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Hota S, Hussain MS, Kumar M. ErpY-like Lipoprotein of Leptospira Outsmarts Host Complement Regulation by Acquiring Complement Regulators, Activating Alternative Pathways, and Intervening in the Membrane Attack Complex. ACS Infect Dis 2022; 8:982-997. [PMID: 35422118 DOI: 10.1021/acsinfecdis.1c00602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The survival of pathogenic Leptospira in the host depends on its proficiency to circumvent the immune response. These pathogens evade the complement system in serum by enticing and amassing the serum complement regulators onto their surface. ErpY-like lipoprotein, a surface-exposed protein of Leptospira spp., is conserved in the pathogenic Leptospira serovars. The recombinant form of this protein interacts with multiple extracellular matrix (ECM) components and serum proteins such as soluble complement regulators factor H (FH) and factor I (FI). Here, we document that the supplementation of rErpY-like protein (10 μg/mL) in human serum inhibits complement-mediated bacterial cell lysis and augments the viability of Escherichia coli and saprophytic Leptospira biflexa by more than two-fold. Complement regulators FH and FI, when bound to rErpY-like protein, preserve their respective cofactor and protease activity and cleave the complement component C3b. The supplementation of rErpY-like protein (40 μg/mL) in serum ensued in an ∼90% reduction of membrane attack complex (C5b-9/MAC) deposition through the alternative pathway (AP) of complement activation. However, rErpY-like protein could moderately reduce (∼16%) MAC deposition in serum through the classical pathway (CP). In addition, the rErpY-like protein solely initiated the AP, suggesting its role in the rapid consumption and depletion of the complement components. Blocking the pathogenic Leptospira interrogans surface with anti-rErpY-like antibodies resulted in an increase in MAC formation on the bacterial surface, indicating a specific role of the ErpY-like lipoprotein in complement-mediated immune evasion. This study underscores the role of the ErpY-like lipoprotein of Leptospira in complement evasion.
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Affiliation(s)
- Saswat Hota
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Md Saddam Hussain
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Manish Kumar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
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Gytz Olesen H, Michailidou I, Zelek WM, Vreijling J, Ruizendaal P, de Klein F, Marquart JA, Kuipers TB, Mei H, Zhang Y, Ahasan M, Johnson KK, Wang Y, Morgan BP, van Dijk M, Fluiter K, Andersen GR, Baas F. Development, Characterization, and in vivo Validation of a Humanized C6 Monoclonal Antibody that Inhibits the Membrane Attack Complex. J Innate Immun 2022; 15:16-36. [PMID: 35551129 PMCID: PMC10643903 DOI: 10.1159/000524587] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 03/08/2022] [Indexed: 11/19/2022] Open
Abstract
Damage and disease of nerves activates the complement system. We demonstrated that activation of the terminal pathway of the complement system leads to the formation of the membrane attack complex (MAC) and delays regeneration in the peripheral nervous system. Animals deficient in the complement component C6 showed improved recovery after neuronal trauma. Thus, inhibitors of the MAC might be of therapeutic use in neurological disease. Here, we describe the development, structure, mode of action, and properties of a novel therapeutic monoclonal antibody, CP010, against C6 that prevents formation of the MAC in vivo. The monoclonal antibody is humanized and specific for C6 and binds to an epitope in the FIM1-2 domain of human and primate C6 with sub-nanomolar affinity. Using biophysical and structural studies, we show that the anti-C6 antibody prevents the interaction between C6 and C5/C5b by blocking the C6 FIM1-2:C5 C345c axis. Systemic administration of the anti-C6 mAb caused complete depletion of free C6 in circulation in transgenic rats expressing human C6 and thereby inhibited MAC formation. The antibody prevented disease in experimental autoimmune myasthenia gravis and ameliorated relapse in chronic relapsing experimental autoimmune encephalomyelitis in human C6 transgenic rats. CP010 is a promising complement C6 inhibitor that prevents MAC formation. Systemic administration of this C6 monoclonal antibody has therapeutic potential in the treatment of neuronal disease.
