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Kogame T, Kabashima K, Egawa G. Putative Immunological Functions of Inducible Skin-Associated Lymphoid Tissue in the Context of Mucosa-Associated Lymphoid Tissue. Front Immunol 2021; 12:733484. [PMID: 34512668 PMCID: PMC8426509 DOI: 10.3389/fimmu.2021.733484] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/05/2021] [Indexed: 12/12/2022] Open
Abstract
Acquired immunity is orchestrated in various lymphoid organs, including bone marrow, thymus, spleen, and lymph nodes in humans. However, mucosa-associated lymphoid tissue (MALT) is evolutionally known to be emerged in the oldest vertebrates as an immunological tissue for acquired immunity, much earlier than the advent of lymph nodes which appeared in endotherms. Furthermore, the lymphocytes which developed in MALT are known to circulate within the limited anatomical areas. Thus, MALT is comprehended as not the structure but the immune network dedicated to local immunity. As for the skin, skin-associated lymphoid tissue (SALT) was previously postulated; however, its existence has not been proven. Our group recently showed that aggregations of dendritic cells, M2 macrophages, and high endothelial venules (HEVs) are essential components to activate effector T cells in the murine contact hypersensitivity model and termed it as inducible SALT (iSALT) since it was a transient entity that serves for acquired immunity of the skin. Furthermore, in various human skin diseases, we reported that the ectopic formation of lymphoid follicles that immunohistochemically analogous to MALT and regarded them as human counterparts of iSALT. These data raised the possibility that SALT can exist as an inducible form, namely iSALT, which shares the biological significance of MALT. In this article, we revisit the evolution of immunological organs and the related components among vertebrates to discuss the conserved functions of MALT. Furthermore, we also discuss the putative characteristics and functions of iSALT in the context of the MALT concept.
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Affiliation(s)
- Toshiaki Kogame
- Department of Dermatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kenji Kabashima
- Department of Dermatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Gyohei Egawa
- Department of Dermatology, Kyoto University Graduate School of Medicine, Kyoto, Japan
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2
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Bemark M, Angeletti D. Know your enemy or find your friend?-Induction of IgA at mucosal surfaces. Immunol Rev 2021; 303:83-102. [PMID: 34331314 PMCID: PMC7612940 DOI: 10.1111/imr.13014] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 06/28/2021] [Indexed: 12/15/2022]
Abstract
Most antibodies produced in the body are of the IgA class. The dominant cell population producing them are plasma cells within the lamina propria of the gastrointestinal tract, but many IgA-producing cells are also found in the airways, within mammary tissues, the urogenital tract and inside the bone marrow. Most IgA antibodies are transported into the lumen by epithelial cells as part of the mucosal secretions, but they are also present in serum and other body fluids. A large part of the commensal microbiota in the gut is covered with IgA antibodies, and it has been demonstrated that this plays a role in maintaining a healthy balance between the host and the bacteria. However, IgA antibodies also play important roles in neutralizing pathogens in the gastrointestinal tract and the upper airways. The distinction between the two roles of IgA - protective and balance-maintaining - not only has implications on function but also on how the production is regulated. Here, we discuss these issues with a special focus on gut and airways.
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Affiliation(s)
- Mats Bemark
- Department of Microbiology and Immunology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Clinical Immunology and Transfusion Medicine, Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Davide Angeletti
- Department of Microbiology and Immunology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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3
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Human gut-associated lymphoid tissues (GALT); diversity, structure, and function. Mucosal Immunol 2021; 14:793-802. [PMID: 33753873 DOI: 10.1038/s41385-021-00389-4] [Citation(s) in RCA: 147] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 02/05/2021] [Accepted: 02/06/2021] [Indexed: 02/07/2023]
Abstract
Gut-associated lymphoid tissues (GALT) are the key antigen sampling and adaptive immune inductive sites within the intestinal wall. Human GALT includes the multi-follicular Peyer's patches of the ileum, the vermiform appendix, and the numerous isolated lymphoid follicles (ILF) which are distributed along the length of the intestine. Our current understanding of GALT diversity and function derives primarily from studies in mice, and the relevance of many of these findings to human GALT remains unclear. Here we review our current understanding of human GALT diversity, structure, and composition as well as their potential for regulating intestinal immune responses during homeostasis and inflammatory bowel disease (IBD). Finally, we outline some key remaining questions regarding human GALT, the answers to which will advance our understanding of intestinal immune responses and provide potential opportunities to improve the treatment of intestinal diseases.
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4
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Fenton TM, Jørgensen PB, Niss K, Rubin SJS, Mörbe UM, Riis LB, Da Silva C, Plumb A, Vandamme J, Jakobsen HL, Brunak S, Habtezion A, Nielsen OH, Johansson-Lindbom B, Agace WW. Immune Profiling of Human Gut-Associated Lymphoid Tissue Identifies a Role for Isolated Lymphoid Follicles in Priming of Region-Specific Immunity. Immunity 2020; 52:557-570.e6. [PMID: 32160523 DOI: 10.1016/j.immuni.2020.02.001] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 01/09/2020] [Accepted: 02/13/2020] [Indexed: 12/19/2022]
Abstract
The intestine contains some of the most diverse and complex immune compartments in the body. Here we describe a method for isolating human gut-associated lymphoid tissues (GALTs) that allows unprecedented profiling of the adaptive immune system in submucosal and mucosal isolated lymphoid follicles (SM-ILFs and M-ILFs, respectively) as well as in GALT-free intestinal lamina propria (LP). SM-ILF and M-ILF showed distinct patterns of distribution along the length of the intestine, were linked to the systemic circulation through MAdCAM-1+ high endothelial venules and efferent lymphatics, and had immune profiles consistent with immune-inductive sites. IgA sequencing analysis indicated that human ILFs are sites where intestinal adaptive immune responses are initiated in an anatomically restricted manner. Our findings position ILFs as key inductive hubs for regional immunity in the human intestine, and the methods presented will allow future assessment of these compartments in health and disease.
