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Noce D, Foco L, Orth-Höller D, König E, Barbieri G, Pietzner M, Ghasemi-Semeskandeh D, Coassin S, Fuchsberger C, Gögele M, Del Greco M F, De Grandi A, Summerer M, Wheeler E, Langenberg C, Lass-Flörl C, Pramstaller PP, Kronenberg F, Würzner R, Pattaro C. Genetic determinants of complement activation in the general population. Cell Rep 2024; 43:113611. [PMID: 38159276 DOI: 10.1016/j.celrep.2023.113611] [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: 09/30/2022] [Revised: 09/08/2023] [Accepted: 12/07/2023] [Indexed: 01/03/2024] Open
Abstract
Complement is a fundamental innate immune response component. Its alterations are associated with severe systemic diseases. To illuminate the complement's genetic underpinnings, we conduct genome-wide association studies of the functional activity of the classical (CP), lectin (LP), and alternative (AP) complement pathways in the Cooperative Health Research in South Tyrol study (n = 4,990). We identify seven loci, encompassing 13 independent, pathway-specific variants located in or near complement genes (CFHR4, C7, C2, MBL2) and non-complement genes (PDE3A, TNXB, ABO), explaining up to 74% of complement pathways' genetic heritability and implicating long-range haplotypes associated with LP at MBL2. Two-sample Mendelian randomization analyses, supported by transcriptome- and proteome-wide colocalization, confirm known causal pathways, establish within-complement feedback loops, and implicate causality of ABO on LP and of CFHR2 and C7 on AP. LP causally influences collectin-11 and KAAG1 levels and the risk of mouth ulcers. These results build a comprehensive resource to investigate the role of complement in human health.
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Affiliation(s)
- Damia Noce
- Institute for Biomedicine (affiliated to the University of Lübeck), Eurac Research, Via Volta 21, 39100 Bolzano, Italy; Institute of Hygiene & Medical Microbiology, Department of Hygiene, Microbiology and Public Health, Medical University of Innsbruck, Schöpfstr. 41, 6020 Innsbruck, Austria
| | - Luisa Foco
- Institute for Biomedicine (affiliated to the University of Lübeck), Eurac Research, Via Volta 21, 39100 Bolzano, Italy
| | - Dorothea Orth-Höller
- Institute of Hygiene & Medical Microbiology, Department of Hygiene, Microbiology and Public Health, Medical University of Innsbruck, Schöpfstr. 41, 6020 Innsbruck, Austria; MB-LAB - Clinical Microbiology Laboratory, Franz-Fischer-Str. 7b, 6020 Innsbruck, Austria
| | - Eva König
- Institute for Biomedicine (affiliated to the University of Lübeck), Eurac Research, Via Volta 21, 39100 Bolzano, Italy
| | - Giulia Barbieri
- Institute for Biomedicine (affiliated to the University of Lübeck), Eurac Research, Via Volta 21, 39100 Bolzano, Italy; Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Maik Pietzner
- Computational Medicine, Berlin Institute of Health (BIH) at Charité - Universitätsmedizin Berlin, Berlin, Germany; MRC Epidemiology Unit, University of Cambridge, Cambridge, UK
| | - Dariush Ghasemi-Semeskandeh
- Institute for Biomedicine (affiliated to the University of Lübeck), Eurac Research, Via Volta 21, 39100 Bolzano, Italy; Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Stefan Coassin
- Institute of Genetic Epidemiology, Medical University of Innsbruck, Schöpfstr. 41, 6020 Innsbruck, Austria
| | - Christian Fuchsberger
- Institute for Biomedicine (affiliated to the University of Lübeck), Eurac Research, Via Volta 21, 39100 Bolzano, Italy
| | - Martin Gögele
- Institute for Biomedicine (affiliated to the University of Lübeck), Eurac Research, Via Volta 21, 39100 Bolzano, Italy
| | - Fabiola Del Greco M
- Institute for Biomedicine (affiliated to the University of Lübeck), Eurac Research, Via Volta 21, 39100 Bolzano, Italy
| | - Alessandro De Grandi
- Institute for Biomedicine (affiliated to the University of Lübeck), Eurac Research, Via Volta 21, 39100 Bolzano, Italy
| | - Monika Summerer
- Institute of Genetic Epidemiology, Medical University of Innsbruck, Schöpfstr. 41, 6020 Innsbruck, Austria
| | - Eleanor Wheeler
- MRC Epidemiology Unit, University of Cambridge, Cambridge, UK
| | - Claudia Langenberg
- Computational Medicine, Berlin Institute of Health (BIH) at Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Cornelia Lass-Flörl
- Institute of Hygiene & Medical Microbiology, Department of Hygiene, Microbiology and Public Health, Medical University of Innsbruck, Schöpfstr. 41, 6020 Innsbruck, Austria
| | - Peter Paul Pramstaller
- Institute for Biomedicine (affiliated to the University of Lübeck), Eurac Research, Via Volta 21, 39100 Bolzano, Italy
| | - Florian Kronenberg
- Institute of Genetic Epidemiology, Medical University of Innsbruck, Schöpfstr. 41, 6020 Innsbruck, Austria.