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Affiliation(s)
- Heidi Gytz Olesen
- Department of Molecular Biology and Genetics - Protein Science, Aarhus University, Aarhus, Denmark
| | | | - Wioleta M Zelek
- Division of Infection and Immunity and Dementia Research Institute, Systems Immunity Research Institute, School of Medicine, Cardiff University, Cardiff, UK
| | | | | | - Ferry de Klein
- Core Facility Genomics, Amsterdam UMC, Amsterdam, The Netherlands
| | | | - Thomas B Kuipers
- Sequencing Analysis Support Core, Department of Biomedical Data Sciences, LUMC, Leiden, The Netherlands
| | - Hailiang Mei
- Sequencing Analysis Support Core, Department of Biomedical Data Sciences, LUMC, Leiden, The Netherlands
| | - Yuchun Zhang
- Alexion, AstraZeneca Rare Disease, New Haven, Connecticut, USA
| | - Muhammad Ahasan
- Alexion, AstraZeneca Rare Disease, New Haven, Connecticut, USA
| | | | - Yi Wang
- Alexion, AstraZeneca Rare Disease, New Haven, Connecticut, USA
| | - B Paul Morgan
- Division of Infection and Immunity and Dementia Research Institute, Systems Immunity Research Institute, School of Medicine, Cardiff University, Cardiff, UK
| | | | - Kees Fluiter
- Department of Clinical Genetics, LUMC, Leiden, The Netherlands,
| | - Gregers Rom Andersen
- Department of Molecular Biology and Genetics - Protein Science, Aarhus University, Aarhus, Denmark
| | - Frank Baas
- Department of Clinical Genetics, LUMC, Leiden, The Netherlands
- Complement Pharma BV, Amsterdam, The Netherlands
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Wu M, Jia BB, Li MF. Complement C3 and Activated Fragment C3a Are Involved in Complement Activation and Anti-Bacterial Immunity. Front Immunol 2022; 13:813173. [PMID: 35281048 PMCID: PMC8913944 DOI: 10.3389/fimmu.2022.813173] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 02/04/2022] [Indexed: 12/13/2022] Open
Abstract
In the complement system, C3 is a central component in complement activation, immune defense and immune regulation. In all pathways of complement activation, the pivotal step is conversion of the component C3 to C3b and C3a, which is responsible to eliminate the pathogen and opsonization. In this study, we examined the immunological properties of C3 and its activated fragment C3a from Japanese flounder (Paralichthys olivaceus) (PoC3 and PoC3a), a teleost species with important economic value. PoC3 is composed of 1655 amino acid residues, contains the six domains and highly conserved GCGEQ sequence of the C3 family. We found that PoC3 expression occurred in nine different tissues and was upregulated by bacterial challenge. In serum, PoC3 was able to bind to a broad-spectrum of bacteria, and purified native PoC3 could directly kill specific pathogen. When PoC3 expression in Japanese flounder was knocked down by siRNA, serum complement activity was significantly decreased, and bacterial replication in fish tissues was significantly increased. Recombinant PoC3a (rPoC3a) exhibited apparent binding capacities to bacteria and Japanese flounder peripheral blood leukocytes (PBL) and induce chemotaxis of PBL. Japanese flounder administered rPoC3a exhibited enhanced resistance against bacterial infection. Taken together, these results indicate that PoC3 is likely a key factor of complement activation, and PoC3 and PoC3a are required for optimal defense against bacterial infection in teleost.
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Affiliation(s)
- Meng Wu
- Chinese Academy of Sciences (CAS) & Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Bei-bei Jia
- Chinese Academy of Sciences (CAS) & Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Mo-fei Li
- Chinese Academy of Sciences (CAS) & Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China
- *Correspondence: Mo-fei Li,
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Chan KF, Poh JJ, Wu WL, Gan SKE. Augmented reality in scientific visualization and communications: a new dawn of looking at antibody interactions. Antib Ther 2020; 3:221-226. [PMID: 33928229 PMCID: PMC7990256 DOI: 10.1093/abt/tbaa021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 08/12/2020] [Accepted: 09/02/2020] [Indexed: 01/01/2023] Open
Abstract
The use of augmented reality (AR) in providing three-dimensional (3D) visual support and image depth have been applied in education, tourism, historical studies, and medical training. In research and development, there has been a slow but growing use of AR tools in chemical and drug discovery, but little has been implemented for whole 3D antibody structures (IgE, IgM, IgA, IgG, and IgD) and in communicating their interactions with the antigens or receptors in publications. Given that antibody interactions can vary significantly between different monoclonal antibodies, a convenient and easy to use 3D visualization can convey structural mechanisms clearer to readers, especially in how residues may interact with one another. While this was previously constrained to the use of stereo images on printed material or molecular visualization software on the computer, the revolution of smartphone and phablets now allows visualization of whole molecular structures on-the-go, allowing rotations, zooming in and out, and even animations without complex devices or the training of visual prowess. While not yet as versatile as molecular visualization software on the computer, such technology is an improvement from stereo-images and bridges the gap with molecular visualization tools. In this report, we discuss the use of AR and how they can be employed in the holistic view of antibodies and the future of the technology for better scientific communication.
