1
|
Cisowska A, Jankowski S. The sensitivity ofEscherichia coli strains with K1 surface antigen and rods without this antigen to the bactericidal effect of serum. Folia Microbiol (Praha) 2008; 49:471-8. [PMID: 15530015 DOI: 10.1007/bf02931611] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The susceptibility of Escherichia coli strains with K1 surface antigen (K1+) and rods without this antigen (K1-) to the bactericidal action of normal bovine serum and human normal cord serum was determined. Seventy E. coli strains (35 K1+ and 35 K1-) were isolated from urine obtained from children with urinary tract infections. The strains investigated showed variable sensitivity to the bactericidal action of the sera. E. coli K1+ strains were characterized by lower sensitivity to bactericidal effect of the sera in comparison with K1- rods. The role of the particular mechanisms of complement activation in the process of killing of the E. coli strains was also determined.
Collapse
Affiliation(s)
- A Cisowska
- Department of Biology and Medical Parasitology, Medical University, 50-367 Wrocław, Poland.
| | | |
Collapse
|
2
|
Bugla-Płoskońska G, Cisowska A, Karpińska K, Jankowski S, Doroszkiewicz W. The mechanisms of activation of normal human serum complement byEscherichia coli strains with K1 surface antigen. Folia Microbiol (Praha) 2006; 51:627-32. [PMID: 17455802 DOI: 10.1007/bf02931630] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Ten E. coli K1 strains isolated from the urine of children with urinary tract infections were sensitive to the bactericidal action of normal human serum (NHS). The role of the particular mechanisms of complement activation was determined in the process of killing these strains, showing variable sensitivity to the bactericidal action of NHS; three mechanisms of activation of human complement were observed. Important role of alternative pathway activation in the bactericidal action of NHS against E. coli K1 strains independent of the classical and lectin pathways was not established.
Collapse
|
3
|
Turina M, Fry DE, Polk HC. Acute hyperglycemia and the innate immune system: clinical, cellular, and molecular aspects. Crit Care Med 2005; 33:1624-33. [PMID: 16003073 DOI: 10.1097/01.ccm.0000170106.61978.d8] [Citation(s) in RCA: 298] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE To extract from the biomedical literature the reported effects of acute hyperglycemia on the major components of the innate immune system and to describe the clinical benefits of strict blood glucose control in certain patients. DATA SOURCE AND SELECTION A Medline/PubMed search (1966 to July 2004) with manual cross-referencing was conducted, including all relevant articles investigating the effects of acutely elevated glucose levels on innate immunity. All publication types, languages, or subsets were searched. DATA EXTRACTION AND SYNTHESIS Original and selected review articles, short communications, letters to the editor, and chapters of selected textbooks were extracted. Most recent and relevant clinical trials were reviewed for the introductory section to provide the clinical background to this topic. The selected bench laboratory articles were then divided into three main categories based on the timing of events: a) the early phase of the innate immune reaction; b) the cytokine network; and c) the phagocytic phase. The most obvious findings related to hyperglycemia included reduced neutrophil activity (e.g., chemotaxis, formation of reactive oxygen species, phagocytosis of bacteria), despite accelerated diapedesis of leukocytes into peripheral tissue, as well as specific alterations of cytokine patterns with increased concentrations of the early proinflammatory cytokines tumor necrosis factor-alpha and interleukin-6. Furthermore, a reduction of endothelial nitric oxide formation takes place, thus decreasing microvascular reactivity to dilating agents such as bradykinin, and complement function (e.g., opsonization, chemotaxis) is impaired, despite elevations of certain complement factors. CONCLUSIONS Acute, short-term hyperglycemia affects all major components of innate immunity and impairs the ability of the host to combat infection, even though certain distinctive proinflammatory alterations of the immune response can be observed under these conditions.
