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Arnold JN, Mitchell DA. Tinker, tailor, soldier, cell: the role of C-type lectins in the defense and promotion of disease. Protein Cell 2022; 14:4-16. [PMID: 36726757 PMCID: PMC9871964 DOI: 10.1093/procel/pwac012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 04/25/2022] [Indexed: 02/04/2023] Open
Abstract
C-type lectins (CTLs) represent a large family of soluble and membrane-bound proteins which bind calcium dependently via carbohydrate recognition domains (CRDs) to glycan residues presented on the surface of a variety of pathogens. The deconvolution of a cell's glycan code by CTLs underpins several important physiological processes in mammals such as pathogen neutralization and opsonization, leukocyte trafficking, and the inflammatory response. However, as our knowledge of CTLs has developed it has become apparent that the role of this innate immune family of proteins can be double-edged, where some pathogens have developed approaches to subvert and exploit CTL interactions to promote infection and sustain the pathological state. Equally, CTL interactions with host glycoproteins can contribute to inflammatory diseases such as arthritis and cancer whereby, in certain contexts, they exacerbate inflammation and drive malignant progression. This review discusses the 'dual agent' roles of some of the major mammalian CTLs in both resolving and promoting infection, inflammation and inflammatory disease and highlights opportunities and emerging approaches for their therapeutic modulation.
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2
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Ovsyannikova IG, Haralambieva IH, Crooke SN, Poland GA, Kennedy RB. The role of host genetics in the immune response to SARS-CoV-2 and COVID-19 susceptibility and severity. Immunol Rev 2020; 296:205-219. [PMID: 32658335 PMCID: PMC7404857 DOI: 10.1111/imr.12897] [Citation(s) in RCA: 149] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 06/14/2020] [Indexed: 01/08/2023]
Abstract
This article provides a review of studies evaluating the role of host (and viral) genetics (including variation in HLA genes) in the immune response to coronaviruses, as well as the clinical outcome of coronavirus-mediated disease. The initial sections focus on seasonal coronaviruses, SARS-CoV, and MERS-CoV. We then examine the state of the knowledge regarding genetic polymorphisms and SARS-CoV-2 and COVID-19. The article concludes by discussing research areas with current knowledge gaps and proposes several avenues for future scientific exploration in order to develop new insights into the immunology of SARS-CoV-2.
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Koelman DLH, Brouwer MC, van de Beek D. Targeting the complement system in bacterial meningitis. Brain 2020; 142:3325-3337. [PMID: 31373605 PMCID: PMC6821383 DOI: 10.1093/brain/awz222] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 05/15/2019] [Accepted: 05/24/2019] [Indexed: 12/12/2022] Open
Abstract
Bacterial meningitis is most commonly caused by Streptococcus pneumoniae and Neisseria meningitidis and continues to pose a major public health threat. Morbidity and mortality of meningitis are driven by an uncontrolled host inflammatory response. This comprehensive update evaluates the role of the complement system in upregulating and maintaining the inflammatory response in bacterial meningitis. Genetic variation studies, complement level measurements in blood and CSF, and experimental work have together led to the identification of anaphylatoxin C5a as a promising treatment target in bacterial meningitis. In animals and patients with pneumococcal meningitis, the accumulation of neutrophils in the CSF was mainly driven by C5-derived chemotactic activity and correlated positively with disease severity and outcome. In murine pneumococcal meningitis, adjunctive treatment with C5 antibodies prevented brain damage and death. Several recently developed therapeutics target C5 conversion, C5a, or its receptor C5aR. Caution is warranted because treatment with C5 antibodies such as eculizumab also inhibits the formation of the membrane attack complex, which may result in decreased meningococcal killing and increased meningococcal disease susceptibility. The use of C5a or C5aR antagonists to specifically target the harmful anaphylatoxins-induced effects, therefore, are most promising and present opportunities for a phase 2 clinical trial.
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Affiliation(s)
- Diederik L H Koelman
- Amsterdam UMC, University of Amsterdam, Department of Neurology, Amsterdam Neuroscience, Meibergdreef 9, AZ, Amsterdam, The Netherlands
| | - Matthijs C Brouwer
- Amsterdam UMC, University of Amsterdam, Department of Neurology, Amsterdam Neuroscience, Meibergdreef 9, AZ, Amsterdam, The Netherlands
| | - Diederik van de Beek
- Amsterdam UMC, University of Amsterdam, Department of Neurology, Amsterdam Neuroscience, Meibergdreef 9, AZ, Amsterdam, The Netherlands
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4
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Hodeib S, Herberg JA, Levin M, Sancho-Shimizu V. Human genetics of meningococcal infections. Hum Genet 2020; 139:961-980. [PMID: 32067109 PMCID: PMC7272491 DOI: 10.1007/s00439-020-02128-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 02/02/2020] [Indexed: 02/07/2023]
Abstract
Neisseria meningitidis is a leading cause of bacterial septicaemia and meningitis worldwide. Meningococcal disease is rare but can be life threatening with a tendency to affect children. Many studies have investigated the role of human genetics in predisposition to N. meningitidis infection. These have identified both rare single-gene mutations as well as more common polymorphisms associated with meningococcal disease susceptibility and severity. These findings provide clues to the pathogenesis of N. meningitidis, the basis of host susceptibility to infection and to the aetiology of severe disease. From the multiple discoveries of monogenic complement deficiencies to the associations of complement factor H and complement factor H-related three polymorphisms to meningococcal disease, the complement pathway is highlighted as being central to the genetic control of meningococcal disease. This review aims to summarise the current understanding of the host genetic basis of meningococcal disease with respect to the different stages of meningococcal infection.
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Affiliation(s)
- Stephanie Hodeib
- Department of Paediatric Infectious Disease, Faculty of Medicine, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - Jethro A Herberg
- Department of Paediatric Infectious Disease, Faculty of Medicine, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - Michael Levin
- Department of Paediatric Infectious Disease, Faculty of Medicine, Imperial College London, Norfolk Place, London, W2 1PG, UK
| | - Vanessa Sancho-Shimizu
- Department of Paediatric Infectious Disease, Faculty of Medicine, Imperial College London, Norfolk Place, London, W2 1PG, UK.