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Affiliation(s)
- Thomas M Fenton
- Mucosal Immunology Group, Department of Health Technology, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark.
| | - Peter B Jørgensen
- Mucosal Immunology Group, Department of Health Technology, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - Kristoffer Niss
- Translational Disease Systems Biology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Samuel J S Rubin
- Department of Medicine, Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Urs M Mörbe
- Immunology Section, Lund University, BMC D14, 221-84 Lund, Sweden
| | - Lene B Riis
- Department of Pathology, Herlev Hospital, University of Copenhagen, 2730 Herlev, Denmark
| | - Clément Da Silva
- Immunology Section, Lund University, BMC D14, 221-84 Lund, Sweden
| | - Adam Plumb
- Immunological Memory Group, Department of Health Technology, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - Julien Vandamme
- Mucosal Immunology Group, Department of Health Technology, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - Henrik L Jakobsen
- Department of Gastroenterology, Surgical Section, Herlev Hospital, University of Copenhagen, 2730 Herlev, Denmark
| | - Søren Brunak
- Translational Disease Systems Biology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Aida Habtezion
- Department of Medicine, Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ole H Nielsen
- Department of Gastroenterology, Medical Section, Herlev Hospital, University of Copenhagen, 2730 Herlev, Denmark
| | - Bengt Johansson-Lindbom
- Immunology Section, Lund University, BMC D14, 221-84 Lund, Sweden; Immunological Memory Group, Department of Health Technology, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - William W Agace
- Mucosal Immunology Group, Department of Health Technology, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark; Immunology Section, Lund University, BMC D14, 221-84 Lund, Sweden.
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5
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Pararasa C, Zhang N, Tull TJ, Chong MHA, Siu JHY, Guesdon W, Chavele KM, Sanderson JD, Langmead L, Kok K, Spencer J, Vossenkamper A. Reduced CD27 -IgD - B Cells in Blood and Raised CD27 -IgD - B Cells in Gut-Associated Lymphoid Tissue in Inflammatory Bowel Disease. Front Immunol 2019; 10:361. [PMID: 30891036 PMCID: PMC6411645 DOI: 10.3389/fimmu.2019.00361] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 02/12/2019] [Indexed: 12/16/2022] Open
Abstract
The intestinal mucosa in inflammatory bowel disease (IBD) contains increased frequencies of lymphocytes and a disproportionate increase in plasma cells secreting immunoglobulin (Ig)G relative to other isotypes compared to healthy controls. Despite consistent evidence of B lineage cells in the mucosa in IBD, little is known of B cell recruitment to the gut in IBD. Here we analyzed B cells in blood of patients with Crohn's disease (CD) and ulcerative colitis (UC) with a range of disease activities. We analyzed the frequencies of known B cell subsets in blood and observed a consistent reduction in the proportion of CD27-IgD- B cells expressing all Ig isotypes in the blood in IBD (independent of severity of disease and treatment) compared to healthy controls. Successful treatment of patients with biologic therapies did not change the profile of B cell subsets in blood. By mass cytometry we demonstrated that CD27-IgD- B cells were proportionately enriched in the gut-associated lymphoid tissue (GALT) in IBD. Since production of TNFα is a feature of IBD relevant to therapies, we sought to determine whether B cells in GALT or the CD27-IgD- subset in particular could contribute to pathology by secretion of TNFα or IL-10. We found that donor matched GALT and blood B cells are capable of producing TNFα as well as IL-10, but we saw no evidence that CD27-IgD- B cells from blood expressed more TNFα compared to other subsets. The reduced proportion of CD27-IgD- B cells in blood and the increased proportion in the gut implies that CD27-IgD- B cells are recruited from the blood to the gut in IBD. CD27-IgD- B cells have been implicated in immune responses to intestinal bacteria and recruitment to GALT, and may contribute to the intestinal inflammatory milieu in IBD.
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Affiliation(s)
- Chathyan Pararasa
- Peter Gorer Department of Immunobiology, King's College London, Guy's Hospital, London, United Kingdom
| | - Na Zhang
- Peter Gorer Department of Immunobiology, King's College London, Guy's Hospital, London, United Kingdom.,Obstetrics and Gynecology Hospital, Institutes of Biomedical Sciences (IBS), Fudan University, Shanghai, China
| | - Thomas J Tull
- Peter Gorer Department of Immunobiology, King's College London, Guy's Hospital, London, United Kingdom
| | - Ming H A Chong
- Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University London, London, United Kingdom
| | - Jacqueline H Y Siu
- Department of Surgery, Addenbrookes Hospital, University of Cambridge, Cambridge, United Kingdom
| | - William Guesdon
- Peter Gorer Department of Immunobiology, King's College London, Guy's Hospital, London, United Kingdom
| | - Konstantia Maria Chavele
- Peter Gorer Department of Immunobiology, King's College London, Guy's Hospital, London, United Kingdom
| | - Jeremy D Sanderson
- Department of Gastroenterology, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Louise Langmead
- Department of Gastroenterology, Royal London Hospital, Barts Health, London, United Kingdom
| | - Klaartje Kok
- Department of Gastroenterology, Royal London Hospital, Barts Health, London, United Kingdom
| | - Jo Spencer
- Peter Gorer Department of Immunobiology, King's College London, Guy's Hospital, London, United Kingdom
| | - Anna Vossenkamper
- Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University London, London, United Kingdom
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6
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Lycke NY, Bemark M. The regulation of gut mucosal IgA B-cell responses: recent developments. Mucosal Immunol 2017; 10:1361-1374. [PMID: 28745325 DOI: 10.1038/mi.2017.62] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 05/20/2017] [Indexed: 02/04/2023]
Abstract
The majority of activated B cells differentiate into IgA plasma cells, with the gut being the largest producer of immunoglobulin in the body. Secretory IgA antibodies have numerous critical functions of which protection against infections and the role for establishing a healthy microbiota appear most important. Expanding our knowledge of the regulation of IgA B-cell responses and how effective mucosal vaccines can be designed are of critical importance. Here we discuss recent developments in the field that shed light on the uniqueness and complexity of mucosal IgA responses and the control of protective IgA responses in the gut, specifically.