Collapse
Affiliation(s)
- Matthias Turina
- Department of Surgery, the Price Institute of Surgical Research, University of Louisville School of Medicine, University of Louisville Hospital, Louisville, KY, USA
| | | | | |
Collapse
|
4
|
Ellison VJ, Mocatta TJ, Winterbourn CC, Darlow BA, Volpe JJ, Inder TE. The relationship of CSF and plasma cytokine levels to cerebral white matter injury in the premature newborn. Pediatr Res 2005; 57:282-6. [PMID: 15585689 DOI: 10.1203/01.pdr.0000148286.53572.95] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Ischemia and systemic infection are implicated in the etiology of periventricular white matter injury, a major cause of adverse motor and cognitive outcome in preterm infants. Cytokines are signaling proteins that can be produced as part of the inflammatory response to both ischemia and infection. The aim of this study was to relate cerebrospinal fluid (CSF) concentrations of IL-6, IL-8, IL-10, tumor necrosis factor alpha (TNF-alpha), and interferon gamma (IFN-gamma) to magnetic resonance-defined white matter injury in preterm infants. Relationships between CSF and plasma cytokine concentrations were also examined. Preterm infants (<or=32 wk) and more mature infants from The Royal Women's Hospital, Melbourne, Australia, and Christchurch Women's Hospital, Christchurch, New Zealand, were eligible for study if they required a clinically indicated lumbar puncture. Plasma samples were obtained in a subgroup of Christchurch infants. Preterm infants underwent advanced quantitative volumetric magnetic resonance imaging using a 1.5-Tesla scanner at term equivalent. One hundred forty-six infants were enrolled and 190 CSF and 42 plasma samples obtained. There was no significant correlation between paired CSF and plasma concentrations for any cytokine. In comparing plasma and CSF concentrations, levels of IL-8 were significantly higher in CSF than plasma. Preterm infants with MRI-defined cerebral white matter injury had higher levels of IL-6, IL-10, and TNF-alpha in the CSF than infants without such injury. Plasma cytokine concentrations may not reflect CSF cytokine levels or inflammatory events within the brain. Elevated CSF levels of cytokines in infants with white matter injury suggest an altered inflammatory balance.
Collapse
Affiliation(s)
- Vanessa J Ellison
- Neonatal Medicine, Royal Women's Hospital, Melbourne, Victoria, Australia
| | | | | | | | | | | |
Collapse
|
5
|
Lathem WW, Bergsbaken T, Welch RA. Potentiation of C1 esterase inhibitor by StcE, a metalloprotease secreted by Escherichia coli O157:H7. ACTA ACUST UNITED AC 2004; 199:1077-87. [PMID: 15096536 PMCID: PMC2211892 DOI: 10.1084/jem.20030255] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The complement system is an essential component of host defense against pathogens. Previous research in our laboratory identified StcE, a metalloprotease secreted by Escherichia coli O157:H7 that cleaves the serpin C1 esterase inhibitor (C1-INH), a major regulator of the classical complement cascade. Analyses of StcE-treated C1-INH activity revealed that surprisingly, StcE enhanced the ability of C1-INH to inhibit the classical complement-mediated lysis of sheep erythrocytes. StcE directly interacts with both cells and C1-INH, thereby binding C1-INH to the cell surface. This suggests that the augmented activity of StcE-treated C1-INH is due to the increased concentration of C1-INH at the sites of potential lytic complex formation. Indeed, removal of StcE abolishes the ability of C1-INH to bind erythrocyte surfaces, whereas the proteolysis of C1-INH is unnecessary to potentiate its inhibitory activity. Physical analyses showed that StcE interacts with C1-INH within its aminoterminal domain, allowing the unaffected serpin domain to interact with its targets. In addition, StcE-treated C1-INH provides significantly increased serum resistance to E. coli K-12 over native C1-INH. These data suggest that by recruiting C1-INH to cell surfaces, StcE may protect both E. coli O157:H7 and the host cells to which the bacterium adheres from complement-mediated lysis and potentially damaging inflammatory events.
Collapse
Affiliation(s)
- Wyndham W Lathem
- Department of Medical Microbiology and Immunology, University of Wisconsin, 1300 University Avenue, Madison, WI 53706, USA
| | | | | |
Collapse
|
6
|
Jakobsen H, Jonsdottir I. Mucosal vaccination against encapsulated respiratory bacteria--new potentials for conjugate vaccines? Scand J Immunol 2003; 58:119-28. [PMID: 12869132 DOI: 10.1046/j.1365-3083.2003.01292.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Polysaccharide (PS)-encapsulated bacteria such as Haemophilus influenzae type b (Hib), Streptococcus pneumoniae (pneumococcus), Neisseria meningitides (meningococcus) and group B streptococcus (GBS), cause a major proportion of disease in early childhood. Native PS vaccines are immunogenic and provide protection against disease in healthy adults but do not induce immunological memory. PSs are T-cell-independent antigens and do not elicit antibodies in infants and young children, but by conjugating PS to proteins they become T-cell dependent and immunogenic at an early age. Despite excellent efficacy of PS-protein conjugate vaccines against invasive disease, protection against mucosal infections such as pneumococcal otitis media has been less efficacious. Circulating PS-specific antibodies may protect against infections at mucosal sites, but mucosal immunoglobulin A antibodies may also contribute significantly to protection against mucosal infections. Mucosal immunization of experimental animals with conjugate vaccines against Hib, pneumococcus, meningococcus and GBS induces systemic and mucosal immune responses, which provide protection against carriage, otitis media and invasive disease in a variety of challenge models, providing new means for protection against encapsulated bacteria. In addition, mucosal immunization of neonatal mice with a pneumococcal conjugate and the nontoxic adjuvant LT-K63 has been superior to parenteral immunization in eliciting protective antibodies and PS-specific memory, and thus circumventing the limitations of antibody responses to PS that are responsible for enhanced susceptibility of neonates and infants to infections caused by encapsulated bacteria. Through T-cell dependent enhanced immunogenicity of PS-protein conjugate vaccines, mucosal immunization could be an attractive approach for early life immunization against encapsulated bacteria.
