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Osman M, Cohen Tervaert JW, Pagnoux C. Avacopan for the treatment of ANCA-associated vasculitis: an update. Expert Rev Clin Immunol 2023; 19:461-471. [PMID: 36545762 DOI: 10.1080/1744666x.2023.2162041] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Glucocorticoids (GC) have been part of the standard treatment of anti-neutrophil cytoplasm autoantibodies (ANCA)-associated vasculitides (AAV) for more than 60 years. Various therapeutic advances have occurred over the past 2 decades and led to a significant reduction of GC exposure, but most patients still have to suffer from complications of GC, including infections, metabolic abnormalities, and cardiovascular morbidity. In 2007, activation of the complement pathway was demonstrated to play a role in the pathogenesis of AAV. Avacopan, an oral competitive inhibitor of the C5a receptor (C5aR1, CD88), was then developed, with an additional aim to decrease the use of GC. AREAS COVERED In this article, we briefly summarize the rationale for targeting the complement pathway in AAV, and review relevant findings from pre-clinical, phase I, II, and III studies, subsequent and more recent case reports and series on the efficacy and safety of avacopan. EXPERT OPINION Based on the results of these studies, avacopan was approved in most countries since late 2021, as an adjunctive induction treatment for patients with AAV. Several newer questions now are pending answers, including as to how avacopan should be used in real-world practice, beyond how it was given in the original clinical trials.
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Affiliation(s)
- Mohammed Osman
- Division of Rheumatology, University of Alberta, Edmonton, Alberta, Canada
| | | | - Christian Pagnoux
- Vasculitis clinic, Division of Rheumatology, Department of Medicine, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
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2
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Shen YC, Hsia NY, Wu WH, Lin CL, Shen TC, Huang WC. Age-related macular degeneration and premorbid allergic diseases: a population-based case-control study. Sci Rep 2021; 11:16537. [PMID: 34400678 PMCID: PMC8368185 DOI: 10.1038/s41598-021-95937-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 07/29/2021] [Indexed: 11/09/2022] Open
Abstract
Evidence indicates that age-related macular degeneration (AMD) is associated with the prior presence of allergic diseases; however, large-scale studies in the literature are limited. A case-control study was conducted to describe the relationship between premorbid allergic diseases and AMD using Taiwan's National Health Insurance database. Eligibility criteria for inclusion of new adult AMD cases from 2000 to 2013 were set up. We defined the year of diagnosis as the index year. Age-, gender-, index year- matched controls who were drawn from the same database. The case control ratio was 1:4. For all participants, all premorbid conditions staring 1996 to index year were documented. Binary logistic regression was used to describe factors related to AMD occurrence. The AMD group consisted of 10,911 patients, and the comparison group consisted of 43,644 individuals. Patients with AMD showed significant associations with premorbid allergic diseases (aOR 1.54, 95% CI 1.47-1.61), specifically with allergic conjunctivitis (aOR 2.07, 95% CI 1.94-2.20), allergic rhinitis (aOR 1.32, 95% CI 1.25-1.39), asthma (aOR 0.99, 95% CI 0.93-1.06), and atopic dermatitis (aOR 1.04, 95% CI 0.94-1.17). Further analyses indicated that patients with more concurrent allergic diseases have higher associations with AMD than those with fewer concurrent diseases. Patients with more annual medical visits for their allergic diseases also showed higher associations with AMD than those with fewer visits. AMD is significantly associated with premorbid allergic diseases. The underlying mechanisms must be further investigated.
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Affiliation(s)
- Yi-Chen Shen
- Graduate Institute of Biomedical Sciences, College of Medicine, China Medical University, No. 91, Hsueh-Shih Road, Taichung, 404, Taiwan
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, No. 2, Yude Road, Taichung, 404, Taiwan
| | - Ning-Yi Hsia
- Department of Ophthalmology, China Medical University Hospital, No. 2, Yude Road, Taichung, 404, Taiwan
| | - Wan-Hua Wu
- Department of Public Health, College of Public Health, China Medical University, No. 100, Jingmao 1st Road, Taichung, 404, Taiwan
| | - Cheng-Li Lin
- Management Office for Health Data, China Medical University Hospital, No. 2, Yude Road, Taichung, 404, Taiwan
| | - Te-Chun Shen
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, No. 2, Yude Road, Taichung, 404, Taiwan.
- School of Medicine, College of Medicine, China Medical University, No. 91, Hsueh-Shih Road, Taichung, 404, Taiwan.
- Department of Internal Medicine, Chu Shang Show Chwan Hospital, No. 75, Section 2, Jishan Road, Nantou, 557, Taiwan.
| | - Wei-Chien Huang
- Graduate Institute of Biomedical Sciences, College of Medicine, China Medical University, No. 91, Hsueh-Shih Road, Taichung, 404, Taiwan
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Osman M, Cohen Tervaert JW, Pagnoux C. Avacopan for the treatment of ANCA-associated vasculitis. Expert Rev Clin Immunol 2021; 17:717-726. [PMID: 34006155 DOI: 10.1080/1744666x.2021.1932466] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Introduction: Anti-neutrophil cytoplasm autoantibodies (ANCA)-associated vasculitides (AAVs) are a group of rare heterogeneous diseases characterized by blood vessel inflammation resulting in organ destruction and death. Although various treatment strategies have resulted in marked improvement in vasculitis-specific outcomes, many patients with AAV continue to suffer from complications related to the prolonged use of glucocorticoids (GC) such as infections, metabolic abnormalities, and increased cardiovascular morbidity. Recently, activation of the alternative complement pathway has been implicated in the augmentation of the damage caused by AAV via the complement C5a receptor (C5aR1, CD88). Specifically targeting this pathway may lead to improved outcomes in patients with AAV.Areas covered: In this article, we have summarized the rationale for targeting the complement pathway in AAV. The relevant pre-clinical, phase I, II and III findings with emphasis on the efficacy, and safety of avacopan, a new oral competitive inhibitor that interferes with the binding of C5a to C5aR1 (CD88), are reviewed.Expert opinion: These results are encouraging, may led to major changes in the treatment approach for AAV, and give rise to future studies utilizing complement inhibitors in AAV patients, and potentially in other immune mediated diseases.