- Department of Virology, Faculty of Medicine, Imperial College London, Norfolk Place, London, W2 1PG, UK.
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5
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Schröder-Braunstein J, Kirschfink M. Complement deficiencies and dysregulation: Pathophysiological consequences, modern analysis, and clinical management. Mol Immunol 2019; 114:299-311. [PMID: 31421540 DOI: 10.1016/j.molimm.2019.08.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 07/31/2019] [Accepted: 08/03/2019] [Indexed: 02/07/2023]
Abstract
Complement defects are associated with an enhanced risk of a broad spectrum of infectious as well as systemic or local inflammatory and thrombotic disorders. Inherited complement deficiencies have been described for virtually all complement components but can be mimicked by autoantibodies, interfering with the activity of specific complement components, convertases or regulators. While being rare, diseases related to complement deficiencies are often severe with a frequent but not exclusive manifestation during childhood. Whereas defects of early components of the classical pathway significantly increase the risk of autoimmune disorders, lack of components of the terminal pathway as well as of properdin are associated with an enhanced susceptibility to meningococcal infections. The impaired synthesis or function of C1 inhibitor results in the development of hereditary angioedema (HAE). Furthermore, complement dysregulation causes renal disorders such as atypical hemolytic uremic syndrome (aHUS) or C3 glomerulopathy (C3G) but also age-related macular degeneration (AMD). While paroxysmal nocturnal hemoglobinuria (PNH) results from the combined deficiency of the regulatory complement proteins CD55 and CD59, which is caused by somatic mutation of a common membrane anchor, isolated CD55 or CD59 deficiency is associated with the CHAPLE syndrome and polyneuropathy, respectively. Here, we provide an overview on clinical disorders related to complement deficiencies or dysregulation and describe diagnostic strategies required for their comprehensive molecular characterization - a prerequisite for informed decisions on the therapeutic management of these disorders.
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Affiliation(s)
- Jutta Schröder-Braunstein
- University of Heidelberg, Institute of Immunology, Im Neuenheimer Feld 305, 69120 Heidelberg, Germany
| | - Michael Kirschfink
- University of Heidelberg, Institute of Immunology, Im Neuenheimer Feld 305, 69120 Heidelberg, Germany.
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Gowin E, Świątek-Kościelna B, Kałużna E, Strauss E, Wysocki J, Nowak J, Michalak M, Januszkiewicz-Lewandowska D. How many single-nucleotide polymorphisms (SNPs) must be tested in order to prove susceptibility to bacterial meningitis in children? Analysis of 11 SNPs in seven genes involved in the immune response and their effect on the susceptibility to bacterial meningitis in children. Innate Immun 2018. [PMID: 29534633 PMCID: PMC6852385 DOI: 10.1177/1753425918762038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The aim of this study is to describe the prevalence of single single-nucleotide
polymorphisms (SNPs) as well as their combinations in genes encoding proteins
involved in the immune response in children with bacterial meningitis. The
prospective study group consisted of 39 children with bacterial meningitis and
49 family members surveyed between 2012 and 2016. Eleven SNPs in seven genes
involved in immune response were analysed. The mean number of minor frequency
alleles (MAF) of studied SNPs was lowest in the control group and highest in
patients with pneumococcal meningitis. We found that carrying ≥6 MAF of studied
SNPs was associated with an increased risk of pneumococcal meningitis. The
prevalence of risky variants was noted to be higher in patients with
pneumococcal meningitis as compared to the control group. In conclusion, genetic
factors are a relevant factor in determining the susceptibility to bacterial
meningitis. A statistically significant cumulative effect of mutated variants on
increasing the risk of bacterial meningitis was detected. Combining all three
SNPs in MBL2 improves the prediction of susceptibility to
pneumococcal meningitis. Analysis of risky alleles can help indicate people
prone to the disease who are ‘gene-immunocompromised’.
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Affiliation(s)
- Ewelina Gowin
- 1 Department of Family Medicine, Poznan University of Medical Sciences, Poland
| | | | - Ewelina Kałużna
- 2 Institute of Human Genetics, Polish Academy of Sciences, Poznan Poland
| | - Ewa Strauss
- 2 Institute of Human Genetics, Polish Academy of Sciences, Poznan Poland
| | - Jacek Wysocki
- 3 Department of Health Promotion, Poznan University of Medical Sciences, Poland
| | - Jerzy Nowak
- 2 Institute of Human Genetics, Polish Academy of Sciences, Poznan Poland
| | - Michał Michalak
- 4 Department of Biostatistics, Poznan University of Medical Sciences, Poland
| | - Danuta Januszkiewicz-Lewandowska
- 2 Institute of Human Genetics, Polish Academy of Sciences, Poznan Poland.,5 Department of Oncology, Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences, Poland
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Alsalahy MM, Almehy GF, Hendy RM, Mohammad RS, Mohammad YM. Mannose binding lectin in patients with pulmonary tuberculosis: Active and inactive. EGYPTIAN JOURNAL OF CHEST DISEASES AND TUBERCULOSIS 2017. [DOI: 10.1016/j.ejcdt.2016.12.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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8
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Johswich K. Innate immune recognition and inflammation in Neisseria meningitidis infection. Pathog Dis 2017; 75:3059204. [PMID: 28334203 DOI: 10.1093/femspd/ftx022] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 02/23/2017] [Indexed: 01/01/2023] Open
Abstract
Neisseria meningitidis (Nme) can cause meningitis and sepsis, diseases which are characterised by an overwhelming inflammatory response. Inflammation is triggered by host pattern recognition receptors (PRRs) which are activated by pathogen-associated molecular patterns (PAMPs). Nme contains multiple PAMPs including lipooligosaccharide, peptidoglycan, proteins and metabolites. Various classes of PRRs including Toll-like receptors, NOD-like receptors, C-type lectins, scavenger receptors, pentraxins and others are expressed by the host to respond to any given microbe. While Toll-like receptors and NOD-like receptors are pivotal in triggering inflammation, other PRRs act as modulators of inflammation or aid in functional antimicrobial responses such as phagocytosis or complement activation. This review aims to give an overview of the various Nme PAMPs reported to date, the PRRs they activate and their implications during the inflammatory response to infection.