Collapse
Affiliation(s)
- H Jakobsen
- Department of Immunology, Landspitali-University Hospital, Hringbraut, 101 Reykjavik, Iceland
| | | |
Collapse
|
7
|
Saeland E, Vidarsson G, Leusen JHW, Van Garderen E, Nahm MH, Vile-Weekhout H, Walraven V, Stemerding AM, Verbeek JS, Rijkers GT, Kuis W, Sanders EAM, Van De Winkel JGJ. Central role of complement in passive protection by human IgG1 and IgG2 anti-pneumococcal antibodies in mice. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:6158-64. [PMID: 12794146 DOI: 10.4049/jimmunol.170.12.6158] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Streptococcus pneumoniae is an important cause of morbitity and mortality worldwide. Capsule-specific IgG1 and IgG2 Abs are induced upon vaccination with polysaccharide-based vaccines that mediate host protection. We compared the protective capacity of human recombinant serogroup 6-specific IgG1 and IgG2 Abs in mice deficient for either leukocyte FcR or complement factors. Human IgG1 was found to interact with mouse leukocyte FcR in vitro, whereas human IgG2 did not. Both subclasses induced complement activation, resulting in C3c deposition on pneumococcal surfaces. Passive immunization of C57BL/6 mice with either subclass before intranasal challenge with serotype 6A induced similar degrees of protection. FcgammaRI- and III-deficient mice, as well as the combined FcgammaRI, II, and III knockout mice, were protected by passive immunization, indicating FcR not to be essential for protection. C1q or C2/factor B knockout mice, however, were not protected by passive immunization. Passively immunized C2/factor B(-/-) mice displayed higher bacteremic load than C1q(-/-) mice, supporting an important protective role of the alternative complement pathway. Spleens from wild-type and C1q(-/-) mice showed hyperemia and thrombotic vessel occlusion, as a result of septicemic shock. Notably, thrombus formation was absent in spleens of C2/factor B(-/-) mice, suggesting that the alternative complement pathway contributes to shock-induced intravascular coagulation. These studies demonstrate complement to play a central role in Ab-mediated protection against pneumococcal infection in vivo, as well as in bacteremia-associated thrombotic complications.
Collapse
MESH Headings
- Animals
- Antibodies, Bacterial/administration & dosage
- Antibodies, Bacterial/metabolism
- Antibody Specificity
- Complement System Proteins/metabolism
- Complement System Proteins/physiology
- Humans
- Immunization, Passive/methods
- Immunoglobulin G/administration & dosage
- Immunoglobulin G/metabolism
- Lung/immunology
- Lung/microbiology
- Lung/pathology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Knockout
- Pneumonia, Pneumococcal/genetics
- Pneumonia, Pneumococcal/immunology
- Pneumonia, Pneumococcal/pathology
- Pneumonia, Pneumococcal/prevention & control
- Polysaccharides, Bacterial/immunology
- Receptors, IgG/metabolism
- Sepsis/genetics
- Sepsis/immunology
- Sepsis/pathology
- Sepsis/prevention & control
- Spleen/immunology
- Spleen/microbiology
- Spleen/pathology
- Streptococcus pneumoniae/immunology
- Streptococcus pneumoniae/pathogenicity
Collapse
Affiliation(s)
- Eirikur Saeland
- Immunotherapy Laboratory, Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Ginsburg I. The role of bacteriolysis in the pathophysiology of inflammation, infection and post-infectious sequelae. APMIS 2002; 110:753-70. [PMID: 12588416 DOI: 10.1034/j.1600-0463.2002.1101101.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The literature dealing with the biochemical basis of bacteriolysis and its role in inflammation, infection and in post-infectious sequelae is reviewed and discussed. Bacteriolysis is an event that may occur when normal microbial multiplication is altered due to an uncontrolled activation of a series of autolytic cell-wall breaking enzymes (muramidases). While a low-level bacteriolysis sometimes occurs physiologically, due to "mistakes" in cell separation, a pronounced cell wall breakdown may occur following bacteriolysis induced either by beta-lactam antibiotics or by a large variety of bacteriolysis-inducing cationic peptides. These include spermine, spermidine, bactericidal peptides defensins, bacterial permeability increasing peptides from neutrophils, cationic proteins from eosinophils, lysozyme, myeloperoxidase, lactoferrin, the highly cationic proteinases elastase and cathepsins, PLA2, and certain synthetic polyamino acids. The cationic agents probably function by deregulating lipoteichoic acid (LTA) in Gram-positive bacteria and phospholipids in Gram-negative bacteria, the presumed regulators of the