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Affiliation(s)
- Kwok-Fong Chan
- Antibody & Product Development Lab, Bioinformatics Institute, Agency for Science, Technology and Research (ASTAR), 30 Biopolis Street, #07-01 Matrix, Singapore 138671
| | - Jun-Jie Poh
- Antibody & Product Development Lab, Bioinformatics Institute, Agency for Science, Technology and Research (ASTAR), 30 Biopolis Street, #07-01 Matrix, Singapore 138671
| | - Wei-Ling Wu
- Antibody & Product Development Lab, Bioinformatics Institute, Agency for Science, Technology and Research (ASTAR), 30 Biopolis Street, #07-01 Matrix, Singapore 138671
| | - Samuel Ken-En Gan
- Antibody & Product Development Lab, Bioinformatics Institute, Agency for Science, Technology and Research (ASTAR), 30 Biopolis Street, #07-01 Matrix, Singapore 138671
- Experimental Drug Development Centre, ASTAR, 10 Biopolis Road, #05-01, Chromos, Singapore 138670
- p53 Laboratory, ASTAR, 8A Biomedical Grove, #06-04/05 Neuros/Immunos, Singapore 138648
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Atikuzzaman M, Mehta Bhai R, Fogelholm J, Wright D, Rodriguez-Martinez H. Mating induces the expression of immune- and pH-regulatory genes in the utero-vaginal junction containing mucosal sperm-storage tubuli of hens. Reproduction 2015; 150:473-83. [PMID: 26370241 PMCID: PMC4625885 DOI: 10.1530/rep-15-0253] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2015] [Indexed: 02/02/2023]
Abstract
The female chicken, as with other species with internal fertilization, can tolerate the presence of spermatozoa within specialized sperm-storage tubuli (SST) located in the mucosa of the utero-vaginal junction (UVJ) for days or weeks, without eliciting an immune response. To determine if the oviduct alters its gene expression in response to sperm entry, segments from the oviduct (UVJ, uterus, isthmus, magnum and infundibulum) of mated and unmated (control) hens, derived from an advanced inter-cross line between Red Junglefowl and White Leghorn, were explored 24 h after mating using cDNA microarray analysis. Mating shifted the expression of fifteen genes in the UVJ (53.33% immune-modulatory and 20.00% pH-regulatory) and seven genes in the uterus, none of the genes in the latter segment overlapping the former (with the differentially expressed genes themselves being less related to immune-modulatory function). The other oviductal segments did not show any significant changes. These findings suggest sperm deposition causes a shift in expression in the UVJ (containing mucosal SST) and the uterus for genes involved in immune-modulatory and pH-regulatory functions, both relevant for sperm survival in the hen's oviduct.
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Affiliation(s)
- Mohammad Atikuzzaman
- Linköping UniversityDepartment of Clinical and Experimental MedicineFaculty of Medicine and Health SciencesDepartment of PhysicsChemistry and Biology, Faculty of Science and Engineering, Campus HU/US, Developmental Biology, Lasarettsgatan 64/65, Lanken, Floor 12, SE-581 85 Linköping, Sweden
| | - Ratnesh Mehta Bhai
- Linköping UniversityDepartment of Clinical and Experimental MedicineFaculty of Medicine and Health SciencesDepartment of PhysicsChemistry and Biology, Faculty of Science and Engineering, Campus HU/US, Developmental Biology, Lasarettsgatan 64/65, Lanken, Floor 12, SE-581 85 Linköping, Sweden
| | - Jesper Fogelholm
- Linköping UniversityDepartment of Clinical and Experimental MedicineFaculty of Medicine and Health SciencesDepartment of PhysicsChemistry and Biology, Faculty of Science and Engineering, Campus HU/US, Developmental Biology, Lasarettsgatan 64/65, Lanken, Floor 12, SE-581 85 Linköping, Sweden
| | - Dominic Wright
- Linköping UniversityDepartment of Clinical and Experimental MedicineFaculty of Medicine and Health SciencesDepartment of PhysicsChemistry and Biology, Faculty of Science and Engineering, Campus HU/US, Developmental Biology, Lasarettsgatan 64/65, Lanken, Floor 12, SE-581 85 Linköping, Sweden
| | - Heriberto Rodriguez-Martinez
- Linköping UniversityDepartment of Clinical and Experimental MedicineFaculty of Medicine and Health SciencesDepartment of PhysicsChemistry and Biology, Faculty of Science and Engineering, Campus HU/US, Developmental Biology, Lasarettsgatan 64/65, Lanken, Floor 12, SE-581 85 Linköping, Sweden
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Zhang F, Zhang Z, Yan X, Chen H, Zhang W, Hong Y, Huang L. Genome-wide association studies for hematological traits in Chinese Sutai pigs. BMC Genet 2014; 15:41. [PMID: 24674592 PMCID: PMC3986688 DOI: 10.1186/1471-2156-15-41] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Accepted: 03/10/2014] [Indexed: 11/10/2022] Open
Abstract
Background It has been shown that hematological traits are strongly associated with the metabolism and the immune system in domestic pig. However, little is known about the genetic architecture of hematological traits. To identify quantitative trait loci (QTL) controlling hematological traits, we performed single marker Genome-wide association studies (GWAS) and haplotype analysis for 15 hematological traits in 495 Chinese Sutai pigs. Results We identified 161 significant SNPs including 44 genome-wide significant SNPs associated with 11 hematological traits by single marker GWAS. Most of them were located on SSC2. Meanwhile, we detected 499 significant SNPs containing 154 genome-wide significant SNPs associated with 9 hematological traits by haplotype analysis. Most of the identified loci were located on SSC7 and SSC9. Conclusions We detected 4 SNPs with pleiotropic effects on SSC2 by single marker GWAS and (or) on SSC7 by haplotype analysis. Furthermore, through checking the gene functional annotations, positions and their expression variation, we finally selected 7 genes as potential candidates. Specially, we found that three genes (TRIM58, TRIM26 and TRIM21) of them originated from the same gene family and executed similar function of innate and adaptive immune. The findings will contribute to dissection the immune gene network, further identification of causative mutations underlying the identified QTLs and providing insights into the molecular basis of hematological trait in domestic pig.