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Affiliation(s)
- Mohammed Osman
- Division of Rheumatology, University of Alberta, Edmonton, Alberta, Canada
| | | | - Christian Pagnoux
- Vasculitis Clinic, Division of Rheumatology, Department of Medicine, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
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Reinmuth-Selzle K, Kampf CJ, Lucas K, Lang-Yona N, Fröhlich-Nowoisky J, Shiraiwa M, Lakey PSJ, Lai S, Liu F, Kunert AT, Ziegler K, Shen F, Sgarbanti R, Weber B, Bellinghausen I, Saloga J, Weller MG, Duschl A, Schuppan D, Pöschl U. Air Pollution and Climate Change Effects on Allergies in the Anthropocene: Abundance, Interaction, and Modification of Allergens and Adjuvants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:4119-4141. [PMID: 28326768 PMCID: PMC5453620 DOI: 10.1021/acs.est.6b04908] [Citation(s) in RCA: 135] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 03/07/2017] [Accepted: 03/22/2017] [Indexed: 05/13/2023]
Abstract
Air pollution and climate change are potential drivers for the increasing burden of allergic diseases. The molecular mechanisms by which air pollutants and climate parameters may influence allergic diseases, however, are complex and elusive. This article provides an overview of physical, chemical and biological interactions between air pollution, climate change, allergens, adjuvants and the immune system, addressing how these interactions may promote the development of allergies. We reviewed and synthesized key findings from atmospheric, climate, and biomedical research. The current state of knowledge, open questions, and future research perspectives are outlined and discussed. The Anthropocene, as the present era of globally pervasive anthropogenic influence on planet Earth and, thus, on the human environment, is characterized by a strong increase of carbon dioxide, ozone, nitrogen oxides, and combustion- or traffic-related particulate matter in the atmosphere. These environmental factors can enhance the abundance and induce chemical modifications of allergens, increase oxidative stress in the human body, and skew the immune system toward allergic reactions. In particular, air pollutants can act as adjuvants and alter the immunogenicity of allergenic proteins, while climate change affects the atmospheric abundance and human exposure to bioaerosols and aeroallergens. To fully understand and effectively mitigate the adverse effects of air pollution and climate change on allergic diseases, several challenges remain to be resolved. Among these are the identification and quantification of immunochemical reaction pathways involving allergens and adjuvants under relevant environmental and physiological conditions.
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Affiliation(s)
| | - Christopher J. Kampf
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, Mainz, 55128, Germany
- Institute
of Inorganic and Analytical Chemistry, Johannes
Gutenberg University, Mainz, 55128, Germany
| | - Kurt Lucas
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, Mainz, 55128, Germany
| | - Naama Lang-Yona
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, Mainz, 55128, Germany
| | | | - Manabu Shiraiwa
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, Mainz, 55128, Germany
- Department
of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Pascale S. J. Lakey
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, Mainz, 55128, Germany
| | - Senchao Lai
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, Mainz, 55128, Germany
- South
China University of Technology, School of
Environment and Energy, Guangzhou, 510006, China
| | - Fobang Liu
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, Mainz, 55128, Germany
| | - Anna T. Kunert
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, Mainz, 55128, Germany
| | - Kira Ziegler
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, Mainz, 55128, Germany
| | - Fangxia Shen
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, Mainz, 55128, Germany
| | - Rossella Sgarbanti
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, Mainz, 55128, Germany
| | - Bettina Weber
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, Mainz, 55128, Germany
| | - Iris Bellinghausen
- Department
of Dermatology, University Medical Center, Johannes Gutenberg University, Mainz, 55131, Germany
| | - Joachim Saloga
- Department
of Dermatology, University Medical Center, Johannes Gutenberg University, Mainz, 55131, Germany
| | - Michael G. Weller
- Division
1.5 Protein Analysis, Federal Institute
for Materials Research and Testing (BAM), Berlin, 12489, Germany
| | - Albert Duschl
- Department
of Molecular Biology, University of Salzburg, 5020 Salzburg, Austria
| | - Detlef Schuppan
- Institute
of Translational Immunology and Research Center for Immunotherapy,
Institute of Translational Immunology, University Medical Center, Johannes Gutenberg University, Mainz, 55131 Germany
- Division
of Gastroenterology, Beth Israel Deaconess
Medical Center and Harvard Medical School, Boston, Massachusetts 02215, United States
| | - Ulrich Pöschl
- Multiphase
Chemistry Department, Max Planck Institute
for Chemistry, Mainz, 55128, Germany
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Khan MA, Assiri AM, Broering DC. Complement mediators: key regulators of airway tissue remodeling in asthma. J Transl Med 2015; 13:272. [PMID: 26289385 PMCID: PMC4544802 DOI: 10.1186/s12967-015-0565-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 06/03/2015] [Indexed: 12/18/2022] Open
Abstract
The complement mediators are the major effectors of the immune balance, which operates at the interface between the innate and adaptive immunity, and is vital for many immunoregulatory functions. Activation of the complement cascade through the classical, alternative or lectin pathways thus generating opsonins like C3b and C5b, anaphylatoxins C3a and C5a, chemotaxin, and inflammatory mediators, which leads to cellular death. Complement mediators that accelerate the airway remodeling are not well defined; however, an uncontrolled Th2-driven adaptive immune response has been linked to the major pathophysiologic features of asthma, including bronchoconstriction, airway hyperresponsiveness, and airway inflammation. The mechanisms leading to complement mediated airway tissue remodeling, and the effect of therapy on preventing and/or reversing it are not clearly understood. This review highlights complement-mediated inflammation, and the mechanism through it triggers the airway tissue injury and remodeling in the airway epithelium that could serve as potential targets for developing a new drug to rescue the asthma patients.
