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Abstract
Mast cell granules are packed with proteases, which are released with other mediators by degranulating stimuli. Several of these proteases are targets of potentially therapeutic inhibitors based on hypothesized contributions to diseases, notably asthma and ulcerative colitis for β-tryptases, heart and kidney scarring for chymases, and airway infection for dipeptidyl peptidase-I. Small-molecule and antibody-based β-tryptase inhibitors showing preclinical promise were tested in early-phase human trials with some evidence of benefit. Chymase inhibitors were given safely in Phase II trials without demonstrating benefits, whereas dipeptidyl peptidase-I inhibitor improved bronchiectasis, in effects likely related to inactivation of the enzyme in neutrophils.
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2
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Maun HR, Jackman JK, Choy DF, Loyet KM, Staton TL, Jia G, Dressen A, Hackney JA, Bremer M, Walters BT, Vij R, Chen X, Trivedi NN, Morando A, Lipari MT, Franke Y, Wu X, Zhang J, Liu J, Wu P, Chang D, Orozco LD, Christensen E, Wong M, Corpuz R, Hang JQ, Lutman J, Sukumaran S, Wu Y, Ubhayakar S, Liang X, Schwartz LB, Babina M, Woodruff PG, Fahy JV, Ahuja R, Caughey GH, Kusi A, Dennis MS, Eigenbrot C, Kirchhofer D, Austin CD, Wu LC, Koerber JT, Lee WP, Yaspan BL, Alatsis KR, Arron JR, Lazarus RA, Yi T. An Allosteric Anti-tryptase Antibody for the Treatment of Mast Cell-Mediated Severe Asthma. Cell 2020; 179:417-431.e19. [PMID: 31585081 DOI: 10.1016/j.cell.2019.09.009] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 07/09/2019] [Accepted: 09/05/2019] [Indexed: 12/18/2022]
Abstract
Severe asthma patients with low type 2 inflammation derive less clinical benefit from therapies targeting type 2 cytokines and represent an unmet need. We show that mast cell tryptase is elevated in severe asthma patients independent of type 2 biomarker status. Active β-tryptase allele count correlates with blood tryptase levels, and asthma patients carrying more active alleles benefit less from anti-IgE treatment. We generated a noncompetitive inhibitory antibody against human β-tryptase, which dissociates active tetramers into inactive monomers. A 2.15 Å crystal structure of a β-tryptase/antibody complex coupled with biochemical studies reveal the molecular basis for allosteric destabilization of small and large interfaces required for tetramerization. This anti-tryptase antibody potently blocks tryptase enzymatic activity in a humanized mouse model, reducing IgE-mediated systemic anaphylaxis, and inhibits airway tryptase in Ascaris-sensitized cynomolgus monkeys with favorable pharmacokinetics. These data provide a foundation for developing anti-tryptase as a clinical therapy for severe asthma.
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Affiliation(s)
- Henry R Maun
- Department of Early Discovery Biochemistry, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Janet K Jackman
- Department of Immunology Discovery, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - David F Choy
- Department of Biomarker Discovery OMNI, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Kelly M Loyet
- Department of Biochemical and Cellular Pharmacology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Tracy L Staton
- Department of OMNI Biomarker Development, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Guiquan Jia
- Department of Biomarker Discovery OMNI, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Amy Dressen
- Department of Human Genetics, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Jason A Hackney
- Department of Bioinformatics, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Meire Bremer
- Department of OMNI Biomarker Development, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Benjamin T Walters
- Department of Biochemical and Cellular Pharmacology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Rajesh Vij
- Department of Antibody Engineering, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Xiaocheng Chen
- Department of Antibody Engineering, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Neil N Trivedi
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Veterans Affairs Medical Center, San Francisco, CA 94121, USA
| | - Ashley Morando
- Department of Biochemical and Cellular Pharmacology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Michael T Lipari
- Department of Early Discovery Biochemistry, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Yvonne Franke
- Depratment of Biomolecular Resources, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Xiumin Wu
- Department of Translational Immunology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Juan Zhang
- Department of Translational Immunology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - John Liu
- Department of Translational Immunology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Ping Wu
- Department of Structural Biology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Diana Chang
- Department of Human Genetics, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Luz D Orozco
- Department of Bioinformatics, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Erin Christensen
- Department of Protein Chemistry, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Manda Wong
- Department of Structural Biology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Racquel Corpuz
- Department of Structural Biology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Julie Q Hang
- Department of Protein Chemistry, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Jeff Lutman
- Department of Preclinical and Translational Pharmacokinetics, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Siddharth Sukumaran
- Department of Preclinical and Translational Pharmacokinetics, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Yan Wu
- Department of Antibody Engineering, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Savita Ubhayakar
- Department of Drug Metabolism and Pharmacokinetics, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Xiaorong Liang
- Department of Drug Metabolism and Pharmacokinetics, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Lawrence B Schwartz
- Department of Internal Medicine, Division of Rheumatology, Allergy and Immunology, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Magda Babina
- Department of Dermatology and Allergy, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Prescott G Woodruff
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - John V Fahy
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Rahul Ahuja
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Veterans Affairs Medical Center, San Francisco, CA 94121, USA
| | - George H Caughey
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Veterans Affairs Medical Center, San Francisco, CA 94121, USA
| | - Aija Kusi
- Department of Safety Assessment, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Mark S Dennis
- Department of Antibody Engineering, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Charles Eigenbrot
- Department of Structural Biology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Daniel Kirchhofer
- Department of Early Discovery Biochemistry, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Cary D Austin
- Department of Pathology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Lawren C Wu
- Department of Immunology Discovery, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - James T Koerber
- Department of Antibody Engineering, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Wyne P Lee
- Department of Translational Immunology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Brian L Yaspan
- Department of Human Genetics, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Kathila R Alatsis
- Department of Safety Assessment, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Joseph R Arron
- Department of Immunology Discovery, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
| | - Robert A Lazarus
- Department of Early Discovery Biochemistry, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
| | - Tangsheng Yi
- Department of Immunology Discovery, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
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Maun HR, Jackman JK, Choy DF, Loyet KM, Staton TL, Jia G, Dressen A, Hackney JA, Bremer M, Walters BT, Vij R, Chen X, Trivedi NN, Morando A, Lipari MT, Franke Y, Wu X, Zhang J, Liu J, Wu P, Chang D, Orozco LD, Christensen E, Wong M, Corpuz R, Hang JQ, Lutman J, Sukumaran S, Wu Y, Ubhayakar S, Liang X, Schwartz LB, Babina M, Woodruff PG, Fahy JV, Ahuja R, Caughey GH, Kusi A, Dennis MS, Eigenbrot C, Kirchhofer D, Austin CD, Wu LC, Koerber JT, Lee WP, Yaspan BL, Alatsis KR, Arron JR, Lazarus RA, Yi T. An Allosteric Anti-tryptase Antibody for the Treatment of Mast Cell-Mediated Severe Asthma. Cell 2020; 180:406. [PMID: 31978350 DOI: 10.1016/j.cell.2020.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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4
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Korkmaz B, Caughey GH, Chapple I, Gauthier F, Hirschfeld J, Jenne DE, Kettritz R, Lalmanach G, Lamort AS, Lauritzen C, Łȩgowska M, Lesner A, Marchand-Adam S, McKaig SJ, Moss C, Pedersen J, Roberts H, Schreiber A, Seren S, Thakker NS. Therapeutic targeting of cathepsin C: from pathophysiology to treatment. Pharmacol Ther 2018; 190:202-236. [DOI: 10.1016/j.pharmthera.2018.05.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Greenland JR, Sun H, Calabrese D, Chong T, Singer JP, Kukreja J, Hays SR, Golden JA, Caughey GH, Venstrom JM, Rajalinginam R. HLA Mismatching Favoring Host-Versus-Graft NK Cell Activity Via KIR3DL1 Is Associated With Improved Outcomes Following Lung Transplantation. Am J Transplant 2017; 17:2192-2199. [PMID: 28375571 PMCID: PMC5519429 DOI: 10.1111/ajt.14295] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 03/07/2017] [Accepted: 03/24/2017] [Indexed: 01/25/2023]
Abstract
Chronic lung allograft dysfunction (CLAD) is linked to rejection and limits survival following lung transplantation. HLA-Bw4 recipients of HLA-Bw6 grafts have enhanced host-versus-graft (HVG) natural killer (NK) cell activity mediated by killer cell immunoglobulin-like receptor (KIR)3DL1 ligand. Because NK cells may promote tolerance by depleting antigen-presenting cells, we hypothesized improved outcomes for HLA-Bw4 recipients of HLA-Bw6 grafts. We evaluated differences in acute cellular rejection and CLAD-free survival across 252 KIR3DL1+ recipients from University of California, San Francisco (UCSF). For validation, we assessed survival and freedom from bronchiolitis obliterans syndrome (BOS), retransplantation, or death in 12 845 non-KIR typed recipients from the United Network for Organ Sharing (UNOS) registry. Cox proportional hazards models were adjusted for age, gender, ethnicity, transplant type, and HLA mismatching. HVG-capable subjects in the UCSF cohort had a decreased risk of CLAD or death (hazard ratio [HR] 0.57, 95% confidence interval [CI] 0.36-0.88) and decreased early lymphocytic bronchitis. The HVG effect was not significant in subjects with genotypes predicting low KIR3DL1 expression. In the UNOS cohort, HVG-capable subjects had a decreased risk of BOS, retransplant, or death (HR 0.95, 95% CI 0.91-0.99). Survival improved with the higher-affinity Bw4-80I ligand and in Bw4 homozygotes. Improved outcomes in HVG-capable recipients are consistent with a protective NK cell role. Augmentation of NK activity could supplement current immunosuppression techniques.
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Affiliation(s)
- John R. Greenland
- Medical Service, Veterans Affairs Medical Center, San Francisco CA, 94121,Department of Medicine, University of California, San Francisco CA, 94143,Corresponding author:
| | - Haibo Sun
- Immunogenetics and Transplantation Laboratory, Department of Surgery, University of California, San Francisco CA, 94143
| | - Daniel Calabrese
- Department of Medicine, University of California, San Francisco CA, 94143
| | - Tiffany Chong
- Department of Medicine, University of California, San Francisco CA, 94143
| | - Jonathan P. Singer
- Department of Medicine, University of California, San Francisco CA, 94143
| | - Jasleen Kukreja
- Department of Surgery, University of California, San Francisco CA, 94143
| | - Steven R. Hays
- Department of Medicine, University of California, San Francisco CA, 94143
| | - Jeffrey A. Golden
- Department of Medicine, University of California, San Francisco CA, 94143,Department of Surgery, University of California, San Francisco CA, 94143
| | - George H. Caughey
- Medical Service, Veterans Affairs Medical Center, San Francisco CA, 94121,Department of Medicine, University of California, San Francisco CA, 94143,Cardiovascular Research Institute, University of California, San Francisco CA, 94143
| | | | - Raja Rajalinginam
- Immunogenetics and Transplantation Laboratory, Department of Surgery, University of California, San Francisco CA, 94143
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6
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Prabhakaran A, Dhaliwal G, Schilf CRJ, Caughey GH, Pile J. A shocking diagnosis. J Hosp Med 2017; 12:104-108. [PMID: 28182807 DOI: 10.12788/jhm.2690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The approach to clinical conundrums by an expert clinician is revealed through the presentation of an actual patient's case in an approach typical of a morning report. Similarly to patient care, sequential pieces of information are provided to the clinician, who is unfamiliar with the case. The focus is on the thought processes of both the clinical team caring for the patient and the discussant.
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Affiliation(s)
| | - Gurpreet Dhaliwal
- Department of Medicine, University of California, San Francisco, CA, USA
- Medical Service, San Francisco VA Medical Center, San Francisco, CA, USA
| | | | - George H Caughey
- Department of Medicine, University of California, San Francisco, CA, USA
- Medical Service, San Francisco VA Medical Center, San Francisco, CA, USA
| | - James Pile
- Department of Medicine, MetroHealth Medical Center, Case Western Reserve University, Cleveland, OH, USA
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7
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Lyons JJ, Yu X, Hughes JD, Le QT, Jamil A, Bai Y, Ho N, Zhao M, Liu Y, O'Connell MP, Trivedi NN, Nelson C, DiMaggio T, Jones N, Matthews H, Lewis KL, Oler AJ, Carlson RJ, Arkwright PD, Hong C, Agama S, Wilson TM, Tucker S, Zhang Y, McElwee JJ, Pao M, Glover SC, Rothenberg ME, Hohman RJ, Stone KD, Caughey GH, Heller T, Metcalfe DD, Biesecker LG, Schwartz LB, Milner JD. Elevated basal serum tryptase identifies a multisystem disorder associated with increased TPSAB1 copy number. Nat Genet 2016; 48:1564-1569. [PMID: 27749843 DOI: 10.1038/ng.3696] [Citation(s) in RCA: 232] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 09/16/2016] [Indexed: 12/14/2022]
Abstract
Elevated basal serum tryptase levels are present in 4-6% of the general population, but the cause and relevance of such increases are unknown. Previously, we described subjects with dominantly inherited elevated basal serum tryptase levels associated with multisystem complaints including cutaneous flushing and pruritus, dysautonomia, functional gastrointestinal symptoms, chronic pain, and connective tissue abnormalities, including joint hypermobility. Here we report the identification of germline duplications and triplications in the TPSAB1 gene encoding α-tryptase that segregate with inherited increases in basal serum tryptase levels in 35 families presenting with associated multisystem complaints. Individuals harboring alleles encoding three copies of α-tryptase had higher basal serum levels of tryptase and were more symptomatic than those with alleles encoding two copies, suggesting a gene-dose effect. Further, we found in two additional cohorts (172 individuals) that elevated basal serum tryptase levels were exclusively associated with duplication of α-tryptase-encoding sequence in TPSAB1, and affected individuals reported symptom complexes seen in our initial familial cohort. Thus, our findings link duplications in TPSAB1 with irritable bowel syndrome, cutaneous complaints, connective tissue abnormalities, and dysautonomia.
