyrosine kinases in systemic lupus erythematosus and their potential as therapeutic targets. Expert Rev Clin Immunol 2014; 10:573-82. [PMID: 24678775 DOI: 10.1586/1744666x.2014.893827] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The autoimmune disease systemic lupus erythematosus is characterized by loss of tolerance to nuclear antigens. Breakdown of tolerance is associated with alterations in T-cell and B-cell receptor signal transduction, including increased protein phosphorylation that may underlie pathogenesis and explain the characteristic hyperactivity of T and B cells and other immune cells in active disease. Tyrosine kinases play a central role in signaling processes in cells known to be important in the pathogenesis of autoimmune diseases. Considerable progress has been made in understanding the function of tyrosine kinases in immune cell signaling pathways. In this review, we will summarize the function of tyrosine kinases and their novel inhibitors from studies made in animal lupus models and systemic lupus erythematosus patients.
Collapse
Affiliation(s)
- Wen-Hai Shao
- Department of Medicine and Temple Autoimmunity Center, Section of Rheumatology, Temple University, Philadelphia, PA, USA
| | | |
Collapse
|
12
|
Koncz G, Hueber AO. The Fas/CD95 Receptor Regulates the Death of Autoreactive B Cells and the Selection of Antigen-Specific B Cells. Front Immunol 2012; 3:207. [PMID: 22848207 PMCID: PMC3404404 DOI: 10.3389/fimmu.2012.00207] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2012] [Accepted: 06/30/2012] [Indexed: 12/13/2022] Open
Abstract
Cell death receptors have crucial roles in the regulation of immune responses. Here we review recent in vivo data confirming that the Fas death receptor (TNFSR6) on B cells is important for the regulation of autoimmunity since the impairment of only Fas function on B cells results in uncontrolled autoantibody production and autoimmunity. Fas plays a role in the elimination of the non-specific and autoreactive B cells in germinal center, while during the selection of antigen-specific B cells different escape signals ensure the resistance to Fas-mediated apoptosis. Antigen-specific survival such as BCR or MHCII signal or coreceptors (CD19) cooperating with BCR inhibits the formation of death inducing signaling complex. Antigen-specific survival can be reinforced by antigen-independent signals of IL-4 or CD40 overproducing the anti-apoptotic members of the Bcl-2 family proteins.
Collapse
Affiliation(s)
- Gabor Koncz
- Immunology Research Group of the Hungarian Academy of Sciences, University Eötvös Lorand Budapest, Hungary
| | | |
Collapse
|
13
|
McGaha TL, Ma Z, Ravishankar B, Gabunia K, McMenamin M, Madaio MP. Heterologous protein incites abnormal plasma cell accumulation and autoimmunity in MRL-MpJ mice. Autoimmunity 2012; 45:279-89. [PMID: 22283427 DOI: 10.3109/08916934.2012.654864] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Although it is evident that there is complex interplay among genetic and environmental factors contributing to systemic autoimmunity, the events inciting autoreactivity are incompletely understood. Previously we demonstrated that MRL-MpJ mice posses a genetic background susceptible to autoimmunity development under conditions of altered inhibitory signaling. To gain better understanding of the influence of exogenous factors on autoreactivity in susceptible individuals, young MRL-MpJ mice were challenged with a single injection of heterologous protein and evaluated for evidence of autoimmunity. We found that MRL-MpJ mice developed high titer serum reactivity to DNA within 1 week of protein administration reaching maximal levels within 1 month. Importantly, the level of autoimmunity was sustained for an extended period of time (6 months). This was accompanied by a substantial increase in germinal center B cell and plasma cell numbers. In contrast, control mice showed no change in autoreactivity or lymphocyte homeostasis. Autoimmunity was dependent on marginal zone B cells as their depletion reduced serum auto-reactivity after challenge, thus suggesting immune stimulation with heterologous proteins can precipitate loss of B cell tolerance and autoimmunity in genetically prone individuals. This model may provide an important tool to further investigate the mechanisms whereby environmental stimuli trigger autoimmune reactivity in susceptible hosts.