autolytic enzyme systems (muramidases). When bacteriolysis occurs in vivo, cell-wall- and -membrane-associated lipopolysaccharide (LPS (endotoxin)), lipoteichoic acid (LTA) and peptidoglycan (PPG), are released. These highly phlogistic agents can act on macrophages, either individually or in synergy, to induce the generation and release of reactive oxygen and nitrogen species, cytotoxic cytokines, hydrolases, proteinases, and also to activate the coagulation and complement cascades. All these agents and processes are involved in the pathophysiology of septic shock and multiple organ failure resulting from severe microbial infections. Bacteriolysis induced in in vitro models, either by polycations or by beta-lactams, could be effectively inhibited by sulfated polysaccharides, by D-amino acids as well as by certain anti-bacteriolytic antibiotics. However, within phagocytic cells in inflammatory sites, bacteriolysis tends to be strongly inhibited presumably due to the inactivation by oxidants and proteinases of the bacterial muramidases. This might results in a long persistence of non-biodegradable cell-wall components causing granulomatous inflammation. However, persistence of microbial cell walls in vivo may also boost innate immunity against infections and against tumor-cell proliferation. Therapeutic strategies to cope with the deleterious effects of bacteriolysis in vivo include combinations of autolysin inhibitors with combinations of certain anti-inflammatory agents. These might inhibit the synergistic tissue- and- organ-damaging "cross talks" which lead to septic shock and to additional post-infectious sequelae.
Collapse
Affiliation(s)
- Isaac Ginsburg
- Department of Oral Biology, Hebrew University, Hadassah Faculty of Dental Medicine, Jerusalem, Israel.
| |
Collapse
|
9
|
Abstract
BACKGROUND Bacterial infections remain important causes of morbidity and mortality in surgical patients. Our understanding of the effects of bacteria on the host, and also the defense mechanisms available to the host, is improving all the time. Modern tools in biochemistry, immunology, and molecular biology have provided powerful methods to further our understanding of the complex interactions that contribute to our host defense response. This review reflects current thinking regarding the factors that contribute to bacterial infection and host defense response. DATA SOURCES This review was compiled after an extensive review of the current and historical literature, and highlights a number of areas involved in the pathogenesis of bacterial infection. CONCLUSIONS Bacteria can have a wide-ranging and deleterious effect on the host. Many different therapeutic approaches have been attempted to modulate the host response and limit the deleterious effects of bacteria. As our understanding of the underlying processes improves, these therapies should improve accordingly.
Collapse
Affiliation(s)
- Michael Heinzelmann
- Department of Surgery and Price Institute of Surgical Research, University of Louisville School of Medicine, Louisville, KY 40292, USA
| | | | | |
Collapse
|
10
|
Barnes MG, Weiss AA. BrkA protein of Bordetella pertussis inhibits the classical pathway of complement after C1 deposition. Infect Immun 2001; 69:3067-72. [PMID: 11292725 PMCID: PMC98261 DOI: 10.1128/iai.69.5.3067-3072.2001] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Bordetella pertussis produces a 73-kDa protein, BrkA (Bordetella resistance to killing), which inhibits the bactericidal activity of complement. In this study we characterized the step in the complement cascade where BrkA acts, using three strains: a wild-type strain, a strain containing an insertional disruption of brkA, and a strain containing two copies of the brkA locus. Following incubation with 10% human serum, killing was greatest for the BrkA mutant, followed by that for the wild-type strain, while the strain with two copies of brkA was the most resistant. Complement activation was monitored by enzyme-linked immunosorbent assay (ELISA) or Western blotting. ELISAs for SC5b-9, the soluble membrane attack complex, showed that production of SC5b-9 was greatest with the brkA mutant, less with the wild type, and least with the strain containing two copies of brkA. Deposition of complement proteins on the bacteria was monitored by Western blotting. A decrease in deposition on the bacteria of C4, C3, and C9 corresponded with decreased complement sensitivity. Deposition of C1, however, was not affected by the presence of BrkA. These studies show that BrkA inhibits the classical pathway of complement activation and prevents accumulation of deposited C4.