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Affiliation(s)
- Jonathan J Lyons
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Xiaomin Yu
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Jason D Hughes
- Merck Research Laboratories, Merck &Co. Inc., Boston, Massachusetts, USA
| | - Quang T Le
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Ali Jamil
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Yun Bai
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Nancy Ho
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Ming Zhao
- Research Technologies Branch, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Rockville, Maryland, USA
| | - Yihui Liu
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Michael P O'Connell
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Neil N Trivedi
- Cardiovascular Research Institute and Department of Medicine, University of California at San Francisco, San Francisco, California, USA.,Veterans Affairs Medical Center, San Francisco, California, USA
| | - Celeste Nelson
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Thomas DiMaggio
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Nina Jones
- Clinical Research Directorate/CMRP, SAIC-Frederick, Inc., Frederick National Laboratory for Clinical Research, Frederick, Maryland, USA
| | - Helen Matthews
- Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Katie L Lewis
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, US National Institutes of Health, Bethesda, Maryland, USA
| | - Andrew J Oler
- Bioinformatics and Computational Biosciences Branch, Office of Cyber Infrastructure and Computational Biology, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Ryan J Carlson
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Peter D Arkwright
- Institute of Infection, Immunity and Respiratory Medicine, University of Manchester, Royal Manchester Children's Hospital, Manchester, UK
| | - Celine Hong
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, US National Institutes of Health, Bethesda, Maryland, USA
| | - Sherene Agama
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Todd M Wilson
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Sofie Tucker
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Yu Zhang
- Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Joshua J McElwee
- Merck Research Laboratories, Merck &Co. Inc., Boston, Massachusetts, USA
| | - Maryland Pao
- National Institute of Mental Health, US National Institutes of Health, Bethesda, Maryland, USA
| | - Sarah C Glover
- Division of Gastroenterology, Hepatology, and Nutrition, University of Florida, Gainesville, Florida, USA
| | - Marc E Rothenberg
- Division of Allergy and Immunology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Robert J Hohman
- Research Technologies Branch, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Rockville, Maryland, USA
| | - Kelly D Stone
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - George H Caughey
- Cardiovascular Research Institute and Department of Medicine, University of California at San Francisco, San Francisco, California, USA.,Veterans Affairs Medical Center, San Francisco, California, USA
| | - Theo Heller
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Dean D Metcalfe
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
| | - Leslie G Biesecker
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, US National Institutes of Health, Bethesda, Maryland, USA
| | - Lawrence B Schwartz
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Joshua D Milner
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, Maryland, USA
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8
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Abstract
Host-derived proteases can augment or help to clear infections. This dichotomy is exemplified by cathepsin L (CTSL), which helps Hendra virus and SARS coronavirus to invade cells, but is essential for survival in mice with mycoplasma pneumonia. The present study tested the hypothesis that CTSL protects mice from serious consequences of infection by the orthomyxovirus influenza A, which is thought to be activated by host-supplied proteases other than CTSL. Ctsl-/- mice infected with influenza A/Puerto Rico/8/34(H1N1) had larger lung viral loads and higher mortality than infected Ctsl+/+ mice. Lung inflammation in surviving infected mice peaked 14 days after initial infection, accompanied marked focal distal airway bronchiolization and epithelial metaplasia followed by desquamation and fibrotic interstitial remodeling, and persisted for at least 6 weeks. Most deaths occurred during the second week of infection in both groups of mice. In contrast to mycoplasma pneumonia, infiltrating cells were predominantly mononuclear rather than polymorphonuclear. The histopathology of lung inflammation and remodeling in survivors was similar in Ctsl-/- and Ctsl+/+ mice, although Ctsl+/+ mice cleared immunoreactive virus sooner. Furthermore, Ctsl-/- mice had profound deficits in CD4+ lymphocytes before and after infection and weaker production of pathogen-specific IgG. Thus, CTSL appears to support innate as well as adaptive responses, which confer a survival advantage on mice infected with the orthomyxovirus influenza A.
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Affiliation(s)
- Xiang Xu
- Department of Medicine, University of California at San Francisco, San Francisco, California, United States of America
| | - John R. Greenland
- Department of Medicine, University of California at San Francisco, San Francisco, California, United States of America
- Veterans Affairs Medical Center, San Francisco, California, United States of America
| | - Jeffrey E. Gotts
- Department of Medicine, University of California at San Francisco, San Francisco, California, United States of America
- Cardiovascular Research Institute, University of California at San Francisco, San Francisco, California, United States of America
| | - Michael A. Matthay
- Department of Medicine, University of California at San Francisco, San Francisco, California, United States of America
- Cardiovascular Research Institute, University of California at San Francisco, San Francisco, California, United States of America
| | - George H. Caughey
- Department of Medicine, University of California at San Francisco, San Francisco, California, United States of America
- Veterans Affairs Medical Center, San Francisco, California, United States of America
- Cardiovascular Research Institute, University of California at San Francisco, San Francisco, California, United States of America
- * E-mail:
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9
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Nimishakavi S, Raymond WW, Gruenert DC, Caughey GH. Divergent Inhibitor Susceptibility among Airway Lumen-Accessible Tryptic Proteases. PLoS One 2015; 10:e0141169. [PMID: 26485396 PMCID: PMC4612780 DOI: 10.1371/journal.pone.0141169] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 10/04/2015] [Indexed: 12/21/2022] Open
Abstract
Tryptic serine proteases of bronchial epithelium regulate ion flux, barrier integrity, and allergic inflammation. Inhibition of some of these proteases is a strategy to improve mucociliary function in cystic fibrosis and asthmatic inflammation. Several inhibitors have been tested in pre-clinical animal models and humans. We hypothesized that these inhibitors inactivate a variety of airway protease targets, potentially with bystander effects. To establish relative potencies and modes of action, we compared inactivation of human prostasin, matriptase, airway trypsin-like protease (HAT), and β-tryptase by nafamostat, camostat, bis(5-amidino-2-benzimidazolyl)methane (BABIM), aprotinin, and benzamidine. Nafamostat achieved complete, nearly stoichiometric and very slowly reversible inhibition of matriptase and tryptase, but inhibited prostasin less potently and was weakest versus HAT. The IC50 of nafamostat’s leaving group, 6-amidino-2-naphthol, was >104-fold higher than that of nafamostat itself, consistent with suicide rather than product inhibition as mechanisms of prolonged inactivation. Stoichiometric release of 6-amidino-2-naphthol allowed highly sensitive fluorometric estimation of active-site concentration in preparations of matriptase and tryptase. Camostat inactivated all enzymes but was less potent overall and weakest towards matriptase, which, however was strongly inhibited by BABIM. Aprotinin exhibited nearly stoichiometric inhibition of prostasin and matriptase, but was much weaker towards HAT and was completely ineffective versus tryptase. Benzamidine was universally weak. Thus, each inhibitor profile was distinct. Nafamostat, camostat and aprotinin markedly reduced tryptic activity on the apical surface of cystic fibrosis airway epithelial monolayers, suggesting prostasin as the major source of such activity and supporting strategies targeting prostasin for inactivation.
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Affiliation(s)
- Shilpa Nimishakavi
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
- Veterans Affairs Medical Center, San Francisco, California, United States of America
| | - Wilfred W. Raymond
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
- Veterans Affairs Medical Center, San Francisco, California, United States of America
| | - Dieter C. Gruenert
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
- Department of Otolaryngology-Head and Neck Surgery, University of California San Francisco, San Francisco, California, United States of America
- Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California San Francisco, San Francisco, California, United States of America
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, California, United States of America
- Institute for Human Genetics, University of California San Francisco, San Francisco, California, United States of America
- Department of Pediatrics, University of Vermont College of Medicine, Burlington, Vermont, United States of America
| | - George H. Caughey
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
- Veterans Affairs Medical Center, San Francisco, California, United States of America
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
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10
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Raymond WW, Xu X, Nimishakavi S, Le C, McDonald DM, Caughey GH. Regulation of hepatocyte growth factor in mice with pneumonia by peptidases and trans-alveolar flux. PLoS One 2015; 10:e0125797. [PMID: 25938594 PMCID: PMC4418689 DOI: 10.1371/journal.pone.0125797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 03/25/2015] [Indexed: 11/23/2022] Open
Abstract
Hepatocyte growth factor (HGF) promotes lung epithelial repair after injury. Because prior studies established that human neutrophil proteases inactivate HGF in vitro, we predicted that HGF levels decrease in lungs infiltrated with neutrophils and that injury is less severe in lungs lacking HGF-inactivating proteases. After establishing that mouse neutrophil elastase cleaves mouse HGF in vitro, we tested our predictions in vivo by examining lung pathology and HGF in mice infected with Mycoplasma pulmonis, which causes neutrophilic tracheobronchitis and pneumonia. Unexpectedly, pneumonia severity was similar in wild type and dipeptidylpeptidase I-deficient (Dppi-/-) mice lacking neutrophil serine protease activity. To assess how this finding related to our prediction that Dppi-activated proteases regulate HGF levels, we measured HGF in serum, bronchoalveolar lavage fluid, and lung tissue from Dppi+/+ and Dppi-/- mice. Contrary to prediction, HGF levels were higher in lavage fluid from infected mice. However, serum and tissue concentrations were not different in infected and uninfected mice, and HGF lung transcript levels did not change. Increased HGF correlated with increased albumin in lavage fluid from infected mice, and immunostaining failed to detect increased lung tissue expression of HGF in infected mice. These findings are consistent with trans-alveolar flux rather than local production as the source of increased HGF in lavage fluid. However, levels of intact HGF from infected mice, normalized for albumin concentration, were two-fold higher in Dppi-/- versus Dppi+/+ lavage fluid, suggesting regulation by Dppi-activated proteases. Consistent with the presence of active HGF, increased expression of activated receptor c-Met was observed in infected tissues. These data suggest that HGF entering alveoli from the bloodstream during pneumonia compensates for destruction by Dppi-activated inflammatory proteases to allow HGF to contribute to epithelial repair.
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Affiliation(s)
- Wilfred W. Raymond
- Cardiovascular Research Institute, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Xiang Xu
- Department of Medicine, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Shilpa Nimishakavi
- Cardiovascular Research Institute, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Catherine Le
- Department of Anatomy, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Donald M. McDonald
- Cardiovascular Research Institute, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Department of Anatomy, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - George H. Caughey
- Cardiovascular Research Institute, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Department of Medicine, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Northern California Institute for Research and Education, San Francisco, California, United States of America
- Veterans Affairs Medical Center, San Francisco, California, United States of America
- * E-mail:
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11
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Bose O, Baluk P, Looney MR, Cheng LE, McDonald DM, Caughey GH, Krummel MF. Mast cells present protrusions into blood vessels upon tracheal allergen challenge in mice. PLoS One 2015; 10:e0118513. [PMID: 25789765 PMCID: PMC4366375 DOI: 10.1371/journal.pone.0118513] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 01/11/2015] [Indexed: 11/18/2022] Open
Abstract
Mast cells (MC) and myeloid dendritic cells (DC) act proximally in detecting and processing antigens and immune insults. We sought to understand their comparative dynamic behavior with respect to the airway epithelium in the steady state and in response to an allergic stimulus in mouse trachea. We devised methods to label MC in living trachea and to demonstrate that MC and DC occupy distinct layers of the tracheal mucosa, with DC being closer to the lumen. DC numbers doubled after allergen challenge, but MC numbers remained stable. MC and DC migrated minimally in either steady state or allergen-challenge conditions, and their interactions with one another appeared to be stochastic and relatively infrequent. While DC, unlike MC, exhibited probing behaviors involving dendrites, these projections did not cross the epithelium into the airway lumen. MC typically were located too far from the epithelial surface to contact the tracheal lumen. However, MC had protrusions toward and into blood vessels, likely to load with IgE. Thus, DC and MC occupy distinct niches and engage in sessile surveillance in the mouse trachea. Little or no access of these cell types to the airway lumen suggests that trans-epithelial transport of proteins in the steady state would be required for them to access luminal antigens.
