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Lawrence B. Schwartz - One of the best experts on this subject based on the ideXlab platform.
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clinical approach to a patient with elevated serum Tryptase implications of acute versus basally elevated levels
2020Co-Authors: Jonathan J Lyons, Lawrence B. SchwartzAbstract:Measurement of Tryptase is a valuable tool in the evaluation of patients with mast cell-related disorders and reactions. Recent advances in our understanding of a common genetic cause underlying elevated basal serum Tryptase levels in the general population have provided additional context to evaluate patients with elevated serum Tryptase levels. This chapter will provide an overview of Tryptase, inherited and acquired causes for basal elevations of serum Tryptase, and clinical applications of this biomarker in diagnosis and risk stratification of patients.
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serum total Tryptase levels are increased in patients with active chronic urticaria
Clinical & Experimental Allergy, 2010Co-Authors: M Ferrer, Jorge M Nunezcordoba, E Luquin, Clive Grattan, J M De La Borbolla, M L Sanz, Lawrence B. SchwartzAbstract:Summary Background We have demonstrated previously mast cell histamine release upon incubation with chronic urticaria (CU) sera, presumably by degranulation. Objective To explore total and mature Tryptase in order to assess whether any increase in total Tryptase levels is due in part to mast cell degranulation or to mast cell burden. We also wanted to explore differences between the autoimmune groups called idiopathic (serum unable to activate basophils), and to correlate total and mature Tryptase levels with different urticaria features. Methods We measured total and mature Tryptase serum levels in 81 CU patients, 16 atopic donors and 21 healthy control sera. We assessed autoimmunity by measuring the CD63 expression in normal basophil donors upon incubation with CU sera. Results We found significantly higher levels of total Tryptase in the sera of CU patients (6.6 ±4.1 μg/L) than in sera from healthy non-atopic subjects (4.4 ±2.8 μg/L) and from atopic subjects (4.5 ±1.7 μg/L). Mature Tryptase levels were undetectable (<1 ng/mL). Total Tryptase levels in the autoimmune urticaria group were significantly higher (9.8 ±5.4 μg/L) than the idiopathic urticaria group (4.4 ±2.2 μg/L). A significant difference in total Tryptase was found between symptomatic patients (7.3 ±4.1 μg/L) compared with asymptomatic ones (5.7 ±4.1 μg/L) at the time of venesection. No difference was found in mature Tryptase levels either. Conclusion Total elevated Tryptase levels are not accompanied by an elevated mature Tryptase levels, as might be expected if the serum levels reflected mast cell degranulation. Cite this as: M. Ferrer, J. M. Nunez-Cordoba, E. Luquin, C. E. Grattan, J. M. De la Borbolla, M. L. Sanz, L. B. Schwartz, Clinical & Experimental Allergy, 2010 (40) 1760–1766.
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generation of anaphylatoxins by human β Tryptase from c3 c4 and c5
Journal of Immunology, 2008Co-Authors: Yoshihiro Fukuoka, Laura Sanchezmunoz, Anthony L Dellinger, Luis Escribano, Lawrence B. SchwartzAbstract:Both mast cells and complement participate in innate and acquired immunity. The current study examines whether β-Tryptase, the major protease of human mast cells, can directly generate bioactive complement anaphylatoxins. Important variables included pH, monomeric vs tetrameric forms of β-Tryptase, and the β-Tryptase-activating polyanion. The B12 mAb was used to stabilize β-Tryptase in its monomeric form. C3a and C4a were best generated from C3 and C4, respectively, by monomeric β-Tryptase in the presence of low molecular weight dextran sulfate or heparin at acidic pH. High molecular weight polyanions increased degradation of these anaphylatoxins. C5a was optimally generated from C5 at acidic pH by β-Tryptase monomers in the presence of high molecular weight dextran sulfate and heparin polyanions, but also was produced by β-Tryptase tetramers under these conditions. Mass spectrometry verified that the molecular mass of each anaphylatoxin was correct. Both β-Tryptase-generated C5a and C3a (but not C4a) were potent activators of human skin mast cells. These complement anaphylatoxins also could be generated by β-Tryptase in releasates of activated skin mast cells. Of further biologic interest, β-Tryptase also generated C3a from C3 in human plasma at acidic pH. These results suggest β-Tryptase might generate complement anaphylatoxins in vivo at sites of inflammation, such as the airway of active asthma patients where the pH is acidic and where elevated levels of β-Tryptase and complement anaphylatoxins are detected.