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Affiliation(s)
- N Y Lycke
- Department of Microbiology and Immunology, Mucosal Immunobiology and Vaccine Center, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - M Bemark
- Department of Microbiology and Immunology, Mucosal Immunobiology and Vaccine Center, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
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7
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Spencer J, Sollid LM. The human intestinal B-cell response. Mucosal Immunol 2016; 9:1113-24. [PMID: 27461177 DOI: 10.1038/mi.2016.59] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 06/10/2016] [Indexed: 02/04/2023]
Abstract
The intestinal immune system is chronically challenged by a huge plethora of antigens derived from the lumen. B-cell responses in organized gut-associated lymphoid tissues and regional lymph nodes that are driven chronically by gut antigens generate the largest population of antibody-producing cells in the body: the gut lamina propria plasma cells. Although animal studies have provided insights into mechanisms that underpin this dynamic process, some very fundamental differences in this system appear to exist between species. Importantly, this prevents extrapolation from mice to humans to inform translational research questions. Therefore, in this review we will describe the structures and mechanisms involved in the propagation, dissemination, and regulation of this immense plasma cell population in man. Uniquely, we will seek our evidence exclusively from studies of human cells and tissues.
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Affiliation(s)
- J Spencer
- Peter Gorer Department of Immunobiology, King's College London, London, UK
| | - L M Sollid
- Centre for Immune Regulation and Department of Immunology, University of Oslo and Oslo University Hospital-Rikshospitalet, Oslo, Norway
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8
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Lycke N, Bemark M, Spencer J. Mucosal B Cell Differentiation and Regulation. Mucosal Immunol 2015. [DOI: 10.1016/b978-0-12-415847-4.00033-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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9
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Chorny A, Cerutti A. Regulation and Function of Mucosal IgA and IgD. Mucosal Immunol 2015. [DOI: 10.1016/b978-0-12-415847-4.00032-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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10
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Limited expression of APRIL and its receptors prior to intestinal IgA plasma cell development during human infancy. Mucosal Immunol 2014; 7:467-77. [PMID: 24045575 PMCID: PMC3959635 DOI: 10.1038/mi.2013.64] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 07/26/2013] [Accepted: 08/07/2013] [Indexed: 02/04/2023]
Abstract
The absence of immunoglobulin A (IgA) in the intestinal tract renders young infants highly susceptible to enteric infections. However, mediators of initial IgA induction in this population are undefined. We determined the temporal acquisition of plasma cells by isotype and expression of T cell-independent (TI) and -dependent (TD) IgA class switch factors in the human intestinal tract during early infancy. We found that IgA plasma cells were largely absent in the infant intestine until after 1 month of age, approaching adult densities later in infancy than both IgM and IgG. The restricted development of IgA plasma cells in the first month was accompanied by reduced expression of the TI factor a proliferation-inducing ligand (APRIL) and its receptors TACI (transmembrane activator and calcium-modulator and cyclophilin ligand interactor) and B cell maturation antigen (BCMA) within isolated lymphoid follicles (ILFs). Moreover, both APRIL and BCMA expression strongly correlated with increasing IgA plasma cell densities over time. Conversely, TD mediators (CD40 ligand (CD40L) and CD40) were expressed within ILFs before 1 month and were not associated with IgA plasma cell generation. In addition, preterm infants had lower densities of IgA plasma cells and reduced APRIL expression compared with full-term infants. Thus, blunted TI responses may contribute to the delayed induction of intestinal IgA during early human infancy.
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11
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Provenzano D, Kovác P, Wade WF. The ABCs (Antibody, B Cells, and Carbohydrate Epitopes) of Cholera Immunity: Considerations for an Improved Vaccine. Microbiol Immunol 2013; 50:899-927. [PMID: 17179659 DOI: 10.1111/j.1348-0421.2006.tb03866.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cholera, a diarrheal disease, is known for explosive epidemics that can quickly kill thousands. Endemic cholera is a seasonal torment that also has a significant mortality. Not all nations with extensive rural communities can achieve the required infrastructure or behavioral changes to prevent epidemic or endemic cholera. For some communities, a single-dose cholera vaccine that protects those at risk is the most efficacious means to reduce morbidity and mortality. It is clear that our understanding of what a protective cholera immune response is has not progressed at the rate our understanding of the pathogenesis and molecular biology of cholera infection has. This review addresses V. cholerae lipopolysaccharide (LPS)-based immunogens because LPS is the only immunogen proven to induce protective antibody in humans. We discuss the role of anti-LPS antibodies in protection from cholera, the importance and the potential role of B cell subsets in protection that is based on their anatomical location and the intrinsic antigen-receptor specificity of various subsets is introduced.
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Affiliation(s)
- Daniele Provenzano
- Department of Biological Sciences, University of Texas-Brownsville, Brownsville, TX 78520, USA
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12
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Abstract
The intestinal mucosa contains the largest population of antibody-secreting plasma cells in the body, and in humans several grams of secretory immunoglobulin A (SIgA) are released into the intestine each day. In the gut lumen, SIgA serves as a first-line barrier that protects the epithelium from pathogens and toxins. Recently, next-generation sequencing has revolutionized our understanding of the nature of the intestinal microbiota and has also shed new light on the important roles of SIgA in the regulation of host-commensal homeostasis. Here, I discuss pathways of IgA induction in the context of SIgA specificity and function.
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Affiliation(s)
- Oliver Pabst
- Institute of Immunology, Hannover Medical School, Carl-Neuberg Strae 1, 30625 Hannover, Germany.
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13
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Mesin L, Sollid LM, Di Niro R. The intestinal B-cell response in celiac disease. Front Immunol 2012; 3:313. [PMID: 23060888 PMCID: PMC3463893 DOI: 10.3389/fimmu.2012.00313] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 09/18/2012] [Indexed: 12/19/2022] Open
Abstract
The function of intestinal immunity is to provide protection toward pathogens while preserving the composition of the microflora and tolerance to orally fed nutrients. This is achieved via a number of tightly regulated mechanisms including production of IgA antibodies by intestinal plasma cells. Celiac disease is a common gut disorder caused by a dysfunctional immune regulation as signified, among other features, by a massive intestinal IgA autoantibody response. Here we review the current knowledge of this B-cell response and how it is induced, and we discuss key questions to be addressed in future research.