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Affiliation(s)
- Oishee Bose
- Department of Pathology, University of California San Francisco, San Francisco, California, United States of America
| | - Peter Baluk
- Department of Anatomy, University of California San Francisco, San Francisco, California, United States of America
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, and Veterans Affairs Medical Center, San Francisco, California, United States of America
| | - Mark R. Looney
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Laurence E. Cheng
- Department of Pediatrics, University of California San Francisco, San Francisco, California, United States of America
| | - Donald M. McDonald
- Department of Anatomy, University of California San Francisco, San Francisco, California, United States of America
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, and Veterans Affairs Medical Center, San Francisco, California, United States of America
| | - George H. Caughey
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
- * E-mail: (MFK); (GHC)
| | - Matthew F. Krummel
- Department of Pathology, University of California San Francisco, San Francisco, California, United States of America
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, and Veterans Affairs Medical Center, San Francisco, California, United States of America
- * E-mail: (MFK); (GHC)
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12
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Greenland JR, Xu X, Sayah DM, Liu FC, Jones KD, Looney MR, Caughey GH. Mast cells in a murine lung ischemia-reperfusion model of primary graft dysfunction. Respir Res 2014; 15:95. [PMID: 25115556 PMCID: PMC4151192 DOI: 10.1186/s12931-014-0095-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 08/04/2014] [Indexed: 01/21/2023] Open
Abstract
Primary graft dysfunction (PGD), as characterized by pulmonary infiltrates and high oxygen requirements shortly after reperfusion, is the major cause of early morbidity and mortality after lung transplantation. Donor, recipient and allograft-handling factors are thought to contribute, although new insights regarding pathogenesis are needed to guide approaches to prevention and therapy. Mast cells have been implicated in ischemic tissue injury in other model systems and in allograft rejection, leading to the hypothesis that mast cell degranulation contributes to lung injury following reperfusion injury. We tested this hypothesis in a mouse model of PGD involving reversible disruption of blood flow to one lung. Metrics of injury included albumin permeability, plasma extravasation, lung histopathology, and mast cell degranulation. Responses were assessed in wild-type (Kit+/+) and mast cell-deficient (KitW-sh/W-sh) mice. Because mouse lungs have few mast cells compared with human lungs, we also tested responses in mice with lung mastocytosis generated by injecting bone marrow-derived cultured mast cells (BMCMC). We found that ischemic lung responses of mast cell-deficient KitW-sh/W-sh mice did not differ from those of Kit+/+ mice, even after priming for injury using LPS. Degranulated mast cells were more abundant in ischemic than in non-ischemic BMCMC-injected KitW-sh/W-sh lungs. However, lung injury in BMCMC-injected KitW-sh/W-sh and Kit+/+ mice did not differ in globally mast cell-deficient, uninjected KitW-sh/W-sh mice or in wild-type Kit+/+ mice relatively deficient in lung mast cells. These findings predict that mast cells, although activated in lungs injured by ischemia and reperfusion, are not necessary for the development of PGD.
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13
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Sutherland RE, Barry SS, Olsen JS, Salantes DB, Caughey GH, Wolters PJ. Dipeptidyl peptidase I controls survival from Klebsiella pneumoniae lung infection by processing surfactant protein D. Biochem Biophys Res Commun 2014; 450:818-823. [PMID: 24955853 DOI: 10.1016/j.bbrc.2014.06.062] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 06/13/2014] [Indexed: 01/01/2023]
Abstract
Prior work established that a deficiency in the cysteine protease dipeptidyl peptidase I (DPPI) improves survival following polymicrobial septic peritonitis. To test whether DPPI regulates survival from severe lung infections, DPPI(-/-) mice were studied in a Klebsiella pneumoniae lung infection model, finding that survival in DPPI(-/-) mice is significantly better than in DPPI(+/+) mice 8d after infection. DPPI(-/-) mice have significantly fewer bacteria in the lung than infected DPPI(+/+) mice, but no difference in lung histopathology, lung injury, or cytokine levels. To explore mechanisms of enhanced bacterial clearance in DPPI(-/-) mice, we examined the status of pulmonary collectins, finding that levels of surfactant protein D, but not of surfactant protein A, are higher in DPPI(-/-) than in DPPI(+/+) BAL fluid, and that DPPI(-/-) BAL fluid aggregate bacteria more effectively than control BAL fluid. Sequencing of the amino terminus of surfactant protein D revealed two or eight additional amino acids in surfactant protein D isolated from DPPI(-/-) mice, suggesting processing by DPPI. These results establish that DPPI is a major determinant of survival following Klebsiella pneumoniae lung infection and suggest that the survival disadvantage in DPPI(+/+) mice is in part due to processing of surfactant protein D by DPPI.
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Affiliation(s)
- Rachel E Sutherland
- Department of Medicine and The Cardiovascular Research Institute, University of California, San Francisco, CA 94143-0111
| | - Sophia S Barry
- Department of Medicine and The Cardiovascular Research Institute, University of California, San Francisco, CA 94143-0111
| | - Joanna S Olsen
- Department of Medicine and The Cardiovascular Research Institute, University of California, San Francisco, CA 94143-0111
| | - D Brenda Salantes
- Department of Medicine and The Cardiovascular Research Institute, University of California, San Francisco, CA 94143-0111
| | - George H Caughey
- Department of Medicine and The Cardiovascular Research Institute, University of California, San Francisco, CA 94143-0111
| | - Paul J Wolters
- Department of Medicine and The Cardiovascular Research Institute, University of California, San Francisco, CA 94143-0111
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14
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Greenland JR, Jewell NP, Gottschall M, Trivedi NN, Kukreja J, Hays SR, Singer JP, Golden JA, Caughey GH. Bronchoalveolar lavage cell immunophenotyping facilitates diagnosis of lung allograft rejection. Am J Transplant 2014; 14:831-40. [PMID: 24512389 PMCID: PMC4300200 DOI: 10.1111/ajt.12630] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 10/21/2013] [Accepted: 10/25/2013] [Indexed: 01/25/2023]
Abstract
Supplementary methods to identify acute rejection and to distinguish rejection from infection may improve clinical outcomes for lung allograft recipients. We hypothesized that distinct bronchoalveolar lavage (BAL) cell profiles are associated with rejection and infection. We retrospectively compared 2939 BAL cell counts and immunophenotypes against concomitantly obtained transbronchial biopsies and microbiologic studies. We randomly assigned 317 subjects to a derivation or validation cohort. BAL samples were classified into four groups: infection, rejection grade ≥A1, both or neither. We employed generalized estimating equation and survival modeling to identify clinical predictors of rejection and infection. We found that CD25(+) and natural killer cell percentages identified a twofold increased odds of rejection compared to either the infection or the neither infection nor rejection groups. Also, monocytes, lymphocytes and eosinophil percentages were independently associated with rejection. A four-predictor scoring system had high negative predictive value (96-98%) for grade ≥A2 rejection, predicted future rejection in the validation cohort and predicted increased risk of bronchiolitis obliterans syndrome in otherwise benign samples. In conclusion, BAL cell immunophenotyping discriminates between infection and acute rejection and predicts future outcomes in lung transplant recipients. Although it cannot replace histopathology, immunophenotyping may be a clinically useful adjunct.
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Affiliation(s)
- JR Greenland
- Department of Medicine, University of California at San Francisco, CA 94143,Medical Service, Veterans Affairs Medical Center, San Francisco, CA 94121
| | - NP Jewell
- Division of Biostatistics, University of California, Berkeley, CA, 94720
| | - M Gottschall
- Department of Pathology, University of California at San Francisco, CA 94143
| | - NN Trivedi
- Department of Medicine, University of California at San Francisco, CA 94143,Medical Service, Veterans Affairs Medical Center, San Francisco, CA 94121
| | - J Kukreja
- Department of Surgery, University of California at San Francisco, CA 94143
| | - SR Hays
- Department of Medicine, University of California at San Francisco, CA 94143
| | - JP Singer
- Department of Medicine, University of California at San Francisco, CA 94143
| | - JA Golden
- Department of Medicine, University of California at San Francisco, CA 94143
| | - GH Caughey
- Department of Medicine, University of California at San Francisco, CA 94143,Cardiovascular Research Institute, University of California at San Francisco, CA 94143,Medical Service, Veterans Affairs Medical Center, San Francisco, CA 94121
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15
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Xu X, Greenland J, Baluk P, Adams A, Bose O, McDonald DM, Caughey GH. Cathepsin L protects mice from mycoplasmal infection and is essential for airway lymphangiogenesis. Am J Respir Cell Mol Biol 2013; 49:437-44. [PMID: 23600672 DOI: 10.1165/rcmb.2013-0016oc] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Cathepsin L (Ctsl) is a proposed therapeutic target to control inflammatory responses in a number of disease states. However, Ctsl is thought to support host defense via its involvement in antigen presentation pathways. Hypothesizing that Ctsl helps combat bacterial infection, we investigated its role in Mycoplasma pulmonis-infected mice as a model of acute and chronic infectious airway inflammation. Responses to the airway inoculation of mycoplasma were compared in Ctsl(-/-) and Ctsl(+/+) mice. After infection, Ctsl(-/-) mice demonstrated more body weight loss, greater mortality (22% versus 0%, respectively), and heavier lungs than Ctsl(+/+) mice, but had smaller bronchial lymph nodes. The burden of live mycoplasma in lungs was 247-fold greater in Ctsl(-/-) mice than in Ctsl(+/+) mice after infection for 3 days. Ctsl(-/-) mice exhibited more severe pneumonia and neutrophil-rich, airway-occlusive exudates, which developed more rapidly than in Ctsl(+/+) mice. Compared with the conspicuous remodeling of lymphatics after infection in Ctsl(+/+) mice, little lymphangiogenesis occurred in Ctsl(-/-) mice, but blood vessel remodeling and tissue inflammation were similarly severe. Titers of mycoplasma-reactive IgM, IgA, and IgG in blood in response to live and heat-killed organisms were similar to those in Ctsl(+/+) mice. However, enzyme-linked immunosorbent spot assays revealed profound reductions in the cellular IFN-γ response to mycoplasma antigen. These findings suggest that Ctsl helps contain mycoplasma infection by supporting lymphangiogenesis and cellular immune responses to infection, and our findings predict that the therapeutic inhibition of Ctsl could increase the severity of mycoplasmal infections.
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Affiliation(s)
- Xiang Xu
- Department of Medicine, University of California at San Francisco, CA 94121, USA
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16
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Raman K, Trivedi NN, Raymond WW, Ganesan R, Kirchhofer D, Verghese GM, Craik CS, Schneider EL, Nimishakavi S, Caughey GH. Mutational tail loss is an evolutionary mechanism for liberating marapsins and other type I serine proteases from transmembrane anchors. J Biol Chem 2013; 288:10588-98. [PMID: 23447538 DOI: 10.1074/jbc.m112.449033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human and mouse marapsins (Prss27) are serine proteases preferentially expressed by stratified squamous epithelia. However, mouse marapsin contains a transmembrane anchor absent from the human enzyme. To gain insights into physical forms, activities, inhibition, and roles in epithelial differentiation, we traced tail loss in human marapsin to a nonsense mutation in an ancestral ape, compared substrate preferences of mouse and human marapsins with those of the epithelial peptidase prostasin, designed a selective substrate and inhibitor, and generated Prss27-null mice. Phylogenetic analysis predicts that most marapsins are transmembrane proteins. However, nonsense mutations caused membrane anchor loss in three clades: human/bonobo/chimpanzee, guinea pig/degu/tuco-tuco/mole rat, and cattle/yak. Most marapsin-related proteases, including prostasins, are type I transmembrane proteins, but the closest relatives (prosemins) are not. Soluble mouse and human marapsins are tryptic with subsite preferences distinct from those of prostasin, lack general proteinase activity, and unlike prostasins resist antiproteases, including leupeptin, aprotinin, serpins, and α2-macroglobulin, suggesting the presence of non-canonical active sites. Prss27-null mice develop normally in barrier conditions and are fertile without overt epithelial defects, indicating that marapsin does not play critical, non-redundant roles in development, reproduction, or epithelial differentiation. In conclusion, marapsins are conserved, inhibitor-resistant, tryptic peptidases. Although marapsins are type I transmembrane proteins in their typical form, they mutated independently into anchorless forms in several mammalian clades, including one involving humans. Similar pathways appear to have been traversed by prosemins and tryptases, suggesting that mutational tail loss is an important means of evolving new functions of tryptic serine proteases from transmembrane ancestors.
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Affiliation(s)
- Kavita Raman
- Cardiovascular Research Institute, University of California, San Francisco, California 94143, USA
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17
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Greenland JR, Jones KD, Hays SR, Golden JA, Urisman A, Jewell NP, Caughey GH, Trivedi NN. Association of large-airway lymphocytic bronchitis with bronchiolitis obliterans syndrome. Am J Respir Crit Care Med 2012; 187:417-23. [PMID: 23239157 DOI: 10.1164/rccm.201206-1025oc] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Lung transplantation offers great promise for otherwise terminal lung diseases, but the development of bronchiolitis obliterans syndrome (BOS) continues to limit survival. Although acute rejection and lymphocytic bronchiolitis have been identified as risk factors for the development of BOS, it is unclear whether large-airway lymphocytic inflammation conveys the same risk. OBJECTIVES We evaluated lymphocytic bronchitis on endobronchial biopsies as a risk factor for BOS and mortality. METHODS Endobronchial biopsies were collected and graded during surveillance after lung transplantation. We assessed samples with negative cultures collected in the first 90 days from 298 subjects and compared large-airway lymphocytic bronchitis assessed by a 0-2 "E-score" and with standard A and BR pathology scores for acute rejection and small-airway lymphocytic bronchiolitis, respectively. MEASUREMENTS AND MAIN RESULTS We found surprisingly little association between large- and small-airway lymphocytic inflammation scores from a given bronchoscopy. Endobronchial lymphocytic bronchitis was more prevalent in subjects in BOS stage 0p and BOS stages 1-3 at the time of biopsy. Within 90 days after transplantation, increasing maximum E-score was associated with greater risk of BOS (adjusted hazard ratio, 1.76; 95% confidence interval, 1.11-2.78; P = 0.02) and in this analysis 90-day maximum E-scores were the only score type predictive of BOS (P < 0.01). CONCLUSIONS These results support a multicenter study to evaluate endoscopic biopsies for the identification of patients at increased risk for BOS. The association of endobronchial lymphocytic inflammation and BOS may have mechanistic implications.