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Tryptase haplotype in mastocytosis: Relationship to disease variant and diagnostic utility of total Tryptase levels
Clinical Immunology, 2007Co-Authors: Cem Akin, George H. Caughey, Lawrence B. Schwartz, Darya Soto, Erica Brittain, Adhuna Chhabra, Dean D MetcalfeAbstract: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 α Tryptase genes; however, it is not known whether lack of α 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 α or β 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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Expression of α-Tryptase and β-Tryptase by human basophils
The Journal of Allergy and Clinical Immunology, 2004Co-Authors: Sherryline Jogie-brahim, Yoshihiro Fukuoka, Lawrence B. SchwartzAbstract:Background α and β-Tryptase levels in serum are clinical tools for the evaluation of systemic anaphylaxis and systemic mastocytosis. Basophils and mast cells are known to produce these proteins. Objective The current study examines the effect of the α,β-Tryptase genotype on basophil Tryptase levels and the type of Tryptase stored in these cells. Methods Tryptase extracted from purified peripheral blood basophils from 20 subjects was examined by using ELISAs measuring mature and total Tryptase and by using an enzymatic assay with tosyl-Gly-Pro-Lys- p -nitroanilide. Tryptase genotypes (4:0, 3:1, and 2:2 β/α ratios) were assessed by using a hot-stop PCR technique with α,β-Tryptase–specific primers. Total α,β-Tryptase mRNA was measured by means of competitive RT-PCR, and ratios of α to β-Tryptase mRNA were measured by means of hot-stop RT-PCR. Results Tryptase in all but one of the basophil preparations was mature and enzymatically active. Tryptase quantities in basophils were less than 1% of those in tissue mast cells. Tryptase genotypes (β/α) among the 20 donors were 4:0 in 7, 3:1 in 7, and 2:2 in 6. Tryptase protein and mRNA levels per basophil were not affected by the Tryptase genotype. Conclusion Basophils from healthy subjects contain modest amounts of mature and enzymatically active Tryptase unaffected by the Tryptase genotype.
R L Stevens - One of the best experts on this subject based on the ideXlab platform.
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mast cell restricted mouse and human Tryptase heparin complexes hinder thrombin induced coagulation of plasma and the generation of fibrin by proteolytically destroying fibrinogen
Journal of Biological Chemistry, 2012Co-Authors: Alicia Prietogarcia, Roberto Adachi, Wei Xing, Dominick Zheng, William S Lane, Kyungmee Chung, Paul Anderson, Philip M Hansbro, Mariana Castells, R L StevensAbstract:The mouse and human TPSB2 and TPSAB1 genes encode tetramer-forming Tryptases stored in the secretory granules of mast cells (MCs) ionically bound to heparin-containing serglycin proteoglycans. In mice these genes encode mouse MC protease-6 (mMCP-6) and mMCP-7. The corresponding human genes encode a family of serine proteases that collectively are called hTryptase-β. We previously showed that the α chain of fibrinogen is a preferred substrate of mMCP-7. We now show that this plasma protein also is highly susceptible to degradation by hTryptase-β· and mMCP-6·heparin complexes and that Lys575 is a preferred cleavage site in the protein α chain. Because cutaneous mouse MCs store substantial amounts of mMCP-6·heparin complexes in their secretory granules, the passive cutaneous anaphylaxis reaction was induced in the skin of mMCP-6+/mMCP-7− and mMCP-6−/mMCP-7− C57BL/6 mice. In support of the in vitro data, fibrin deposits were markedly increased in the skin of the double-deficient mice 6 h after IgE-sensitized animals were given the relevant antigen. Fibrinogen is a major constituent of the edema fluid that accumulates in tissues when MCs degranulate. Our discovery that mouse and human tetramer-forming Tryptases destroy fibrinogen before this circulating protein can be converted to fibrin changes the paradigm of how MCs hinder fibrin deposition and blood coagulation internally. Because of the adverse consequences of fibrin deposits in tissues, our data explain why mice and humans lack a circulating protease inhibitor that rapidly inactivates MC Tryptases and why mammals have two genes that encode tetramer-forming serine proteases that preferentially degrade fibrinogen.