| | - Reinhard Würzner
- Institute of Hygiene & Medical Microbiology, Department of Hygiene, Microbiology and Public Health, Medical University of Innsbruck, Schöpfstr. 41, 6020 Innsbruck, Austria.
| | - Cristian Pattaro
- Institute for Biomedicine (affiliated to the University of Lübeck), Eurac Research, Via Volta 21, 39100 Bolzano, Italy.
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Alharbi AF, Sheng N, Nicol K, Strömberg N, Hollox EJ. Balancing selection at the human salivary agglutinin gene (DMBT1) driven by host-microbe interactions. iScience 2022; 25:104189. [PMID: 35494225 PMCID: PMC9038570 DOI: 10.1016/j.isci.2022.104189] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 02/07/2022] [Accepted: 03/30/2022] [Indexed: 11/19/2022] Open
Abstract
Discovering loci under balancing selection in humans can identify loci with alleles that affect response to the environment and disease. Genome variation data have identified the 5′ region of the DMBT1 gene as undergoing balancing selection in humans. DMBT1 encodes the pattern-recognition glycoprotein DMBT1, also known as SALSA, gp340, or salivary agglutinin. DMBT1 binds to a variety of pathogens through a tandemly arranged scavenger receptor cysteine-rich (SRCR) domain, with the number of domains polymorphic in humans. We show that the signal of balancing selection is driven by one haplotype usually carrying a shorter SRCR repeat and another usually carrying a longer SRCR repeat. DMBT1 encoded by a shorter SRCR repeat allele does not bind a cariogenic and invasive Streptococcus mutans strain, in contrast to the long SRCR allele that shows binding. Our results suggest that balancing selection at DMBT1 is due to host-microbe interactions of encoded SRCR tandem repeat alleles. Clear evidence from many analyses show balancing selection at DMBT1 Scavenger-receptor cysteine-rich domain array associated with balancing selection Genetic variation, not alternative splicing, responsible for protein isoforms Long, but not short, DMBT1 isoforms bind a cariogenic strain of Streptococcus mutans
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Affiliation(s)
- Adel F. Alharbi
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
- Medina Regional Laboratory, General Directorate of Health Affairs, Ministry of Health, Medina, Saudi Arabia
| | - Nongfei Sheng
- Department of Odontology, Umeå University, Umeå, Sweden
| | - Katie Nicol
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
| | | | - Edward J. Hollox
- Department of Genetics and Genome Biology, University of Leicester, Leicester, UK
- Corresponding author
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Baioumy SA, Fouad SH, Abdalgeleel SA, Baiomy AA, Sallam DE, Taha SI. Mannose-binding lectin serum levels and (Gly54asp) gene polymorphism in recurrent aphthous stomatitis: A case-control study. Int J Immunopathol Pharmacol 2021; 35:20587384211064454. [PMID: 34907799 PMCID: PMC8689634 DOI: 10.1177/20587384211064454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Objectives: Dysregulation of the immune response appears to play a significant role in recurrent aphthous stomatitis (RAS) development. The main objective of this case–control study is to investigate the blood levels of mannose-binding lectin (MBL) and the frequency of the MBL2 gene (gly54asp) polymorphism in RAS patients, including 40 RAS patients and 40 healthy controls. Methods: Serum MBL levels were determined by ELISA, while the PCR-restriction fragment length polymorphism was used in MBL2 genotyping. Results: The median serum MBL level was significantly lower in the RAS group than in the control group (975 ng/mL (545–1320) vs. 1760 ng/mL (1254–2134); p≤ 0.001). The MBL levels were significantly lower in the BB genotype, whereas they were significantly higher in the wild type AA with a median of 525 and 1340 ng/mL, respectively (p =0.005). The B allele was expressed in significantly higher percentages of RAS patients than in controls. There was no significant association between MBL serum levels (p=0.685) or MBL2 codon 54 genotypes (p=0.382) with the type of ulcers. Conclusion: There was an association between low MBL serum levels and the variant allele B of the MBL2 (gly54asp) gene, and the susceptibility to RAS. As a result, potential novel therapeutic options for RAS patients with MBL deficiency should be investigated.
