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Bodega-Mayor I, Delgado-Wicke P, Arrabal A, Alegría-Carrasco E, Nicolao-Gómez A, Jaén-Castaño M, Espadas C, Dopazo A, Martín-Gayo E, Gaspar ML, de Andrés B, Fernández-Ruiz E. Tyrosine kinase 2 modulates splenic B cells through type I IFN and TLR7 signaling. Cell Mol Life Sci 2024; 81:199. [PMID: 38683377 PMCID: PMC11058799 DOI: 10.1007/s00018-024-05234-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 01/29/2024] [Accepted: 04/05/2024] [Indexed: 05/01/2024]
Abstract
Tyrosine kinase 2 (TYK2) is involved in type I interferon (IFN-I) signaling through IFN receptor 1 (IFNAR1). This signaling pathway is crucial in the early antiviral response and remains incompletely understood on B cells. Therefore, to understand the role of TYK2 in B cells, we studied these cells under homeostatic conditions and following in vitro activation using Tyk2-deficient (Tyk2-/-) mice. Splenic B cell subpopulations were altered in Tyk2-/- compared to wild type (WT) mice. Marginal zone (MZ) cells were decreased and aged B cells (ABC) were increased, whereas follicular (FO) cells remained unchanged. Likewise, there was an imbalance in transitional B cells in juvenile Tyk2-/- mice. RNA sequencing analysis of adult MZ and FO cells isolated from Tyk2-/- and WT mice in homeostasis revealed altered expression of IFN-I and Toll-like receptor 7 (TLR7) signaling pathway genes. Flow cytometry assays corroborated a lower expression of TLR7 in MZ B cells from Tyk2-/- mice. Splenic B cell cultures showed reduced proliferation and differentiation responses after activation with TLR7 ligands in Tyk2-/- compared to WT mice, with a similar response to lipopolysaccharide (LPS) or anti-CD40 + IL-4. IgM, IgG, IL-10 and IL-6 secretion was also decreased in Tyk2-/- B cell cultures. This reduced response of the TLR7 pathway in Tyk2-/- mice was partially restored by IFNα addition. In conclusion, there is a crosstalk between TYK2 and TLR7 mediated by an IFN-I feedback loop, which contributes to the establishment of MZ B cells and to B cell proliferation and differentiation.
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Affiliation(s)
- Irene Bodega-Mayor
- Molecular Biology Unit, Hospital Universitario de La Princesa and Research Institute (IIS-Princesa), Madrid, Spain
- Immunobiology Unit, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Pablo Delgado-Wicke
- Molecular Biology Unit, Hospital Universitario de La Princesa and Research Institute (IIS-Princesa), Madrid, Spain
| | - Alejandro Arrabal
- Molecular Biology Unit, Hospital Universitario de La Princesa and Research Institute (IIS-Princesa), Madrid, Spain
- Immunobiology Unit, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Estíbaliz Alegría-Carrasco
- Molecular Biology Unit, Hospital Universitario de La Princesa and Research Institute (IIS-Princesa), Madrid, Spain
| | - Ana Nicolao-Gómez
- Molecular Biology Unit, Hospital Universitario de La Princesa and Research Institute (IIS-Princesa), Madrid, Spain
| | - Marta Jaén-Castaño
- Molecular Biology Unit, Hospital Universitario de La Princesa and Research Institute (IIS-Princesa), Madrid, Spain
| | - Cristina Espadas
- Genomics Unit, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
| | - Ana Dopazo
- Genomics Unit, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
- CIBER de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Enrique Martín-Gayo
- Immunology Department, Hospital Universitario de La Princesa and IIS-Princesa, Madrid, Spain
- Faculty of Medicine, Universidad Autónoma de Madrid, Madrid, Spain
| | - María Luisa Gaspar
- Immunobiology Unit, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Belén de Andrés
- Immunobiology Unit, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Elena Fernández-Ruiz
- Molecular Biology Unit, Hospital Universitario de La Princesa and Research Institute (IIS-Princesa), Madrid, Spain.
- Faculty of Medicine, Universidad Autónoma de Madrid, Madrid, Spain.