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Affiliation(s)
- Mohammad Afzal Khan
- Department of Comparative Medicine, King Faisal Specialist Hospital & Research Centre, P.O. Box 3354, Riyadh, 11211 MBC-03, Kingdom of Saudi Arabia.
| | - Abdullah Mohammed Assiri
- Department of Comparative Medicine, King Faisal Specialist Hospital & Research Centre, P.O. Box 3354, Riyadh, 11211 MBC-03, Kingdom of Saudi Arabia.
| | - Dieter Clemens Broering
- Organ Transplant Centre, King Faisal Specialist Hospital & Research Centre, Riyadh, Kingdom of Saudi Arabia.
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Scambi C, Ugolini S, Jokiranta TS, De Franceschi L, Bortolami O, La Verde V, Guarini P, Caramaschi P, Ravagnani V, Martignoni G, Colato C, Pedron S, Benedetti F, Sorio M, Poli F, Biasi D. The local complement activation on vascular bed of patients with systemic sclerosis: a hypothesis-generating study. PLoS One 2015; 10:e0114856. [PMID: 25658605 PMCID: PMC4319765 DOI: 10.1371/journal.pone.0114856] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 11/13/2014] [Indexed: 11/26/2022] Open
Abstract
Objective The role of complement system in the pathogenesis of systemic sclerosis (SSc) has been debated during the last decade but an evident implication in this disease has never been found. We carried out an explorative study on SSc patients to evaluate the expression of soluble and local C5b-9 complement complex and its relation with a complement regulator, the Membrane Cofactor Protein (MCP, CD46) on skin vascular bed as target distinctive of SSc disease. We also analyzed two polymorphic variants in the complement activation gene cluster involving the MCP region. Methods C5b-9 plasma levels of SSc patients and healthy subjects were analyzed by ELISA assay. Archival skin biopsies of SSc patients and controls were subjected to immunofluorescence analysis to detect C5b-9 and MCP on vascular endothelial cells. The expression of MCP was validated by immunoblot analysis with specific antibody. Polymorphic variants in the MCP gene promoter were tested by a quantitative PCR technique-based allelic discrimination method. Results Even though circulating levels of C5b-9 did not differ between SSc and controls, C5b-9 deposition was detected in skin biopsies of SSc patients but not in healthy subjects. MCP was significantly lower in skin vessels of SSc patients than in healthy controls and was associated with the over-expression of two polymorphic variants in the MCP gene promoter, which has been related to more aggressive phenotypes in other immune-mediated diseases. Conclusions Our results firsty document the local complement activation with an abnormal expression of MCP in skin vessels of SSc patients, suggesting that a subset of SSc patients might be exposed to more severe organ complications and clinical evolution due to abnormal local complement activation.
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Affiliation(s)
- Cinzia Scambi
- Department of Medicine, University of Verona, Verona, Italy
- * E-mail:
| | - Sara Ugolini
- Department of Medicine, University of Verona, Verona, Italy
| | - T. Sakari Jokiranta
- Department of Bacteriology and Immunology, Haartman Institute and Research Programs Unit, Immunobiology, University of Helsinki, Helsinki, Finland
| | | | - Oscar Bortolami
- Research Support Unit and Biostatistics, Verona University Hospital, Verona, Italy
| | | | | | | | | | - Guido Martignoni
- Department of Pathology and Diagnostics, University of Verona, Verona, Italy
| | - Chiara Colato
- Department of Pathology and Diagnostics, University of Verona, Verona, Italy
| | - Serena Pedron
- Department of Pathology and Diagnostics, University of Verona, Verona, Italy
| | | | - Marco Sorio
- Department of Medicine, University of Verona, Verona, Italy
| | - Fabio Poli
- Department of Medicine, University of Verona, Verona, Italy
| | - Domenico Biasi
- Department of Medicine, University of Verona, Verona, Italy
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Ramacciotti E, Clark M, Sadeghi N, Hoppensteadt D, Thethi I, Gomes M, Fareed J. Review: Contaminants in Heparin: Review of the Literature, Molecular Profiling, and Clinical Implications. Clin Appl Thromb Hemost 2011; 17:126-35. [DOI: 10.1177/1076029610392214] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background: The contaminant isolated from contaminated heparin was oversulfated chondroitin sulfate (OSCS). Other possible contaminants should be evaluated. Methods: Contaminants were isolated from recalled contaminated heparin and were compared to OSCS from animal sources and to heparin by-products synthetically persulfated. Results: A great variability in molecular weight was observed in the isolated contaminants. Dermatan sulfate with high-molecular-weight in addition to OSCS was detected. Oversulfated chondroitin sulfate from different sources as well as heparin by-products produced activation of prekallikrein to kallikrein at variable rates as measured by the generation of kallikrein. All agents produced activation of the complement system. All compounds formed complexes with platelet factor 4 (PF4) and all produced 14C serotonin release in the heparin-induced thrombocytopenia (HIT) analysis. The agents also exhibited variable anticoagulant responses that were mostly mediated via heparin cofactor II. Conclusion: These results suggest that heparin contaminants represent a heterogeneous group of oversulfated glycosaminoglycans (OSGAGs) which may mediate multiple pathophysiologic responses.