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Affiliation(s)
- Shereen A Baioumy
- Department of Microbiology and Immunology, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Shaimaa H Fouad
- Department of Internal Medicine / Allergy and Clinical Immunology, 68792Ain Shams University, Cairo, Egypt
| | - Shaimaa A Abdalgeleel
- Department of Biostatistics and Epidemiology, National Cancer Institute, 63526Cairo University, Cairo, Egypt
| | - Ahmed A Baiomy
- Department of Fixed prosthodontics, Egyptian Russian University, Badr City, Egypt
| | - Dina E Sallam
- Department of Pediatrics & Pediatric Nephrology, Faculty of Medicine, 68792Ain-Shams University, Cairo, Egypt
| | - Sara I Taha
- Department of Clinical Pathology/ Immunology, Faculty of Medicine, 68792Ain Shams University, Cairo, Egypt
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Zhang S, Huo X, Li M, Hou R, Cong X, Xu X. Oral antimicrobial activity weakened in children with electronic waste lead exposure. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:14763-14770. [PMID: 32056098 DOI: 10.1007/s11356-020-08037-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 02/10/2020] [Indexed: 02/05/2023]
Abstract
Environmental lead (Pb) exposure can induce dysbacteriosis, impair oral health, and is associated with the development of dental caries. However, the mechanism is unclear. The aim of this study was to explore the effects of Pb toxicity on oral antimicrobial activity in children in an e-waste area. Results showed higher blood Pb levels in e-waste-exposed group children, accompanied by decreased saliva SAG (salivary agglutinin) concentrations, increased peripheral WBC (white blood cell) counts and monocyte counts, and elevated peripheral monocyte percentage. LnPb (natural logarithmic transformation of blood Pb level) was negatively correlated with saliva SAG concentration, while positively correlated with peripheral monocyte percentage. Saliva SAG concentration played a complete mediating role in the correlation of LnPb to peripheral monocyte percentage. To our knowledge, this is the first study on the relationship of environmental Pb exposure and oral antimicrobial activity in children, showing that environmental Pb exposure may weaken oral antimicrobial activity through reducing saliva SAG concentration, which may raise the risk of oral dysbacteriosis and ultimately pathogen infection.
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Affiliation(s)
- Shaocheng Zhang
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, 22 Xinling Rd, Shantou, 515041, Guangdong, China
| | - Xia Huo
- Laboratory of Environmental Medicine and Developmental Toxicology, Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 511486, Guangdong, China
| | - Minghui Li
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, 22 Xinling Rd, Shantou, 515041, Guangdong, China
- Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, 9713 GZ, Groningen, The Netherlands
| | - Ruikun Hou
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, 22 Xinling Rd, Shantou, 515041, Guangdong, China
| | - Xiaowei Cong
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, 22 Xinling Rd, Shantou, 515041, Guangdong, China
- Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, 9713 GZ, Groningen, The Netherlands
| | - Xijin Xu
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, 22 Xinling Rd, Shantou, 515041, Guangdong, China.
- Department of Cell Biology and Genetics, Shantou University Medical College, Shantou, 515041, Guangdong, China.