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2
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Sánchez-Tarjuelo R, Cortegano I, Manosalva J, Rodríguez M, Ruíz C, Alía M, Prado MC, Cano EM, Ferrándiz MJ, de la Campa AG, Gaspar ML, de Andrés B. The TLR4-MyD88 Signaling Axis Regulates Lung Monocyte Differentiation Pathways in Response to Streptococcus pneumoniae. Front Immunol 2020; 11:2120. [PMID: 33042124 PMCID: PMC7525032 DOI: 10.3389/fimmu.2020.02120] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 08/05/2020] [Indexed: 12/20/2022] Open
Abstract
Streptococcus pneumoniae is the main cause of bacterial pneumonia, a condition that currently produces significant global morbidity and mortality. The initial immune response to this bacterium occurs when the innate system recognizes common motifs expressed by many pathogens, events driven by pattern recognition receptors like the Toll-like family receptors (TLRs). In this study, lung myeloid-cell populations responsible for the innate immune response (IIR) against S. pneumoniae, and their dependence on the TLR4-signaling axis, were analyzed in TLR4-/- and Myeloid-Differentiation factor-88 deficient (MyD88-/-) mice. Neutrophils and monocyte-derived cells were recruited in infected mice 3-days post-infection. Compared to wild-type mice, there was an increased bacterial load in both these deficient mouse strains and an altered IIR, although TLR4-/- mice were more susceptible to bacterial infection. These mice also developed fewer alveolar macrophages, weaker neutrophil infiltration, less Ly6Chigh monocyte differentiation and a disrupted classical and non-classical monocyte profile. The pro-inflammatory cytokine profile (CXCL1, TNF-α, IL-6, and IL-1β) was also severely affected by the lack of TLR4 and no induction of Th1 was observed in these mice. The respiratory burst (ROS production) after infection was profoundly dampened in TLR4-/- and MyD88-/- mice. These data demonstrate the complex dynamics of myeloid populations and a key role of the TLR4-signaling axis in the IIR to S. pneumoniae, which involves both the MyD88 and TRIF (Toll/IL-1R domain-containing adaptor-inducing IFN-β) dependent pathways.
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Affiliation(s)
| | - Isabel Cortegano
- Immunobiology Department, Carlos III Health Institute, Madrid, Spain
| | - Juliana Manosalva
- Immunobiology Department, Carlos III Health Institute, Madrid, Spain
| | | | - Carolina Ruíz
- Immunobiology Department, Carlos III Health Institute, Madrid, Spain
| | - Mario Alía
- Immunobiology Department, Carlos III Health Institute, Madrid, Spain
| | | | - Eva M. Cano
- Chronic Disease Programme, Carlos III Health Institute, Madrid, Spain
| | | | - Adela G. de la Campa
- Bacterial Genetics Department, Carlos III Health Institute, Madrid, Spain
- Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | | | - Belén de Andrés
- Immunobiology Department, Carlos III Health Institute, Madrid, Spain
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3
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Cortegano I, Rodríguez M, Martín I, Prado MC, Ruíz C, Hortigüela R, Alía M, Vilar M, Mira H, Cano E, Domínguez M, de Andrés B, Gaspar ML. Altered marginal zone and innate-like B cells in aged senescence-accelerated SAMP8 mice with defective IgG1 responses. Cell Death Dis 2017; 8:e3000. [PMID: 28817118 PMCID: PMC5596542 DOI: 10.1038/cddis.2017.351] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 06/27/2017] [Accepted: 07/02/2017] [Indexed: 12/31/2022]
Abstract
Aging has a strong impact on the activity of the immune system, enhancing susceptibility to pathogens and provoking a predominant pre-inflammatory status, whereas dampening responses to vaccines in humans and mice. Here, we demonstrate a loss of marginal zone B lymphocytes (MZ, CD19+CD45R+CD21++CD23lo) and a decrease of naive B cells (CD19+IgD+), whereas there is an enhancement of a CD19+CD45Rlo innate-like B cell population (B1REL) and the so-called aged B cell compartment (ABC, CD45R+CD21loCD23loCD5-CD11b-) in aged senescence-accelerated (SAMP8) mice but not in aged senescence-resistant (SAMR1) mice. These changes in aged SAMP8 mice were associated with lower IgG isotype levels, displaying low variable gene usage repertoires of the immunoglobulin heavy chain (VH) diversity, with a diminution on IgG1-memory B cells (CD11b-Gr1-CD138-IgM-IgD-CD19+CD38+IgG1+), an increase in T follicular helper (TFH, CD4+CXCR5+PD1+) cell numbers, and an altered MOMA-1 (metallophilic macrophages) band in primary follicles. LPS-mediated IgG1 responses were impaired in the B1REL and ABC cell compartments, both in vitro and in vivo. These data demonstrate the prominent changes to different B cell populations and in structural follicle organization that occur upon aging in SAMP8 mice. These novel results raise new questions regarding the importance of the cellular distribution in the B cell layers, and their effector functions needed to mount a coordinated and effective humoral response.