Collapse
Affiliation(s)
- M G Barnes
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio 45267, USA
| | | |
Collapse
|
11
|
Araújo-Jorge TC. Biology and ultra-structure of Trypanosoma cruzi: a 90-year old challenge for scientists. Mem Inst Oswaldo Cruz 2000; 94 Suppl 1:131-4. [PMID: 10677699 DOI: 10.1590/s0074-02761999000700013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- T C Araújo-Jorge
- Laboratório de Biologia Celular, Departamento de Ultra-estrutura e Biologia Celular, Instituto Oswaldo Cruz, Rio de Janeiro, Brasil.
| |
Collapse
|
12
|
Da Costa XJ, Brockman MA, Alicot E, Ma M, Fischer MB, Zhou X, Knipe DM, Carroll MC. Humoral response to herpes simplex virus is complement-dependent. Proc Natl Acad Sci U S A 1999; 96:12708-12. [PMID: 10535987 PMCID: PMC23060 DOI: 10.1073/pnas.96.22.12708] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The complement system represents a cascade of serum proteins, which provide a major effector function in innate immunity. Recent studies have revealed that complement links innate and adaptive immunity via complement receptors CD21/CD35 in that it enhances the B cell memory response to noninfectious protein antigens introduced i.v. To examine the importance of complement for immune responses to virus infection in a peripheral tissue, we compared the B cell memory response of mice deficient in complement C3, C4, or CD21/CD35 with wild-type controls. We found that the deficient mice failed to generate a normal memory response, which is characterized by a reduction in IgG antibody and germinal centers. Thus, complement is important not only in the effector function of innate immunity but also in the stimulation of memory B cell responses to viral-infected cell antigens in both blood and peripheral tissues.
Collapse
Affiliation(s)
- X J Da Costa
- Department of Microbiology, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Rosengard AM, Alonso LC, Korb LC, Baldwin WM, Sanfilippo F, Turka LA, Ahearn JM. Functional characterization of soluble and membrane-bound forms of vaccinia virus complement control protein (VCP). Mol Immunol 1999; 36:685-97. [PMID: 10509819 DOI: 10.1016/s0161-5890(99)00081-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Vaccinia virus secretes a 35 kD protein, vaccinia virus complement control protein (VCP), that inhibits the classical and alternative pathways of complement at several points, indicating that it may be a viral analogue of human complement receptor type 1 (CR1; CD35). Structurally, however, CR1 is composed of 30 short consensus repeats (SCRs), whereas VCP consists entirely of four SCRs. We have begun a structure-function analysis of VCP to define the minimum number of SCRs necessary for function, the functional differences between VCP and CR1, and the potential therapeutic roles for VCP. We addressed these questions by creating and characterizing recombinant soluble and membrane-bound forms of VCP. We have determined that (1) VCP requires all four SCRs to bind C3b, (2) whereas CR1 binds C3b and iC3b, VCP binds C3b but not iC3b, and (3) although normally secreted, if expressed on the membrane of mammalian cells, VCP effectively protects the cells from complement-mediated lysis. Thus, VCP appears to be a compact and unique complement regulatory protein with the ability to inhibit both arms of the complement cascade, but lacking affinity for iC3b. By releasing rather than capturing iC3b-bearing complexes following inactivation of C3b, VCP may 'recycle' its active site locally among infected cells, and thereby enable the virus to evade more efficiently host immune and inflammatory responses. The unique function, compact structure, and capacity of VCP to protect mammalian cells from complement-mediated attack, suggests that it could be used both to better understand the structure-function relationship of complement regulatory proteins, in general, and also to rationally design and develop novel therapeutic agents.
Collapse
Affiliation(s)
- A M Rosengard
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, USA.
| | | | | | | | | | | | | |
Collapse
|
14
|
Weiss AA, Mobberley PS, Fernandez RC, Mink CM. Characterization of human bactericidal antibodies to Bordetella pertussis. Infect Immun 1999; 67:1424-31. [PMID: 10024590 PMCID: PMC96476 DOI: 10.1128/iai.67.3.1424-1431.1999] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Bordetella pertussis BrkA protein protects against the bactericidal activity of complement and antibody; however, some individuals mount an immune response that overcomes this bacterial defense. To further characterize this process, the bactericidal activities of sera from 13 adults with different modes of exposure to B. pertussis (infected as adults, occupational exposure, immunized with an acellular vaccine, or no identified exposure) against a wild-type strain and a BrkA complement-sensitive mutant were evaluated. All of the sera killed the BrkA mutant, suggesting past exposure to B. pertussis or cross-reactive organisms. Several samples had no or minimal activity against the wild type. All of the sera collected from the infected and occupationally exposed individuals but not all of the sera from vaccinated individuals had bactericidal activity against the wild-type strain, suggesting that some types of exposure can induce an immune response that can overcome the BrkA resistance mechanism. Adsorbing serum with the wild-type strain removed the bactericidal antibodies; however, adsorbing the serum with a lipopolysaccharide (LPS) mutant or an avirulent (bvg mutant) strain did not always result in loss of bactericidal activity, suggesting that antibodies to either LPS or bvg-regulated proteins could be bactericidal. All the samples, including those that lacked bactericidal activity, contained antibodies that recognized the LPS of B. pertussis. Bactericidal activity correlated best with the presence of the immunoglobulin G3 (IgG3) antibodies to LPS, the IgG subtype that is most effective at fixing complement.