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Saku A, Hirose K, Ito T, Iwata A, Sato T, Kaji H, Tamachi T, Suto A, Goto Y, Domino SE, Narimatsu H, Kiyono H, Nakajima H. Fucosyltransferase 2 induces lung epithelial fucosylation and exacerbates house dust mite-induced airway inflammation. J Allergy Clin Immunol 2019; 144:698-709.e9. [PMID: 31125592 DOI: 10.1016/j.jaci.2019.05.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 04/30/2019] [Accepted: 05/06/2019] [Indexed: 12/15/2022]
Abstract
BACKGROUND One of the pathognomonic features of asthma is epithelial hyperproduction of mucus, which is composed of a series of glycoproteins; however, it remains unclear how glycosylation is induced in lung epithelial cells from asthmatic patients and how glycan residues play a role in the pathogenesis of asthma. OBJECTIVE The objective of this study was to explore comprehensive epithelial glycosylation status induced by allergic inflammation and reveal its possible role in the pathogenesis of asthma. METHODS We evaluated the glycosylation status of lung epithelium using a lectin microarray. We next searched for molecular mechanisms underlying epithelial glycosylation. We also examined whether epithelial glycosylation is involved in induction of allergic inflammation. RESULTS On allergen inhalation, lung epithelial cells were heavily α(1,2)fucosylated by fucosyltransferase 2 (Fut2), which was induced by the IL-13-signal transducer and activator of transcription 6 pathway. Importantly, Fut2-deficient (Fut2-/-) mice, which lacked lung epithelial fucosylation, showed significantly attenuated eosinophilic inflammation and airway hyperresponsiveness in house dust mite (HDM)-induced asthma models. Proteome analyses and immunostaining of the HDM-challenged lung identified that complement C3 was accumulated in fucosylated areas. Indeed, Fut2-/- mice showed significantly reduced levels of C3a and impaired accumulation of C3a receptor-expressing monocyte-derived dendritic cells in the lung on HDM challenge. CONCLUSION Fut2 induces epithelial fucosylation and exacerbates airway inflammation in asthmatic patients in part through C3a production and monocyte-derived dendritic cell accumulation in the lung.
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Affiliation(s)
- Aiko Saku
- Department of Allergy and Clinical Immunology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Koichi Hirose
- Department of Allergy and Clinical Immunology, Graduate School of Medicine, Chiba University, Chiba, Japan; Department of Rheumatology, School of Medicine, International University of Health and Welfare, Chiba, Japan.
| | - Takashi Ito
- Department of Allergy and Clinical Immunology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Arifumi Iwata
- Department of Allergy and Clinical Immunology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Takashi Sato
- Glycoscience and Glycotechnology Research Group, Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Ibaraki, Japan
| | - Hiroyuki Kaji
- Glycoscience and Glycotechnology Research Group, Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Ibaraki, Japan
| | - Tomohiro Tamachi
- Department of Allergy and Clinical Immunology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Akira Suto
- Department of Allergy and Clinical Immunology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Yoshiyuki Goto
- Division of Molecular Immunology, Medical Mycology Research Center, Chiba University, Chiba, Japan; International Research and Development Center for Mucosal Vaccines, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Steven E Domino
- Department of Obstetrics and Gynecology, Cellular and Molecular Biology Program, University of Michigan Medical Center, Ann Arbor, Mich
| | - Hisashi Narimatsu
- Glycoscience and Glycotechnology Research Group, Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Ibaraki, Japan
| | - Hiroshi Kiyono
- International Research and Development Center for Mucosal Vaccines, Institute of Medical Science, University of Tokyo, Tokyo, Japan; Department of Immunology, Graduate School of Medicine, Chiba University, Chiba, Japan; Division of Mucosal Immunology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Hiroshi Nakajima
- Department of Allergy and Clinical Immunology, Graduate School of Medicine, Chiba University, Chiba, Japan.