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Affiliation(s)
- John R Greenland
- Department of Medicine, University of California at San Francisco, San Francisco, CA 94121, USA
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18
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Nimishakavi S, Besprozvannaya M, Raymond WW, Craik CS, Gruenert DC, Caughey GH. Activity and inhibition of prostasin and matriptase on apical and basolateral surfaces of human airway epithelial cells. Am J Physiol Lung Cell Mol Physiol 2012; 303:L97-106. [PMID: 22582115 DOI: 10.1152/ajplung.00303.2011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Prostasin is a membrane-anchored protease expressed in airway epithelium, where it stimulates salt and water uptake by cleaving the epithelial Na(+) channel (ENaC). Prostasin is activated by another transmembrane tryptic protease, matriptase. Because ENaC-mediated dehydration contributes to cystic fibrosis (CF), prostasin and matriptase are potential therapeutic targets, but their catalytic competence on airway epithelial surfaces has been unclear. Seeking tools for exploring sites and modulation of activity, we used recombinant prostasin and matriptase to identify substrate t-butyloxycarbonyl-l-Gln-Ala-Arg-4-nitroanilide (QAR-4NA), which allowed direct assay of proteases in living cells. Comparisons of bronchial epithelial cells (CFBE41o-) with and without functioning cystic fibrosis transmembrane conductance regulator (CFTR) revealed similar levels of apical and basolateral aprotinin-inhibitable activity. Although recombinant matriptase was more active than prostasin in hydrolyzing QAR-4NA, cell surface activity resisted matriptase-selective inhibition, suggesting that prostasin dominates. Surface biotinylation revealed similar expression of matriptase and prostasin in epithelial cells expressing wild-type vs. ΔF508-mutated CFTR. However, the ratio of mature to inactive proprostasin suggested surface enrichment of active enzyme. Although small amounts of matriptase and prostasin were shed spontaneously, prostasin anchored to the cell surface by glycosylphosphatidylinositol was the major contributor to observed QAR-4NA-hydrolyzing activity. For example, the apical surface of wild-type CFBE41o- epithelial cells express 22% of total, extractable, aprotinin-inhibitable, QAR-4NA-hydrolyzing activity and 16% of prostasin immunoreactivity. In conclusion, prostasin is present, mature and active on the apical surface of wild-type and CF bronchial epithelial cells, where it can be targeted for inhibition via the airway lumen.
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19
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Sugimoto K, Kudo M, Sundaram A, Ren X, Huang K, Bernstein X, Wang Y, Raymond WW, Erle DJ, Abrink M, Caughey GH, Huang X, Sheppard D. The αvβ6 integrin modulates airway hyperresponsiveness in mice by regulating intraepithelial mast cells. J Clin Invest 2012; 122:748-58. [PMID: 22232213 DOI: 10.1172/jci58815] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Accepted: 11/30/2011] [Indexed: 12/14/2022] Open
Abstract
Allergic asthma is the most common form of asthma, affecting more than 10 million Americans. Although it is clear that mast cells have a key role in the pathogenesis of allergic asthma, the mechanisms by which they regulate airway narrowing in vivo remain to be elucidated. Here we report that mice lacking αvβ6 integrin are protected from exaggerated airway narrowing in a model of allergic asthma. Expression microarrays of the airway epithelium revealed mast cell proteases among the most prominent differentially expressed genes, with expression of mouse mast cell protease 1 (mMCP-1) induced by allergen challenge in WT mice and expression of mMCP-4, -5, and -6 increased at baseline in β6-deficient mice. These findings were most likely explained by loss of TGF-β activation, since the epithelial integrin αvβ6 is a critical activator of latent TGF-β, and in vitro-differentiated mast cells showed TGF-β-dependent expression of mMCP-1 and suppression of mMCP-4 and -6. In vitro, mMCP-1 increased contractility of murine tracheal rings, an effect that depended on intact airway epithelium, whereas mMCP-4 inhibited IL-13-induced epithelial-independent enhancement of contractility. These results suggest that intraepithelial activation of TGF-β by the αvβ6 integrin regulates airway responsiveness by modulating mast cell protease expression and that these proteases and their proteolytic substrates could be novel targets for improved treatment of allergic asthma.
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Affiliation(s)
- Kotaro Sugimoto
- Lung Biology Center, Department of Medicine, UCSF, San Francisco, California, USA
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20
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Sutherland RE, Xu X, Kim SS, Seeley EJ, Caughey GH, Wolters PJ. Parasitic infection improves survival from septic peritonitis by enhancing mast cell responses to bacteria in mice. PLoS One 2011; 6:e27564. [PMID: 22110673 PMCID: PMC3217977 DOI: 10.1371/journal.pone.0027564] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Accepted: 10/19/2011] [Indexed: 12/26/2022] Open
Abstract
Mammals are serially infected with a variety of microorganisms, including bacteria and parasites. Each infection reprograms the immune system's responses to re-exposure and potentially alters responses to first-time infection by different microorganisms. To examine whether infection with a metazoan parasite modulates host responses to subsequent bacterial infection, mice were infected with the hookworm-like intestinal nematode Nippostrongylus brasiliensis, followed in 2–4 weeks by peritoneal injection of the pathogenic bacterium Klebsiella pneumoniae. Survival from Klebsiella peritonitis two weeks after parasite infection was better in Nippostrongylus-infected animals than in unparasitized mice, with Nippostrongylus-infected mice having fewer peritoneal bacteria, more neutrophils, and higher levels of protective interleukin 6. The improved survival of Nippostrongylus-infected mice depends on IL-4 because the survival benefit is lost in mice lacking IL-4. Because mast cells protect mice from Klebsiella peritonitis, we examined responses in mast cell-deficient KitW-sh/KitW-sh mice, in which parasitosis failed to improve survival from Klebsiella peritonitis. However, adoptive transfer of cultured mast cells to KitW-sh/KitW-sh mice restored survival benefits of parasitosis. These results show that recent infection with Nippostrongylus brasiliensis protects mice from Klebsiella peritonitis by modulating mast cell contributions to host defense, and suggest more generally that parasitosis can yield survival advantages to a bacterially infected host.
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Affiliation(s)
- Rachel E. Sutherland
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Xiang Xu
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Sophia S. Kim
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Eric J. Seeley
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - George H. Caughey
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Paul J. Wolters
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
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21
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Xu X, Zhang H, Song Y, Lynch SV, Lowell CA, Wiener-Kronish JP, Caughey GH. Strain-dependent induction of neutrophil histamine production and cell death by Pseudomonas aeruginosa. J Leukoc Biol 2011; 91:275-84. [PMID: 22075928 DOI: 10.1189/jlb.0711356] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Airway diseases often feature persistent neutrophilic inflammation and infection. In cystic fibrosis bronchitis, for example, Pseudomonas aeruginosa is isolated frequently. Previously, this laboratory revealed that neutrophils become major sources of histamine in mice with tracheobronchitis caused by the wall-less bacterium Mycoplasma pulmonis. To test the hypothesis that more-broadly pathogenic P. aeruginosa (which expresses cell wall-associated LPS and novel toxins) has similar effects, we incubated naïve mouse neutrophils with two strains of P. aeruginosa. Strain PAO1 greatly increased neutrophil histamine content and secretion, whereas strain PA103 depressed histamine production by killing neutrophils. The histamine-stimulating capacity of PAO1, but not PA103-mediated toxicity, persisted in heat-killed organisms. In PAO1-infected mice, lung and neutrophil histamine content increased. However, PAO1 did not alter production by mast cells (classical histamine reservoirs), which also resisted PA103 toxicity. To explore mechanisms of neutrophil-selective induction, we measured changes in mRNA encoding histidine decarboxylase (rate-limiting for histamine synthesis), probed involvement of endotoxin-TLR pathways in Myd88-deficient neutrophils, and examined contributions of pyocyanin and exotoxins. Results revealed that PAO1 increased histamine production by up-regulating histidine decarboxylase mRNA via pathways largely independent of TLR, pyocyanin, and type III secretion system exotoxins. PAO1 also increased histidine decarboxylase mRNA in neutrophils purified from infected lung. Stimulation required direct contact with neutrophils and was blocked by phagocytosis inhibitor cytochalasin D. In summary, Pseudomonas-augmented histamine production by neutrophils is strain-dependent in vitro and likely mediated by up-regulation of histidine decarboxylase. These findings raise the possibility that Pseudomonas-stimulated neutrophils can enhance airway inflammation by producing histamine.
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Affiliation(s)
- Xiang Xu
- Department of Medicine, University of California at San Francisco, San Francisco, California, USA
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Raymond WW, Trivedi NN, Makarova A, Ray M, Craik CS, Caughey GH. How immune peptidases change specificity: cathepsin G gained tryptic function but lost efficiency during primate evolution. J Immunol 2010; 185:5360-8. [PMID: 20889553 DOI: 10.4049/jimmunol.1002292] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cathepsin G is a major secreted serine peptidase of neutrophils and mast cells. Studies in Ctsg-null mice suggest that cathepsin G supports antimicrobial defenses but can injure host tissues. The human enzyme has an unusual "Janus-faced" ability to cleave peptides at basic (tryptic) as well as aromatic (chymotryptic) sites. Tryptic activity has been attributed to acidic Glu(226) in the primary specificity pocket and underlies proposed important functions, such as activation of prourokinase. However, most mammals, including mice, substitute Ala(226) for Glu(226), suggesting that human tryptic activity may be anomalous. To test this hypothesis, human cathepsin G was compared with mouse wild-type and humanized active site mutants, revealing that mouse primary specificity is markedly narrower than that of human cathepsin G, with much greater Tyr activity and selectivity and near absence of tryptic activity. It also differs from human in resisting tryptic peptidase inhibitors (e.g., aprotinin), while favoring angiotensin destruction at Tyr(4) over activation at Phe(8). Ala(226)Glu mutants of mouse cathepsin G acquire tryptic activity and human ability to activate prourokinase. Phylogenetic analysis reveals that the Ala(226)Glu missense mutation appearing in primates 31-43 million years ago represented an apparently unprecedented way to create tryptic activity in a serine peptidase. We propose that tryptic activity is not an attribute of ancestral mammalian cathepsin G, which was primarily chymotryptic, and that primate-selective broadening of specificity opposed the general trend of increased specialization by immune peptidases and allowed acquisition of new functions.
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Affiliation(s)
- Wilfred W Raymond
- Cardiovascular Research Institute, University of California at San Francisco, San Francisco, CA 94143, USA
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Dougherty RH, Sidhu SS, Raman K, Solon M, Solberg OD, Caughey GH, Woodruff PG, Fahy JV. Accumulation of intraepithelial mast cells with a unique protease phenotype in T(H)2-high asthma. J Allergy Clin Immunol 2010; 125:1046-1053.e8. [PMID: 20451039 DOI: 10.1016/j.jaci.2010.03.003] [Citation(s) in RCA: 201] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Revised: 03/01/2010] [Accepted: 03/02/2010] [Indexed: 02/06/2023]
Abstract
BACKGROUND Previously, we found that mast cell tryptases and carboxypeptidase A3 (CPA3) are differentially expressed in the airway epithelium in asthmatic subjects. We also found that asthmatic subjects can be divided into 2 subgroups ("T(H)2 high" and "T(H)2 low" asthma) based on epithelial cell gene signatures for the activity of T(H)2 cytokines. OBJECTIVES We sought to characterize intraepithelial mast cells (IEMCs) in asthma. METHODS We performed gene expression profiling in epithelial brushings and stereology-based quantification of mast cell numbers in endobronchial biopsy specimens from healthy control and asthmatic subjects before and after treatment with inhaled corticosteroids (ICSs). We also performed gene expression and protein quantification studies in cultured airway epithelial cells and mast cells. RESULTS By means of unsupervised clustering, mast cell gene expression in the airway epithelium related closely to the expression of IL-13 signature genes. The levels of expression of mast cell genes correlate positively with lung function improvements with ICSs. IEMC density was 2-fold higher than normal in subjects with T(H)2-high asthma compared with that seen in subjects with T(H)2-low asthma or healthy control subjects (P = .015 for both comparisons), and these cells were characterized by expression of tryptases and CPA3 but not chymase. IL-13 induced expression of stem cell factor in cultured airway epithelial cells, and mast cells exposed to conditioned media from IL-13-activated epithelial cells showed downregulation of chymase but no change in tryptase or CPA3 expression. CONCLUSION IEMC numbers are increased in subjects with T(H)2-high asthma, have an unusual protease phenotype (tryptase and CPA3 high and chymase low), and predict responsiveness to ICSs. IL-13-stimulated production of stem cell factor by epithelial cells potentially explains mast cell accumulation in T(H)2-high asthmatic epithelium.