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Abstract
BACKGROUND Bacterial meningitis is a significant burden of disease and mortality in all age groups worldwide despite the development of effective conjugated vaccines. The pathogenesis of bacterial meningitis is based on complex and incompletely understood host-pathogen interactions. Some of these are pathogen-specific, while some are shared between different bacteria. METHODS We searched the database PubMed to identify host risk factors for bacterial meningitis caused by the pathogens Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae type b, because they are three most common causative bacteria beyond the neonatal period. RESULTS We describe a number of risk factors; including socioeconomic factors, age, genetic variation of the host and underlying medical conditions associated with increased susceptibility to invasive bacterial infections in both children and adults. CONCLUSIONS As conjugated vaccines are available for these infections, it is of utmost importance to identify high risk patients to be able to prevent invasive disease.
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Affiliation(s)
- Lene Fogt Lundbo
- a Department of Infectious Diseases , Copenhagen University Hospital , Hvidovre , Denmark.,b Clinical Research Centre , Copenhagen University Hospital , Hvidovre , Denmark.,c Faculty of Health and Medical Sciences , University of Copenhagen , København , Denmark
| | - Thomas Benfield
- a Department of Infectious Diseases , Copenhagen University Hospital , Hvidovre , Denmark.,b Clinical Research Centre , Copenhagen University Hospital , Hvidovre , Denmark.,c Faculty of Health and Medical Sciences , University of Copenhagen , København , Denmark
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10
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A Case-Control Study on the Risk Factors for Meningococcal Disease among Children in Greece. PLoS One 2016; 11:e0158524. [PMID: 27351742 PMCID: PMC4924850 DOI: 10.1371/journal.pone.0158524] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 06/16/2016] [Indexed: 11/19/2022] Open
Abstract
Purpose The aim of this study was to identify environmental or genetic risk factors that are associated with invasive meningococcal disease (IMD) in children in Greece. Methods A case-control study was performed in 133 children (44 cases and 89 controls) aged between 0–14 years, who were hospitalized in a children's hospital in Athens. Demographics and possible risk factors were collected by the use of a structured questionnaire. To investigate the association of mannose binding lectin (MBL) with IMD, a frequency analysis of the haplotypes of the MBL2 gene and quantitative measurement of MBL serum protein levels were performed using Nanogen NanoChipR 400 technology and immuno-enzyme techniques, respectively. Results The multivariate analysis revealed that changes in a child's life setting (relocation or vacation, OR = 7.16), paternal smoking (OR = 4.51), upper respiratory tract infection within the previous month (OR = 3.04) and the density of people in the house/100m2 (OR = 3.16), were independent risk factors associated with IMD. Overall 18.8% of patients had a MBL2 genotype with low functionality compared to 10.1% of healthy controls, but this was not statistically significant (p = 0.189). Conclusion Prevention strategies aimed at reducing parental smoking and other risk factors identified in this study could decrease the risk of IMD among children in Greece.
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11
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Lundbo LF, Sørensen HT, Clausen LN, Hollegaard MV, Hougaard DM, Konradsen HB, Harboe ZB, Nørgaard M, Benfield T. Mannose-Binding Lectin Gene, MBL2, Polymorphisms Do Not Increase Susceptibility to Invasive Meningococcal Disease in a Population of Danish Children. Open Forum Infect Dis 2015; 2:ofv127. [PMID: 26464842 PMCID: PMC4602025 DOI: 10.1093/ofid/ofv127] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 08/27/2015] [Indexed: 01/17/2023] Open
Abstract
Background. Neisseria meningitidis is the cause of meningococcal bacteremia and meningitis, and nasopharyngeal colonization with this pathogen is common. The incidence of invasive disease is highest in infants, whereas adolescents more often are carriers. Altered regulation or dysfunction of the innate immune system may predispose to invasive meningococcal disease (IMD). In this study, we investigated the effect of genetic variation in the mannose-binding lectin gene, MBL2, and its promoter on susceptibility to IMD and IMD-associated mortality among children. Methods. Children (<5 years) diagnosed during 1982-2007 with IMD and controls were identified through Danish national registries. DNA was obtained from the Danish Neonatal Screening Biobank. The associations between MBL2 diplotypes and IMD susceptibility and 30- and 90-day mortality were investigated using logistic regression analysis. Results. We included 1351 children: 406 with meningitis, 272 with bacteremia, and 673 age- and sex-matched controls. Of the children studied, 1292 (96%) were successfully genotyped and assigned MBL2 diplotypes. The median age in IMD cases was 19.1 months (interquartile range [IQR], 8.8-32.2 months). Children with defective MBL2 diplotypes were not at higher risk for meningococcal meningitis than children with intermediate and normal diplotypes (odds ratio [OR] = 0.69; 95% confidence interval [CI], .47-1.02). Similar results were found for children with bacteremia and defective diplotypes (OR = 0.84; 95% CI, .53-1.32) as well as for all cases (OR = 0.75; 95% CI, .56-1.01). There was no association between MBL2 diplotypes and mortality. Conclusions. Defective MBL2 diplotypes did not predict either an increased IMD susceptibility or mortality in a Danish population of children.
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Affiliation(s)
- Lene F Lundbo
- Department of Infectious Diseases ; Clinical Research Centre , Hvidovre Hospital ; Faculty of Health Sciences , University of Copenhagen
| | | | | | - Mads V Hollegaard
- Danish Centre for Neonatal Screening, Department for Congenital Disorders
| | - David M Hougaard
- Danish Centre for Neonatal Screening, Department for Congenital Disorders
| | | | - Zitta Barrella Harboe
- Department of Microbiological Surveillance and Research , Statens Serum Institut , Copenhagen ; Department for Pulmonary and Infectious Diseases , North Zealand Hospital Hillerød , Denmark
| | - Mette Nørgaard
- Department of Clinical Epidemiology , Aarhus University Hospital
| | - Thomas Benfield
- Department of Infectious Diseases ; Clinical Research Centre , Hvidovre Hospital ; Faculty of Health Sciences , University of Copenhagen
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12
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Darton T, Jack D, Johnson M, Borrow R, Guiver M, Kaczmarski E, Turner M, Klein N, Read R. MBL2 deficiency is associated with higher genomic bacterial loads during meningococcemia in young children. Clin Microbiol Infect 2014; 20:1337-42. [DOI: 10.1111/1469-0691.12745] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 06/12/2014] [Accepted: 06/26/2014] [Indexed: 11/30/2022]
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13
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Keizer MP, Wouters D, Schlapbach LJ, Kuijpers TW. Restoration of MBL-deficiency: redefining the safety, efficacy and viability of MBL-substitution therapy. Mol Immunol 2014; 61:174-84. [PMID: 25044097 DOI: 10.1016/j.molimm.2014.06.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 05/30/2014] [Accepted: 06/03/2014] [Indexed: 12/28/2022]
Abstract
MBL-deficiency is a commonly occurring deficiency of the innate immune system, affecting a substantial part of the population and has been extensively studied. MBL appears to function as a disease modifier. The role of MBL in different conditions is context-dependent. Many clinical studies show conflicting results, which can be partially explained by different definitions of MBL-deficiency, including phenotype- and genotype-based approaches. In this review we give an overview of literature of MBL, its role in different pathologies, diseases and patient populations. We review MBL replacement studies, and discuss the potential of MBL substitution therapy. We finally suggest that new MBL substitution trials should be conducted within a predefined patient population. MBL-deficiency should be based on serum levels and confirmed by genotyping.