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Zhang S, Huo X, Zhang Y, Lu X, Xu C, Xu X. The association of PM 2.5 with airway innate antimicrobial activities of salivary agglutinin and surfactant protein D. CHEMOSPHERE 2019; 226:915-923. [PMID: 31509921 DOI: 10.1016/j.chemosphere.2019.04.032] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 04/04/2019] [Accepted: 04/04/2019] [Indexed: 02/05/2023]
Abstract
Fine particulate matter ≤2.5 μm (PM2.5) is a prominent global public health risk factor that can cause respiratory infection by downregulating the amounts of antimicrobial proteins and peptides (AMPs). Both salivary agglutinin (SAG) and surfactant protein D (SPD) are important AMPs in respiratory mucosal fluid, providing protection against airway pathogen invasion and infection by inducing microbial aggregation and enhancing pathogen clearance. However, the relationship between PM2.5 and these AMPs is unclear. To better understand the relationship between PM2.5 and airway innate immune defenses, we review the respiratory antimicrobial activities of SAG and SPD, as well as the adverse effects of PM2.5 on airway innate antimicrobial defense. We speculate there exists a dual effect between PM2.5 and respiratory antimicrobial activity, which means that PM2.5 suppresses respiratory antimicrobial activity through downregulating airway AMPs, while airway AMPs accelerate PM2.5 clearance by inducing PM2.5 microbial aggregation. We propose further research on the relationship between PM2.5 and these AMPs.
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Affiliation(s)
- Shaocheng Zhang
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, Shantou, 515041, Guangdong, China
| | - Xia Huo
- Laboratory of Environmental Medicine and Developmental Toxicology, Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 511486, Guangdong, China
| | - Yuling Zhang
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, Shantou, 515041, Guangdong, China
| | - Xueling Lu
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, Shantou, 515041, Guangdong, China
| | - Cheng Xu
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, Shantou, 515041, Guangdong, China
| | - Xijin Xu
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, Shantou, 515041, Guangdong, China; Department of Cell Biology and Genetics, Shantou University Medical College, Shantou, 515041, Guangdong, China.
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Zhang S, Huo X, Zhang Y, Huang Y, Zheng X, Xu X. Ambient fine particulate matter inhibits innate airway antimicrobial activity in preschool children in e-waste areas. ENVIRONMENT INTERNATIONAL 2019; 123:535-542. [PMID: 30622078 DOI: 10.1016/j.envint.2018.12.061] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 12/12/2018] [Accepted: 12/28/2018] [Indexed: 02/05/2023]
Abstract
Ambient fine particulate matter (PM2.5) is a risk factor for respiratory diseases. Previous studies suggest that PM2.5 exposure may down-regulate airway antimicrobial proteins and peptides (AMPs), thereby accelerating airway pathogen infection. However, epidemiological research is scarce. Hence, we estimated the associations between individual PM2.5 chronic daily intake (CDI) and the levels of the airway AMP salivary agglutinin (SAG), as well as peripheral leukocyte counts and pro-inflammatory cytokines, of preschool children in Guiyu (an e-waste area) and Haojiang (a reference area located 31.6 km to the east of Guiyu). We recruited 581 preschool children from Guiyu and Haojiang, of which 222 were included in this study for a matching design (Guiyu: n = 110 vs. Haojiang: n = 112). Air PM2.5 pollution data was collected to calculate individual PM2.5 CDI. The mean concentration of PM2.5 in Guiyu was higher than in Haojiang, resulting in a higher individual PM2.5 CDI. Concomitantly, saliva SAG levels were lower in Guiyu children (5.05 ng/mL) than in Haojiang children (8.68 ng/mL), and were negatively correlated with CDI. Additionally, peripheral counts of white blood cells, and the concentrations of interleukin-8 and tumor necrosis factor-alpha, in Guiyu children were greater than in Haojiang children, and were positively associated with CDI. Similar results were found for neutrophils and monocytes. To our knowledge, this is the first study on the relationship between PM2.5 exposure and innate airway antimicrobial activity in children, in an e-waste area, showing that PM2.5 pollution may weaken airway antimicrobial activity by down-regulation of saliva SAG levels, which might accelerate airway pathogen infection in children.