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Affiliation(s)
- Ryan H Dougherty
- Division of Pulmonary and Critical Care Medicine, University of California, San Francisco, CA, USA
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Abstract
Mast cells make and secrete an abundance of peptidases, which are stored in such large amounts in granules that they comprise a high fraction of all cellular protein. Perhaps no other immune cell is so generously endowed with peptidases. For many years after the main peptidases were first described, they were best known as markers of degranulation, for they are released locally in response to mast cell stimulation and can be distributed systemically and detected in blood. The principal peptidases are tryptases, chymases, carboxypeptidase A3, and dipeptidylpeptidase I (cathepsin C). Numerous studies suggest that these enzymes are important and even critical for host defense and homeostasis. Endogenous and allergen or pathogen-associated targets have been identified. Belying the narrow notion of peptidases as proinflammatory, several of the peptidases limit inflammation and toxicity of endogenous peptides and venoms. The peptidases are interdependent, so that absence or inactivity of one enzyme can alter levels and activity of others. Mammalian mast cell peptidases--chymases and tryptases especially--vary remarkably in number, expression, biophysical properties, and specificity, perhaps because they hyper-evolved under pressure from the very pathogens they help to repel. Tryptase and chymase involvement in some pathologies stimulated development of therapeutic inhibitors for use in asthma, lung fibrosis, pulmonary hypertension, ulcerative colitis, and cardiovascular diseases. While animal studies support the potential for mast cell peptidase inhibitors to mitigate certain diseases, other studies, as in mice lacking selected peptidases, predict roles in defense against bacteria and parasites and that systemic inactivation may impair host defense.
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Affiliation(s)
- Neil N Trivedi
- Section of Pulmonary and Critical Care Medicine, Medicine Service, Veterans Affairs Medical Center, Mailstop 111-D, 4150 Clement Street, San Francisco, CA 94121, USA
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Trivedi NN, Tamraz B, Chu C, Kwok PY, Caughey GH. Human subjects are protected from mast cell tryptase deficiency despite frequent inheritance of loss-of-function mutations. J Allergy Clin Immunol 2009; 124:1099-105.e1-4. [PMID: 19748655 DOI: 10.1016/j.jaci.2009.07.026] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Revised: 07/13/2009] [Accepted: 07/16/2009] [Indexed: 12/29/2022]
Abstract
BACKGROUND Mast cell tryptases have proposed roles in allergic inflammation and host defense against infection. Tryptase gene loci TPSAB1 and TPSB2 are known to be polymorphic, but the nature and extent of diversity at these loci have not been fully explored. OBJECTIVE We sought to compare functional and nonfunctional tryptase allele frequencies and establish haplotypes in human populations. METHODS Tryptase allele frequencies were determined by means of direct sequencing in 270 individuals from HapMap populations of European, African, Chinese, and Japanese ancestry. Haplotypes were predicted, validated in parent-child trios, and compared between populations. RESULTS We identify a new frame-shifted tryptase allele (betaIII(FS)) carried by 23% and 19% of individuals of European and African ancestry but 0% of Asian subjects. Homology models predict that betaIII(FS) is functionless. Our genotyping assay shows that allele and haplotype distributions in each population are unique. Strong linkage disequilibrium between TPSAB1 and TPSB2 (r(2)=0.83, D'=0.85) yields 2 major and 5 minor tryptase haplotypes. CONCLUSIONS Tryptase deficiency alleles (alpha and the newly discovered betaIII(FS)) are common, causing the number of inherited active genes to range from a minimum of 2 to a maximum of 4, with major differences between populations in the proportion of individuals inheriting 2 versus 4 active alleles. African and Asian populations are especially enriched in genes encoding functional and nonfunctional tryptases, respectively. Strong linkage of TPSAB1 and TPSB2 and pairing of deficiency alleles with functional alleles in observed haplotypes protect human subjects from "knockout" genomes and indeed from inheritance of fewer than 2 active alleles.
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Affiliation(s)
- Neil N Trivedi
- Cardiovascular Research Institute, University of California at San Francisco, San Francisco, Calif, USA
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Raymond WW, Su S, Makarova A, Wilson TM, Carter MC, Metcalfe DD, Caughey GH. Alpha 2-macroglobulin capture allows detection of mast cell chymase in serum and creates a reservoir of angiotensin II-generating activity. J Immunol 2009; 182:5770-7. [PMID: 19380825 DOI: 10.4049/jimmunol.0900127] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Human chymase is a highly efficient angiotensin II-generating serine peptidase expressed by mast cells. When secreted from degranulating cells, it can interact with a variety of circulating antipeptidases, but is mostly captured by alpha(2)-macroglobulin, which sequesters peptidases in a cage-like structure that precludes interactions with large protein substrates and inhibitors, like serpins. The present work shows that alpha(2)-macroglobulin-bound chymase remains accessible to small substrates, including angiotensin I, with activity in serum that is stable with prolonged incubation. We used alpha(2)-macroglobulin capture to develop a sensitive, microtiter plate-based assay for serum chymase, assisted by a novel substrate synthesized based on results of combinatorial screening of peptide substrates. The substrate has low background hydrolysis in serum and is chymase-selective, with minimal cleavage by the chymotryptic peptidases cathepsin G and chymotrypsin. The assay detects activity in chymase-spiked serum with a threshold of approximately 1 pM (30 pg/ml), and reveals native chymase activity in serum of most subjects with systemic mastocytosis. alpha(2)-Macroglobulin-bound chymase generates angiotensin II in chymase-spiked serum, and it appears in native serum as chymostatin-inhibited activity, which can exceed activity of captopril-sensitive angiotensin-converting enzyme. These findings suggest that chymase bound to alpha(2)-macroglobulin is active, that the complex is an angiotensin-converting enzyme inhibitor-resistant reservoir of angiotensin II-generating activity, and that alpha(2)-macroglobulin capture may be exploited in assessing systemic release of secreted peptidases.
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Affiliation(s)
- Wilfred W Raymond
- Cardiovascular Research Institute, University of California at San Francisco, San Francisco, CA 94143, USA
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Innes AL, Carrington SD, Thornton DJ, Kirkham S, Rousseau K, Dougherty RH, Raymond WW, Caughey GH, Muller SJ, Fahy JV. Ex vivo sputum analysis reveals impairment of protease-dependent mucus degradation by plasma proteins in acute asthma. Am J Respir Crit Care Med 2009; 180:203-10. [PMID: 19423716 DOI: 10.1164/rccm.200807-1056oc] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Airway mucus plugs, composed of mucin glycoproteins mixed with plasma proteins, are an important cause of airway obstruction in acute severe asthma, and they are poorly treated with current therapies. OBJECTIVES To investigate mechanisms of airway mucus clearance in health and in acute severe asthma. METHODS We collected airway mucus from patients with asthma and nonasthmatic control subjects, using sputum induction or tracheal aspiration. We used rheological methods complemented by centrifugation-based mucin size profiling and immunoblotting to characterize the physical properties of the mucus gel, the size profiles of mucins, and the degradation products of albumin in airway mucus. MEASUREMENTS AND MAIN RESULTS Repeated ex vivo measures of size and entanglement of mucin polymers in airway mucus from nonasthmatic control subjects showed that the mucus gel is normally degraded by proteases and that albumin inhibits this degradation. In airway mucus collected from patients with asthma at various time points during acute asthma exacerbation, protease-driven mucus degradation was inhibited at the height of exacerbation but was restored during recovery. In immunoblots of human serum albumin digested by neutrophil elastase and in immunoblots of airway mucus, we found that albumin was a substrate of neutrophil elastase and that products of albumin degradation were abundant in airway mucus during acute asthma exacerbation. CONCLUSIONS Rheological methods complemented by centrifugation-based mucin size profiling of airway mucins in health and acute asthma reveal that mucin degradation is inhibited in acute asthma, and that an excess of plasma proteins present in acute asthma inhibits the degradation of mucins in a protease-dependent manner. These findings identify a novel mechanism whereby plasma exudation may impair airway mucus clearance.
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Affiliation(s)
- Anh L Innes
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California, USA
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Trivedi NN, Raymond WW, Caughey GH. Chimerism, point mutation, and truncation dramatically transformed mast cell δ-tryptases during primate evolution. J Allergy Clin Immunol 2008; 121:1262-8. [DOI: 10.1016/j.jaci.2008.01.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2007] [Revised: 01/03/2008] [Accepted: 01/16/2008] [Indexed: 11/24/2022]
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Caughey GH, Beauchamp J, Schlatter D, Raymond WW, Trivedi NN, Banner D, Mauser H, Fingerle J. Guinea pig chymase is leucine-specific: a novel example of functional plasticity in the chymase/granzyme family of serine peptidases. J Biol Chem 2008; 283:13943-51. [PMID: 18353771 DOI: 10.1074/jbc.m710502200] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To explore guinea pigs as models of chymase biology, we cloned and expressed the guinea pig ortholog of human chymase. In contrast to rats and mice, guinea pigs appear to express just one chymase, which belongs to the alpha clade, like primate chymases and mouse mast cell protease-5. The guinea pig enzyme autolyzes at Leu residues in the loop where human chymase autolyzes at Phe. In addition, guinea pig alpha-chymase selects P1 Leu in a combinatorial peptide library and cleaves Ala-Ala-Pro-Leu-4-nitroanilide but has negligible activity toward substrates with P1 Phe and does not cleave angiotensin I. This contrasts with human chymase, which cleaves after Phe or Tyr, prefers P1 Phe in peptidyl 4-nitroanilides, and avidly hydrolyzes angiotensin I at Phe8 to generate bioactive angiotensin II. The guinea pig enzyme also is inactivated more effectively by alpha1-antichymotrypsin, which features P1 Leu in the reactive loop. Unlike mouse, rat, and hamster alpha-chymases, guinea pig chymase lacks elastase-like preference for P1 Val or Ala. Partially humanized A216G guinea pig chymase acquires human-like P1 Phe- and angiotensin-cleaving capacity. Molecular models suggest that the wild type active site is crowded by the Ala216 side chain, which potentially blocks access by bulky P1 aromatic residues. On the other hand, the guinea pig pocket is deeper than in Val-selective chymases, explaining the preference for the longer aliphatic side chain of Leu. These findings are evidence that chymase-like peptidase specificity is sensitive to small changes in structure and provide the first example of a vertebrate Leu-selective peptidase.
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Affiliation(s)
- George H Caughey
- Cardiovascular Research Institute, University of California, San Francisco, California 94143, USA.
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Trivedi NN, Tong Q, Raman K, Bhagwandin VJ, Caughey GH. Mast cell alpha and beta tryptases changed rapidly during primate speciation and evolved from gamma-like transmembrane peptidases in ancestral vertebrates. J Immunol 2007; 179:6072-9. [PMID: 17947681 DOI: 10.4049/jimmunol.179.9.6072] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Human mast cell tryptases vary strikingly in secretion, catalytic competence, and inheritance. To explore the basis of variation, we compared genes from a range of primates, including humans, great apes (chimpanzee, gorilla, orangutan), Old- and New-World monkeys (macaque and marmoset), and a prosimian (galago), tracking key changes. Our analysis reveals that extant soluble tryptase-like proteins, including alpha- and beta-like tryptases, mastins, and implantation serine proteases, likely evolved from membrane-anchored ancestors because their more deeply rooted relatives (gamma tryptases, pancreasins, prostasins) are type I transmembrane peptidases. Function-altering mutations appeared at widely separated times during primate speciation, with tryptases evolving by duplication, gene conversion, and point mutation. The alpha-tryptase Gly(216)Asp catalytic domain mutation, which diminishes activity, is present in macaque tryptases, and thus arose before great apes and Old World monkeys shared an ancestor, and before the alphabeta split. However, the Arg(-3)Gln processing mutation appeared recently, affecting only human alpha. By comparison, the transmembrane gamma-tryptase gene, which anchors the telomeric end of the multigene tryptase locus, changed little during primate evolution. Related transmembrane peptidase genes were found in reptiles, amphibians, and fish. We identified soluble tryptase-like genes in the full spectrum of mammals, including marsupial (opossum) and monotreme (platypus), but not in nonmammalian vertebrates. Overall, our analysis suggests that soluble tryptases evolved rapidly from membrane-anchored, two-chain peptidases in ancestral vertebrates into soluble, single-chain, self-compartmentalizing, inhibitor-resistant oligomers expressed primarily by mast cells, and that much of present numerical, behavioral, and genetic diversity of alpha- and beta-like tryptases was acquired during primate evolution.