Collapse
Affiliation(s)
- A A Weiss
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio 45267-0524, USA.
| | | | | | | |
Collapse
|
15
|
Abstract
BrkA confers resistance to killing by complement in Bordetella pertussis. Complement resistance in Bordetella bronchiseptica was examined. Four B. bronchiseptica strains possessed the brkA gene; however, only three expressed the protein. Only the strain lacking BrkA was susceptible to complement. Introduction of the B. pertussis brkA gene restored BrkA expression to this strain but did not confer resistance. brkA was mutated in the strains that naturally expressed BrkA, and loss of BrkA did not confer sensitivity to complement. As a species, B. bronchiseptica is more resistant to complement than B. pertussis, and BrkA does not mediate resistance.
Collapse
Affiliation(s)
- A A Rambow
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio 45267, USA
| | | | | |
Collapse
|
16
|
Schmidt C, Stehling P, Schnitzer J, Reutter W, Horstkorte R. Biochemical engineering of neural cell surfaces by the synthetic N-propanoyl-substituted neuraminic acid precursor. J Biol Chem 1998; 273:19146-52. [PMID: 9668100 DOI: 10.1074/jbc.273.30.19146] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sialylation of glycoproteins and glycolipids plays an important role during development, regeneration, and pathogenesis of diseases. During times of intense plasticity within the nervous system, such as development and regeneration, sialylation of neural cells is distinct from the time of its maintenance. In this study, a synthetic precursor of neuraminic acid, N-propanoylmannosamine (N-propanoyl neuraminic acid precursor (P-NAP)), is applied to the culture medium of oligodendrocyte progenitor cells, microglia, astrocytes, and neurons from neonatal rat brains to alter sialylation of glycoconjugates within these cells. P-NAP is metabolized and incorporated as N-propanoyl neuraminic acid into glycoproteins of the cell membrane. P-NAP stimulates the proliferation of astrocytes and microglia but not of oligodendrocyte progenitor in vitro. However, P-NAP increases the number of oligodendrocyte progenitor cells expressing the early oligodendroglial surface marker A2B5 epitope. In the presence of P-NAP, cerebellar neurons (but not astrocytes) in microexplant cultures start to express the oligodendroglial progenitor marker A2B5 epitope, which is normally undetectable on these cells. The controls, which were performed in the absence of any additive or in the presence of the physiological precursor of neuraminic acid, N-acetylmannosamine, did not show any increase in A2B5 expression.
Collapse
Affiliation(s)
- C Schmidt
- Max-Delbrück-Centrum für Molekulare Medizin, Robert-Rössle-Str. 10, D-13122 Berlin-Buch, Germany
| | | | | | | | | |
Collapse
|
17
|
Vidarsson G, Sigurdardottir ST, Gudnason T, Kjartansson S, Kristinsson KG, Ingolfsdottir G, Jonsson S, Valdimarsson H, Schiffman G, Schneerson R, Jonsdottir I. Isotypes and opsonophagocytosis of pneumococcus type 6B antibodies elicited in infants and adults by an experimental pneumococcus type 6B-tetanus toxoid vaccine. Infect Immun 1998; 66:2866-70. [PMID: 9596761 PMCID: PMC108283 DOI: 10.1128/iai.66.6.2866-2870.1998] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Streptococcus pneumoniae is a major respiratory pathogen of infants, children, and the elderly. Polysaccharide vaccines have been useful in adult populations but do not elicit protective immunity in infants and young children. To enhance their immunogenicity, vaccines of pneumococcal polysaccharides conjugated to proteins are being developed. In this study antibody levels and opsonic activities were compared in sera of infants and adults injected with pneumococcal polysaccharide type 6B (Pn6B) conjugated to tetanus toxoid (TT) (Pn6B-TT). Healthy infants were injected with Pn6B-TT; group A was injected at 3, 4, and 6 months of age, and group B was injected at 7 and 9 months of age. A booster injection was given at 18 months. Adults were injected once. Antibodies were measured by enzyme-linked immunosorbent assay and radioimmunoassay, and their functional activities were measured by opsonophagocytosis of radiolabelled pneumococci. In adults, increases in immunoglobulin M (IgM), IgG, IgA, IgG1, and IgG2 to Pn6B were observed. Infants reached adult levels of IgG1 anti-Pn6B after the primary injections. After the booster injection the infant groups had total IgG- and IgM-Pn6B antibody levels similar to those of adults. After the booster injection, IgG1 was the dominant infant anti-Pn6B isotype and at a level higher than in vaccinated adults, but IgA and IgG2 antibodies remained at very low levels. Opsonic activity increased significantly after Pn6B-TT injections; the highest infant sera showed opsonic activity comparable to that of vaccinated adults. Overall, opsonic activity correlated best with total and IgG anti-Pn6B antibodies (r = 0.741, r = 0.653, respectively; n = 35) and was highest in sera with high levels of all Pn6B antibody isotypes. The results indicate the protective potential of a pneumococcal 6B polysaccharide protein conjugate vaccine for young infants.