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Affiliation(s)
- Shaocheng Zhang
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, Shantou 515041, Guangdong, China
| | - Xia Huo
- Laboratory of Environmental Medicine and Developmental Toxicology, Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511486, Guangdong, China
| | - Yu Zhang
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, Shantou 515041, Guangdong, China; Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen 9713, GZ, the Netherlands
| | - Yu Huang
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, Shantou 515041, Guangdong, China
| | - Xiangbin Zheng
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, Shantou 515041, Guangdong, China
| | - Xijin Xu
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, Shantou 515041, Guangdong, China; Department of Cell Biology and Genetics, Shantou University Medical College, Shantou 515041, Guangdong, China.
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Novel Two-Component System of Streptococcus sanguinis Affecting Functions Associated with Viability in Saliva and Biofilm Formation. Infect Immun 2018; 86:IAI.00942-17. [PMID: 29339459 DOI: 10.1128/iai.00942-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 01/08/2018] [Indexed: 02/07/2023] Open
Abstract
Streptococcus sanguinis is a pioneer species of teeth and a common opportunistic pathogen of infective endocarditis. In this study, we identified a two-component system, S. sanguinis SptRS (SptRS Ss ), affecting S. sanguinis survival in saliva and biofilm formation. Isogenic mutants of sptRSs (SKsptR) and sptSSs (SKsptS) showed reduced cell counts in ex vivo assays of viability in saliva compared to those of parent strain SK36 and complemented mutants. Reduced counts of the mutants in saliva were associated with reduced growth rates in nutrient-poor medium (RPMI) and increased susceptibility to the deposition of C3b and the membrane attach complex (MAC) of the complement system, a defense component of saliva and serum. Conversely, sptRSs and sptSSs mutants showed increased biofilm formation associated with higher levels of production of H2O2 and extracellular DNA. Reverse transcription-quantitative PCR (RT-qPCR) comparisons of strains indicated a global role of SptRS Ss in repressing genes for H2O2 production (2.5- to 15-fold upregulation of spxB, spxR, vicR, tpk, and ackA in sptRSs and sptSSs mutants), biofilm formation, and/or evasion of host immunity (2.1- to 11.4-fold upregulation of srtA, pcsB, cwdP, iga, and nt5e). Compatible with the homology of SptR Ss with AraC-type regulators, duplicate to multiple conserved repeats were identified in 1,000-bp regulatory regions of downstream genes, suggesting that SptR Ss regulates transcription by DNA looping. Significant transcriptional changes in the regulatory genes vicR, spxR, comE, comX, and mecA in the sptRSs and sptSSs mutants further indicated that SptRS Ss is part of a regulatory network that coordinates cell wall homeostasis, H2O2 production, and competence. This study reveals that SptRS Ss is involved in the regulation of crucial functions for S. sanguinis persistence in the oral cavity.
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Reichhardt M, Holmskov U, Meri S. SALSA—A dance on a slippery floor with changing partners. Mol Immunol 2017; 89:100-110. [DOI: 10.1016/j.molimm.2017.05.029] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 05/31/2017] [Accepted: 05/31/2017] [Indexed: 02/06/2023]
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The scavenging capacity of DMBT1 is impaired by germline deletions. Immunogenetics 2017; 69:401-407. [PMID: 28364129 PMCID: PMC5435793 DOI: 10.1007/s00251-017-0982-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 03/27/2017] [Indexed: 12/31/2022]
Abstract
The Scavenger Receptor Cysteine-Rich (SRCR) proteins are an archaic group of proteins characterized by the presence of multiple SRCR domains. They are membrane-bound or secreted proteins, which are generally related to host defense systems in animals. Deleted in Malignant Brain Tumors 1 (DMBT1) is a SRCR protein which is secreted in mucosal fluids and involved in host defense by pathogen binding by its SRCR domains. Genetic polymorphism within DMBT1 leads to DMBT1-alleles giving rise to polypeptides with interindividually different numbers of SRCR domains, ranging from 8 SRCR domains (encoded by 6 kb DMBT1 variant) to 13 SRCR domains (encoded by the 8 kb DMBT1 variant). In the present study, we have investigated whether reduction from 13 to 8 amino-terminal SRCR domains leads to reduction of bacterial binding. The 6 kb variant bound ~20–45% less bacteria compared to the 8 kb variant. These results support the hypothesis that genetic variation in DMBT1 may influence microbial defense.
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