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Affiliation(s)
- M P Keizer
- Department of Immunopathology, Sanquin Blood Supply, Division Research and Landsteiner Laboratory of the Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Department of Pediatric Hematology, Immunology & Infectious Diseases, Emma Children's Hospital, AMC, University of Amsterdam, Amsterdam, The Netherlands.
| | - D Wouters
- Department of Immunopathology, Sanquin Blood Supply, Division Research and Landsteiner Laboratory of the Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - L J Schlapbach
- Paediatric Critical Care Research Group, Mater Research, University of Queensland, Brisbane, Australia
| | - T W Kuijpers
- Department of Pediatric Hematology, Immunology & Infectious Diseases, Emma Children's Hospital, AMC, University of Amsterdam, Amsterdam, The Netherlands; Department of Blood Cell Research, Sanquin Blood Supply, Division Research and Landsteiner Laboratory of the AMC, University of Amsterdam, Amsterdam, The Netherlands
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14
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Ballegaard V, Haugaard AK, Garred P, Nielsen SD, Munthe-Fog L. The lectin pathway of complement: advantage or disadvantage in HIV pathogenesis? Clin Immunol 2014; 154:13-25. [PMID: 24928325 DOI: 10.1016/j.clim.2014.06.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 06/01/2014] [Accepted: 06/02/2014] [Indexed: 02/02/2023]
Abstract
The pattern recognition molecules of the lectin complement pathway are important components of the innate immune system with known functions in host-virus interactions. This paper summarizes current knowledge of how these intriguing molecules, including mannose-binding lectin (MBL), Ficolin-1, -2 and -3, and collectin-11 (CL-11) may influence HIV-pathogenesis. It has been demonstrated that MBL is capable of binding and neutralizing HIV and may affect host susceptibility to HIV infection and disease progression. In addition, MBL may cause variations in the host immune response against HIV. Ficolin-1, -2 and -3 and CL-11 could have similar functions in HIV infection as the ficolins have been shown to play a role in other viral infections, and CL-11 resembles MBL and the ficolins in structure and binding capacity.
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Affiliation(s)
- V Ballegaard
- Viro-Immunology, Department of Infectious Diseases, Rigshospitalet (Copenhagen University Hospital), Denmark
| | - A K Haugaard
- Viro-Immunology, Department of Infectious Diseases, Rigshospitalet (Copenhagen University Hospital), Denmark
| | - P Garred
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet (Copenhagen University Hospital), Denmark
| | - S D Nielsen
- Viro-Immunology, Department of Infectious Diseases, Rigshospitalet (Copenhagen University Hospital), Denmark.
| | - L Munthe-Fog
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Section 7631, Rigshospitalet (Copenhagen University Hospital), Denmark
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15
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Abstract
Despite considerable advances in the understanding of the pathogenesis of meningococcal disease, this infection remains a major cause of morbidity and mortality globally. The role of the complement system in innate immune defenses against invasive meningococcal disease is well established. Individuals deficient in components of the alternative and terminal complement pathways are highly predisposed to invasive, often recurrent meningococcal infections. Genome-wide analysis studies also point to a central role for complement in disease pathogenesis. Here we review the pathophysiologic events pertinent to the complement system that accompany meningococcal sepsis in humans. Meningococci use several often redundant mechanisms to evade killing by human complement. Capsular polysaccharide and lipooligosaccharide glycan composition play critical roles in complement evasion. Some of the newly described protein vaccine antigens interact with complement components and have sparked considerable research interest.
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Affiliation(s)
- Lisa A Lewis
- Division of Infectious Diseases and Immunology; University of Massachusetts Medical School; Worcester, MA USA
| | - Sanjay Ram
- Division of Infectious Diseases and Immunology; University of Massachusetts Medical School; Worcester, MA USA
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16
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Dale AP, Read RC. Genetic susceptibility to meningococcal infection. Expert Rev Anti Infect Ther 2013; 11:187-99. [PMID: 23409824 DOI: 10.1586/eri.12.161] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Meningococcal disease is caused by a limited range of clonal complexes of Neisseria meningitidis. The disease occurs in people who lack bactericidal antibodies to this pathogen, and therefore the patients are reliant on innate immunity or components of acquired immunity other than bactericidal antibodies. Gene variants that influence the function of innate and acquired immune response components have been associated with altered host susceptibility to meningococcal disease, and some genetic factors have also been associated with more severe disease. Identification of genetic factors associated with meningococcal disease will enhance our understanding of this rare but dangerous condition which causes death and serious morbidity in young, previously fit individuals. Genetic variations in the gene cluster encoding IL-1 and in key genes including TNF, SP-A2 and CFH have been associated with susceptibility to meningococcal disease. Understanding the mechanisms underlying genetic susceptibility to meningococcal disease will permit the development of novel therapeutic measures for the treatment of Gram-negative sepsis. To enable the discovery of new mechanisms of the disease, future research will move away from small-scale association studies and instead include analysis of large patient cohorts with accurately linked clinical and demographic information.