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MESH Headings
- Aging/genetics
- Aging/immunology
- Animals
- Antigens, CD/genetics
- Antigens, CD/immunology
- B-Lymphocytes/drug effects
- B-Lymphocytes/immunology
- B-Lymphocytes/pathology
- Cell Death/drug effects
- Cell Proliferation/drug effects
- Gene Expression Regulation, Developmental
- IgG Deficiency/genetics
- IgG Deficiency/metabolism
- IgG Deficiency/pathology
- Immunity, Humoral
- Immunity, Innate
- Immunoglobulin D/genetics
- Immunoglobulin D/metabolism
- Immunoglobulin G/genetics
- Immunoglobulin G/metabolism
- Immunoglobulin Heavy Chains
- Immunoglobulin M/genetics
- Immunoglobulin M/metabolism
- Immunologic Memory
- Lipopolysaccharides/pharmacology
- Mice, Inbred C57BL
- Mice, Transgenic
- Primary Cell Culture
- Signal Transduction
- Spleen/cytology
- Spleen/drug effects
- Spleen/immunology
- T-Lymphocytes, Helper-Inducer/cytology
- T-Lymphocytes, Helper-Inducer/drug effects
- T-Lymphocytes, Helper-Inducer/immunology
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Affiliation(s)
- Isabel Cortegano
- Centro Nacional de Microbiología, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
| | - Mercedes Rodríguez
- Centro Nacional de Microbiología, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
| | - Isabel Martín
- Centro Nacional de Microbiología, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
| | - Maria Carmen Prado
- Centro Nacional de Microbiología, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
| | - Carolina Ruíz
- Centro Nacional de Microbiología, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
| | - Rafael Hortigüela
- Unidad Funcional de Investigación en Enfermedades Crónicas, Instituto de Salud Carlos III (ISCIII), Majadahonda, 28220 Madrid, Spain
| | - Mario Alía
- Centro Nacional de Microbiología, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
| | - Marçal Vilar
- Instituto de Biomedicina de Valencia, Valencia 46010, Spain
| | - Helena Mira
- Instituto de Biomedicina de Valencia, Valencia 46010, Spain
| | - Eva Cano
- Unidad Funcional de Investigación en Enfermedades Crónicas, Instituto de Salud Carlos III (ISCIII), Majadahonda, 28220 Madrid, Spain
| | - Mercedes Domínguez
- Centro Nacional de Microbiología, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
| | - Belén de Andrés
- Centro Nacional de Microbiología, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
| | - María Luisa Gaspar
- Centro Nacional de Microbiología, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
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4
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Mion F, Vetrano S, Tonon S, Valeri V, Piontini A, Burocchi A, Petti L, Frossi B, Gulino A, Tripodo C, Colombo MP, Pucillo CE. Reciprocal influence of B cells and tumor macro and microenvironments in the ApcMin/+ model of colorectal cancer. Oncoimmunology 2017; 6:e1336593. [PMID: 28919998 DOI: 10.1080/2162402x.2017.1336593] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 05/25/2017] [Accepted: 05/26/2017] [Indexed: 12/22/2022] Open
Abstract
One of the most fascinating aspects of the immune system is its dynamism, meant as the ability to change and readapt according to the organism needs. Following an insult, we assist to the spontaneous organization of different immune cells which cooperate, locally and at distance, to build up an appropriate response. Throughout tumor progression, adaptations within the systemic tumor environment, or macroenvironment, result in the promotion of tumor growth, tumor invasion and metastasis to distal organs, but also to dramatic changes in the activity and composition of the immune system. In this work, we show the changes of the B-cell arm of the immune system following tumor progression in the ApcMin/+ model of colorectal cancer. Tumor macroenvironment leads to an increased proportion of total and IL-10-competent B cells in draining LNs while activates a differentiation route that leads to the expansion of IgA+ lymphocytes in the spleen and peritoneum. Importantly, serum IgA levels were significantly higher in ApcMin/+ than Wt mice. The peculiar involvement of IgA response in the adenomatous transformation had correlates in the gut-mucosal compartment where IgA-positive elements increased from normal mucosa to areas of low grade dysplasia while decreasing upon overt carcinomatous transformation. Altogether, our findings provide a snapshot of the tumor education of B lymphocytes in the ApcMin/+ model of colorectal cancer. Understanding how tumor macroenvironment affects the differentiation, function and distribution of B lymphocytes is pivotal to the generation of specific therapies, targeted to switching B cells to an anti-, rather than pro-, tumoral phenotype.