Collapse
Affiliation(s)
- Tracy L McGaha
- Department of Medicine, Georgia Health Sciences University, 1120 15th Street, Augusta, GA 30912, USA.
| | | | | | | | | | | |
Collapse
|
14
|
Zhang W, Xu W, Xiong S. Macrophage differentiation and polarization via phosphatidylinositol 3-kinase/Akt-ERK signaling pathway conferred by serum amyloid P component. THE JOURNAL OF IMMUNOLOGY 2011; 187:1764-77. [PMID: 21753147 DOI: 10.4049/jimmunol.1002315] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Macrophage differentiation and polarization is influenced by, and act on, many processes associated with autoimmunity. However, the molecular mechanisms underlying macrophage polarization in systemic lupus erythematosus (SLE) remain largely debated. We previously demonstrated that macrophage M2b polarization conferred by activated lymphocyte-derived (ALD)-DNA immunization could initiate and propagate murine lupus nephritis. Serum amyloid P component (SAP), a conserved acute-phase protein in mice, has been reported to bind to DNA and modulate immune responses. In this study, murine SAP was shown to promote macrophage-mediated ALD-DNA uptake through binding to ALD-DNA (SAP/ALD-DNA). Moreover, macrophage phenotypic switch from a proinflammatory M2b phenotype induced by ALD-DNA alone to an anti-inflammatory M2a phenotype stimulated with SAP/ALD-DNA were found because of PI3K/Akt-ERK signaling activation. Both in vivo SAP supplements and adoptive transfer of ex vivo programmed M2a macrophages induced by SAP/ALD-DNA into SLE mice could efficiently alleviate lupus nephritis. Importantly, increased IL-10 secretion, accompanied by anti-inflammatory effect exerted by M2a macrophages, was found to predominantly impede macrophage M2b polarization. Furthermore, neutralization of IL-10 notably reduced the suppressive effect of M2a macrophages. Our results demonstrate that binding of SAP to ALD-DNA could switch macrophage phenotypic polarization from proinflammatory M2b to anti-inflammatory M2a via PI3K/Akt-ERK signaling activation, thus exerting protective and therapeutic interventions on murine lupus nephritis. These data provide a possible molecular mechanism responsible for modulation of macrophage polarization in the context of lupus nephritis and open a new potential therapeutic avenue for SLE.
Collapse
Affiliation(s)
- Weijuan Zhang
- Department of Immunology, Institute for Immunobiology, Shanghai Medical College, Fudan University, Shanghai 200032, People's Republic of China
| | | | | |
Collapse
|
15
|
A-Gonzalez N, Bensinger SJ, Hong C, Beceiro S, Bradley MN, Zelcer N, Deniz J, Ramirez C, Díaz M, Gallardo G, de Galarreta CR, Salazar J, Lopez F, Edwards P, Parks J, Andujar M, Tontonoz P, Castrillo A. Apoptotic cells promote their own clearance and immune tolerance through activation of the nuclear receptor LXR. Immunity 2009; 31:245-58. [PMID: 19646905 DOI: 10.1016/j.immuni.2009.06.018] [Citation(s) in RCA: 511] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Revised: 05/06/2009] [Accepted: 06/01/2009] [Indexed: 12/21/2022]
Abstract
Effective clearance of apoptotic cells by macrophages is essential for immune homeostasis. The transcriptional pathways that allow macrophages to sense and respond to apoptotic cells are poorly defined. We found that liver X receptor (LXR) signaling was important for both apoptotic cell clearance and the maintenance of immune tolerance. Apoptotic cell engulfment activated LXR and thereby induced the expression of Mer, a receptor tyrosine kinase critical for phagocytosis. LXR-deficient macrophages exhibited a selective defect in phagocytosis of apoptotic cells and an aberrant proinflammatory response to them. As a consequence of these defects, mice lacking LXRs manifested a breakdown in self-tolerance and developed autoantibodies and autoimmune glomerulonephritis. Treatment with an LXR agonist ameliorated disease progression in a mouse model of lupus-like autoimmunity. Thus, activation of LXR by apoptotic cells engages a virtuous cycle that promotes their own clearance and couples engulfment to the suppression of inflammatory pathways.
Collapse
Affiliation(s)
- Noelia A-Gonzalez
- Immune Signaling Laboratory, Department of Biochemistry and Molecular Biology, School of Medicine, University of Las Palmas, ULPGC, 35016 Las Palmas, Spain
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Chou MY, Fogelstrand L, Hartvigsen K, Hansen LF, Woelkers D, Shaw PX, Choi J, Perkmann T, Bäckhed F, Miller YI, Hörkkö S, Corr M, Witztum JL, Binder CJ. Oxidation-specific epitopes are dominant targets of innate natural antibodies in mice and humans. J Clin Invest 2009; 119:1335-49. [PMID: 19363291 DOI: 10.1172/jci36800] [Citation(s) in RCA: 365] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2008] [Accepted: 02/25/2009] [Indexed: 12/31/2022] Open
Abstract
Atherosclerosis is a chronic inflammatory disease characterized by the accumulation of oxidized lipoproteins and apoptotic cells. Adaptive immune responses to various oxidation-specific epitopes play an important role in atherogenesis. However, accumulating evidence suggests that these epitopes are also recognized by innate receptors, such as scavenger receptors on macrophages, and plasma proteins, such as C-reactive protein (CRP). Here, we provide multiple lines of evidence that oxidation-specific epitopes constitute a dominant, previously unrecognized target of natural Abs (NAbs) in both mice and humans. Using reconstituted mice expressing solely IgM NAbs, we have shown that approximately 30% of all NAbs bound to model oxidation-specific epitopes, as well as to atherosclerotic lesions and apoptotic cells. Because oxidative processes are ubiquitous, we hypothesized that these epitopes exert selective pressure to expand NAbs, which in turn play an important role in mediating homeostatic functions consequent to inflammation and cell death, as demonstrated by their ability to facilitate apoptotic cell clearance. These findings provide novel insights into the functions of NAbs in mediating host homeostasis and into their roles in health and diseases, such as chronic inflammatory diseases and atherosclerosis.