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Affiliation(s)
- Neil N Trivedi
- Cardiovascular Research Institute and Department of Medicine, University of California, San Francisco, CA 94143, USA
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Abstract
Tryptases and chymases are the major proteins stored and secreted by mast cells. The types, amounts, and properties of these serine peptidases vary by mast cell subtype, tissue, and mammal of origin. Membrane-anchored gamma-tryptases are tryptic, prostasin-like, type I peptidases that remain membrane attached on release and act locally. Soluble tryptases, including their close relatives, mastins, form inhibitor-resistant oligomers that act more remotely. Befitting their greater destructive potential, chymases are quickly inhibited after release, although some gain protection by associating with proteoglycans. Most chymase-like enzymes, including mast cell cathepsin G, hydrolyze chymotryptic substrates, an uncommon capability in the proteome. Some rodent chymases, however, have mutations resulting in elastolytic activity. Secreted tryptases and chymases promote inflammation, matrix destruction, and tissue remodeling by several mechanisms, including destroying procoagulant, matrix, growth, and differentiation factors and activating proteinase-activated receptors, urokinase, metalloproteinases, and angiotensin. They also modulate immune responses by hydrolyzing chemokines and cytokines. At least one chymase protects mice from intestinal worms. Tryptases and chymases can also oppose inflammation by inactivating allergens and neuropeptides causing inflammation and bronchoconstriction. Thus, like mast cells themselves, mast cell serine peptidases play multiple roles in host defense, and any accounting of benefit versus harm is necessarily context specific.
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Affiliation(s)
- George H Caughey
- Cardiovascular Research Institute, University of California at San Francisco, San Francisco, CA, USA.
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Cottrell GS, Amadesi S, Pikios S, Camerer E, Willardsen JA, Murphy BR, Caughey GH, Wolters PJ, Coughlin SR, Peterson A, Knecht W, Pothoulakis C, Bunnett NW, Grady EF. Protease-activated receptor 2, dipeptidyl peptidase I, and proteases mediate Clostridium difficile toxin A enteritis. Gastroenterology 2007; 132:2422-37. [PMID: 17570216 PMCID: PMC2366898 DOI: 10.1053/j.gastro.2007.03.101] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2006] [Accepted: 03/15/2007] [Indexed: 12/23/2022]
Abstract
BACKGROUND & AIMS We studied the role of protease-activated receptor 2 (PAR(2)) and its activating enzymes, trypsins and tryptase, in Clostridium difficile toxin A (TxA)-induced enteritis. METHODS We injected TxA into ileal loops in PAR(2) or dipeptidyl peptidase I (DPPI) knockout mice or in wild-type mice pretreated with tryptase inhibitors (FUT-175 or MPI-0442352) or soybean trypsin inhibitor. We examined the effect of TxA on expression and activity of PAR(2) and trypsin IV messenger RNA in the ileum and cultured colonocytes. We injected activating peptide (AP), trypsins, tryptase, and p23 in wild-type mice, some pretreated with the neurokinin 1 receptor antagonist SR140333. RESULTS TxA increased fluid secretion, myeloperoxidase activity in fluid and tissue, and histologic damage. PAR(2) deletion decreased TxA-induced ileitis, reduced luminal fluid secretion by 20%, decreased tissue and fluid myeloperoxidase by 50%, and diminished epithelial damage, edema, and neutrophil infiltration. DPPI deletion reduced secretion by 20% and fluid myeloperoxidase by 55%. In wild-type mice, FUT-175 or MPI-0442352 inhibited secretion by 24%-28% and tissue and fluid myeloperoxidase by 31%-71%. Soybean trypsin inhibitor reduced secretion to background levels and tissue myeloperoxidase by up to 50%. TxA increased expression of PAR(2) and trypsin IV in enterocytes and colonocytes and caused a 2-fold increase in Ca(2+) responses to PAR(2) AP. AP, tryptase, and trypsin isozymes (trypsin I/II, trypsin IV, p23) caused ileitis. SR140333 prevented AP-induced ileitis. CONCLUSIONS PAR(2) and its activators are proinflammatory in TxA-induced enteritis. TxA stimulates existing PAR(2) and up-regulates PAR(2) and activating proteases, and PAR(2) causes inflammation by neurogenic mechanisms.
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Affiliation(s)
- Graeme S Cottrell
- Center for the Neurobiology of Digestive Disease, Department of Surgery, University of California, San Francisco, San Francisco, California 94143-0660, USA
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Akin C, Soto D, Brittain E, Chhabra A, Schwartz LB, Caughey GH, Metcalfe DD. Tryptase haplotype in mastocytosis: relationship to disease variant and diagnostic utility of total tryptase levels. Clin Immunol 2007; 123:268-71. [PMID: 17449330 PMCID: PMC1949411 DOI: 10.1016/j.clim.2007.02.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Revised: 02/20/2007] [Accepted: 02/26/2007] [Indexed: 01/08/2023]
Abstract
Serum mast cell tryptase levels are used as a diagnostic criterion and surrogate marker of disease severity in mastocytosis. Approximately 29% of the healthy population lacks alpha tryptase genes; however, it is not known whether lack of alpha tryptase genes leads to variability in tryptase levels or impacts on disease severity in mastocytosis. We have thus analyzed tryptase haplotype in patients with mastocytosis, computing correlations between haplotype and plasma total and mature tryptase levels; and disease category. We found: (1) the distribution of tryptase haplotype in patients with mastocytosis appeared consistent with Hardy-Weinberg equilibrium and the distribution in the general population; (2) the disease severity and plasma tryptase levels were not affected by the number of alpha or beta tryptase alleles in this study; and (3) information about the tryptase haplotype did not provide any prognostic value about the severity of disease. Total and mature tryptase levels positively correlated with disease severity, as well as prothrombin time and partial thromboplastin time, and negatively correlated with the hemoglobin concentration.
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Affiliation(s)
- Cem Akin
- Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA.
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Abstract
Recent investigations point to an important role for peptidases in regulating transcellular ion transport by the epithelial Na(+) channel, ENaC. Several peptidases, including furins and proteasomal hydrolases, modulate ENaC maturation and disposal. More idiosyncratically, apical Na(+) transport by ENaC in polarized epithelia of kidney, airway, and gut is stimulated constitutively by one or more trypsin-family serine peptidases, as revealed by inhibition of amiloride-sensitive Na(+) transport by broad-spectrum antipeptidases, including aprotinin and bikunin/SPINT2. In vitro, the transporting activity of aprotinin-suppressed ENaC can be restored by exposure to trypsin. The prototypical channel-activating peptidase (CAP) is a type 1 membrane-anchored tryptic peptidase first identified in Xenopus kidney cells. Frog CAP1 strongly upregulates Na(+) transport when coexpressed with ENaC in oocytes. The amphibian enzyme's apparent mammalian orthologue is prostasin, otherwise known as CAP1, which is coexpressed with ENaC in a variety of epithelia. In airway cells, prostasin is the major basal regulator of ENaC activity, as suggested by inhibition and knockdown experiments. Other candidate regulators of mature ENaC include CAP2/TMPRSS4 and CAP3/matriptase (also known as membrane-type serine protease 1/ST14). Mammalian CAPs are potential targets for treatment of ENaC-mediated Na(+) hyperabsorption by the airway in cystic fibrosis (CF) and by the kidney in hypertension. CAPs can be important for mammalian development, as indicated by embryonic lethality in mice with null mutations of CAP1/prostasin. Mice with selectively knocked out expression of CAP1/prostasin in the epidermis and mice with globally knocked out expression of CAP3/matriptase exhibit phenotypically similar defects in skin barrier function and neonatal death from dehydration. In rats, transgenic overexpression of human prostasin disturbs salt balance and causes hypertension. Thus, several converging lines of evidence indicate that ENaC function is regulated by peptidases, and that such regulation is critical for embryonic development and adult function of organs such as skin, kidney, and lung.
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Affiliation(s)
- Carole Planès
- INSERM U773, Centre de Recherche Biomédicale Bichat-Beaujon (CRB3), Université Paris 7, 75018 Paris, France
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Mallen-St. Clair J, Shi GP, Sutherland RE, Chapman HA, Caughey GH, Wolters PJ. Cathepsins L and S are not required for activation of dipeptidyl peptidase I (cathepsin C) in mice. Biol Chem 2006; 387:1143-6. [PMID: 16895486 PMCID: PMC2271110 DOI: 10.1515/bc.2006.141] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The cysteine protease dipeptidyl peptidase I (DPPI) activates granule-associated immune-cell serine proteases. The in vivo activator of DPPI itself is unknown; however, cathepsins L and S are candidates because they activate pro-DPPI in vitro. In this study, we tested whether cathepsins L and S activate pro-DPPI in vivo by characterizing DPPI activity and processing in cells lacking cathepsins L and S. DPPI activity, and the relative size and amounts of DPPI heavy and light chains, were identical in mast cells from wild-type and cathepsin L/S double-null mice. Furthermore, the activity of DPPI-dependent chymase was preserved in tissues of cathepsin L/S double-null mice. These results show that neither cathepsin L nor S is required for activation of DPPI and suggest that one or more additional proteases is responsible.
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Xu X, Zhang D, Zhang H, Wolters PJ, Killeen NP, Sullivan BM, Locksley RM, Lowell CA, Caughey GH. Neutrophil histamine contributes to inflammation in mycoplasma pneumonia. ACTA ACUST UNITED AC 2006; 203:2907-17. [PMID: 17158962 PMCID: PMC2118183 DOI: 10.1084/jem.20061232] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Mycoplasmas cause chronic inflammation and are implicated in asthma. Mast cells defend against mycoplasma infection and worsen allergic inflammation, which is mediated partly by histamine. To address the hypothesis that mycoplasma provokes histamine release, we exposed mice to Mycoplasma pulmonis, comparing responses in wild-type and mast cell–deficient KitW-sh/KitW-sh (W-sh) mice. Low histamine levels in uninfected W-sh mice confirmed the conventional wisdom that mast cells are principal sources of airway and serum histamine. Although mycoplasma did not release histamine acutely in wild-type airways, levels rose up to 50-fold above baseline 1 week after infection in mice heavily burdened with neutrophils. Surprisingly, histamine levels also rose profoundly in infected W-sh lungs, increasing in parallel with neutrophils and declining with neutrophil depletion. Furthermore, neutrophils from infected airway were highly enriched in histamine compared with naive neutrophils. In vitro, mycoplasma directly stimulated histamine production by naive neutrophils and strongly upregulated mRNA encoding histidine decarboxylase, the rate-limiting enzyme in histamine synthesis. In vivo, treatment with antihistamines pyrilamine or cimetidine decreased lung weight and severity of pneumonia and tracheobronchitis in infected W-sh mice. These findings suggest that neutrophils, provoked by mycoplasma, greatly expand their capacity to synthesize histamine, thereby contributing to lung and airway inflammation.
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Affiliation(s)
- Xiang Xu
- Cardiovascular Research Institute, Department of Microbiology/Immunology, University of California at San Francisco, and Veterans Affairs Medical Center, San Francisco 94121, USA
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Abstract
Airways are protected from pathogens by forces allied with innate and adaptive immunity. Recent investigations establish critical defensive roles for leukocyte and mast cell serine-class peptidases garrisoned in membrane-bound organelles-here termed Granule-Associated Serine Peptidases of Immune Defense, or GASPIDs. Some better characterized GASPIDs include neutrophil elastase and cathepsin G (which defend against bacteria), proteinase-3 (targeted by antineutrophil antibodies in Wegener's vasculitis), mast cell beta-tryptase and chymase (which promote allergic inflammation), granzymes A and B (which launch apoptosis pathways in infected host cells), and factor D (which activates complement's alternative pathway). GASPIDs can defend against pathogens but can harm host cells in the process, and therefore become targets for pharmaceutical inhibition. They vary widely in specificity, yet are phylogenetically similar. Mammalian speciation supported a remarkable flowering of these enzymes as they co-evolved with specialized immune cells, including mast cells, basophils, eosinophils, cytolytic T-cells, natural killer cells, neutrophils, macrophages and dendritic cells. Many GASPIDs continue to evolve rapidly, providing some of the most conspicuous examples of divergent protein evolution. Consequently, students of GASPIDs are rewarded not only with insights into their roles in lung immune defense but also with clues to the origins of cellular specialization in vertebrate immunity.
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Affiliation(s)
- George H Caughey
- The Cardiovascular Research Institute and Department of Medicine, University of California at San Francisco, USA, Northern California Institute for Research and Education, USA, San Francisco Veterans Affairs Medical Center, USA
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Verghese GM, Gutknecht MF, Caughey GH. Prostasin regulates epithelial monolayer function: cell-specific Gpld1-mediated secretion and functional role for GPI anchor. Am J Physiol Cell Physiol 2006; 291:C1258-70. [PMID: 16822939 PMCID: PMC2271112 DOI: 10.1152/ajpcell.00637.2005] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Prostasin, a trypsinlike serine peptidase, is highly expressed in prostate, kidney, and lung epithelia, where it is bound to the cell surface, secreted, or both. Prostasin activates the epithelial sodium channel (ENaC) and suppresses invasion of prostate and breast cancer cells. The studies reported here establish mechanisms of membrane anchoring and secretion in kidney and lung epithelial cells and demonstrate a critical role for prostasin in regulating epithelial monolayer function. We report that endogenous mouse prostasin is glycosylphosphatidylinositol (GPI) anchored to the cell surface and is constitutively secreted from the apical surface of kidney cortical collecting duct cells. Using site-directed mutagenesis, detergent phase separation, and RNA interference approaches, we show that prostasin secretion depends on GPI anchor cleavage by endogenous GPI-specific phospholipase D1 (Gpld1). Secretion of prostasin by kidney and lung epithelial cells, in contrast to prostate epithelium, does not depend on COOH-terminal processing at conserved Arg(322). Using stably transfected M-1 cells expressing wild-type, catalytically inactive, or chimeric transmembrane (not GPI)-anchored prostasins we establish that prostasin regulates transepithelial resistance, current, and paracellular permeability by GPI anchor- and protease activity-dependent mechanisms. These studies demonstrate a novel role for prostasin in regulating epithelial monolayer resistance and permeability in kidney epithelial cells and, furthermore, show specifically that prostasin is a critical regulator of transepithelial ion transport in M-1 cells. These functions depend on the GPI anchor as well as the peptidase activity of prostasin. These studies suggest that cell-specific Gpld1- or peptidase-dependent pathways for prostasin secretion may control prostasin functions in a tissue-specific manner.