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Affiliation(s)
| | | | | | | | | | | | - Lusheng Huang
- Key Laboratory for Animal Biotechnology of Jiangxi Province and the Ministry of Agriculture of China, Jiangxi Agricultural University, 330045 Nanchang, China.
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7
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Gao Z, Li M, Wu J, Zhang S. Interplay between invertebrate C3a with vertebrate macrophages: functional characterization of immune activities of amphioxus C3a. FISH & SHELLFISH IMMUNOLOGY 2013; 35:1249-1259. [PMID: 23954696 DOI: 10.1016/j.fsi.2013.07.049] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Revised: 07/29/2013] [Accepted: 07/30/2013] [Indexed: 06/02/2023]
Abstract
Our current knowledge of the structure and function of C3a comes from the study of vertebrate C3a anaphylatoxins, virtually nothing is known about the structure and function of C3a molecules in invertebrates. Here we demonstrated that C3a from the invertebrate chordate Branchiostoma japonicum, BjC3a, was similar to vertebrate C3a possessing potential antibacterial activity, as revealed by sequence analysis and computational modeling. The antibacterial activity of BjC3a was definitely confirmed by both antibacterial assay and TEM observation showing that recombinant BjC3a was directly bactericidal. Additionally, recombinant BjC3a, like vertebrate C3a, was capable of inducing sea bass macrophage migration and enhancing macrophage phagocytosis and respiratory burst response. Moreover, recombinant BjC3a-desArg (generated by removal of the C-terminal arginine), like mammalian C3a-desArg, retained the immunological activities of BjC3a such as antibacterial and respiratory burst-stimulating activities, indicating that the immunological functions of C3a-desArg were conserved throughout chordate evolution. Altogether, our findings show that invertebrate (amphioxus) BjC3a is able to interact with vertebrate (sea bass) macrophages and mediate immune activities, suggesting the emergence of the inflammatory pathway of the complement system similar to that of vertebrates in the basal chordate amphioxus.
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Affiliation(s)
- Zhan Gao
- Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China
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8
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Silva EM, Conde JN, Allonso D, Nogueira ML, Mohana-Borges R. Mapping the interactions of dengue virus NS1 protein with human liver proteins using a yeast two-hybrid system: identification of C1q as an interacting partner. PLoS One 2013; 8:e57514. [PMID: 23516407 PMCID: PMC3597719 DOI: 10.1371/journal.pone.0057514] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 01/22/2013] [Indexed: 01/21/2023] Open
Abstract
Dengue constitutes a global health concern. The clinical manifestation of this disease varies from mild febrile illness to severe hemorrhage and/or fatal hypovolemic shock. Flavivirus nonstructural protein 1 (NS1) is a secreted glycoprotein that is displayed on the surface of infected cells but is absent in viral particles. NS1 accumulates at high levels in the plasma of dengue virus (DENV)-infected patients, and previous reports highlight its involvement in immune evasion, dengue severity, liver dysfunction and pathogenesis. In the present study, we performed a yeast two-hybrid screen to search for DENV2 NS1-interacting partners using a human liver cDNA library. We identified fifty genes, including human complement component 1 (C1q), which was confirmed by coimmunoprecipitation, ELISA and immunofluorescence assays, revealing for the first time the direct binding of this protein to NS1. Furthermore, the majority of the identified genes encode proteins that are secreted into the plasma of patients, and most of these proteins are classified as acute-phase proteins (APPs), such as plasminogen, haptoglobin, hemopexin, α-2-HS-glycoprotein, retinol binding protein 4, transferrin, and C4. The results presented here confirm the direct interaction of DENV NS1 with a key protein of the complement system and suggest a role for this complement protein in the pathogenesis of DENV infection.
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Affiliation(s)
- Emiliana M. Silva
- Laboratório de Genômica Estrutural, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jonas N. Conde
- Laboratório de Genômica Estrutural, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Diego Allonso
- Laboratório de Genômica Estrutural, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Mauricio L. Nogueira
- Departamento de Doenças Dermatológicas, Infecciosas e Parasitárias, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, São Paulo, Brazil
| | - Ronaldo Mohana-Borges
- Laboratório de Genômica Estrutural, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
- * E-mail:
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Altered polarization, morphology, and impaired innate immunity germane to resident peritoneal macrophages in mice with long-term type 2 diabetes. J Biomed Biotechnol 2012; 2012:867023. [PMID: 23093868 PMCID: PMC3469280 DOI: 10.1155/2012/867023] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2012] [Revised: 06/13/2012] [Accepted: 06/29/2012] [Indexed: 12/16/2022] Open
Abstract
Type 2 diabetes (T2D) is associated with perturbed innate immunity. Macrophages, bridging innate immunity and metabolic disturbances, play important roles in controlling immune homeostasis. However, the effect of long-term diabetic milieu (DM) on the functions and phenotypes of macrophages is still not clear. In this study, we used resident peritoneal macrophages (RPMs) from 5-month-old db/db mice to investigate the changes of macrophages. It was found that RPMs in db/db mice significantly reduced phagocytosis and adhesion capacity. After standardization with body weight, the number of F4/80+ RPMs markedly reduced in db/db mice, and, furthermore, the macrophages skewed to M2-polarizated macrophages. The results of morphology found that the RPMs shape of db/db mice was nearly round, but the RPMs shape of control mice was spindle-shaped and irregular. In this study, we found the cell numbers, morphology, and innate immunity functions of RPMs in 5-month-old type 2 diabetic mice (db/db mice) obtained by abdominal cavity lavage were significantly altered. Importantly, we also found the remarkably increased M2-RPMs in diabetic mice for the first time.