Collapse
Affiliation(s)
- Meng-Yun Chou
- Department of Medicine, UCSD, La Jolla, California 92093, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Diz R, McCray SK, Clarke SH. B cell receptor affinity and B cell subset identity integrate to define the effectiveness, affinity threshold, and mechanism of anergy. THE JOURNAL OF IMMUNOLOGY 2008; 181:3834-40. [PMID: 18768837 DOI: 10.4049/jimmunol.181.6.3834] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In this study we show that BCR affinity and subset identity make unique contributions to anergy. Analysis of anti-Smith (Sm) B cells of different affinities indicates that increasing affinity improves anergy's effectiveness while paradoxically increasing the likelihood of marginal zone (MZ) and B-1 B cell differentiation rather than just follicular (FO) B cell differentiation. Subset identity in turn determines the affinity threshold and mechanism of anergy. Subset-specific affinity thresholds for anergy induction allow discordant regulation of low-affinity anti-Sm FO and MZ B cells and could account for the higher frequency of autoreactive MZ B cells than that of FO B cells in normal mice. The mechanism of anergy changes during differentiation and differs between subsets. This is strikingly illustrated by the observation that blockade of BCR-mediated activation of FO and MZ B cells occurs at different levels in the signaling cascade. Thus, attributes unique to B cells of each subset integrate with signals from the BCR to determine the effectiveness, affinity threshold, and mechanism of anergy.
Collapse
Affiliation(s)
- Ramiro Diz
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27599, USA
| | | | | |
Collapse
|
18
|
|
19
|
Abstract
Systemic lupus erythematosus (SLE) highlights the dangers of dysregulated B cells and the importance of initiating and maintaining tolerance. In addition to central deletion, receptor editing, peripheral deletion, receptor revision, anergy, and indifference, we have described a new mechanism of B cell tolerance wherein dendritic cells (DCs) and macrophages (MPhis) regulate autoreactive B cells during innate immune responses. In part, DCs and MPhis repress autoreactive B cells by releasing IL-6 and soluble CD40L (sCD40L). This mechanism is selective in that IL-6 and sCD40L do not affect Ig secretion by naïve cells during innate immune responses, allowing immunity in the absence of autoimmunity. In lupus-prone mice, DCs and MPhis are defective in secretion of IL-6 and sCD40L and cannot effectively repress autoantibody secretion suggesting that defects in DC/MPhi-mediated tolerance may contribute to the autoimmune phenotype. Further, these studies suggest that reconstituting DCs and MPhis in SLE patients might restore regulation of autoreactive B cells and provide an alternative to immunosuppressive therapies.
Collapse
Affiliation(s)
- Barbara J Vilen
- Department of Microbiology, University of North Carolina, CB 7290, Chapel Hill, NC 27599, USA.
| | | |
Collapse
|
20
|
Wrenshall LE, Smith DR, Stevens ET, Miller JD. Influence of interleukin-2 deficiency on the generation of autoimmune B cells. J Autoimmun 2007; 29:125-33. [PMID: 17692504 PMCID: PMC2080878 DOI: 10.1016/j.jaut.2007.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 06/14/2007] [Accepted: 06/18/2007] [Indexed: 10/23/2022]
Abstract
The production of auto-antibodies is one of the predominant characteristics of autoimmune disorders. Because IL-2 deficient mice develop autoimmunity, we asked how IL-2 deficiency might impair endogenous mechanisms of B cell tolerance. To this end, we mated BALB/c anti-dsDNA H chain knock-in mice, in which B cells producing anti-dsDNA antibodies are properly regulated, with IL-2 deficient mice and assessed the phenotype of their offspring. IL-2 deficient mice expressing the anti-dsDNA H chain knock-in allele developed anti-dsDNA antibodies of both IgM and IgG isotypes. Production of these antibodies occurred through the disruption of several mechanisms of endogenous tolerance, including deletion, maturational arrest, and follicular exclusion. In summary, our results suggest that IL-2 plays an important role in regulating B cell tolerance.