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Affiliation(s)
- Adam P Dale
- Department of Infection & Immunity, University of Sheffield, Medical School, Beech Hill Road, Sheffield, South Yorkshire, S10 2RX, UK.
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17
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van Well GTJ, Sanders MS, Ouburg S, van Furth AM, Morré SA. Polymorphisms in Toll-like receptors 2, 4, and 9 are highly associated with hearing loss in survivors of bacterial meningitis. PLoS One 2012; 7:e35837. [PMID: 22662111 PMCID: PMC3360733 DOI: 10.1371/journal.pone.0035837] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Accepted: 03/23/2012] [Indexed: 12/20/2022] Open
Abstract
Genetic variation in innate immune response genes contributes to inter-individual differences in disease manifestation and degree of complications upon infection. We recently described an association of single nucleotide polymorphisms (SNPs) in TLR9 with susceptibility to meningococcal meningitis (MM). In this study, we investigate the association of SNPs in multiple pathogen recognition and immune response genes with clinical features that determine severity and outcome (especially hearing loss) of childhood MM and pneumococcal meningitis (PM). Eleven SNPs in seven genes (TLR2, TLR4, TLR9, NOD1, NOD2, CASP1, and TRAIL) were genotyped in 393 survivors of childhood bacterial meningitis (BM) (327 MM patients and 66 PM patients). Genotype distributions of single SNPs and combination of SNPs were compared between thirteen clinical characteristics associated with severity of BM. After correction for multiple testing, TLR4+896 mutant alleles were highly associated with post-meningitis hearing loss, especially MM (p= 0.001, OR 4.0 for BM, p= 0.0004, OR 6.2 for MM). In a multigene analysis, combined carriership of the TLR2+2477 wild type (WT) with TLR4+896 mutant alleles increases the risk of hearing loss (p<0.0001, OR 5.7 in BM and p= 0.0001, OR 7.6 in MM). Carriage of one or both mutant alleles in TLR4+896 and TLR9 -1237 increases the risk for hearing loss (p = 0.0006, OR 4.1 in BM). SNPs in immune response genes contribute to differences in clinical severity and outcome of BM. The TLR system seems to play an important role in the immune response to BM and subsequent neuronal damage as well as in cochlear inflammation. Genetic markers may be used for identification of high-risk patients by creating prediction rules for post-meningitis hearing loss and other sequelae, and provide more insight in the complex immune response in the CNS possibly resulting in new therapeutic interventions.
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Affiliation(s)
- Gijs Th J. van Well
- Department of Pediatric Infectious Diseases, Immunology and Rheumatology, VU University Medical Center, Amsterdam, The Netherlands
- Department of Pediatrics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Marieke S. Sanders
- Department of Pediatric Infectious Diseases, Immunology and Rheumatology, VU University Medical Center, Amsterdam, The Netherlands
- Laboratory of Immunogenetics, Department of Medical Microbiology, VU University Medical Center, Amsterdam, The Netherlands
- Department of Surgery, Antonius Hospital, Nieuwegein, The Netherlands
| | - Sander Ouburg
- Laboratory of Immunogenetics, Department of Medical Microbiology, VU University Medical Center, Amsterdam, The Netherlands
| | - A. Marceline van Furth
- Department of Pediatric Infectious Diseases, Immunology and Rheumatology, VU University Medical Center, Amsterdam, The Netherlands
| | - Servaas A. Morré
- Laboratory of Immunogenetics, Department of Medical Microbiology, VU University Medical Center, Amsterdam, The Netherlands
- Institute of Public Health Genomics, Department of Genetics and Cell Biology, Research Institutes CAPHRI (School for Public Health and Primary Care) and GROW (School for Oncology & Developmental Biology), Faculty of Health, Medicine & Life Sciences, University of Maastricht, Maastricht, The Netherlands
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18
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Helminen M, Seitsonen S, Jarva H, Meri S, Järvelä IE. A novel mutation W388X underlying properdin deficiency in a Finnish family. Scand J Immunol 2012; 75:445-8. [PMID: 22229731 DOI: 10.1111/j.1365-3083.2012.02674.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Properdin deficiency is a rare immunological disorder inherited as an X-chromosomal recessive trait. Properdin deficiency poses a significant risk for severe meningococcal infections. About 20 mutations have been reported to underlie properdin deficiency. Here we report a large Finnish family with a novel mutation in the properdin gene (CFP). Based on the total absence of properdin activity in a 14-year-old male patient with an infection resembling meningococcal bacteraemia, the coding region and splice sites of the gene were sequenced. The mutation is located in exon 9 and changes guanine to adenine at nucleotide 1164 (c.1164G>A) that causes tryptophan to change to a premature stop codon (W388X). The mother of the patient was shown to be a carrier of the mutation. In total, the mutation was identified in six females and three young males in the family. The mutation must be inherited from the grandfather who had died of an unknown infectious disease. This is the first mutation of the properdin gene identified in Finland.
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Affiliation(s)
- M Helminen
- Department of Pediatrics, Tampere University Hospital, University of Tampere, Tampere, Finland.
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19
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Takahashi K. Mannose-binding lectin and the balance between immune protection and complication. Expert Rev Anti Infect Ther 2012; 9:1179-90. [PMID: 22114968 DOI: 10.1586/eri.11.136] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The innate immune system is evolutionarily ancient and biologically primitive. Historically, it was first identified as an element of the immune system that provides the first-line response to pathogens, and increasingly it is recognized for its central housekeeping role and its essential functions in tissue homeostasis, including coagulation and inflammation, among others. A pivotal link between the innate immune system and other functions is mannose-binding lectin (MBL), a pattern recognition molecule. Multiple studies have demonstrated that MBL deficiency increases susceptibility to infection, and the mechanisms associated with this susceptibility to infection include reduced opsonophagocytic killing and reduced activation of the lectin complement pathway. Results from our laboratory have demonstrated that MBL and MBL-associated serine protease (MASP)-1/3 together mediate coagulation factor-like activities, including thrombin-like activity. MBL and/or MASP-1/3-deficient hosts demonstrate in vivo evidence that MBL and MASP-1/3 are involved with hemostasis following injury. Staphylococcus aureus-infected MBL null mice developed disseminated intravascular coagulation, which was associated with elevated blood IL-6 levels (but not TNF-α) and systemic inflammatory responses. Infected MBL null mice also develop liver injury. These findings suggest that MBL deficiency may manifest as disseminated intravascular coagulation and organ failure with infection. Beginning from these observations, this review focuses on the interaction of innate immunity and other homeostatic systems, the derangement of which may lead to complications in infection and other inflammatory states.