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Weckbach S, Neher M, Losacco JT, Bolden AL, Kulik L, Flierl MA, Bell SE, Holers VM, Stahel PF. Challenging the role of adaptive immunity in neurotrauma: Rag1(-/-) mice lacking mature B and T cells do not show neuroprotection after closed head injury. J Neurotrauma 2012; 29:1233-42. [PMID: 22335783 DOI: 10.1089/neu.2011.2169] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The role of adaptive immunity in contributing to post-traumatic neuroinflammation and neuropathology after head injury remains largely unexplored. The present study was designed to investigate the pathophysiological sequelae of closed head injury in Rag1(-/-) mice devoid of mature B and T lymphocytes. C57BL/6 wild-type and Rag1(-/-) mice were subjected to experimental closed head injury, using a standardized weight-drop device. Outcome parameters consisted of neurological scoring, quantification of blood-brain barrier (BBB) function, measurement of inflammatory markers and mediators of apoptosis in serum and brain tissue, and assessment of neuronal cell death, astrogliosis, and tissue destruction. There was no difference between wild-type and Rag1(-/-) mice with regard to injury severity and neurological impairment for up to 7 days after head injury. The extent of BBB dysfunction was in a similar range for both groups. Quantification of complement activation fragments in serum revealed significantly attenuated C3a levels in Rag1(-/-) mice compared to wild-type animals. In contrast, the levels of pro- and anti-inflammatory cytokines and pro-apoptotic and anti-apoptotic mediators remained in a similar range for both groups, and the histological analysis of brain sections did not reveal a difference in reactive astrogliosis, tissue destruction, and neuronal cell death in Rag1(-/-) compared to wild-type mice. These findings suggest that adaptive immunity is not of crucial importance for initiating and sustaining the inflammatory neuropathology after closed head injury. The attenuated extent of post-traumatic complement activation seen in Rag1(-/-) mice implies a cross-talk between innate and adaptive immune responses, which requires further investigation in future studies.
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Affiliation(s)
- Sebastian Weckbach
- Department of Orthopaedics, Denver Health Medical Center, University of Colorado School of Medicine, Denver, Colorado 80204, USA
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Anastasiou V, Mikrou A, Papanastasiou AD, Zarkadis IK. The molecular identification of factor H and factor I molecules in rainbow trout provides insights into complement C3 regulation. FISH & SHELLFISH IMMUNOLOGY 2011; 31:491-499. [PMID: 21703349 DOI: 10.1016/j.fsi.2011.06.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 05/24/2011] [Accepted: 06/05/2011] [Indexed: 05/31/2023]
Abstract
The complement system in vertebrates plays a crucial role in the elimination of pathogens. To regulate complement on self-tissue and to prevent spontaneous activation and systemic depletion, complement is controlled by both fluid-phase and membrane-bound inhibitors. One such inhibitor, complement factor I (CFI) regulates complement by proteolytic cleavage of components C3b and C4b in the presence of specific cofactors. Complement factor H (CFH), the main cofactor for CFI, regulates the alternative pathway of complement activation by acting in the breakdown of C3b to iC3b. To gain further insight into the origin of C3 regulation in bony fish we have cloned and characterized the CFI and CFH1 cDNAs in the rainbow trout (Oncorhynchus mykiss). In this study we report the primary sequence, the tissue expression profile, the polypeptide domain architecture and the phylogenetic analysis of trout CFI and CFH1 genes. The deduced amino acid sequences of trout CFI and CFH1 polypeptides exhibit 42% and 32% identity with human orthologs, respectively. RNA expression analysis showed that CFI is expressed differentially in trout tissues, while liver is the main source of CFH1 expression. Our data indicate that factor H and I genes have emerged during evolution as early as the divergence of teleost fish.