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Affiliation(s)
- Luka Mesin
- Centre for Immune Regulation, Department of Immunology, Oslo University Hospital-Rikshospitalet, University of Oslo, Oslo, Norway
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14
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Spencer J, Klavinskis LS, Fraser LD. The human intestinal IgA response; burning questions. Front Immunol 2012; 3:108. [PMID: 22593756 PMCID: PMC3349913 DOI: 10.3389/fimmu.2012.00108] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 04/17/2012] [Indexed: 12/14/2022] Open
Abstract
The title of this special topic invites us to identify areas in the field of IgA biology that are uncertain or in need of clarification. The inductive phase of the human intestinal IgA response has been a controversial area for some years. Therefore, to structure this review, we have identified key questions that are debated in this field. We have provided explanations of the origins of the uncertainties and have provided our own reasoned answers to the questions we pose.
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Affiliation(s)
- Jo Spencer
- Peter Gorer Department of Immunobiology, King’s College London School of Medicine at Guy’s King’s College and St. Thomas’ HospitalsLondon, UK
| | - Linda S. Klavinskis
- Peter Gorer Department of Immunobiology, King’s College London School of Medicine at Guy’s King’s College and St. Thomas’ HospitalsLondon, UK
| | - Louise D. Fraser
- Peter Gorer Department of Immunobiology, King’s College London School of Medicine at Guy’s King’s College and St. Thomas’ HospitalsLondon, UK
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15
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Berkowska MA, van der Burg M, van Dongen JJM, van Zelm MC. Checkpoints of B cell differentiation: visualizing Ig-centric processes. Ann N Y Acad Sci 2012; 1246:11-25. [PMID: 22236426 DOI: 10.1111/j.1749-6632.2011.06278.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The generation of antibody responses and B cell memory can only take place following multiple steps of differentiation. Key molecular processes during precursor B cell differentiation in bone marrow generate unique antibodies. These antibodies are further optimized via molecular modifications during immune responses in peripheral lymphoid organs. Multiple checkpoints ensure proper differentiation of precursor and mature B lymphocytes. Many of these checkpoints have been found disrupted in patients with a primary immunodeficiency. Based on studies in these patients and in mouse models, new insights have been generated in B cell differentiation and antibody responses. Still, in many patients with impaired antibody formation, it remains unclear how B cells are affected. In this perspective, we present 11 critical processes in B cell differentiation. We discuss how defects in these processes can result in impaired checkpoint selection and how they can be visualized in healthy subjects and patients with immunodeficiency or other immunological disease.
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Affiliation(s)
- Magdalena A Berkowska
- Department of Immunology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
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16
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Bemark M, Boysen P, Lycke NY. Induction of gut IgA production through T cell-dependent and T cell-independent pathways. Ann N Y Acad Sci 2012; 1247:97-116. [PMID: 22260403 DOI: 10.1111/j.1749-6632.2011.06378.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The gut immune system protects against mucosal pathogens, maintains a mutualistic relationship with the microbiota, and establishes tolerance against food antigens. This requires a balance between immune effector responses and induction of tolerance. Disturbances of this strictly regulated balance can lead to infections or the development inflammatory diseases and allergies. Production of secretory IgA is a unique effector function at mucosal surfaces, and basal mechanisms regulating IgA production have been the focus of much recent research. These investigations have aimed at understanding how long-term IgA-mediated mucosal immunity can best be achieved by oral or sublingual vaccination, or at analyzing the relationship between IgA production, the composition of the gut microbiota, and protection from allergies and autoimmunity. This research has lead to a better understanding of the IgA system; but at the same time seemingly conflicting data have been generated. Here, we discuss how gut IgA production is controlled, with special focus on how differences between T cell-dependent and T cell-independent IgA production may explain some of these discrepancies.
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Affiliation(s)
- Mats Bemark
- Department of Microbiology and Immunology, Mucosal Immunobiology and Vaccine Center, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.
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17
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Human memory B cells originate from three distinct germinal center-dependent and -independent maturation pathways. Blood 2011; 118:2150-8. [PMID: 21690558 DOI: 10.1182/blood-2011-04-345579] [Citation(s) in RCA: 289] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Multiple distinct memory B-cell subsets have been identified in humans, but it remains unclear how their phenotypic diversity corresponds to the type of responses from which they originate. Especially, the contribution of germinal center-independent responses in humans remains controversial. We defined 6 memory B-cell subsets based on their antigen-experienced phenotype and differential expression of CD27 and IgH isotypes. Molecular characterization of their replication history, Ig somatic hypermutation, and class-switch profiles demonstrated their origin from 3 different pathways. CD27⁻IgG⁺ and CD27⁺IgM⁺ B cells are derived from primary germinal center reactions, and CD27⁺IgA⁺ and CD27⁺IgG⁺ B cells are from consecutive germinal center responses (pathway 1). In contrast, natural effector and CD27⁻IgA⁺ memory B cells have limited proliferation and are also present in CD40L-deficient patients, reflecting a germinal center-independent origin. Natural effector cells at least in part originate from systemic responses in the splenic marginal zone (pathway 2). CD27⁻IgA⁺ cells share low replication history and dominant Igλ and IgA2 use with gut lamina propria IgA+ B cells, suggesting their common origin from local germinal center-independent responses (pathway 3). Our findings shed light on human germinal center-dependent and -independent B-cell memory formation and provide new opportunities to study these processes in immunologic diseases.