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synovial fibroblasts promote the expression and granule accumulation of Tryptase via interleukin 33 and its receptor st 2 il1rl1
Journal of Biological Chemistry, 2010Co-Authors: Shinjiro Kaieda, Peter A Nigrovic, Ki Chul Shin, Kenjiro Seki, R L StevensAbstract:A characteristic feature of tissue resident human mast cells (MCs) is their hTryptase-β-rich cytoplasmic granules. Mouse MC protease-6 (mMCP-6) is the ortholog of hTryptase-β, and we have shown that this tetramer-forming Tryptase has beneficial roles in innate immunity but adverse roles in inflammatory disorders like experimental arthritis. Because the key tissue factors that control Tryptase expression in MCs have not been identified, we investigated the mechanisms by which fibroblasts mediate the expression and granule accumulation of mMCP-6. Immature mouse bone marrow-derived MCs (mBMMCs) co-cultured with fibroblast-like synoviocytes (FLS) or mouse 3T3 fibroblasts markedly increased their levels of mMCP-6. This effect was caused by an undefined soluble factor whose levels could be increased by exposing FLS to tumor necrosis factor-α or interleukin (IL)-1β. Gene expression profiling of mBMMCs and FLS for receptor·ligand pairs of potential relevance raised the possibility that IL-33 was a sought after fibroblast-derived factor that promotes Tryptase expression and granule maturation via its receptor IL1RL1/ST2. MCs lacking IL1RL1 exhibited defective fibroblast-driven Tryptase accumulation, whereas recombinant IL-33 induced mMCP-6 mRNA and protein accumulation in wild-type mBMMCs. In agreement with these data, synovial MCs from IL1RL1-null mice exhibited a marked reduction in mMCP-6 expression. IL-33 is the first factor shown to modulate Tryptase expression in MCs at the mRNA and protein levels. We therefore have identified a novel pathway by which mesenchymal cells exposed to inflammatory cytokines modulate the phenotype of local MCs to shape their immune responses.
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mast cells contribute to autoimmune inflammatory arthritis via their Tryptase heparin complexes
Journal of Immunology, 2009Co-Authors: Ki Chul Shin, Peter A Nigrovic, James F Crish, Eric Boilard, Patrick H Mcneil, Katherine Larabee, Roberto Adachi, Michael F Gurish, Reuben Gobezie, R L StevensAbstract:Although mast cells (MCs) often are abundant in the synovial tissues of patients with rheumatoid arthritis, the contribution of MCs to joint inflammation and cartilage loss remains poorly understood. MC-restricted Tryptase/heparin complexes have proinflammatory activity, and significant amounts of human Tryptase β (hTryptase-β) are present in rheumatoid arthritis synovial fluid. Mouse MC protease-6 (mMCP-6) is the ortholog of hTryptase-β, and this serine protease is abundant in the synovium of arthritic mice. We now report that C57BL/6 (B6) mice lacking their Tryptase/heparin complexes have attenuated arthritic responses, with mMCP-6 as the dominant Tryptase responsible for augmenting neutrophil infiltration in the K/BxN mouse serum-transfer arthritis model. While inflammation in this experimental arthritis model was not dependent on protease-activated receptor-2, it was dependent on the chemokine receptor CXCR2. In support of the latter data, exposure of synovial fibroblasts to hTryptase-β/heparin or mMCP-6/heparin complexes resulted in expression of the neutrophil chemotactic factors CXCL1/KC, CXCL5/LIX, and CXCL8/IL-8. Our proteomics, histochemistry, and immunohistochemistry data also revealed substantial loss of cartilage-derived aggrecan proteoglycans in the arthritic joints of wild-type B6 mice but not mMCP-6-null B6 mice. These observations demonstrate the functional contribution of MC-restricted Tryptase/heparin complexes in the K/BxN mouse arthritis model and connect our mouse findings with rheumatoid arthritis pathophysiology.
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protease proteoglycan complexes of mouse and human mast cells and importance of their β Tryptase heparin complexes in inflammation and innate immunity
Immunological Reviews, 2007Co-Authors: R L Stevens, Roberto AdachiAbstract:Summary: Approximately 50% of the weight of a mature mast cell (MC) consists of varied neutral proteases stored in the cell’s secretory granules ionically bound to serglycin proteoglycans that contain heparin and/or chondroitin sulfate E/diB chains. Mouse MCs express the exopeptidase carboxypeptidase A3 and at least 15 serine proteases [designated as mouse MC protease (mMCP) 1–11, transmembrane Tryptase/Tryptase γ/protease serine member S (Prss) 31, cathepsin G, granzyme B, and neuropsin/Prss19]. mMCP-6, mMCP-7, mMCP-11/Prss34, and Prss31 are the four members of the chromosome 17A3.3 family of Tryptases that are preferentially expressed in MCs. One of the challenges ahead is to understand why MCs express so many different protease–proteoglycan macromolecular complexes. MC-like cells that contain Tryptase–heparin complexes in their secretory granules have been identified in the Ciona intestinalis and Styela plicata urochordates that appeared approximately 500 million years ago. Because sea squirts lack B cells and T cells, it is likely that MCs and their Tryptase–proteoglycan granule mediators initially appeared in lower organisms as part of their innate immune system. The conservation of MCs throughout evolution suggests that some of these protease–proteoglycan complexes are essential to our survival. In support of this conclusion, no human has been identified that lacks MCs. Moreover, transgenic mice lacking the β-Tryptase mMCP-6 are unable to combat a Klebsiella pneumoniae infection effectively. Here we summarize the nature and function of some of the Tryptase–serglycin proteoglycan complexes found in mouse and human MCs.