Collapse
Affiliation(s)
- Lucile E Wrenshall
- Division of Transplantation, University of Nebraska Medical Center, 983285 Nebraska Medical Center, Omaha, NE 68198-3285, USA
| | | | | | | |
Collapse
|
21
|
Cambier JC, Gauld SB, Merrell KT, Vilen BJ. B-cell anergy: from transgenic models to naturally occurring anergic B cells? Nat Rev Immunol 2007; 7:633-43. [PMID: 17641666 PMCID: PMC3714009 DOI: 10.1038/nri2133] [Citation(s) in RCA: 259] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Anergy, a condition in which cells persist in the periphery but are unresponsive to antigen, is responsible for silencing many self-reactive B cells. Loss of anergy is known to contribute to the development of autoimmune diseases, including systemic lupus erythematosus and type 1 diabetes. Multiple transgenic mouse models have enabled the dissection of mechanisms that underlie anergy, and recently, anergic B cells have been identified in the periphery of wild-type mice. Heterogeneity of mechanistic concepts developed using model systems has complicated our understanding of anergy and its biological features. In this Review, we compare and contrast the salient features of anergic B cells with a view to developing unifying mechanistic hypotheses that explain their lifestyles.
Collapse
Affiliation(s)
- John C Cambier
- Department of Immunology, University of Colorado Health Science Center and National Jewish Medical Research Center, 1400 Jackson Street, Denver, Colorado 80206, USA.
| | | | | | | |
Collapse
|
22
|
Seitz HM, Camenisch TD, Lemke G, Earp HS, Matsushima GK. Macrophages and dendritic cells use different Axl/Mertk/Tyro3 receptors in clearance of apoptotic cells. THE JOURNAL OF IMMUNOLOGY 2007; 178:5635-42. [PMID: 17442946 DOI: 10.4049/jimmunol.178.9.5635] [Citation(s) in RCA: 293] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The clearance of apoptotic cells is important for regulating tissue homeostasis, inflammation, and autoimmune responses. The absence of receptor tyrosine kinases (Axl, Mertk, and Tyro3) results in widespread accumulation of apoptotic cells and autoantibody production in mice. In this report, we examine the function of the three family members in apoptotic cell clearance by different phagocytic cell types. Mertk elimination nearly abolished macrophage apoptotic cell phagocytosis; elimination of Axl, Tyro3, or both, reduced macrophage phagocytosis by approximately half, indicating that these also play a role. In contrast, apoptotic cell clearance in splenic and bone marrow-derived dendritic cells (DCs) is prolonged compared with macrophages and relied primarily on Axl and Tyro3. The slower ingestion may be due to lower DC expression of Axl and Tyro3 or absence of GAS6 expression, a known ligand for this receptor family. In vivo, phagocytosis of apoptotic material by retinal epithelial cells required Mertk. Unlike macrophages, there did not appear to be any role for Axl or Tyro3 in retinal homeostasis. Likewise, clearance of apoptotic thymocytes in vivo was dramatically reduced in mertk(kd) mice, but was normal in axl/tyro3(-/-) mice. Thus, cell and organ type specificity is clearly delineated, with DCs relying on Axl and Tyro3, retina and thymus requiring Mertk, and macrophages exhibiting an interaction that involves all three family members. Surprisingly, in macrophages, tyrosine phosphorylation of Mertk in response to apoptotic cells is markedly diminished from axl/tyro3(-/-) mice, suggesting that the interactions of these receptors by heterodimerization may be important in some cells.
Collapse
Affiliation(s)
- Heather M Seitz
- Department of Microbiology and Immunology, University of North Carolina-Chapel Hill, Chapel Hill, NC 27599, USA
| | | | | | | | | |
Collapse
|
23
|
Hardy RR. B-1 B cells: development, selection, natural autoantibody and leukemia. Curr Opin Immunol 2006; 18:547-55. [PMID: 16879952 DOI: 10.1016/j.coi.2006.07.010] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Accepted: 07/20/2006] [Indexed: 01/22/2023]
Abstract
B-1 (CD5+) B cells constitute a phenotypic and functionally distinct population of B cells in mouse that show enriched expression of autoreactive B-cell antigen receptors and that produce several types of natural autoantibodies. Recently, there has been much progress in this field of research. Evidence has appeared for the existence of distinctive B-cell precursors that preferentially generate B-1 B cells, and the crucial requirement for strong B-cell antigen receptor signaling in the maturation of B-1 B cells has been established. Other work focuses on a phenotypically similar population that lacks CD5, termed 'B-1b', which shows similarities and differences from most CD5+ B cells in both development and function. The relationship of normal B-1 cells with B-cell lymphomas and leukemias continues to be a subject of interest and debate.
Collapse
Affiliation(s)
- Richard R Hardy
- Division of Basic Science, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
| |
Collapse
|