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Affiliation(s)
- Kazue Takahashi
- Department of Pediatrics, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, GRJ1402, Boston, MA 02114, USA.
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20
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Mannose-binding lectin binds to amyloid β protein and modulates inflammation. J Biomed Biotechnol 2012; 2012:929803. [PMID: 22536027 PMCID: PMC3322523 DOI: 10.1155/2012/929803] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 11/26/2011] [Accepted: 12/04/2011] [Indexed: 01/20/2023] Open
Abstract
Mannose-binding lectin (MBL), a soluble factor of the innate immune system, is a pattern recognition molecule with a number of known ligands, including viruses, bacteria, and molecules from abnormal self tissues. In addition to its role in immunity, MBL also functions in the maintenance of tissue homeostasis. We present evidence here that MBL binds to amyloid β peptides. MBL binding to other known carbohydrate ligands is calcium-dependent and has been attributed to the carbohydrate-recognition domain, a common feature of other C-type lectins. In contrast, we find that the features of MBL binding to Aβ are more similar to the reported binding characteristics of the cysteine-rich domain of the unrelated mannose receptor and therefore may involve the MBL cysteine-rich domain. Differences in MBL ligand binding may contribute to modulation of inflammatory response and may correlate with the function of MBL in processes such as coagulation and tissue homeostasis.
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21
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Judelsohn R, Marshall GS. The Burden of Infant Meningococcal Disease in the United States. J Pediatric Infect Dis Soc 2012; 1:64-73. [PMID: 23687573 PMCID: PMC3656548 DOI: 10.1093/jpids/pir003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 12/20/2011] [Indexed: 11/18/2022]
Affiliation(s)
- R Judelsohn
- School of Medicine, State University of New York at Buffalo
| | - G S Marshall
- Division of Pediatric Infectious Diseases, University of Louisville School of Medicine, Kentucky
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22
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Bradley DT, Bourke TW, Fairley DJ, Borrow R, Shields MD, Young IS, Zipfel PF, Hughes AE. Genetic susceptibility to invasive meningococcal disease: MBL2 structural polymorphisms revisited in a large case-control study and a systematic review. Int J Immunogenet 2012; 39:328-37. [PMID: 22296677 DOI: 10.1111/j.1744-313x.2012.01095.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Invasive infection caused by Neisseria meningitidis is a worldwide public health problem. Previous reports have indicated that carriage of common 'defective' structural polymorphisms of the host mannose-binding lectin gene (MBL2) greatly increases an individual's risk of developing the disease. We report the largest case-control study so far to investigate the effect of these polymorphisms in meningococcal disease (296 PCR-positive cases and 5196 population controls, all of European ancestry) and demonstrate that no change in risk is associated with the polymorphisms overall or in any age-defined subgroup. This finding contrasts with two smaller studies that reported an increase in risk. A systematic review of all studies of MBL2 polymorphisms in people of European ancestry published since 1999, including 24,693 individuals, revealed a population frequency of the combined 'defective'MBL2 allele of 0.230 (95% confidence limits: 0.226-0.234). The past reported associations of increased risk of meningococcal disease were because of low 'defective' allele frequencies in their study control populations (0.13 and 0.04) that indicate systematic problems with the studies. The data from our study and all other available evidence indicate that MBL2 structural polymorphisms do not predispose children or adults to invasive meningococcal disease.
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Affiliation(s)
- D T Bradley
- Centre for Public Health, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, UK.
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23
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Ermini L, Wilson IJ, Goodship THJ, Sheerin NS. Complement polymorphisms: geographical distribution and relevance to disease. Immunobiology 2011; 217:265-71. [PMID: 21899915 DOI: 10.1016/j.imbio.2011.07.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2011] [Revised: 06/20/2011] [Accepted: 07/18/2011] [Indexed: 10/17/2022]
Abstract
The evolution of man has been characterised by recurrent episodes of migration and settlement with infectious disease a constant threat. This long history of demographic change, together with the action of evolutionary forces such as natural selection and genetic drift, has shaped human genetic diversity. In particular, the interaction between humans, pathogens and the environment has played a crucial role in generating patterns of human genetic variation. The complement system plays a crucial role in the early protective immune response after exposure to a pathogen. Pathogens, over time, have developed mechanisms to circumvent the effects of complement which in turn has led to development of a more complex complement system. During the evolution of the complement system genes coding complement proteins have evolved polymorphisms, some of which have a functional effect, and this may reflect human-pathogen interaction and geographical origin. An example is the polymorphism Ile62Val (rs800292 (A>G)) in the complement regulator Factor H gene which alters the susceptibility to age-related macular degeneration (AMD), with the Ile62 polymorphism protecting against AMD. When sub-Saharan African and European populations are compared, the frequency of this polymorphism shows a very marked geographical distribution. Polymorphisms in other complement genes such as complement factor B show similar trends. This paper describes the geographical variation present in complement genes and discusses the implications of these observations. The analysis of genetic variation in complement genes is a promising tool to unravel mechanisms of host-pathogen interaction and can provide new insights into the evolution of the human immune system.