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Affiliation(s)
- Vivian Anastasiou
- Department of Biology, School of Medicine, University of Patras, Panepistimioupolis, Patras, Greece
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Downregulation of constitutive and cytokine-induced complement 3 expression by morphine in rat astrocytes. CURRENT THERAPEUTIC RESEARCH 2011; 72:23-35. [PMID: 24648573 DOI: 10.1016/j.curtheres.2011.02.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/23/2011] [Indexed: 11/23/2022]
Abstract
BACKGROUND The effect of opioids on inflammation and immune responses is an important subject of investigation because immunoregulatory cytokines are produced in the central nervous system and opioid receptors are widespread in these cells. OBJECTIVES The aim of this study was to evaluate the immunomodulatory effect of morphine on the C3 expression (both constitutive and proinflammatory cytokine-induced C3 expression) in primary rat astrocytes. METHODS Primary rat astrocytes were untreated or treated with morphine in different concentrations (10(-6) to 10(-2) M) before incubation without or with 5 U/mL tumor necrosis factor-α (TNF-α), and C3 protein and mRNA expressions were measured. Similarly, astrocytes were treated with 10(-3) M morphine and stimulated with other proinflammatory cytokines, including 10 ng/mL interleukin-8 (IL-8) and 5 U/mL IL-1β. Astrocytes were exposed to 10(-5) M naloxone for 2 hours before adding morphine, and TNF-α and C3 protein was measured. Tumor growth factor-β (TGF-β) was measured from the supernatants of each proinflammatory cytokine. RESULTS All results are expressed as mean percentages of C3 production by normalizing C3 without morphine or any cytokine treatment as 100%. Constitutive C3 protein production was decreased at morphine 10(-3) M (57.2%) and 10(-2) M (30.1%). Pretreatment with morphine suppressed induction of C3 expression at both the protein and mRNA levels in astrocytes stimulated with TNF-α, IL-8, and IL-1β (P < 0.05) in a dose-dependent manner. The inhibition of C3 protein production by morphine (10(-3) M; 33%) was partially attenuated by naloxone (52.0%) (P < 0.05). The pretreatment of astrocytes with morphine (10(-3) M) before stimulation with TNF-α, IL-8, and IL-1β increased by 33% (P < 0.05), decreased by 15.2% (P < 0.05), and did not change the production of TGF-β protein, respectively. CONCLUSIONS Morphine downregulated both constitutive and proinflammatory cytokine-induced C3 expression of astrocytes at the transcriptional level, but not in a cytokine-specific manner.
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Mehlhop E, Nelson S, Jost CA, Gorlatov S, Johnson S, Fremont DH, Diamond MS, Pierson TC. Complement protein C1q reduces the stoichiometric threshold for antibody-mediated neutralization of West Nile virus. Cell Host Microbe 2009; 6:381-91. [PMID: 19837377 DOI: 10.1016/j.chom.2009.09.003] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2009] [Revised: 07/23/2009] [Accepted: 09/15/2009] [Indexed: 01/16/2023]
Abstract
Virus neutralization is governed by the number of antibodies that bind a virion during the cellular entry process. Cellular and serum factors that interact with antibodies have the potential to modulate neutralization potency. Although the addition of serum complement can increase the neutralizing activity of antiviral antibodies in vitro, the mechanism and significance of this augmented potency in vivo remain uncertain. Herein, we show that the complement component C1q increases the potency of antibodies against West Nile virus by modulating the stoichiometric requirements for neutralization. The addition of C1q does not result in virolysis but instead reduces the number of antibodies that must bind the virion to neutralize infectivity. For IgG subclasses that bind C1q avidly, this reduced stoichiometric threshold falls below the minimal number of antibodies required for antibody-dependent enhancement (ADE) of infection of cells expressing Fc-gamma receptors (CD32) and explains how C1q restricts the ADE of flavivirus infection.
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Affiliation(s)
- Erin Mehlhop
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA
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Rees-Roberts D, Mullen LM, Gounaris K, Selkirk ME. Inactivation of the complement anaphylatoxin C5a by secreted products of parasitic nematodes. Int J Parasitol 2009; 40:527-32. [PMID: 19874826 PMCID: PMC2852653 DOI: 10.1016/j.ijpara.2009.10.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Revised: 10/04/2009] [Accepted: 10/08/2009] [Indexed: 11/30/2022]
Abstract
Given the importance of the complement anaphylatoxins in cellular recruitment during infection, the ability of secreted products from larval stages of Brugia malayi and Trichinella spiralis to influence C5a-mediated chemotaxis of human peripheral blood granulocytes in vitro was examined. Secreted products from B. malayi microfilariae almost completely abolished chemotaxis. This inhibition was blocked by phenylmethylsulphonyl fluoride, indicating the presence of a serine protease, which was subsequently shown to cleave C5a. In contrast, secreted products from T. spiralis infective larvae showed modest inhibition of C5a-mediated granulocyte chemotaxis, and this was blocked by potato carboxypeptidase inhibitor, an inhibitor of several metallocarboxypeptidases. Adult and larval stages of both parasites were demonstrated to secrete carboxypeptidases which cleaved hippuryl-L-lysine and hippuryl-L-arginine, and the T. spiralis enzyme was partially characterised. The data are discussed with reference to inflammation in parasitic nematode infection.