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18
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Abstract
Mucosal surfaces are colonized by large communities of commensal bacteria and represent the primary site of entry for pathogenic agents. To prevent microbial intrusion, mucosal B cells release large amounts of immunoglobulin (Ig) molecules through multiple follicular and extrafollicular pathways. IgA is the most abundant antibody isotype in mucosal secretions and owes its success in frontline immunity to its ability to undergo transcytosis across epithelial cells. In addition to translocating IgA onto the mucosal surface, epithelial cells educate the mucosal immune system as to the composition of the local microbiota and instruct B cells to initiate IgA responses that generate immune protection while preserving immune homeostasis. Here we review recent advances in our understanding of the cellular interactions and signaling pathways governing IgA production at mucosal surfaces and discuss new findings on the regulation and function of mucosal IgD, the most enigmatic isotype of our mucosal antibody repertoire.
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Affiliation(s)
- Andrea Cerutti
- ICREA, Catalan Institute for Research and Advanced Studies, Barcelona Biomedical Research Park, Spain.
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19
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Barone F, Vossenkamper A, Boursier L, Su W, Watson A, John S, Dunn-Walters DK, Fields P, Wijetilleka S, Edgeworth JD, Spencer J. IgA-producing plasma cells originate from germinal centers that are induced by B-cell receptor engagement in humans. Gastroenterology 2011; 140:947-56. [PMID: 21147106 PMCID: PMC7115992 DOI: 10.1053/j.gastro.2010.12.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 11/25/2010] [Accepted: 12/02/2010] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS IgA contributes to homeostatic balance between host and intestinal microbiota. Mechanisms that initiate the IgA response are unclear and likely to differ between humans and animal models. We used multiple experimental approaches to investigate the origin of human intestinal plasma cells that produce IgA in the gastrointestinal tract. METHODS Complexity of IgA-producing plasma cell populations in human gastrointestinal mucosa and bone marrow and the specific response to oral cholera vaccine were compared by analysis of immunoglobulin genes. Flow cytometry, gene expression analysis, and immunohistochemistry were used to analyze signaling pathways induced by B-cell receptor engagement in human gut-associated lymphoid tissue (GALT) and involvement of innate immunity in B-cell activation in GALT compared with nonintestinal sites. RESULTS Human intestinal IgA-producing plasma cells appeared to be of germinal center origin; there was no evidence for the population complexity that accompanies multiple pathways of derivation observed in bone marrow. In germinal center B cells of human GALT, Btk and Erk are phosphorylated, CD22 is down-regulated, Lyn is translocated to the cell membrane, and Fos and Jun are up-regulated; these features indicate B-cell receptor ligation during germinal center evolution. No differences in innate activation of B cells were observed in GALT, compared with peripheral immune compartments. CONCLUSIONS IgA-producing plasma cells appear to be derived from GALT germinal centers in humans. B-cell receptor engagement promotes formation of germinal centers of GALT, with no more evidence for innate immune receptor activation in the mucosa than nonintestinal immune compartments. Germinal centers in GALT should be targets of mucosal vaccinations because they are the source of human intestinal IgA response.
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Affiliation(s)
- Francesca Barone
- Peter Gorer Department of Immunobiology, King’s College London, Guy’s Hospital, London SE1 9RT, UK
| | - Anna Vossenkamper
- Queen Mary University of London, Barts & The London School of Medicine and Dentistry, Institute of Cell and Molecular Science, Whitechapel, London E1 2AT, UK
| | - Laurent Boursier
- Peter Gorer Department of Immunobiology, King’s College London, Guy’s Hospital, London SE1 9RT, UK
| | - Wen Su
- Peter Gorer Department of Immunobiology, King’s College London, Guy’s Hospital, London SE1 9RT, UK
| | - Alan Watson
- Centre for Gastroenterology, Barts and the London NHS Trust, London, E1 1BB, UK
| | - Susan John
- Peter Gorer Department of Immunobiology, King’s College London, Guy’s Hospital, London SE1 9RT, UK
| | - Deborah K. Dunn-Walters
- Peter Gorer Department of Immunobiology, King’s College London, Guy’s Hospital, London SE1 9RT, UK
| | - Paul Fields
- Department of Haematology, Guy’s and St Thomas’ NHS Foundation Trust, Guy’s Hospital SE1 9RT, UK
| | - Sonali Wijetilleka
- Peter Gorer Department of Immunobiology, King’s College London, Guy’s Hospital, London SE1 9RT, UK
| | - Jonathan D. Edgeworth
- Directorate of Infection, Guy’s and St Thomas’ NHS Foundation Trust, St Thomas’ Hospital, London SE1 7EH, UK
| | - Jo Spencer
- Peter Gorer Department of Immunobiology, King’s College London, Guy’s Hospital, London SE1 9RT, UK
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Gibbons DL, Spencer J. Mouse and human intestinal immunity: same ballpark, different players; different rules, same score. Mucosal Immunol 2011; 4:148-57. [PMID: 21228770 DOI: 10.1038/mi.2010.85] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The study of animal immune physiology and animal models of human disease have accelerated many aspects of translational research by allowing direct, definitive investigations. In particular, the use of mice has allowed genetic manipulation, adoptive transfer, immunization, and focused cell and tissue sampling, which would obviously be unthinkable for studies in humans. However, the disease relevance of some animal models may be uncertain and difficulties in interpretation may occur as a consequence of immunological differences between the two species. In this review, we will consider general differences in the structure and development of human and mouse mucosal lymphoid microenvironments and then discuss species differences in mucosal B- and T-cell biology that relate to the current concepts of intestinal immune function.
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Affiliation(s)
- D L Gibbons
- Peter Gorer Department of Immunobiology, Kings College London, London, UK.