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Affiliation(s)
- L Ermini
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK
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24
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Sanders MS, van Well GTJ, Ouburg S, Morré SA, van Furth AM. Genetic variation of innate immune response genes in invasive pneumococcal and meningococcal disease applied to the pathogenesis of meningitis. Genes Immun 2011; 12:321-34. [DOI: 10.1038/gene.2011.20] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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25
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Infections of people with complement deficiencies and patients who have undergone splenectomy. Clin Microbiol Rev 2010; 23:740-80. [PMID: 20930072 DOI: 10.1128/cmr.00048-09] [Citation(s) in RCA: 252] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The complement system comprises several fluid-phase and membrane-associated proteins. Under physiological conditions, activation of the fluid-phase components of complement is maintained under tight control and complement activation occurs primarily on surfaces recognized as "nonself" in an attempt to minimize damage to bystander host cells. Membrane complement components act to limit complement activation on host cells or to facilitate uptake of antigens or microbes "tagged" with complement fragments. While this review focuses on the role of complement in infectious diseases, work over the past couple of decades has defined several important functions of complement distinct from that of combating infections. Activation of complement in the fluid phase can occur through the classical, lectin, or alternative pathway. Deficiencies of components of the classical pathway lead to the development of autoimmune disorders and predispose individuals to recurrent respiratory infections and infections caused by encapsulated organisms, including Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. While no individual with complete mannan-binding lectin (MBL) deficiency has been identified, low MBL levels have been linked to predisposition to, or severity of, several diseases. It appears that MBL may play an important role in children, who have a relatively immature adaptive immune response. C3 is the point at which all complement pathways converge, and complete deficiency of C3 invariably leads to severe infections, including those caused by meningococci and pneumococci. Deficiencies of the alternative and terminal complement pathways result in an almost exclusive predisposition to invasive meningococcal disease. The spleen plays an important role in antigen processing and the production of antibodies. Splenic macrophages are critical in clearing opsonized encapsulated bacteria (such as pneumococci, meningococci, and Escherichia coli) and intraerythrocytic parasites such as those causing malaria and babesiosis, which explains the fulminant nature of these infections in persons with anatomic or functional asplenia. Paramount to the management of patients with complement deficiencies and asplenia is educating patients about their predisposition to infection and the importance of preventive immunizations and seeking prompt medical attention.
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26
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Halla MC, do Carmo RF, Silva Vasconcelos LR, Pereira LB, Moura P, de Siqueira ERF, Pereira LMMB, Mendonça Cavalcanti MDSD. Association of hepatitis C virus infection and liver fibrosis severity with the variants alleles of MBL2 gene in a Brazilian population. Hum Immunol 2010; 71:883-7. [PMID: 20570631 DOI: 10.1016/j.humimm.2010.05.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Revised: 05/18/2010] [Accepted: 05/26/2010] [Indexed: 12/11/2022]
Abstract
Mannose binding lectin (MBL) is a molecule of the innate immunity, which activates the complement system and modulates inflammation. We investigated the association of the polymorphisms in the exon 1 and promoter region of the MBL gene (MBL2) with the susceptibility to hepatitis C virus (HCV) infection and the degree of liver fibrosis in Brazilian patients chronically infected with HCV. The study was performed in 232 healthy control subjects and 186 patients, 157 of whom underwent liver biopsy after histopathology analysis and classification of fibrosis according to Metavir score. Exon 1 was genotyped by melting temperature assay and the promoter region by Taqman real-time polymerase chain reacation. The frequency of genotypes related to low production of MBL was higher in patients with HCV than in controls (p(c) = 0.0001, odds ratio = 3.52; confidence interval = 1.86-6.71). In addition, the frequency of variant haplotype, HYO was higher in patients with the severe fibrosis stage F4 (10.7%) than in patients with the mild/moderate fibrosis stage F1/F2 (3.4%), when compared with the HYA haplotype (p(c) = 0.04, odds ratio = 5.25, confidence interval = 1.11-23.62). We conclude that MBL variant alleles expressing low levels of MBL are associated with the susceptibility to HCV infection and that the inheritance of HYO haplotype could be associated with fibrosis severity.
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Affiliation(s)
- Maria Cristina Halla
- Postgraduate Program RENORBIO, Brazil; Institute of Biological Sciences, University of Pernambuco, Recife, Brazil
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27
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Host genetics and outcome in meningococcal disease: a systematic review and meta-analysis. THE LANCET. INFECTIOUS DISEASES 2010; 10:262-74. [DOI: 10.1016/s1473-3099(10)70045-1] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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28
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Critical roles of complement and antibodies in host defense mechanisms against Neisseria meningitidis as revealed by human complement genetic deficiencies. Infect Immun 2009; 78:802-9. [PMID: 19933829 DOI: 10.1128/iai.01044-09] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Certain complement defects are associated with an increased propensity to contract Neisseria meningitidis infections. We performed detailed analyses of complement-mediated defense mechanisms against N. meningitidis 44/76 with whole blood and serum from two adult patients who were completely C2 or C5 deficient. The C5-deficient patient and the matched control were also deficient in mannose-binding lectin (MBL). The proliferation of meningococci incubated in freshly drawn whole blood was estimated by CFU and quantitative DNA real-time PCR. The serum bactericidal activity and opsonophagocytic activity by granulocytes were investigated, including heat-inactivated postvaccination sera, to examine the influence of antimeningococcal antibodies. The meningococci proliferated equally in C2- and C5-deficient blood, with a 2 log(10) increase of CFU and 4- to 5-log(10) increase in DNA copies. Proliferation was modestly decreased in reconstituted C2-deficient and control blood. After reconstitution of C5-deficient blood, all meningococci were killed, which is consistent with high antibody titers being present. The opsonophagocytic activity was strictly C2 dependent, appeared with normal serum, and increased with postvaccination serum. Serum bactericidal activity was strictly dependent on C2, C5, and high antibody titers. MBL did not influence any of the parameters observed. Complement-mediated defense against meningococci was thus dependent on the classical pathway. Some opsonophagocytic activity occurred despite low levels of antimeningococcal antibodies but was more efficient with immune sera. Serum bactericidal activity was dependent on C2, C5, and immune sera. MBL did not influence any of the parameters observed.
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29
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Genetic polymorphisms in host response to meningococcal infection: The role of susceptibility and severity genes. Vaccine 2009; 27 Suppl 2:B90-102. [DOI: 10.1016/j.vaccine.2009.05.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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30
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Kugelberg E, Gollan B, Tang CM. Mechanisms in Neisseria meningitidis for resistance against complement-mediated killing. Vaccine 2009; 26 Suppl 8:I34-9. [PMID: 19388162 PMCID: PMC2686086 DOI: 10.1016/j.vaccine.2008.11.059] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Bacterial meningitis and septicaemia is a global health problem often caused by Neisseria meningitidis. The complement system is the most important aspect of host defence against this pathogen, and the critical interaction between the two is influenced by genetic polymorphisms on both the bacterial and the host side; variations of the meningococcus may lead to increased survival in human sera, whereas humans with complement deficiencies are more susceptible to meningococcal infections. Here we discuss the mechanisms of meningococcal resistance against complement-mediated killing and the influence of both bacterial and host genetic factors.