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Affiliation(s)
- Eduardo Ramacciotti
- Department of Pathology and Pharmacology, Cardiovascular Institute, Loyola University Medical Center, Maywood, IL 60153, USA
| | - Melanie Clark
- Department of Pathology and Pharmacology, Cardiovascular Institute, Loyola University Medical Center, Maywood, IL 60153, USA
| | - Nasir Sadeghi
- Department of Pathology and Pharmacology, Cardiovascular Institute, Loyola University Medical Center, Maywood, IL 60153, USA
| | - Debra Hoppensteadt
- Department of Pathology and Pharmacology, Cardiovascular Institute, Loyola University Medical Center, Maywood, IL 60153, USA
| | - Indermohan Thethi
- Department of Pathology and Pharmacology, Cardiovascular Institute, Loyola University Medical Center, Maywood, IL 60153, USA
| | - Marise Gomes
- Department of Pathology and Pharmacology, Cardiovascular Institute, Loyola University Medical Center, Maywood, IL 60153, USA
| | - Jawed Fareed
- Department of Pathology and Pharmacology, Cardiovascular Institute, Loyola University Medical Center, Maywood, IL 60153, USA,
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Husain M, Boermans HJ, Karrow NA. Mesenteric lymph node transcriptome profiles in BALB/c mice sensitized to three common food allergens. BMC Genomics 2011; 12:12. [PMID: 21211037 PMCID: PMC3023748 DOI: 10.1186/1471-2164-12-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Accepted: 01/06/2011] [Indexed: 12/14/2022] Open
Abstract
Background Food allergy is a serious health concern among infants and young children. Although immunological mechanism of food allergy is well documented, the molecular mechanism(s) involved in food allergen sensitization have not been well characterized. Therefore, the present study analyzed the mesenteric lymph node (MLN) transcriptome profiles of BALB/c mice in response to three common food allergens. Results Microarray analysis identified a total of 1361, 533 and 488 differentially expressed genes in response to β-lactoglobulin (BLG) from cow's milk, ovalbumin (OVA) from hen's egg white and peanut agglutinin (PNA) sensitizations, respectively (p < 0.05). A total of 150 genes were commonly expressed in all antigen sensitized groups. The expression of seven representative genes from microarray experiment was validated by real-time RT-PCR. All allergens induced significant ear swelling and serum IgG1 concentrations, whereas IgE concentrations were increased in BLG- and PNA-treated mice (p < 0.05). Treatment with OVA and PNA significantly induced plasma histamine concentrations (p < 0.05). The PCA demonstrated the presence of allergen-specific IgE in the serum of previously sensitized and challenged mice. Conclusions Immunological profiles indicate that the allergen dosages used are sufficient to sensitize the BALB/c mice and to conduct transcriptome profiling. Microarray studies identified several differentially expressed genes in the sensitization phase of the food allergy. These findings will help to better understand the underlying molecular mechanism(s) of food allergen sensitizations and may be useful in identifying the potential biomarkers of food allergy.
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Affiliation(s)
- Mainul Husain
- Department of Animal & Poultry Science, University of Guelph, Guelph, Ontario, Canada
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Abdel Fattah M, El Baz M, Sherif A, Adel A. Complement components (C3, C4) as inflammatory markers in asthma. Indian J Pediatr 2010; 77:771-3. [PMID: 20589464 DOI: 10.1007/s12098-010-0117-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Accepted: 02/22/2010] [Indexed: 01/15/2023]
Abstract
OBJECTIVE To assess the serum levels of complement factors C3 and C4 in Egyptian asthmatic children. METHODS This case-controlled study comprised of 60 Egyptian children with the diagnosis of bronchial asthma (not in acute attack) and 60 age-and sex-matched healthy controls. All candidates were subjected to a thorough clinical study, complete blood counts, absolute eosinophil count and serum complements (C3, C4). RESULTS Serum C3 was significantly higher in asthmatics when compared to controls (140.60 +/- 38.80 mg/dl vs 107.70 +/- 45.00 mg/dl respectively, (p = 0.01). However, differences in serum C4 levels were not significant (41.30+/-48.80 mg/dl vs 44.60 +/- 39.70 mg/dl respectively, p = 0.69). There was a significant positive correlation between severity of asthma and serum C3 (p=0.02) but not with serum C4. CONCLUSIONS Serum levels of C3 - but not C4 - are elevated in children with stable asthma, with a positive correlation between serum C3 and severity of asthma.
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Zhang X, Köhl J. A complex role for complement in allergic asthma. Expert Rev Clin Immunol 2010; 6:269-77. [PMID: 20402389 DOI: 10.1586/eci.09.84] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Allergic asthma is a chronic inflammatory disease of the upper airway. It is well appreciated that maladaptive Th2 immunity promotes the allergic phenotype, the underlying mechanisms of which remain elusive. The disease is associated with activation of complement, an ancient danger-sensing component of the innate immune system. Different models of experimental allergic asthma suggest that the small complement fragments of C3 and C5, the anaphylatoxins C3a and C5a, not only promote proallergic effector functions during the allergic effector phase but regulate the development of Th2 immunity during allergen sensitization. The available data support a concept in which C5a is dominant during allergen sensitization and protects against the development of maladaptive Th2 immunity. By contrast, C3a and C5a appear to act synergistically and drive allergic inflammation during the effector phase. In this article, we will review the recent findings in the field to judge the benefit of complement targeting in allergic asthma.