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21
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Steady-state generation of mucosal IgA+ plasmablasts is not abrogated by B-cell depletion therapy with rituximab. Blood 2010; 116:5181-90. [DOI: 10.1182/blood-2010-01-266536] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
AbstractThe anti-CD20 antibody rituximab depletes human B cells from peripheral blood, but it remains controversial to what extent tissue-resident B cells are affected. In representative patients with rheumatoid arthritis, we here demonstrate that recently activated presumably short-lived plasmablasts expressing HLA-DRhigh and Ki-67 continuously circulate in peripheral blood after B-cell depletion by rituximab at 26%-119% of their initial numbers. They circulate independent of splenectomy, express immunoglobulin A (IgA), β7 integrin, and C-C motif receptor 10 (CCR10) and migrate along CCL28 gradients in vitro, suggesting their mucosal origin. These plasmablasts express somatically hypermutated VH gene rearrangements and spontaneously secrete IgA, exhibiting binding to microbial antigens. Notably, IgA+ plasmablasts and plasma cells were identified in the lamina propria of patients treated with rituximab during peripheral B-cell depletion. Although a relation of these “steady state”–like plasmablasts with rheumatoid arthritis activity could not be found, their persistence during B-cell depletion indicates that their precursors, that is, B cells resident in the mucosa are not deleted by this treatment. These data suggest that a population of mucosal B cells is self-sufficient in adult humans and not replenished by CD20+ B cells immigrating from blood, lymphoid tissue, or bone marrow, that is, B cells depleted by rituximab.
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22
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Patel P, Barone F, Nunes C, Boursier L, Odell E, Escudier M, Challacombe S, Brostoff J, Spencer J, Sanderson J. Subepithelial dendritic B cells in orofacial granulomatosis. Inflamm Bowel Dis 2010; 16:1051-60. [PMID: 19924808 DOI: 10.1002/ibd.21169] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
BACKGROUND Orofacial granulomatosis (OFG) is a chronic, disfiguring, granulomatous inflammation of the lips and oral mucosa. The pathogenesis is unknown, but it has been linked previously to Crohn's disease (CD) and more recently to dietary sensitivity. The oral mucosa is an immunologically responsive site associated with the generation of protective mucosal and systemic immune responses to vaccination and also hyperresponsiveness to allergens in some individuals. Classically, immune responses in oral mucosa are considered to be mediated by mucosa-associated lymphoid tissues (MALT), secondary lymphoid follicles that are intimately associated with epithelia. METHODS Immunohistochemistry was used to investigate the inflammatory infiltrate in OFG and control tissue samples. Polymerase chain reaction (PCR), cloning of PCR products, and sequencing were used to characterize the local immunoglobulin gene profile in OFG. RESULTS We describe large, active, dendritic B cells in oral mucosa that were not associated with any organized lymphoid tissues in the local subepithelial microenvironment. They express activation induced cytidine deaminase, which is essential for immunoglobulin gene diversification by somatic hypermutation and class switch recombination. IgE is also expressed by these B cells. They do not align with any other previously described B-cell subset in secondary lymphoid tissues in terms of morphology, proliferative activity, or phenotype. CONCLUSIONS These subepithelial dendritic B cells may contribute to the immune responsiveness of the oral mucosa, including IgE-mediated allergic responses. In patients with OFG, further understanding of the role these cells play in oral immunity may lead to novel therapeutic possibilities.
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Affiliation(s)
- Pritash Patel
- Department of Gastroenterology at Guy's & St. Thomas NHS Foundation Trust, London, UK
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23
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Bergqvist P, Stensson A, Lycke NY, Bemark M. T cell-independent IgA class switch recombination is restricted to the GALT and occurs prior to manifest germinal center formation. THE JOURNAL OF IMMUNOLOGY 2010; 184:3545-53. [PMID: 20207993 DOI: 10.4049/jimmunol.0901895] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Recently, we reported that CD40(-/-) mice, exhibiting exclusively T cell-independent IgA class switch recombination (CSR), demonstrated near normal levels of IgA plasma cells in the gut lamina propria (LP), despite the complete lack of germinal centers (GCs). In this study, we have extended our analysis focusing on how to reconcile these findings using flow cytometry and molecular markers for IgA CSR. In agreement with our previous results with small intestinal LP, the colon LP was found to host IgA CSR only when lymphoid follicles were present. Thus, no IgA CSR was observed in the nonorganized colon LP. By contrast, the Peyer's patch (PP) was the dominant IgA CSR site in both CD40(-/-) and wild type (WT) mice, and they both hosted similar levels of mRNA expression for B cell activating factor of the TNF family, a proliferation inducing ligand, and inducible NO synthase, potential switch-factors for IgA. Unexpectedly, we found that PP B cells undergoing IgA CSR were GL7-intermediate. These cells had not undergone somatic hypermutations (SHMs), whereas GL7-high cells in WT PP, which exhibited GCs, were heavily mutated. Moreover, IgA plasma cells in the LP of CD40(-/-) mice demonstrated few mutations in their Ig V regions, whereas WT LP B cells from different sites showed extensive SHMs, which were also clonally related. Therefore, IgA CSR can occur in PP at a stage preceding manifest GC (GL7-intermediate), whereas SHM require GC formations (GL7-high). These findings reconcile that IgA CSR can occur in PP in the absence of GC with the fact that CD40(-/-) mice host near normal levels of IgA plasma cells in the LP.
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Affiliation(s)
- Peter Bergqvist
- Department of Microbiology and Immunology, Mucosal Immunobiology and Vaccine Center, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
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24
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Reply to “Gut-associated lymphoid tissue contains the molecular machinery to support T-cell-dependent and T-cell-independent class switch recombination”. Mucosal Immunol 2009. [DOI: 10.1038/mi.2009.126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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25
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Gut-associated lymphoid tissue contains the molecular machinery to support T-cell-dependent and T-cell-independent class switch recombination. Mucosal Immunol 2009; 2:495-503. [PMID: 19741596 DOI: 10.1038/mi.2009.106] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A PRoliferation-Inducing Ligand (APRIL) is a secreted cytokine member of the tumor necrosis factor family. It is a B-cell survival factor that also induces class switch recombination (CSR) toward immunoglobulin A (IgA), independent of T cells. It is therefore an important contributor to the maintenance of the mucosal immunological barrier, which has been linked to a putative extrafollicular inductive phase of the IgA response in lamina propria. By immunohistochemistry (IHC) and quantitative real-time PCR (qRT-PCR) on microdissected tissue from normal human gut, we observed APRIL expression, together with TACI (transmembrane activator and CAML interactor) and BCMA (B-cell maturation antigen), in gut-associated lymphoid tissue (GALT), lamina propria, and in the epithelium of stomach, small and large intestine, and rectum. However, no activation-induced cytidine deaminase (AID) expression (an absolute requirement for class switching) was detected in lamina propria by IHC or qRT-PCR. APRIL and its receptors were only observed alongside AID in GALT, showing that GALT contains the apparatus to support both T-independent and T-dependent routes to IgA CSR.