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Affiliation(s)
- George M Verghese
- Department of Medicine, University of Virginia, Charlottesville, Virginia 22908-0546, USA.
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Abstract
Tryptases secreted by tissue mast cells and basophils can enter the bloodstream. In human subjects tryptases are encoded by several genes and alleles, including alpha, beta, gamma, and delta. Common variations include complete absence of alpha genes. Until recently, alpha tryptase was considered to be the major tryptase secreted at baseline and in mastocytosis. However, lack of alpha tryptase genes has little effect on circulating tryptase levels, which are now thought mainly to consist of inactive pro-beta tryptase secreted constitutively rather than stored in granules with mature tryptases. Pro-beta tryptase levels thus might reflect total body mast cell content. In contrast, mature beta tryptase can increase transiently in severe systemic anaphylaxis and confirm the diagnosis. However, it might fail to increase in food anaphylaxis or might increase nonspecifically in samples acquired after death. Thus pro- and mature beta tryptase measurements are useful but associated with false-negative and false-positive results, which need to be considered in drawing clinical conclusions in cases of suspected anaphylaxis.
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Affiliation(s)
- George H Caughey
- Cardiovascular Research Institute and Department of Medicine, University of California at San Francisco, CA 94121, USA.
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Xu X, Zhang D, Lyubynska N, Wolters PJ, Killeen NP, Baluk P, McDonald DM, Hawgood S, Caughey GH. Mast cells protect mice from Mycoplasma pneumonia. Am J Respir Crit Care Med 2006; 173:219-25. [PMID: 16210667 PMCID: PMC2662990 DOI: 10.1164/rccm.200507-1034oc] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2005] [Accepted: 10/06/2005] [Indexed: 11/16/2022] Open
Abstract
RATIONALE As the smallest free-living bacteria and a frequent cause of respiratory infections, mycoplasmas are unique pathogens. Mice infected with Mycoplasma pulmonis can develop localized, life-long airway infection accompanied by persistent inflammation and remodeling. OBJECTIVE Because mast cells protect mice from acute septic peritonitis and gram-negative pneumonia, we hypothesized that they defend against mycoplasma infection. This study tests this hypothesis using mast cell-deficient mice. METHODS Responses to airway infection with M. pulmonis were compared in wild-type and mast cell-deficient Kit(W-sh)/Kit(W-sh) mice and sham-infected control mice. MEASUREMENTS AND MAIN RESULTS Endpoints include mortality, body and lymph node weight, mycoplasma antibody titer, and lung mycoplasma burden and histopathology at intervals after infection. The results reveal that infected Kit(W-sh)/Kit(W-sh) mice, compared with other groups, lose more weight and are more likely to die. Live mycoplasma burden is greater in Kit(W-sh)/Kit(W-sh) than in wild-type mice at early time points. Four days after infection, the difference is 162-fold. Titers of mycoplasma-specific IgM and IgA appear earlier and rise higher in Kit(W-sh)/Kit(W-sh) mice, but antibody responses to heat-killed mycoplasma are not different compared with wild-type mice. Infected Kit(W-sh)/Kit(W-sh) mice develop larger bronchial lymph nodes and progressive pneumonia and airway occlusion with neutrophil-rich exudates, accompanied by angiogenesis and lymphangiogenesis. In wild-type mice, pneumonia and exudates are less severe, quicker to resolve, and are not associated with increased angiogenesis. CONCLUSIONS These findings suggest that mast cells are important for innate immune containment of and recovery from respiratory mycoplasma infection.
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Affiliation(s)
- Xiang Xu
- Pulmonary and Critical Care Medicine, Mailstop 111-D, Veterans Affairs Medical Center, 4150 Clement Street, San Francisco, CA 94121
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Xu X, Golden JA, Dolganov G, Jones KD, Donnelly S, Weaver T, Caughey GH. Transcript signatures of lymphocytic bronchitis in lung allograft biopsy specimens. J Heart Lung Transplant 2005; 24:1055-66. [PMID: 16102441 PMCID: PMC2271113 DOI: 10.1016/j.healun.2004.06.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2004] [Revised: 06/16/2004] [Accepted: 06/19/2004] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Rejection and obliterative bronchiolitis are barriers to sustained graft function in recipients of transplanted lungs. Early detection is hindered by inadequate tests and an incomplete understanding of the molecular events preceding or accompanying graft deterioration. METHODS Hypothesizing that genes involved in immune responses and tissue remodeling produce biomarkers of rejection, we measured the expression of 192 selected genes in 72 sets of biopsy specimens from human lung allografts. Gene transcripts were quantified using a 2-step, multiplex, real-time polymerase chain reaction approach in endobronchial and transbronchial biopsy specimens from transplant recipients without acute infections undergoing routine surveillance bronchoscopy. RESULTS Comparisons of histopathology in parallel biopsy specimens identified 6 genes correlating with rejection as manifested by lymphocytic bronchitis, a suspected harbinger of obliterative bronchiolitis. For example, beta2-defensin and collagenase transcripts in inflamed bronchi increased 37-fold and 163-fold, respectively. By contrast, these transcripts did not correlate with acute rejection in transbronchial specimens. Further, no correspondence was noted between histopathologic bronchitis and parenchymal rejection when endobronchial and transbronchial samples were obtained from the same patient. CONCLUSIONS Our highly sensitive method permits quantitation of many gene transcripts simultaneously in small, bronchoscopically acquired biopsy specimens of allografts. Transcript signatures obtained by this approach suggest that airway and alveolar responses to rejection differ and that endobronchial biopsy specimens assess lymphocytic bronchitis and chronic rejection but are not proxies for transbronchial biopsy specimens. Further, they reveal changes in airway expression of the specific genes involved in host defense and remodeling and suggest that the measurement of transcripts correlating with lymphocytic bronchitis may be diagnostic adjuncts to histopathology.
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Affiliation(s)
| | - Jeffrey A. Golden
- Department of Medicine (GHC, JAG, SD, TW), University of California at San Francisco, San Francisco, California
| | | | - Kirk D. Jones
- Department of Pathology (KDJ), University of California at San Francisco, San Francisco, California
| | - Samantha Donnelly
- Department of Medicine (GHC, JAG, SD, TW), University of California at San Francisco, San Francisco, California
| | - Timothy Weaver
- Department of Medicine (GHC, JAG, SD, TW), University of California at San Francisco, San Francisco, California
| | - George H. Caughey
- Cardiovascular Research Institute (GHC), University of California at San Francisco, San Francisco, California
- Department of Medicine (GHC, JAG, SD, TW), University of California at San Francisco, San Francisco, California
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Raymond WW, Cruz AC, Caughey GH. Mast cell and neutrophil peptidases attack an inactivation segment in hepatocyte growth factor to generate NK4-like antagonists. J Biol Chem 2005; 281:1489-94. [PMID: 16303761 PMCID: PMC2271111 DOI: 10.1074/jbc.m511154200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hepatocyte growth factor (HGF) is a plasminogen-like protein with an alpha chain linked to a trypsin-like beta chain without peptidase activity. The interaction of HGF with c-met, a receptor tyrosine kinase expressed by many cells, is important in cell growth, migration, and formation of endothelial and epithelial tubes. Stimulation of c-met requires two-chain, disulfide-linked HGF. Portions of an alpha chain containing an N-terminal segment and four kringle domains (NK4) antagonize HGF activity. Until now, no physiological pathway for generating NK4 was known. Here we show that chymases, which are chymotryptic peptidases secreted by mast cells, hydrolyze HGF, thereby abolishing scatter factor activity while generating an NK4-like antagonist of HGF scatter factor activity. Thus, chymase interferes with HGF directly by destroying active protein and indirectly by generating an antagonist. The site of hydrolysis, Leu480, lies in the alpha chain on the N-terminal side of the cysteine linking the alpha and beta chains. This site appears to be specific for HGF because chymase does not hydrolyze other plasminogen-like proteins, such as macrophage-stimulating protein and plasminogen itself. Mast cell/neutrophil cathepsin G and neutrophil elastase generate similar fragments of HGF by cleaving near the chymase site. Mast cell and neutrophil peptidases are secreted during tissue injury, infection, ischemia, and allergic inflammation, where they may oppose HGF effects on epithelial repair. Thus, HGF possesses an "inactivation segment" that serves as an Achilles' heel attacked by inflammatory proteases. This work reveals a potential physiological pathway for inactivation of HGF and generation of NK4-like antagonists.
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Affiliation(s)
- Wilfred W. Raymond
- Department of Medicine and Cardiovascular Research Institute, The University of California at San Francisco, San Francisco, California 94143
- The Veterans Affairs Medical Center, San Francisco, California 94121
| | - Anthony C. Cruz
- Department of Medicine and Cardiovascular Research Institute, The University of California at San Francisco, San Francisco, California 94143
- The Veterans Affairs Medical Center, San Francisco, California 94121
| | - George H. Caughey
- Department of Medicine and Cardiovascular Research Institute, The University of California at San Francisco, San Francisco, California 94143
- The Veterans Affairs Medical Center, San Francisco, California 94121
- To whom correspondence should be addressed: Veterans Affairs Medical Center 111-D, 4150 Clement St., San Francisco, CA 94121; Tel.: 415-221-4810 (ext. 2385); Fax: 415-387-3568; E-mail:
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Wolters PJ, Mallen-St Clair J, Lewis CC, Villalta SA, Baluk P, Erle DJ, Caughey GH. Tissue-selective mast cell reconstitution and differential lung gene expression in mast cell-deficient Kit(W-sh)/Kit(W-sh) sash mice. Clin Exp Allergy 2005; 35:82-8. [PMID: 15649271 PMCID: PMC2271075 DOI: 10.1111/j.1365-2222.2005.02136.x] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Mast cell-deficient Kit(W)/Kit(W-v) mice are an important resource for studying mast cell functions in vivo. However, because they are compound heterozygotes in a mixed genetic background and are infertile, they cannot be crossed easily with other mice. OBJECTIVE To overcome this limitation, we explored the use of Kit(W-sh)/Kit(W-sh) mice for studying mast cell biology in vivo. RESULTS These mice are in a C57BL/6 background, are fertile and can be bred directly with other genetically modified mice. Ten-week-old Kit(W-sh)/Kit(W-sh) are profoundly mast cell-deficient. No mast cells are detected in any major organ, including the lung. Gene microarrays detect differential expression of just seven of 16,463 genes in lungs of Kit(W-sh)/Kit(W-sh) mice compared with wild-type mice, indicating that resting mast cells regulate expression of a small set of genes in the normal lung. Injecting 10(7) bone marrow-derived mast cells (BMMC) into tail veins of Kit(W-sh)/Kit(W-sh) mice reconstitutes mast cell populations in lung, stomach, liver, inguinal lymph nodes, and spleen, but not in the tongue, trachea or skin. Injection of BMMC into ear dermis or peritoneum reconstitutes mast cells locally in these tissues. When splenectomized Kit(W-sh)/Kit(W-sh) mice are intravenously injected with BMMC, mast cells circulate longer and are found more often in the liver and inguinal lymph nodes, indicating that the spleen acts as a reservoir for mast cells following injection and limits migration to some tissues. CONCLUSION In summary, these findings show that mast cell-deficient Kit(W-sh)/Kit(W-sh) mice possess unique attributes that favour their use for studying mast cell functions in vivo.
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Affiliation(s)
- P J Wolters
- Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco, CA 94143-0911, USA.
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Raymond WW, Sommerhoff CP, Caughey GH. Mastin is a gelatinolytic mast cell peptidase resembling a mini-proteasome. Arch Biochem Biophys 2005; 435:311-22. [PMID: 15708374 DOI: 10.1016/j.abb.2004.12.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2004] [Revised: 12/23/2004] [Indexed: 11/28/2022]
Abstract
Mastin is a tryptic peptidase secreted by canine mast cells. This work reveals that mastin is composed of catalytic domain singlets and disulfide-linked dimers. Monomers unite non-covalently to form tryptase-like tetramers, whereas dimers aggregate with monomers into larger clusters stabilized by hydrophobic contacts. Unlike tryptases, mastin resists inactivation by leech-derived tryptase inhibitor, indicating a smaller central cavity, as confirmed by structural models. Nonetheless, mastin is strongly gelatinolytic while not cleaving native collagen or casein, suggesting a preference for denatured proteins threaded into its central cavity. Phylogenetic analysis suggests that mammalian mastins shared more recent ancestors with soluble alpha/beta/delta tryptases than with membrane-anchored gamma-tryptases, and diverged more rapidly. We hypothesize that gelatinase activity and formation of inhibitor-resistant oligomers are ancestral characteristics shared by soluble tryptases and mastins, and that secreted mastin is a mini-proteasome-like complex that breaks down partially degraded proteins without causing bystander damage to intact, native proteins.