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Affiliation(s)
- Xun Zhang
- Division of Molecular Immunology, Cincinnati Children's Hospital Medical Center and University of Cincinnati College of Medicine, OH 45229, USA
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11
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Schlosser RJ, Mulligan RM, Casey SE, Varela JC, Harvey RJ, Atkinson C. Alterations in gene expression of complement components in chronic rhinosinusitis. Am J Rhinol Allergy 2010; 24:21-5. [PMID: 20109314 DOI: 10.2500/ajra.2010.24.3399] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
BACKGROUND The complement cascade forms part of the initial innate response to pathogens in the airway. Complement activation is important in the maintenance of host homeostasis, but excessive and uncontrolled activation may lead to inflammation and disease. The role of the complement pathway in the innate response in chronic rhinosinusitis (CRS) is poorly characterized Methods: Sinus mucosa biopsy specimens from the anterior ethmoid or uncinate process of patients with allergic fungal rhinosinusitis (AFRS), CRS without NPs (CRS-NPs), and controls were harvested and gene and protein expression of C3, factor B (fB), C5, and C7 complement proteins were analyzed using quantitative polymerase chain reaction and immunohistochemical techniques. RESULTS fB, C3, and C5 gene expression were increased in both AFRS and CRS-NPs compared with controls (p < 0.05). Transcriptional activity for the terminal pathway protein C7 was not significantly increased when compared with controls, with C7 levels actually reduced in AFRS patients when compared with controls. Immunohistochemistry studies showed the presence of C3 and fB on the mucosal surface and in submucosa of both AFRS and CRS-NPs, but not normal controls. Terminal pathway protein C9 was not found in our specimens. CONCLUSION Both AFRS and CRS-NPs display up-regulation of the complement pathway, in particular, the alternative pathway (fB) and common pathways (C3 and C5). Enhanced innate responses as shown by alterations in complement components may play a pivotal role in the inflammatory response noted in CRS and provide potential therapeutic targets in the future.
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Affiliation(s)
- Rodney J Schlosser
- Department of Otolaryngology-Head and Neck Surgery, Medical University of South Carolina, Charleston, South Carolina, USA.
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Staley KG, Kuehni CE, Strippoli MPF, McNally T, Silverman M, Stover C. Properdin in childhood and its association with wheezing and atopy. Pediatr Allergy Immunol 2010; 21:e787-91. [PMID: 20337960 DOI: 10.1111/j.1399-3038.2009.00979.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Properdin, a serum glycoprotein, is an important component of innate immunity, the only known positive regulator of complement, acting as an initiation point for alternative pathway activation. As an X-linked protein, we hypothesized that properdin may play a modulatory role in the pathogenesis of viral wheeze in children, which tends to be more common and more severe in boys. We aimed to determine properdin levels in a community-based paediatric sample, and to assess whether levels of properdin were associated with childhood wheeze phenotypes and atopy. We studied 137 school-children aged 8-12 yrs, a nested sample from a cohort study. Properdin was measured by a commercial enzyme-linked immunoabsorbant assay. We assessed wheeze by questionnaire, validated it by a nurse-led interview and performed skin prick tests and a methacholine challenge in all children. Forty children (29%) reported current wheeze. Serum properdin levels ranged between 18 and 40 microg/ml. Properdin was not associated with age, gender, atopy, bronchial responsiveness, current wheeze (neither the viral wheeze nor multiple-trigger wheeze phenotype) or severity of wheeze, but was slightly lower in south Asian (median 21.8 microg/ml) compared with white children (23.3 microg/ml; p = 0.006). Our data make it unlikely that properdin deficiency is common in healthy children or that levels of properdin are a major risk factor for wheeze or atopy.
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Affiliation(s)
- Kathryn Grace Staley
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK
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13
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Ali H. Regulation of human mast cell and basophil function by anaphylatoxins C3a and C5a. Immunol Lett 2009; 128:36-45. [PMID: 19895849 DOI: 10.1016/j.imlet.2009.10.007] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Revised: 10/21/2009] [Accepted: 10/23/2009] [Indexed: 12/18/2022]
Abstract
Allergic diseases such as asthma result from inappropriate immunologic responses to common environmental allergens in genetically susceptible individuals. Following allergen exposure, interaction of dendritic cells (DC) with CD4(+) T cells leads to the production of Th2 cytokines, which induce B cells to synthesize IgE molecules (sensitization phase). These IgE molecules bind to their high affinity receptors (FcvarepsilonRI) on the surface of mast cells and basophils and their subsequent cross-linking by allergen results in the release of preformed and newly synthesized mediators, which cause bronchoconstriction, lung inflammation and airway hyperresponsiveness (AHR) in asthma (effector phase). The complement components C3a and C5a levels are increased in the lungs of patients with asthma and are likely generated via the actions of both allergen and mast cell proteases. In vivo studies with rodents have shown that while C3a facilitates allergen sensitization in some models C5a inhibits this response. Despite this difference, both anaphylatoxins promote lung inflammation and AHR in vivo indicating that cells other than DC and T cells likely mediate the functional effects of C3a and C5a in asthma. This review focuses on the contribution of C3a and C5a in the pathogenesis of asthma with a particular emphasis on mast cells and basophils. It discusses the mechanisms by which anaphylatoxins activate mast cells and basophils and the associated signaling pathways via which their receptors are regulated by priming and desensitization.
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Affiliation(s)
- Hydar Ali
- Department of Pathology, University of Pennsylvania School of Dental Medicine, 240 South 40th Street, Philadelphia, PA 19104-6030, USA.
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Mobini R, Andersson BA, Erjefält J, Hahn-Zoric M, Langston MA, Perkins AD, Cardell LO, Benson M. A module-based analytical strategy to identify novel disease-associated genes shows an inhibitory role for interleukin 7 Receptor in allergic inflammation. BMC SYSTEMS BIOLOGY 2009; 3:19. [PMID: 19216740 PMCID: PMC2653464 DOI: 10.1186/1752-0509-3-19] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 02/12/2009] [Indexed: 12/04/2022]
Abstract
Background The identification of novel genes by high-throughput studies of complex diseases is complicated by the large number of potential genes. However, since disease-associated genes tend to interact, one solution is to arrange them in modules based on co-expression data and known gene interactions. The hypothesis of this study was that such a module could be a) found and validated in allergic disease and b) used to find and validate one ore more novel disease-associated genes. Results To test these hypotheses integrated analysis of a large number of gene expression microarray experiments from different forms of allergy was performed. This led to the identification of an experimentally validated reference gene that was used to construct a module of co-expressed and interacting genes. This module was validated in an independent material, by replicating the expression changes in allergen-challenged CD4+ cells. Moreover, the changes were reversed following treatment with corticosteroids. The module contained several novel disease-associated genes, of which the one with the highest number of interactions with known disease genes, IL7R, was selected for further validation. The expression levels of IL7R in allergen challenged CD4+ cells decreased following challenge but increased after treatment. This suggested an inhibitory role, which was confirmed by functional studies. Conclusion We propose that a module-based analytical strategy is generally applicable to find novel genes in complex diseases.