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Yuvaraj S, Dijkstra G, Burgerhof JGM, Dammers PM, Stoel M, Visser A, Kroese FGM, Bos NA. Evidence for local expansion of IgA plasma cell precursors in human ileum. THE JOURNAL OF IMMUNOLOGY 2009; 183:4871-8. [PMID: 19786537 DOI: 10.4049/jimmunol.0901315] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
IgA plays a crucial role in establishment and maintenance of mucosal homeostasis between host cells and commensal bacteria. To this end, numerous IgA plasma cells are located in the intestinal lamina propria. Whether the (immediate) precursor cells for these plasma cells can expand locally is not completely known and was studied here. The total number of IgA plasma cells in human ileal biopsies was counted. Sequence analysis of IgA V(H) genes from human ileal biopsies revealed the occurrence of many clonally related sequences within a biopsy, but not between different biopsies. This observation strongly argues for local expansion of IgA precursor cells. By comparing the number of unique sequences with the number of clonally related sequences within a biopsy, we estimated that approximately 100-300 precursors were responsible for the 75,000 IgA-producing cells that were present per biopsy. These precursor cells must therefore have divided locally 9-10 times. Since all sequences contained mutations and most of the mutations present in clonally related sequences were shared, the IgA precursor cells must have arrived initially as mutated cells in the lamina propria. Our data show evidence for the existence of two waves of expansion for IgA-producing cells in human ileum. The first wave occurs during initial stimulation in germinal centers as evidenced by somatic hypermutations. A second wave of expansion of IgA-committed cells occurs locally within the lamina propria as evidenced by the high frequency of clonally related cells.
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Affiliation(s)
- Saravanan Yuvaraj
- Department of Cell Biology, Section Immunology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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27
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Suzuki K, Fagarasan S. How host-bacterial interactions lead to IgA synthesis in the gut. Trends Immunol 2009; 29:523-31. [PMID: 18838301 DOI: 10.1016/j.it.2008.08.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2008] [Revised: 08/01/2008] [Accepted: 08/18/2008] [Indexed: 12/30/2022]
Abstract
In mammals, the gut is populated with an extremely dense and diverse bacterial community. One response following intestinal colonization is the production of immunoglobulin (Ig) A by B cells present in the gut-associated lymphoid tissues (GALT). In this review, we summarize recent advances in our understanding of the sites, mechanisms, and functions of intestinal IgA synthesis. We discuss here the pathways leading to IgA production, in organized structures as well as nonorganized tissues, by T-dependent as well as T-independent mechanisms. In addition, we discuss new insights into the role of gut IgA in the regulation of bacterial communities and maintenance of immune homeostasis.
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Affiliation(s)
- Keiichiro Suzuki
- Laboratory for Mucosal Immunity, RIKEN Research Center for Allergy and Immunology, 230-0045 Tsurumi, Yokohama, Japan.
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28
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Spencer J, Barone F, Dunn-Walters D. Generation of Immunoglobulin diversity in human gut-associated lymphoid tissue. Semin Immunol 2009; 21:139-46. [PMID: 19233686 DOI: 10.1016/j.smim.2009.01.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Accepted: 01/20/2009] [Indexed: 02/05/2023]
Abstract
The organised gut associated lymphoid tissue (GALT) exists adjacent to an extensive and diverse luminal flora. The follicle associated epithelium and associated dendritic cells and lymphocytes form a tightly fortified gateway between the flora and the host that permits connectivity between them and chronic activation of the lymphoid compartment. As a consequence, plasma cell precursors are generated continuously, and in abundance, in GALT by clonal proliferation. Clonal proliferation alone on this scale would reduce the spectrum of B cell specificity. To compensate, GALT also houses molecular machinery that diversifies the receptor repertoire by somatic hypermutation, class switch recombination and receptor revision. These three processes of enhancing the diversity of mature B cells ensure that although clonally related plasma cells may secrete immunoglobulin side by side in the mucosa they rarely have identical antigen binding sites.
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Affiliation(s)
- Jo Spencer
- Peter Gorer Department of Immunobiology, King's College London, Guy's Hospital Campus, St Thomas' St, London SE1 9RT, United Kingdom
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29
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Su W, Gordon JN, Barone F, Boursier L, Turnbull W, Mendis S, Dunn-Walters DK, Spencer J. Lambda light chain revision in the human intestinal IgA response. THE JOURNAL OF IMMUNOLOGY 2008; 181:1264-71. [PMID: 18606680 DOI: 10.4049/jimmunol.181.2.1264] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Revision of Ab L chains by secondary rearrangement in mature B cells has the potential to change the specific target of the immune response. In this study, we show for the first time that L chain revision is normal and widespread in the largest Ab producing population in man: intestinal IgA plasma cells (PC). Biases in the productive and non-productive repertoire of lambda L chains, identification of the circular products of rearrangement that have the characteristic biases of revision, and identification of RAG genes and protein all reflect revision during normal intestinal IgA PC development. We saw no evidence of IgH revision, probably due to inappropriately orientated recombination signal sequences, and little evidence of kappa-chain revision, probably due to locus inactivation by the kappa-deleting element. We propose that the lambda L chain locus is available and a principal modifier and diversifier of Ab specificity in intestinal IgA PCs.