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Affiliation(s)
- Francesca Mion
- Department of Medicine, University of Udine, Udine, Italy
| | - Stefania Vetrano
- Inflammatory Bowel Disease Center, Humanitas Research Hospital, Rozzano, Italy.,Department of Biomedical Sciences, Humanitas University, Milano, Italy
| | - Silvia Tonon
- Department of Medicine, University of Udine, Udine, Italy
| | - Viviana Valeri
- Department of Medicine, University of Udine, Udine, Italy
| | - Andrea Piontini
- Department of Biomedical Sciences, Humanitas University, Milano, Italy
| | - Alessia Burocchi
- Department of Experimental Oncology and Molecular Medicine, Molecular Immunology Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milano, Italy
| | - Luciana Petti
- Department of Biotechnology and Translational Medicine, University of Milan, Milano, Italy
| | - Barbara Frossi
- Department of Medicine, University of Udine, Udine, Italy
| | - Alessandro Gulino
- Department of Health Science, Tumor Immunology Unit, Human Pathology Section, Palermo University School of Medicine, Palermo, Italy
| | - Claudio Tripodo
- Department of Health Science, Tumor Immunology Unit, Human Pathology Section, Palermo University School of Medicine, Palermo, Italy
| | - Mario P Colombo
- Department of Experimental Oncology and Molecular Medicine, Molecular Immunology Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milano, Italy
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5
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Yu X, Wang Y, Lin J, Hu Y, Kawai T, Taubman MA, Han X. Lipopolysaccharides-Induced Suppression of Innate-Like B Cell Apoptosis Is Enhanced by CpG Oligodeoxynucleotide and Requires Toll-Like Receptors 2 and 4. PLoS One 2016; 11:e0165862. [PMID: 27812176 PMCID: PMC5094738 DOI: 10.1371/journal.pone.0165862] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 10/19/2016] [Indexed: 12/30/2022] Open
Abstract
Innate-like B lymphocytes play an important role in innate immunity in periodontal disease through Toll-like receptor (TLR) signaling. However, it is unknown how innate-like B cell apoptosis is affected by the periodontal infection-associated innate signals. This study is to determine the effects of two major TLR ligands, lipopolysaccharide (LPS) and CpG-oligodeoxynucleotides (CpG-ODN), on innate-like B cell apoptosis. Spleen B cells were isolated from wild type (WT), TLR2 knockout (KO) and TLR4 KO mice and cultured with E. coli LPS alone, P. gingivalis LPS alone, or combined with CpG-ODN for 2 days. B cell apoptosis and expressions of specific apoptosis-related genes were analyzed by flow cytometry and real-time PCR respectively. P. gingivalis LPS, but not E. coli LPS, reduced the percentage of AnnexinV+/7-AAD- cells within IgMhighCD23lowCD43-CD93- marginal zone (MZ) B cell sub-population and IgMhighCD23lowCD43+CD93+ innate response activator (IRA) B cell sub-population in WT but not TLR2KO or TLR4KO mice. CpG-ODN combined with P. gingivalis LPS further reduced the percentage of AnnexinV+/7-AAD- cells within MZ B cells and IRA B cells in WT but not TLR2 KO or TLR4 KO mice. Pro-apoptotic CASP4, CASP9 and Dapk1 were significantly down-regulated in P. gingivalis LPS- and CpG-ODN-treated B cells from WT but not TLR2 KO or TLR4 KO mice. Anti-apoptotic IL-10 was significantly up-regulated in P. gingivalis LPS- and CpG-ODN-treated B cells from WT and TLR2 KO but not TLR4 KO mice. These results suggested that both TLR2 and TLR4 signaling are required for P. gingivalis LPS-induced, CpG-ODN-enhanced suppression of innate-like B cell apoptosis.