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Affiliation(s)
- Reza Mobini
- Unit for Clinical Systems Biology, Department of Pediatrics, University of Gothenburg, Gothenburg, Sweden.
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15
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Lee HA, Kwon B, Hur GY, Choi SJ, Nahm DH, Park HS. Isotype and IgG subclass distribution of autoantibody response to alpha-enolase protein in adult patients with severe asthma. Yonsei Med J 2008; 49:923-30. [PMID: 19108015 PMCID: PMC2628024 DOI: 10.3349/ymj.2008.49.6.923] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
PURPOSE A possible involvement of autoimmune mechanism in the pathogenesis of bronchial asthma has been proposed. Recently, alpha-enolase protein was identified as a major autoantigen recognized by circulating IgG autoantibodies in patients with severe asthma. To evaluate a possible pathogenetic significance of these autoantibodies in severe asthma, isotype (IgG, IgA, IgM, and IgE) and IgG subclass (IgG1, IgG2, IgG3, and IgG4) distributions of autoantibodies to recombinant human alpha-enolase protein were analyzed. PATIENTS AND METHODS We examined serum samples from 10 patients with severe asthma and 7 patients with mild-to-moderate asthma, and 5 healthy controls by immunoblot analysis. Severe asthma was defined as patients having at least 1 severe asthmatic exacerbation requiring an emergency department visit or admission in the last year despite continuous typical therapies. RESULTS IgG1 was the predominant IgG subclass antibody response to alpha-enolase protein in patients with severe asthma. IgG1 autoantibody to alpha-enolase protein was detected in 7 of 10 patients with severe asthma (70%), 1 of 7 patients with mild-to-moderate asthma (14.3%), and none of 5 healthy controls (0%) (chi-square test; p < 0.05). IgA, IgM, and IgE autoantibodies to alpha-enolase protein could not be detected in patients with severe asthma. CONCLUSION IgG1 subclass was the predominant type of autoantibody response to alpha-enolase protein in patients with severe asthma, suggests a possibility of IgG1 autoantibody-mediated complement activation in the pathogenesis of severe asthma.
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Affiliation(s)
- Hye-Ah Lee
- Department of Allergy and Rheumatology, Ajou University School of Medicine, Suwon, Korea
| | - Byul Kwon
- Department of Allergy and Rheumatology, Ajou University School of Medicine, Suwon, Korea
| | - Gyu-Young Hur
- Department of Allergy and Rheumatology, Ajou University School of Medicine, Suwon, Korea
| | - Sung-Jin Choi
- Department of Allergy and Rheumatology, Ajou University School of Medicine, Suwon, Korea
| | - Dong-Ho Nahm
- Department of Allergy and Rheumatology, Ajou University School of Medicine, Suwon, Korea
| | - Hae-Sim Park
- Department of Allergy and Rheumatology, Ajou University School of Medicine, Suwon, Korea
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16
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Gueler F, Rong S, Gwinner W, Mengel M, Bröcker V, Schön S, Greten TF, Hawlisch H, Polakowski T, Schnatbaum K, Menne J, Haller H, Shushakova N. Complement 5a receptor inhibition improves renal allograft survival. J Am Soc Nephrol 2008; 19:2302-12. [PMID: 18753257 DOI: 10.1681/asn.2007111267] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Complement activation plays a key role in mediating apoptosis, inflammation, and transplant rejection. In this study, the role of the complement 5a receptor (C5aR) was examined in human renal allografts and in an allogenic mouse model of renal transplant rejection. In human kidney transplants with acute rejection, C5aR expression was increased in renal tissue and in cells infiltrating the tubulointerstitium. Similar findings were observed in mice. When recipient mice were treated once daily with a C5aR antagonist before transplantation, long-term renal allograft survival was markedly improved compared with vehicle-treatment (75 versus 0%), and apoptosis was reduced. Furthermore, treatment with a C5aR antagonist significantly attenuated monocyte/macrophage infiltration, perhaps a result of reduced levels of monocyte chemoattractant protein 1 and the intercellular adhesion molecule 1. In vitro, C5aR antagonism inhibited intercellular adhesion molecule 1 upregulation in primary mouse aortic endothelial cells and reduced adhesion of peripheral blood mononuclear cells. Furthermore, C5aR blockade markedly reduced alloreactive T cell priming. These results demonstrate that C5aR plays an important role in mediating acute kidney allograft rejection, suggesting that pharmaceutical targeting of C5aR may have potential in transplantation medicine.
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Affiliation(s)
- Faikah Gueler
- Department of Nephrology, Medical School Hannover, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany.
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Hammad H, Lambrecht BN. Dendritic cells and epithelial cells: linking innate and adaptive immunity in asthma. Nat Rev Immunol 2008; 8:193-204. [PMID: 18301423 DOI: 10.1038/nri2275] [Citation(s) in RCA: 445] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Dendritic cells (DCs) are generally held responsible for initiating and maintaining allergic T helper 2 (T(H)2)-cell responses to inhaled allergens in asthma. Although the epithelium was initially considered to function solely as a physical barrier, it is now seen as a central player in the T(H)2-cell sensitization process by influencing the function of DCs. Clinically relevant allergens, as well as known environmental and genetic risk factors for allergy and asthma, often interfere directly or indirectly with the innate immune functions of airway epithelial cells and DCs. A better understanding of these interactions, ascertained from human and animal studies, might lead to better prevention and treatment of asthma.