Collapse
Affiliation(s)
- G Vidarsson
- Departments of Immunology, Reykjavik, Iceland
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Polk HC, Heinzelmann M, Mercer-Jones MA, Malangoni MA, Cheadle WG. Pneumonia in the surgical patient. Curr Probl Surg 1997; 34:117-200. [PMID: 9024178 DOI: 10.1016/s0011-3840(97)80012-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- H C Polk
- Department of Surgery, University of Louisville, Kentucky, USA
| | | | | | | | | |
Collapse
|
19
|
Jankowski S, Rowiński S, Cisowska A, Gamian A. The sensitivity of Hafnia alvei strains to the bactericidal effect of serum. FEMS IMMUNOLOGY AND MEDICAL MICROBIOLOGY 1996; 13:59-64. [PMID: 8821399 DOI: 10.1111/j.1574-695x.1996.tb00216.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Most Hafnia alvei strains are sensitive to the bactericidal action of normal bovine serum (NBS) as well as to a serum in which the alternative pathway of complement activation has been thermally blocked. Introduction of polysaccharides (PS) to NBS lowers the bactericidal effect. In a serum in which the alternative pathway of complement activation is blocked, PS completely cancels the bacterial effect.
Collapse
Affiliation(s)
- S Jankowski
- Department of Microbiology, Academy of Medicine, Wrocław, Poland
| | | | | | | |
Collapse
|
20
|
Morgan BP. Chapter 10 Activation and control of the complement system. Immunobiology 1996. [DOI: 10.1016/s1569-2582(96)80078-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
21
|
Marschang P, Sodroski J, Würzner R, Dierich MP. Decay-accelerating factor (CD55) protects human immunodeficiency virus type 1 from inactivation by human complement. Eur J Immunol 1995; 25:285-90. [PMID: 7531147 DOI: 10.1002/eji.1830250147] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
HIV-1, in contrast to animal retroviruses, is not lysed by human complement, but is readily inactivated by the sera from different animal species. To identify a possible species-specific protection mechanism. HIV-1 was expressed in cells of non-human origin. Recombinant HIV-1 virions that could encode the chloramphenicol acetyltransferase (CAT) protein were produced in African green monkey COS-1 cells, mink cells and, as a control, in human HEp-2 cells and were then used to infect CD4-positive target cells. Analysis of the CAT activity of the target cells revealed that fresh HIV-1-negative human serum reduced the infectivity of HIV-1 derived from monkey and mink cells five- to tenfold, but had no effect on HIV-1 produced in human cells. In addition, human serum efficiently lysed HIV-1 produced in non-human cells in contrast to HIV-1 originating from human cells, suggesting lysis as an important mechanism of virus inactivation. Mammalian cells are protected against lysis by homologous complement by membrane-bound regulatory molecules. Two of these complement inhibitors, namely decay-accelerating factor (DAF) and, to a lesser extent, CD59 were found on the surface of HIV-1 virions by means of a virus capture assay. Antibodies against DAF, but not against other host cell molecules found on the viral surface, efficiently blocked the resistance of HIV-1 produced in human cells to human complement. These results suggest that the acquisition of DAF during the budding process from human cells protects HIV-1 in a species-specific way against the attack of human complement.