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Affiliation(s)
- Xiaoqian Yu
- The Forsyth Institute, Department of Immunology and Infectious Diseases, Cambridge, MA, United States of America
- Peking University School and Hospital of Stomatology, Department of Periodontology, Beijing, China
| | - Yuhua Wang
- The Forsyth Institute, Department of Immunology and Infectious Diseases, Cambridge, MA, United States of America
- Ninth People’s Hospital, College of Stomatology, Shanghai JiaoTong University School of Medicine, Department of Prosthodontics, Shanghai Key laboratory, Shanghai, China
| | - Jiang Lin
- The Forsyth Institute, Department of Immunology and Infectious Diseases, Cambridge, MA, United States of America
- The Fourth Hospital of Harbin Medical University, Department of stomatology, Harbin, China
| | - Yang Hu
- The Forsyth Institute, Department of Immunology and Infectious Diseases, Cambridge, MA, United States of America
| | - Toshihisa Kawai
- The Forsyth Institute, Department of Immunology and Infectious Diseases, Cambridge, MA, United States of America
| | - Martin A. Taubman
- The Forsyth Institute, Department of Immunology and Infectious Diseases, Cambridge, MA, United States of America
| | - Xiaozhe Han
- The Forsyth Institute, Department of Immunology and Infectious Diseases, Cambridge, MA, United States of America
- * E-mail:
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6
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PSGL-1 on Leukocytes is a Critical Component of the Host Immune Response against Invasive Pneumococcal Disease. PLoS Pathog 2016; 12:e1005500. [PMID: 26975045 PMCID: PMC4790886 DOI: 10.1371/journal.ppat.1005500] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 02/19/2016] [Indexed: 12/21/2022] Open
Abstract
Bacterial uptake by phagocytic cells is a vital event in the clearance of invading pathogens such as Streptococcus pneumoniae. A major role of the P-selectin glycoprotein ligand-1 (PSGL-1) on leukocytes against invasive pneumococcal disease is described in this study. Phagocytosis experiments using different serotypes demonstrated that PSGL-1 is involved in the recognition, uptake and killing of S. pneumoniae. Co-localization of several clinical isolates of S. pneumoniae with PSGL-1 was demonstrated, observing a rapid and active phagocytosis in the presence of PSGL-1. Furthermore, the pneumococcal capsular polysaccharide and the main autolysin of the bacterium ―the amidase LytA― were identified as bacterial ligands for PSGL-1. Experimental models of pneumococcal disease including invasive pneumonia and systemic infection showed that bacterial levels were markedly increased in the blood of PSGL-1−/− mice. During pneumonia, PSGL-1 controls the severity of pneumococcal dissemination from the lung to the bloodstream. In systemic infection, a major role of PSGL-1 in host defense is to clear the bacteria in the systemic circulation controlling bacterial replication. These results confirmed the importance of this receptor in the recognition and clearance of S. pneumoniae during invasive pneumococcal disease. Histological and cellular analysis demonstrated that PSGL-1−/− mice have increased levels of T cells migrating to the lung than the corresponding wild-type mice. In contrast, during systemic infection, PSGL-1−/− mice had increased numbers of neutrophils and macrophages in blood, but were less effective controlling the infection process due to the lack of this functional receptor. Overall, this study demonstrates that PSGL-1 is a novel receptor for S. pneumoniae that contributes to protection against invasive pneumococcal disease. S. pneumoniae is one of the most important and devastating human pathogens worldwide, mainly affecting young children, elderly people and immunocompromised patients. In terms of host immune defense against invasive pneumococcal isolates, professional phagocytes require receptor-mediated recognition of certain ligands on the bacterial surface for the uptake and clearance of the microorganism. In this study, we demonstrate that the P-selectin glycoprotein ligand-1 (PSGL-1) on leukocytes is involved in the phagocytosis process of S. pneumoniae by targeting the capsule and the surface protein LytA as pathogen-associated molecular patterns. To explore this process in more detail, we have used wild-type mice and mice deficient in PSGL-1 demonstrating that lack of PSGL-1 is detrimental for the host by increasing the susceptibility to the infection and the severity of the pneumococcal invasive disease. Overall, these data show the importance of PSGL-1 on leukocytes in host defense against S. pneumoniae and confirm that PSGL-1 plays a critical protective role against invasive bacterial disease.