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Affiliation(s)
- Dominic Rees-Roberts
- Division of Cell & Molecular Biology, Department of Life Sciences, Imperial College London, London SW72AZ, UK
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Cell surface expression of the vaccinia virus complement control protein is mediated by interaction with the viral A56 protein and protects infected cells from complement attack. J Virol 2008; 82:4205-14. [PMID: 18287241 DOI: 10.1128/jvi.02426-07] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The vaccinia virus (VACV) complement control protein (VCP) is the major protein secreted from VACV-infected cells. It has been reported that VCP binds to the surfaces of uninfected cells by interacting with heparan sulfate proteoglycans (HSPGs). In this study, we show that VCP is also expressed on the surfaces of infected cells and demonstrate that surface localization occurs independently of HSPGs. Since VCP does not contain a transmembrane domain, we hypothesized that VCP interacts with a membrane protein that localizes to the infected-cell surface. We show that the VACV A56 membrane protein is necessary for the cell surface expression of VCP and demonstrate that VCP and A56 interact in VACV-infected cells. Since the surface expression of VCP was abrogated by reducing agents, we examined the contribution of an unpaired cysteine residue on VCP to VCP surface expression and VCP's interaction with A56. To do this, we mutated the unpaired cysteine in VCP and generated a recombinant virus expressing the altered form of VCP. Following the infection of cells with the mutant virus, VCP was neither expressed on the cell surface nor able to interact with A56. Importantly, the cell surface expression of VCP was found to protect infected cells from complement-mediated lysis. Our findings suggest a new function for VCP that may be important for poxvirus pathogenesis and impact immune responses to VACV-based vaccines.
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Mehlhop E, Ansarah-Sobrinho C, Johnson S, Engle M, Fremont DH, Pierson TC, Diamond MS. Complement protein C1q inhibits antibody-dependent enhancement of flavivirus infection in an IgG subclass-specific manner. Cell Host Microbe 2008; 2:417-26. [PMID: 18078693 DOI: 10.1016/j.chom.2007.09.015] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Revised: 08/28/2007] [Accepted: 09/26/2007] [Indexed: 01/11/2023]
Abstract
Severe dengue virus infection can occur in humans with pre-existing antibodies against the virus. This observation led to the hypothesis that a subneutralizing antibody level in vivo can increase viral burden and cause more severe disease. Indeed, antibody-dependent enhancement of infection (ADE) in vitro has been described for multiple viruses, including the flaviviruses dengue virus and West Nile virus. Here, we demonstrate that the complement component C1q restricts ADE by anti-flavivirus IgG antibodies in an IgG subclass-specific manner in cell culture and in mice. IgG subclasses that avidly bind C1q induced minimal ADE in the presence of C1q. These findings add a layer of complexity for the analysis of humoral immunity and flavivirus infection.
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Affiliation(s)
- Erin Mehlhop
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
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Maranto J, Rappaport J, Datta PK. Regulation of complement component C3 in astrocytes by IL-1beta and morphine. J Neuroimmune Pharmacol 2007; 3:43-51. [PMID: 18247123 DOI: 10.1007/s11481-007-9096-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2007] [Accepted: 10/19/2007] [Indexed: 01/12/2023]
Abstract
Substances of abuse, such as opiates, and astroglial-derived proinflammatory cytokines, such as interleukin (IL)-1beta, likely contribute to the neuroinflammatory and neurodegenerative processes observed in NeuroAIDS in injection drug users. Furthermore, uncontrolled synthesis and activation of complement component C3 in the brain can also lead to inflammation and neurodegeneration. We hypothesized that morphine may alter regulation of the C3 gene by IL-1beta in astrocytes. Our studies demonstrate that IL-1beta induces C3 promoter activity in a CAAT/enhancer-binding protein (C/EBP)-dependent manner. Inhibition of IL-1beta mediated C3 promoter activation by the dominant negative mutant of p38-alpha mitogen-activated protein kinase suggests that IL-1beta induces C3 expression through the activation of C/EBP. Morphine (0.01 microM) in combination with IL-1beta further induced C3 promoter activity. Similarly, the C/EBP-beta isoform liver activating protein and C/EBP-delta-induced C3 promoter activity were upregulated by morphine and IL-1beta. Taken together, this study illustrates that morphine modulates IL-1beta-mediated C3 expression in astrocytic cells.
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Affiliation(s)
- Jeffrey Maranto
- Department of Neuroscience, Temple University School of Medicine, 1900 N. 12th Street, Philadelphia, PA, USA
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Chung KM, Liszewski MK, Nybakken G, Davis AE, Townsend RR, Fremont DH, Atkinson JP, Diamond MS. West Nile virus nonstructural protein NS1 inhibits complement activation by binding the regulatory protein factor H. Proc Natl Acad Sci U S A 2006; 103:19111-6. [PMID: 17132743 PMCID: PMC1664712 DOI: 10.1073/pnas.0605668103] [Citation(s) in RCA: 182] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The complement system, by virtue of its dual effector and priming functions, is a major host defense against pathogens. Flavivirus nonstructural protein (NS)-1 has been speculated to have immune evasion activity, because it is a secreted glycoprotein, binds back to cell surfaces, and accumulates to high levels in the serum of infected patients. Herein, we demonstrate an immunomodulatory function of West Nile virus NS1. Soluble and cell-surface-associated NS1 binds to and recruits the complement regulatory protein factor H, resulting in decreased complement activation in solution and attenuated deposition of C3 fragments and C5b-9 membrane attack complexes on cell surfaces. Accordingly, extracellular NS1 may function to minimize immune system targeting of West Nile virus by decreasing complement recognition of infected cells.