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Affiliation(s)
- Wen Su
- Department of Immunobiology, Kings College London School of Medicine, Guy's King's College, St Thomas' Hospitals, London, United Kingdom
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30
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Abstract
Most antibody-secreting cells (ASCs) in mucosal tissues produce immunoglobulin A (IgA), the most abundant immunoglobulin in the body and the main class of antibody found in secretions. IgA-ASCs differentiate in the mucosal-associated lymphoid tissues and are usually considered as a homogeneous population of cells. However, IgA-ASCs that travel to the small intestine have unique characteristics in terms of their migratory requirements. These IgA-ASCs require the homing molecules alpha4beta7 and CCR9 to interact with their ligands, mucosal addressin cell adhesion molecule-1 and CCL25, which are constitutively expressed in the small intestine. Indeed, recent work has shown that IgA-ASCs specific for the small bowel are generated under different conditions as compared with IgA-ASCs in other mucosal compartments. Moreover, the mechanisms inducing IgA class switching may also vary according to the tissue where IgA-ASCs differentiate. Here we describe the mechanisms involved in the differentiation of IgA-ASCs in mucosal compartments, in particular those involved in the generation of gut-homing IgA-ASCs.
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31
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Abstract
The intestinal immune system includes an immunoglobulin (Ig)A-inductive site represented by Peyer's patches (PPs) and an IgA effector site represented by the lamina propria (LP). This canonical map of intestinal IgA production has been blurred recently by studies showing the presence of active IgA class switching in the LP. Here we discuss the functional implications and controversial nature of these findings.
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32
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Brandtzaeg P, Kiyono H, Pabst R, Russell MW. Terminology: nomenclature of mucosa-associated lymphoid tissue. Mucosal Immunol 2008; 1:31-7. [PMID: 19079158 DOI: 10.1038/mi.2007.9] [Citation(s) in RCA: 234] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Stimulation of mucosal immunity has great potential in vaccinology and immunotherapy. However, the mucosal immune system is more complex than the systemic counterpart, both in terms of anatomy (inductive and effector tissues) and effectors (cells and molecules). Therefore, immunologists entering this field need a precise terminology as a crucial means of communication. Abbreviations for mucosal immune-function molecules related to the secretory immunoglobulin A system were defined by the Society for Mucosal Immunolgy Nomenclature Committee in 1997, and are briefly recapitulated in this article. In addition, we recommend and justify standard nomenclature and abbreviations for discrete mucosal immune-cell compartments, belonging to, and beyond, mucosa-associated lymphoid tissue.
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Affiliation(s)
- P Brandtzaeg
- Department of Pathology, Rikshospitalet University Hospital, Oslo, Norway.
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33
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McGhee JR, Kunisawa J, Kiyono H. Gut lymphocyte migration: we are halfway ‘home’. Trends Immunol 2007; 28:150-3. [PMID: 17293162 DOI: 10.1016/j.it.2007.02.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2006] [Accepted: 02/02/2007] [Indexed: 12/12/2022]
Abstract
The gastrointestinal immune system consists of immune cells in organized gut-associated lymphoreticular tissues (GALT) and diffuse lamina propria, which give rise to mucosal secretory IgA antibody responses. A recent study showed that the retinoic acid produced by GALT dendritic cells (DCs) imprints B cells for gut homing. Surprisingly, GALT DCs, together with interleukin-5 (IL-5) and IL-6, also provided a milieu for both B cell switching to IgA and IgA synthesis.
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Affiliation(s)
- Jerry R McGhee
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL 35294-2170, USA.
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Bergqvist P, Gärdby E, Stensson A, Bemark M, Lycke NY. Gut IgA class switch recombination in the absence of CD40 does not occur in the lamina propria and is independent of germinal centers. THE JOURNAL OF IMMUNOLOGY 2007; 177:7772-83. [PMID: 17114448 DOI: 10.4049/jimmunol.177.11.7772] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Conflicting findings have recently been presented as to the sites and sources of B cells that undergo class switch recombination (CSR) to IgA in the gut. In this study we provide compelling evidence in CD40(-/-) mice demonstrating that IgA CSR can be independent of CD40 signaling and germinal center formation and does not occur in the gut lamina propria (LP) itself. We found that CD40(-/-) mice had near normal levels of gut total IgA despite lacking germinal centers and completely failing to raise specific responses against the T cell-dependent Ags cholera toxin and keyhole limpet hemocyanin. The Peyer's patches in CD40(-/-) mice expressed unexpectedly high levels of activation-induced cytidine deaminase mRNA and germline alpha transcripts, but few postswitch circular DNA transcripts, arguing against significant IgA CSR. Moreover and more surprisingly, wild-type mice exhibited no to low IgA CSR in mesenteric lymph nodes or isolated lymphoid follicles. Importantly, both strains failed to demonstrate any of the molecular markers for IgA CSR in the gut LP itself. Whereas all of the classical sites for IgA CSR in the GALT in CD40(-/-) mice appeared severely compromised for IgA CSR, B cells in the peritoneal cavity demonstrated the expression of activation-induced cytidine deaminase mRNA comparable to that of wild-type mice. However, peritoneal cavity B cells in both strains expressed intermediate levels of the germinal center marker GL7 and exhibited no germline alpha transcripts, and only three of 51 mice analyzed showed the presence of postswitch circular DNA transcripts. Taken together, these findings strongly argue for alternative inductive sites for gut IgA CSR against T cell-independent Ags outside of the GALT and the nonorganized LP.
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Affiliation(s)
- Peter Bergqvist
- Department of Microbiology and Immunology, Mucosal Immunobiology and Vaccine Research Center, Institute of Biomedicine, Göteborg University, 405 30 Göteborg, Sweden
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35
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Abstract
The vast surfaces of the gastrointestinal, respiratory, and genitourinary tracts represent major sites of potential attack by invading micro-organisms. Immunoglobulin A (IgA), as the principal antibody class in the secretions that bathe these mucosal surfaces, acts as an important first line of defence. IgA, also an important serum immunoglobulin, mediates a variety of protective functions through interaction with specific receptors and immune mediators. The importance of such protection is underlined by the fact that certain pathogens have evolved mechanisms to compromise IgA-mediated defence, providing an opportunity for more effective invasion. IgA function may also be perturbed in certain disease states, some of which are characterized by deposition of IgA in specific tissues. This review details current understanding of the roles played by IgA in both health and disease.
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Affiliation(s)
- Jenny M Woof
- Division of Pathology and Neuroscience, University of Dundee Medical School, Ninewells Hospital, UK.
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