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7
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Prado C, Rodríguez M, Cortegano I, Ruiz C, Alía M, de Andrés B, Gaspar ML. Postnatal and adult immunoglobulin repertoires of innate-like CD19(+)CD45R(lo) B Cells. J Innate Immun 2014; 6:499-514. [PMID: 24603602 DOI: 10.1159/000358237] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 12/27/2013] [Indexed: 01/06/2023] Open
Abstract
The diversity in antibody repertoire relies on different B cell populations working efficiently to fulfil distinct specific functions. We recently described an innate-like CD19(+)CD45R(-/lo) (19(+)45R(lo)) cell population in postnatal unstimulated adult mice, a heterogeneous population containing cells expressing immunoglobulin M (IgM) and others behaving as differentiated mature B lymphocytes (intracytoplasmic IgG1, AID(+), Blimp-1(+)RAG2(-)). In the present study, we characterized the Ig repertoire expressed by splenic 19(+)45R(lo) cells, assuming that they would bear a restricted repertoire biased for germline rearrangements and low mutation rates similar to other innate-like cells. Sequences from 19(+)45R(lo) cells displayed a variety of V, D and J regions, and the analysis of the CDR-H3 region revealed an intermediate overall CDR-H3 length and moderate hydrophobicity. Both IgM and switched sequences of PD15 19(+)45R(lo) cells had shorter CDR-H3 region and fewer non-template N nucleotides than adult sequences, as expected for profiles that correspond to an immature phenotype. Regarding the mutation rate in the VH regions, IgG1 sequences already carried a high rate of replacement mutations at PD15, which increased further in the sequences obtained from adult mice. Moreover, statistical models suggest that a proportion of the switched sequences in adult 19(+)45R(lo) cells had experienced antigen selection, unlike other innate-like B cell compartments.
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Affiliation(s)
- Carmen Prado
- Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
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8
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Zhang X. Regulatory functions of innate-like B cells. Cell Mol Immunol 2013; 10:113-21. [PMID: 23396472 PMCID: PMC4003048 DOI: 10.1038/cmi.2012.63] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Accepted: 11/06/2012] [Indexed: 12/24/2022] Open
Abstract
Innate-like B cells (ILBs) are heterogeneous populations of unconventional B cells with innate sensing and responding properties. ILBs in mice are composed of B1 cells, marginal zone (MZ) B cells and other related B cells. ILBs maintain natural IgM levels at steady state, and after innate activation, they can rapidly acquire immune regulatory activities through the secretion of natural IgM and IL-10. Thus, ILBs constitute an important source of IL-10-producing regulatory B cells (Bregs), which have been shown to play critical roles in autoimmunity, inflammation and infection. The present review highlights the latest advances in the field of ILBs and focuses on their regulatory functions. Understanding the regulatory activities of ILBs and their underlying mechanisms could open new avenues in manipulating their functions in inflammatory, infectious and other relevant diseases.
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Affiliation(s)
- Xiaoming Zhang
- Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.
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