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Affiliation(s)
- Hamida Hammad
- Department of Respiratory Diseases, Laboratory of Immunoregulation and Mucosal Immunology, University Hospital Ghent, Belgium
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18
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Zaidi AK, Ali H. C3a receptors signaling in mast cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 598:126-40. [PMID: 17892209 DOI: 10.1007/978-0-387-71767-8_10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Asifa K Zaidi
- University of Pennsylvania School of Dental Medicine, Department of Pathology, Philadelphia, PA 19104, USA.
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19
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Wang X, Saito J, Tanino Y, Ishida T, Fujita T, Munakata M. Mannose binding lectin gene polymorphisms and asthma. Clin Exp Allergy 2007; 37:1334-9. [PMID: 17845414 DOI: 10.1111/j.1365-2222.2007.02761.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Bronchial asthma is a chronic inflammatory disorder of the airways. Recently, it has been suggested that complement plays significant roles in asthma. Mannose-binding lectin (MBL) is one of the key molecules in complement activation pathways that are associated with several infectious and immune disorders. SUBJECTS AND METHOD To investigate whether MBL plays roles in asthma, we analysed MBL2 polymorphisms (allele B, H/L and Y/X) and plasma MBL levels in a Japanese adult population including 232 healthy controls and 579 asthmatics. RESULTS Although there was linkage disequilibrium among the three polymorphisms, each polymorphism significantly affects serum MBL levels independently. However, there were no significant differences between asthmatics and controls in MBL2 genotype distribution and in MBL concentrations [1.47+/-0.07(SE) mg/L for asthmatics and 1.66+/-0.14 mg/L for controls, P=0.2]. MBL levels and genotype have no significant relationship with serum IgE, pulmonary functions, and the severity of asthma. CONCLUSION Although plasma MBL levels depend on the MBL2 polymorphisms, these polymorphisms and plasma MBL levels are not associated with the asthma phenotype.
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Affiliation(s)
- X Wang
- Department of Pulmonary Medicine, School of Medicine, Fukushima Medical University, Fukushima City, Japan
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20
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Benninghoff AD, Williams DE. Identification of a transcriptional fingerprint of estrogen exposure in rainbow trout liver. Toxicol Sci 2007; 101:65-80. [PMID: 17823450 PMCID: PMC2917912 DOI: 10.1093/toxsci/kfm238] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The goal of this study was to identify a set of hepatic genes regulated by ligand-dependent activation of the estrogen receptor in juvenile rainbow trout (Oncorhynchus mykiss). A custom rainbow trout oligo DNA microarray, which contains probes targeting approximately 1450 genes relevant to carcinogenesis, toxicology, endocrinology, and stress physiology was utilized to identify transcriptional fingerprints of in vivo dietary exposure to 17 beta-estradiol (E2), tamoxifen (TAM), estradiol + tamoxifen (E2 + TAM), diethylstilbestrol (DES), dehydroepiandrosterone (DHEA), dihydrotestosterone (DHT), and cortisol (CORT). Estrogen exposure altered the expression of up to 49 genes involved in reproduction, immune response, cell growth, transcriptional regulation, protein synthesis and modification, drug metabolism, redox regulation, and signal transduction. E2, DES, and DHEA regulated 18 genes in common, mostly those associated with vitellogenesis, cell proliferation, and signal transduction. Interestingly, DHEA uniquely regulated several complement component genes of importance to immune response. While the effect of TAM on E2-induced changes in gene expression was mostly antagonistic, TAM alone increased expression of VTG1 and other genes associated with egg development and immune response. Few genes responded to CORT treatment, and DHT significantly altered expression of only one gene targeted by the OSUrbt array. Hierarchical cluster and principal components analyses revealed distinct patterns of gene expression corresponding to estrogens and non-estrogens, though unique patterns could also be detected for individual chemicals. A set of estrogen-responsive genes has been identified that can serve as a biomarker of environmental exposure to xenoestrogens.
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Affiliation(s)
- Abby D Benninghoff
- Department of Environmental and Molecular Toxicology, the Marine and Freshwater Biomedical Sciences Center, 1007 Agricultural and Life Sciences Building, Corvallis, OR 97331, USA.
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Köhl J. Self, non-self, and danger: a complementary view. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 586:71-94. [PMID: 16893066 DOI: 10.1007/0-387-34134-x_6] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Complement is a sophisticated system of molecules that is critical to the functional integrity of the body. Initially considered as a defense system to ward off infections, it becomes increasingly clear that the complement system is one of the most important humoral systems to sense danger, i.e., to recognize conserved patterns on pathogens and on altered/damaged self. In addition to this important role in danger recognition, the complement system has the ability to translate the danger information into an adequate cellular innate or adaptive immune response. This is accomplished by two distinct mechanisms: (a) danger sensors that have recognized altered cells or pathogens can directly activate cell-bound receptors (e.g., C1q/C1q receptor interaction), and/or (b) danger sensors initiate cleavage of complement factors C3 and C5, the fragments of which acquire the ability to bind to complement receptors and/or regulators. It is the specific interaction of the danger sensors and of the cleavage fragments with distinct cell-bound receptors/regulators that directs the immune response toward an innate or an adaptive phenotype. Further, the expression pattern of the complement receptors critically impacts the shape of the immune response. Complement has the ability to discriminate between physiological and pathological danger, i.e., physiological cell death and death in response to injury. In the former case, cells are merely flagged for enhanced phagocytosis (by C3 fragments) without accompanying inflammation (through CR3), whereas in the latter case inflammatory signals are accessorily triggered (e.g., by the release of ATs, which recruit and activate neutrophils, eosinophils, etc.). This function is of major importance for apoptotic cell clearance and tissue repair but plays also important roles in fibrotic tissue remodeling in response to chronic tissue injury. Further, complement cleavage fragments may prevent the development of maldaptive immune responses at the mucosal surface. Here, complement fragment C5a does not act as a danger transmitter but as a "homeostasis transmitter," as its interaction with the C5a receptor on DCs provides a signal that prevents DCs from activating CD4+ T cells. The generation of regulatory T cells in response to CD46 ligation may have a similar function, as injured cells lose CD46 expresssion, which may lead to decreased proliferation of Tregs and, consecutively, increased production of T effector cells. Although we are still at the beginning of understanding the complex interaction patterns within the complement system, recent data suggest substantial crosstalk between the signaling pathways downstream of complement receptors and other receptors of the innate immune system that function as immune sensors and/or transmitters (i.e., TLRs, FcgammaRs130,131). Given the importance of complement as a sensor and effector system of innate and adaptive immune responses, a complement-related view of the immune system might help to unravel some enigmas of autoimmunity, allergy, and transplantation.