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Affiliation(s)
- Wilfred W Raymond
- Department of Medicine, Cardiovascular Research Institute, University of California at San Francisco, San Francisco, CA 94143-0911, USA
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Somasundaram P, Ren G, Nagar H, Kraemer D, Mendoza L, Michael LH, Caughey GH, Entman ML, Frangogiannis NG. Mast cell tryptase may modulate endothelial cell phenotype in healing myocardial infarcts. J Pathol 2005; 205:102-11. [PMID: 15586361 PMCID: PMC2275298 DOI: 10.1002/path.1690] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Mast cells and macrophages infiltrate healing myocardial infarcts and may play an important role in regulating fibrous tissue deposition and extracellular matrix remodelling. This study examined the time-course of macrophage and mast cell accumulation in healing infarcts and studied the histological characteristics and protease expression profile of mast cells in a canine model of experimental infarction. Although macrophages were more numerous than mast cells in infarct granulation tissue, macrophage density decreased during maturation of the scar, whereas mast cell numbers remained persistently elevated. During the inflammatory phase of infarction, newly recruited leucocytes infiltrated the injured myocardium and appeared to be clustered in close proximity to degranulating cardiac mast cells. During the proliferative phase of healing, mast cells had decreased granular content and were localized close to infarct neovessels. In contrast, macrophages showed no selective localization. Mast cells in healing canine infarcts were alcian blue/safranin-positive cells that expressed both tryptase and chymase. In order to explain the pro-inflammatory and angiogenic actions of tryptase--the major secretory protein of mast cells--its effects on endothelial chemokine expression were examined. Chemokines are chemotactic cytokines that play an important role in leucocyte trafficking and angiogenesis and are highly induced in infarcts. Tryptase, a proteinase-activated receptor (PAR)-2 agonist, induced endothelial expression of the angiogenic chemokines CCL2/MCP-1 and CXCL8/IL-8, but not the angiostatic chemokine CXCL10/IP-10. Endothelial PAR-2 stimulation with the agonist peptide SLIGKV induced a similar chemokine expression profile. Mast cell tryptase may exert its angiogenic effects in part through selective stimulation of angiogenic chemokines.
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Affiliation(s)
- Porur Somasundaram
- Section of Cardiovascular Sciences, DeBakey Heart Center, Baylor College of Medicine, and the Methodist Hospital, Houston Texas, USA
| | - Guofeng Ren
- Section of Cardiovascular Sciences, DeBakey Heart Center, Baylor College of Medicine, and the Methodist Hospital, Houston Texas, USA
| | - Himanshu Nagar
- Section of Cardiovascular Sciences, DeBakey Heart Center, Baylor College of Medicine, and the Methodist Hospital, Houston Texas, USA
| | - Daniela Kraemer
- Section of Cardiovascular Sciences, DeBakey Heart Center, Baylor College of Medicine, and the Methodist Hospital, Houston Texas, USA
| | - Leonardo Mendoza
- Section of Cardiovascular Sciences, DeBakey Heart Center, Baylor College of Medicine, and the Methodist Hospital, Houston Texas, USA
| | - Lloyd H Michael
- Section of Cardiovascular Sciences, DeBakey Heart Center, Baylor College of Medicine, and the Methodist Hospital, Houston Texas, USA
| | - George H Caughey
- Cardiovascular Research Institute and Department of Medicine, University of California at San Francisco, San Francisco, California, USA
| | - Mark L Entman
- Section of Cardiovascular Sciences, DeBakey Heart Center, Baylor College of Medicine, and the Methodist Hospital, Houston Texas, USA
| | - Nikolaos G Frangogiannis
- Section of Cardiovascular Sciences, DeBakey Heart Center, Baylor College of Medicine, and the Methodist Hospital, Houston Texas, USA
- Correspondence to: Nikolaos G Frangogiannis, Section of Cardiovascular Sciences, One Baylor Plaza M/S F-602, Baylor College of Medicine, Houston, TX 77030, USA. E-mail:
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Tong Z, Illek B, Bhagwandin VJ, Verghese GM, Caughey GH. Prostasin, a membrane-anchored serine peptidase, regulates sodium currents in JME/CF15 cells, a cystic fibrosis airway epithelial cell line. Am J Physiol Lung Cell Mol Physiol 2004; 287:L928-35. [PMID: 15246975 DOI: 10.1152/ajplung.00160.2004] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Prostasin is a tryptic peptidase expressed in prostate, kidney, lung, and airway. Mammalian prostasins are related to Xenopus channel-activating protease, which stimulates epithelial Na+channel (ENaC) activity in frogs. In human epithelia, prostasin is one of several membrane peptidases proposed to regulate ENaC. This study tests the hypothesis that prostasin can regulate ENaC in cystic fibrosis epithelia in which excessive Na+uptake contributes to salt and water imbalance. We show that prostasin mRNA and protein are strongly expressed by human airway epithelial cell lines, including immortalized JME/CF15 nasal epithelial cells homozygous for the ΔF508 cystic fibrosis mutation. Epithelial cells transfected with vectors encoding recombinant soluble prostasin secrete active, tryptic peptidase that is highly sensitive to inactivation by aprotinin. When studied as monolayers in Ussing chambers, JME/CF15 cells exhibit amiloride-sensitive, transepithelial Na+currents that are markedly diminished by aprotinin, suggesting regulation by serine-class peptidases. Overproduction of membrane-anchored prostasin in transfected JME/CF15 cells does not augment Na+currents, and trypsin-induced increases are small, suggesting that baseline serine peptidase-dependent ENaC activation is maximal in these cells. To probe prostasin’s involvement in basal ENaC activity, we silenced expression of prostasin using short interfering RNA targeting of prostasin mRNA’s 3′-untranslated region. This drops ENaC currents to 26 ± 9% of baseline. These data predict that prostasin is a major regulator of ENaC-mediated Na+current in ΔF508 cystic fibrosis epithelia and suggest that airway prostasin is a target for therapeutic inhibition to normalize ion current in cystic fibrosis airway.
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Affiliation(s)
- Zhenyue Tong
- Cardiovascular Research Institute, and Department of Medicine, University of California at San Francisco, San Francisco 94143, USA
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47
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Henningsson F, Wolters P, Chapman HA, Caughey GH, Pejler G. Mast cell cathepsins C and S control levels of carboxypeptidase A and the chymase, mouse mast cell protease 5. Biol Chem 2004; 384:1527-31. [PMID: 14669996 DOI: 10.1515/bc.2003.169] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Carboxypeptidase A (CPA) is a metalloprotease, residing in the mast cell secretory granules together with chymases and tryptases. Little information is available with respect to the mechanisms that maintain or regulate the levels of stored proteases in the mast cell secretory granules. In this study we examined whether cathepsins C and S may be involved in the control of the levels of mast cell proteases. Mast cells cultured from bone marrow of cathepsin C- or S-null mice expressed higher levels of CPA protein and activity than cells from wild-type mice. Similar increases in protein were observed for the mouse chymase, mast cell protease-5 (mMCP-5), but not for the tryptase, mMCP-6. Steady-state levels of CPA and mMCP-5 mRNA were similar in wild-type and cathepsin C-null mast cells, indicating that post-transcriptional mechanisms explain the observed cathepsin C-dependence of CPA and mMCP-5 expression. The present study thus indicates novel roles for cathepsins C and S in regulating the levels of stored proteases in the mast cell secretory granules.
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Affiliation(s)
- Frida Henningsson
- Swedish University of Agricultural Sciences, Department of Veterinary Medical Chemistry, The Biomedical Center, Box 575, S-751 23 Uppsala, Sweden
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Baluk P, Raymond WW, Ator E, Coussens LM, McDonald DM, Caughey GH. Matrix metalloproteinase-2 and -9 expression increases in Mycoplasma-infected airways but is not required for microvascular remodeling. Am J Physiol Lung Cell Mol Physiol 2004; 287:L307-17. [PMID: 15075248 DOI: 10.1152/ajplung.00404.2003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Murine Mycoplasma pulmonis infection induces chronic lung and airway inflammation accompanied by profound and persistent microvascular remodeling in tracheobronchial mucosa. Because matrix metalloproteinase (MMP)-2 and -9 are important for angiogenesis associated with placental and long bone development and skin cancer, we hypothesized that they contribute to microvascular remodeling in airways infected with M. pulmonis. To test this hypothesis, we compared microvascular changes in airways after M. pulmonis infection of wild-type FVB/N mice with those of MMP-9−/− and MMP-2−/−/MMP-9−/− double-null mice and mice treated with the broad-spectrum MMP inhibitor AG3340 (Prinomastat). Using zymography and immunohistochemistry, we find that MMP-2 and MMP-9 rise strikingly in lungs and airways of infected wild-type FVB/N and C57BL/6 mice, with no zymographic activity or immunoreactivity in MMP-2−/−/MMP-9−/− animals. However, microvascular remodeling as assessed by Lycopersicon esculentum lectin staining of whole-mounted tracheae is as severe in infected MMP-9−/−, MMP-2−/−/MMP-9−/− and AG3340-treated mice as in wild-type mice. Furthermore, all groups of infected mice develop similar inflammatory infiltrates and exhibit similar overall disease severity as indicated by decrease in body weight and increase in lung weight. Uninfected wild-type tracheae show negligible MMP-2 immunoreactivity, with scant MMP-9 immunoreactivity in and around growing cartilage. By contrast, MMP-2 appears in epithelial cells of infected, wild-type tracheae, and MMP-9 localizes to a large population of infiltrating leukocytes. We conclude that despite major increases in expression, MMP-2 and MMP-9 are not essential for microvascular remodeling in M. pulmonis-induced chronic airway inflammation.
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Affiliation(s)
- Peter Baluk
- Cardiovascular Research Institute, University of California, San Francisco, CA 94143-0130, USA.
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Verghese GM, Tong ZY, Bhagwandin V, Caughey GH. Mouse prostasin gene structure, promoter analysis, and restricted expression in lung and kidney. Am J Respir Cell Mol Biol 2004; 30:519-29. [PMID: 12959947 DOI: 10.1165/rcmb.2003-0251oc] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Human prostasin is a membrane-anchored serine peptidase hypothesized to regulate lung epithelial sodium transport. It belongs to a unique family of genes on chromosome 16p11.2/13.3. Here we describe genomic cloning, promoter analysis, and expression of prostasin's mouse ortholog. The 4.3-kb mouse prostasin gene (prss8) has a six-exon organization identical to human prostasin. Prss8 spans two signal tagged-sites localized to chromosome 7. Multiple mRNA transcripts arise from two consensus initiator elements of a TATA-less promoter and an alternatively spliced, 5' untranslated region intron. Reporter assay establishes that the initiator elements and a GC-rich domain comprise the core promoter and identifies 5' flanking regions with strong enhancer and repressor activity. The 3' untranslated region overlaps the 3' untranslated region of the Myst1 gene oriented tail-to-tail at this locus. Prss8 is highly transcribed in pancreas, kidney, submaxillary gland, lung, thyroid, prostate, and epididymis, and is developmentally regulated. Using selective riboprobes and antibodies to mouse prostasin, we localized its expression to lung airway epithelial and alveolar type II cells and kidney cortical tubule epithelium. Mouse prostasin highly resembles its human ortholog in gene organization and tissue specificity, including strong expression in pulmonary epithelium, suggesting that mice will be useful for probing prostasin's functions in vivo.
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Affiliation(s)
- George M Verghese
- Department of Medicine, University of Virginia, Charlottesville, Virginia 22908-0546, USA.
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Mallen-St Clair J, Pham CTN, Villalta SA, Caughey GH, Wolters PJ. Mast cell dipeptidyl peptidase I mediates survival from sepsis. J Clin Invest 2004; 113:628-34. [PMID: 14966572 PMCID: PMC338261 DOI: 10.1172/jci19062] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2003] [Accepted: 12/02/2003] [Indexed: 11/17/2022] Open
Abstract
Sepsis is a common, life-threatening disease for which there is little treatment. The cysteine protease dipeptidyl peptidase I (DPPI) activates granule-associated serine proteases, several of which play important roles in host responses to bacterial infection. To examine DPPI's role in sepsis, we compared DPPI(-/-) and DPPI(+/+) mice using the cecal ligation and puncture (CLP) model of septic peritonitis, finding that DPPI(-/-) mice are far more likely to survive sepsis. Outcomes of CLP in mice lacking mast cell DPPI reveal that the absence of DPPI in mast cells, rather than in other cell types, is responsible for the survival advantage. Among several cytokines surveyed in peritoneal fluid and serum, IL-6 is highly and differentially expressed in DPPI(-/-) mice compared with DPPI(+/+) mice. Remarkably, deleting IL-6 expression in DPPI(-/-) mice eliminates the survival advantage. The increase in IL-6 in septic DPPI(-/-) mice, which appears to protect these mice from death, may be related to reduced DPPI-mediated activation of mast cell tryptase and other peptidases, which we show cleave IL-6 in vitro. These results indicate that mast cell DPPI harms the septic host and that DPPI is a novel potential therapeutic target for treatment of sepsis.
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Affiliation(s)
- Jon Mallen-St Clair
- Department of Medicine and The Cardiovascular Research Institute, University of California, San Francisco, California 94143-0911, USA
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