Collapse
Affiliation(s)
- P Marschang
- Institut für Hygiene, Leopold-Franzens-Universität, Innsbruck, Austria
| | | | | | | |
Collapse
|
22
|
Moffitt MC, Frank MM. Complement resistance in microbes. SPRINGER SEMINARS IN IMMUNOPATHOLOGY 1994; 15:327-44. [PMID: 8153871 DOI: 10.1007/bf01837364] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- M C Moffitt
- Department of Pediatrics, Duke University Medical Center, Durham, NC 27710
| | | |
Collapse
|
23
|
Fishelson Z. Complement-related proteins in pathogenic organisms. SPRINGER SEMINARS IN IMMUNOPATHOLOGY 1994; 15:345-68. [PMID: 8153872 DOI: 10.1007/bf01837365] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Z Fishelson
- Department of Histology and Cell Biology, Sackler School of Medicine, University of Tel Aviv, Israel
| |
Collapse
|
24
|
Bakács T, Lutz HU, Tusnády G, Varga L, Merry AH, Sim RR. An indirect effect of an antibody on complement deposition and lysis of differently sensitized surrounding cells. Mol Immunol 1994; 31:901-11. [PMID: 8065373 DOI: 10.1016/0161-5890(94)90010-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Lysis of papain-treated group A and B erythrocytes by human complement was studied by an anti-A (BRIC. 131) and an anti-B (BRIC. 30) IgM monoclonal antibody in 51Cr release assays. The indirect effect of membrane-bound antibody, i.e. its influence on complement binding to sensitized surrounding cells, was examined in a cold target competition test in which sensitized, non-labelled cells are present along with sensitized labelled cells and complement. The mode by which anti-A antibodies indirectly suppressed lysis of sensitized B cells up to 20-fold was studied by following C1q and C3b binding. C1q binding to both types of erythrocytes was not altered in mixed populations of erythrocytes in the presence of both antibodies. Binding of C3b to a mixture of both cell types was, however, suppressed, when both antibodies were present. C3b deposition in mixed cell populations did not reach a significantly higher extent than deposited to one type of erythrocyte alone. This was consistent with the results from competitive lysis and suggests that the anti-A captured most C3b at high anti-A concentrations and deprived the similarly sensitized B erythrocytes of complement. We think that this phenomenon is not due to an uneven removal of complement regulatory proteins from A and B erythrocytes by papain. Instead, the phenomenon might be due to an inherent property of anti-A mAb to better produce nucleation sites for C3 convertases which, upon binding factor B, better compete for the limiting factor D. A mathematical analysis of cold target competition experiment (containing 2430 individual measurements) also shows that the distribution of complement between the competing A and B erythrocyte population is uneven, since it predicts that in any given antibody combination the majority of complement is bound to A erythrocytes. This is consistent with the measured average percentage of lysis.
Collapse
Affiliation(s)
- T Bakács
- Department of Immunology, National Institute of Oncology, Budapest, Hungary
| | | | | | | | | | | |
Collapse
|
25
|
van Dam GJ, Seino J, Rotmans JP, Daha MR, Deelder AM. Schistosoma mansoni circulating anodic antigen but not circulating cathodic antigen interacts with complement component C1q. Eur J Immunol 1993; 23:2807-12. [PMID: 8223856 DOI: 10.1002/eji.1830231113] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Adult schistosome parasites, living in the blood vessels of their mammalian hosts, protect themselves against immune damage in a variety of ways. In addition to the tegument, the intestinal epithelium of the blood-feeding worms is permanently exposed to both the innate and the acquired immune system. In this study, we investigated whether the Schistosoma gut-associated antigens CAA and CCA (circulating anodic antigen and circulating cathodic antigen, respectively), which are excreted in relatively large quantities into the host's circulation, might play a role in evading complement attack. Of several complement components tested, only purified C1q showed significant binding to CAA, a negatively charged highly glycosylated glycoprotein. CCA, also highly glycosylated, but neutral or slightly positively charged, did not bind to C1q. CAA bound only to the collagen-like stalks of C1q and not to the globular heads. No detectable interaction of CAA with precursor human C1 was found and CAA did not induce activation of C1 in whole human serum as assessed by consumption of hemolytic C4 activity. Also CAA could not induce activation of precursor C1 in vitro. These results suggest that CAA behaves like a receptor for C1q, and might be involved in protecting the vulnerable schistosome gut against complement-mediated attack.
Collapse
Affiliation(s)
- G J van Dam
- Laboratory of Parasitology, University of Leiden, The Netherlands
| | | | | | | | | |
Collapse
|
26
|
Abstract
The susceptibility of complement-deficient individuals to various severe infections, and studies of the effector mechanisms involved in the destruction of infectious agents, demonstrate the importance of complement in providing an effective host defense system. It is also becoming increasingly apparent that complement not only plays a role in 'natural' defenses against infection and in enhancing the antibody-mediated effector mechanisms, but also influences adaptive immune responses directly.
Collapse
Affiliation(s)
- S Tomlinson
- Department of Pathology, New York University Medical Center, New York 10016
| |
Collapse
|