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Affiliation(s)
- Jörg Köhl
- Division of Molecular Immunology, Cincinnati Children's Hospital Research Foundation, MLC 7021, Cincinnati, OH 45229, USA.
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22
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Köhl J, Wills-Karp M. Complement regulates inhalation tolerance at the dendritic cell/T cell interface. Mol Immunol 2006; 44:44-56. [PMID: 16889830 DOI: 10.1016/j.molimm.2006.06.016] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Accepted: 06/22/2006] [Indexed: 12/31/2022]
Abstract
Pulmonary exposure to innocuous aeroallergens is a common event leading to inhalation tolerance. Distinct subsets of pulmonary dendritic cells (DC) and regulatory T cells (T(Reg)) play critical roles in mediating and maintaining such tolerance. In asthmatics, the same aeroallergens drive a maladaptive, Th2-biased immune response resulting in airway inflammation and airway hyper-reactivity. The mechanisms underlying the breakdown of inhalation tolerance, leading to the Th2-driven inflammation in rising numbers of asthmatic patients from industrialized countries remain elusive. The recent resurgence of interest in the role of the innate immune mediators in regulating adaptive immune response has sparked studies aimed at identifying the role of complement in allergic asthma. In this context, an unexpected role for the anaphylatoxin C5a receptor in allergic sensitization has been found. In models of experimental allergic asthma, ablation of C5aR signaling during initial allergen exposure either induced or enhanced Th2 sensitization. Mechanistically, C5aR signaling directly affected the function of distinct pulmonary DC subsets that induce or control allergen-induced adaptive immune responses. Signaling pathways downstream of C5 may also impact the function of T(Reg), as T(Reg) from C5 sufficient, but not from C5 deficient mice, suppress DC activation and subsequent development of Th2-driven inflammation. The emerging paradigm is that constitutive local generation of C5a and C5aR signaling in airway DCs controls inhalation tolerance directly as well as indirectly through sensitization of airway DCs for T(Reg)-mediated immunosuppression.
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Affiliation(s)
- Jörg Köhl
- Division of Molecular Immunology, Cincinnati Children's Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA.
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23
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Köhl J. The role of complement in danger sensing and transmission. Immunol Res 2006; 34:157-76. [PMID: 16760575 DOI: 10.1385/ir:34:2:157] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 01/08/2023]
Abstract
Self-non-self discrimination has long been considered the main function of the immune system. Increasing evidence supports the view of the immune system as a network of complex danger sensors and transmitters in which self-non-self discrimination is only one facet. To meet the challenge of danger sensing, the immune system carries a large stock of germline-encoded, highly conserved molecules that can recognize microbial as well as modified host structures. Among those are the Toll-like receptors (TLR), which comprise a dozen membrane-bound pattern-recognition receptors that directly link danger recognition to danger transmission through activation of several distinct cellular signaling pathways. Here, I discuss the function and biology of a complex, evolutionary ancient system, the complement system, which has long been considered critical to host defense. In contrast to TLRs, the complement system senses danger by a panel of soluble molecules that can directly bind to specific complement receptors and/or initiate a complex cascade of proteolytic events that lead to the generation of soluble complement fragments able to bind to another, distinct set of specific complement receptors. As I will outline in this review, complement- mediated danger sensing and the complex transition of this information into distinct cellular activation profiles is critical for tissue homeostasis under steady-state conditions and in response to infection and cell injury. Furthermore, I will discuss recent findings that support a concept of intense cross-talk between the complement system and TLRs, which defines the quality and the magnitude of immune responses in vivo.
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Affiliation(s)
- Jörg Köhl
- Division of Molecular Immunology, Cincinnati Children's Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, Ohio 45229, USA.
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Pirofski LA. Of mice and men, revisited: new insights into an ancient molecule from studies of complement activation by Cryptococcus neoformans. Infect Immun 2006; 74:3079-84. [PMID: 16714535 PMCID: PMC1479240 DOI: 10.1128/iai.00431-06] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Affiliation(s)
- Liise-Anne Pirofski
- Division of Infectious Diseases, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA.
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25
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Born WK, Reardon CL, O'Brien RL. The function of gammadelta T cells in innate immunity. Curr Opin Immunol 2005; 18:31-8. [PMID: 16337364 DOI: 10.1016/j.coi.2005.11.007] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2005] [Accepted: 11/24/2005] [Indexed: 02/06/2023]
Abstract
Many researchers believe that gammadelta T lymphocytes belong somewhere 'in-between' the innate and adaptive immune systems. Recent studies strongly emphasize the innate features and functions of these cells, including the use of germline elements of the T cell receptor for ligand recognition, segregation into functionally specialized cell populations in correlation with T cell receptor variable gene or protein expression, interactions with cells of the innate system at many levels and, the latest addition, the ability to present antigen. Thus, at present, much evidence suggests that gammadelta T cells function in an innate manner, although they are arguably the most complex and advanced cellular representatives of the innate immune system.
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Affiliation(s)
- Willi K Born
- Department of Immunology, at National Jewish Medical and Research Center, 1400 Jackson Street, Denver, CO 80206, USA.
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