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Affiliation(s)
| | | | | | - Alan E. Davis
- Departments of *Medicine
- Cell Biology and Physiology, and
| | | | | | - John P. Atkinson
- Departments of *Medicine
- Pathology and Immunology
- Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110
| | - Michael S. Diamond
- Departments of *Medicine
- Pathology and Immunology
- Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110
- To whom correspondence should be addressed. E-mail:
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Mehlhop E, Whitby K, Oliphant T, Marri A, Engle M, Diamond MS. Complement activation is required for induction of a protective antibody response against West Nile virus infection. J Virol 2005; 79:7466-77. [PMID: 15919902 PMCID: PMC1143684 DOI: 10.1128/jvi.79.12.7466-7477.2005] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2004] [Accepted: 02/15/2005] [Indexed: 01/21/2023] Open
Abstract
Infection with West Nile virus (WNV) causes a severe infection of the central nervous system (CNS) with higher levels of morbidity and mortality in the elderly and the immunocompromised. Experiments with mice have begun to define how the innate and adaptive immune responses function to limit infection. Here, we demonstrate that the complement system, a major component of innate immunity, controls WNV infection in vitro primarily in an antibody-dependent manner by neutralizing virus particles in solution and lysing WNV-infected cells. More decisively, mice that genetically lack the third component of complement or complement receptor 1 (CR1) and CR2 developed increased CNS virus burdens and were vulnerable to lethal infection at a low dose of WNV. Both C3-deficient and CR1- and CR2-deficient mice also had significant deficits in their humoral responses after infection with markedly reduced levels of specific anti-WNV immunoglobulin M (IgM) and IgG. Overall, these results suggest that complement controls WNV infection, in part through its ability to induce a protective antibody response.
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Affiliation(s)
- Erin Mehlhop
- Department of Medicine, Molecular Microbiology, and Pathology & Immunology, Washington University School of Medicine, 660 South Euclid Ave., Box 8051, St. Louis, MO 63110, USA
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Campos-Rodríguezp R, Jarillo-Luna A. The pathogenicity of Entamoeba histolytica is related to the capacity of evading innate immunity. Parasite Immunol 2005; 27:1-8. [PMID: 15813717 DOI: 10.1111/j.1365-3024.2005.00743.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The host and parasite factors that influence susceptibility to Entamoeba histolytica infection and disease are not well understood. Entamoeba histolytica pathogenicity has been considered by focusing principally on parasite rather than host factors. Thus, research has concentrated on explaining the molecular differences between pathogenic E. histolytica and non-pathogenic E. dispar. However, the amoeba molecules considered most important for host tissue destruction (amoebapore, galactose/N-acetyl galactosamine inhibitable lectin, and cysteine proteinases) are present in both pathogenic E. histolytica and non-pathogenic E. dispar. In addition, the genetic differences in pathogenicity among E. histolytica isolates are unlikely to completely explain the different outcomes of infection. Considering that the principal difference between pathogenic and non-pathogenic amoebas lies in their surface coats, we propose that pathogenicity of the amoebas is related to the composition and properties of the surface coat components (or pathogen-associated molecular patterns, PAMPs), and the ability of innate immune response to recognize these components and eliminate the parasite. According to this hypothesis, a key feature that may distinguish pathogenic (E. histolytica) from non-pathogenic (E. dispar) strains is whether or not they can overcome innate immune defences. A corollary of this hypothesis is that in susceptible individuals the PAMPs are either not recognized or they are recognized by a set of Toll-like receptors (TLRs) that leads to an inflammatory response. In both cases, the result is tissue damage. On the contrary, in resistant individuals the innate/inflammatory response, induced through the activation of a different set of TLRs, eliminates the parasite.
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Affiliation(s)
- Rafael Campos-Rodríguezp
- Departamento de Bioquímica, Escuela Superior de Medicina, Instituto Politécnico Nacional, México, DF.
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Abstract
Within the flavivirus family, viruses that cause natural infections of the central nervous system (CNS) principally include members of the Japanese encephalitis virus (JEV) serogroup and the tick-borne encephalitis virus (TBEV) serocomplex. The pathogenesis of diseases involves complex interactions of viruses, which differ in neurovirulence potential, and a number of host factors, which govern susceptibility to infection and the capacity to mount effective antiviral immune responses both in the periphery and within the CNS. This chapter summarizes progress in the field of flavivirus neuropathogenesis. Mosquito-borne and tickborne viruses are considered together. Flavivirus neuropathogenesis involves both neuroinvasiveness (capacity to enter the CNS) and neurovirulence (replication within the CNS), both of which can be manipulated experimentally. Neuronal injury as a result of bystander effects may be a factor during flavivirus neuropathogenesis given that microglial activation and elaboration of inflammatory mediators, including IL-1β and TNF-α, occur in the CNS during these infections and may accompany the production of nitric oxide and peroxynitrite, which can cause neurotoxicity.
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Affiliation(s)
- Thomas J Chambers
- Department of Molecular Microbiology and Immunology, St. Louis University Health Sciences Center, School of Medicine, St. Louis, Missouri 63104, USA
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