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Affiliation(s)
- Elisabeth Kugelberg
- Centre for Molecular Microbiology and Infection, Flowers Building, Armstrong Road, Imperial College London, London SW7 2AZ, United Kingdom
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31
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Singh KK, Spector SA. Host genetic determinants of human immunodeficiency virus infection and disease progression in children. Pediatr Res 2009; 65:55R-63R. [PMID: 19190524 PMCID: PMC2802664 DOI: 10.1203/pdr.0b013e31819dca03] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Increasing data support host genetic factors as an important determinants of human immunodeficiency virus type-1 (HIV-1) susceptibility, mother-to-child transmission (MTCT), and disease progression. Of these genetic mediators, those impacting innate and adaptive immune responses seem to play a critical role in viral infectivity and pathogenesis. During primary infection, CCR5 using virus is predominantly transmitted and polymorphisms that affect the expression of CCR5 alter the risk for MTCT and rate of disease. Chemokines that naturally bind to coreceptors alter infectivity and viral pathogenesis. Additional genes that affect innate immunity including those encoding for MBL2 and those modulating the adaptive immune response including CX3CR1 and human leukocyte antigen types can significantly modify susceptibility and response to HIV-1 infection. As young children develop, the dependence on certain arms of the immune system varies and can alter the effect of genetic variants. Additionally, host genetic factors may alter the response to antiretrovirals. Finally, because HIV-infected children progress more rapidly than adults and have fewer background cofactors, such as drug use and coinfections, the effects of host factors on HIV-1 disease may be more clearly identified. In this review, we summarize available data on the impact of host genetics on MTCT and disease progression of HIV-infected children.
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Affiliation(s)
- Kumud K Singh
- Department of Pediatrics, University of California, San Diego, La Jolla, California 92093, USA
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32
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Faber J, Henninger N, Finn A, Zenz W, Zepp F, Knuf M. A toll-like receptor 4 variant is associated with fatal outcome in children with invasive meningococcal disease. Acta Paediatr 2009; 98:548-52. [PMID: 19067670 DOI: 10.1111/j.1651-2227.2008.01163.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
AIMS Toll-like receptor 4 (TLR4) is the major endotoxin signalling receptor of the innate immune system and is required for efficient recognition of bacterial infections. Here, we analysed a possible association between the TLR4 variant Asp299Gly and disease outcome in children with invasive meningococcal disease. METHODS In total, 197 children with invasive meningococcal disease were analysed for the TLR4 Asp299Gly variant. Genotyping results were correlated with mortality, the frequency of ventilation support, application of inotropic substances, skin grafting, and limb loss. RESULTS The overall Asp299Gly allele frequency was 9.4%. Detection of a heterozygous Asp299Gly TLR4 mutation was significantly associated with fatal outcome (non-survivor group: 31.6% vs. survivor group: 12.1%; p = 0.021) and was even more pronounced in patients with disease onset less than 24 months of age (non-survivor group: 42.8% vs. survivor group: 10.2%; p = 0.006). In this age group, ventilation support was also more frequent in patients with the Asp299Gly genotype (37.5% vs. 6.2%). CONCLUSION Our data suggest that the heterozygous TLR4 Asp299Gly genotype is associated with an increased mortality in children with invasive meningococcal disease.
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Affiliation(s)
- Joerg Faber
- Children's Hospital, University of Mainz, Mainz, Germany.
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33
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Brouwer MC, de Gans J, Heckenberg SGB, Zwinderman AH, van der Poll T, van de Beek D. Host genetic susceptibility to pneumococcal and meningococcal disease: a systematic review and meta-analysis. THE LANCET. INFECTIOUS DISEASES 2009; 9:31-44. [DOI: 10.1016/s1473-3099(08)70261-5] [Citation(s) in RCA: 168] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Singh KK, Lieser A, Ruan PK, Fenton T, Spector SA. An age-dependent association of mannose-binding lectin-2 genetic variants on HIV-1-related disease in children. J Allergy Clin Immunol 2008; 122:173-80, 180.e1-2. [PMID: 18602571 DOI: 10.1016/j.jaci.2008.05.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Revised: 05/12/2008] [Accepted: 05/16/2008] [Indexed: 11/25/2022]
Abstract
BACKGROUND Mannose-binding lectin (MBL) is part of the lectin pathway of complement activation against various pathogens; however, its role in innate immune responses against HIV-1 infection in children is unknown. OBJECTIVE This study evaluated the effects of mannose-binding lectin-2 (MBL2) alleles on HIV-1 disease progression and central nervous system (CNS) impairment in children. METHODS A cohort of 1037 HIV-1-infected children enrolled in Pediatrics AIDS Clinical Trial Group protocols P152 and P300 before the availability of effective antiretroviral therapy was genotyped for MBL2 and evaluated for disease progression. RESULTS Children with the homozygous variant MBL2-O/O genotype were more likely to experience rapid disease progression and CNS impairment than those with the wild-type AA genotype. The effects were predominantly observed in children younger than 2 years. In unadjusted Cox proportional hazards models, children younger than 2 years with MBL2-O/O experienced more rapid disease progression (O/O vs AA: relative hazard [RH], 1.54; 95% CI, 1.07-2.22; P = .02; O/O vs A/O: RH, 2.28; 95% CI, 1.09-4.79; P = .029). Similarly, children with MBL2-O/O were more likely to experience rapid progression to CNS impairment (O/O vs A/A: RH, 2.78; 95% CI, 1.06-2.69, P = .027; O/O vs A/O: RH, 1.69; 95% CI, 1.07-7.21; P = .035). The effects remained significant after adjustment for CD4(+) lymphocyte count, plasma HIV-1 RNA, and other genotypes. CONCLUSIONS MBL2-O/O genotypes, which result in lower expression of MBL, are associated with more rapid HIV-1-related disease progression, including CNS impairment, predominantly in children younger than 2 years. These data suggest that MBL2 variants are associated with altered HIV-1 disease progression, particularly in young children.
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Affiliation(s)
- Kumud K Singh
- Department of Pediatrics, Division of Infectious Diseases, University of California, San Diego, La Jolla, Calif 92093-0672, USA.
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