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evaluation of the substrate specificity of human mast cell Tryptase βi and demonstration of its importance in bacterial infections of the lung
Journal of Biological Chemistry, 2001Co-Authors: Chifu Huang, George T De Sanctis, Peter J Obrien, Joseph P Mizgerd, Daniel S Friend, Jeffrey M Drazen, Lawrence F Brass, R L StevensAbstract:Human pulmonary mast cells (MCs) express Tryptases a and bI, and both granule serine proteases are exocytosed during inflammatory events. Recombinant forms of these Tryptases were generated for the first time to evaluate their substrate specificities at the biochemical level and then to address their physiologic roles in pulmonary inflammation. Analysis of a Tryptase-specific, phage display peptide library revealed that Tryptase bI prefers to cleave peptides with 1 or more Pro residues flanked by 2 positively charged residues. Although recombinant Tryptase bI was unable to activate cultured cells that express different types of protease-activated receptors, the numbers of neutrophils increased >100fold when enzymatically active Tryptase bI was instilled into the lungs of mice. In contrast, the numbers of lymphocytes and eosinophils in the airspaces did not change significantly. More important, the Tryptase bItreated mice exhibited normal airway responsiveness. Neutrophils did not extravasate into the lungs of Tryptase a-treated mice. Thus, this is the first study to demonstrate that the two nearly identical human MC Tryptases are functionally distinct in vivo. When MCdeficient W/W v mice were given enzymatically active
Roberto Adachi - One of the best experts on this subject based on the ideXlab platform.
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mast cell restricted mouse and human Tryptase heparin complexes hinder thrombin induced coagulation of plasma and the generation of fibrin by proteolytically destroying fibrinogen
Journal of Biological Chemistry, 2012Co-Authors: Alicia Prietogarcia, Roberto Adachi, Wei Xing, Dominick Zheng, William S Lane, Kyungmee Chung, Paul Anderson, Philip M Hansbro, Mariana Castells, R L StevensAbstract:The mouse and human TPSB2 and TPSAB1 genes encode tetramer-forming Tryptases stored in the secretory granules of mast cells (MCs) ionically bound to heparin-containing serglycin proteoglycans. In mice these genes encode mouse MC protease-6 (mMCP-6) and mMCP-7. The corresponding human genes encode a family of serine proteases that collectively are called hTryptase-β. We previously showed that the α chain of fibrinogen is a preferred substrate of mMCP-7. We now show that this plasma protein also is highly susceptible to degradation by hTryptase-β· and mMCP-6·heparin complexes and that Lys575 is a preferred cleavage site in the protein α chain. Because cutaneous mouse MCs store substantial amounts of mMCP-6·heparin complexes in their secretory granules, the passive cutaneous anaphylaxis reaction was induced in the skin of mMCP-6+/mMCP-7− and mMCP-6−/mMCP-7− C57BL/6 mice. In support of the in vitro data, fibrin deposits were markedly increased in the skin of the double-deficient mice 6 h after IgE-sensitized animals were given the relevant antigen. Fibrinogen is a major constituent of the edema fluid that accumulates in tissues when MCs degranulate. Our discovery that mouse and human tetramer-forming Tryptases destroy fibrinogen before this circulating protein can be converted to fibrin changes the paradigm of how MCs hinder fibrin deposition and blood coagulation internally. Because of the adverse consequences of fibrin deposits in tissues, our data explain why mice and humans lack a circulating protease inhibitor that rapidly inactivates MC Tryptases and why mammals have two genes that encode tetramer-forming serine proteases that preferentially degrade fibrinogen.
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essential role for mast cell Tryptase in acute experimental colitis
Proceedings of the National Academy of Sciences of the United States of America, 2011Co-Authors: Matthew J Hamilton, Mark J Sinnamon, Gregory D Lyng, Jonathan N Glickman, Xueli Wang, Wei Xing, Steven A Krilis, Richard S Blumberg, Roberto AdachiAbstract:Patients with inflammatory bowel disease (IBD) have increased numbers of human Tryptase-β (hTryptase-β)-positive mast cells (MCs) in the gastrointestinal tract. The amino acid sequence of mouse mast cell protease (mMCP)-6 is most similar to that of hTryptase-β. We therefore hypothesized that this mMCP, or the related Tryptase mMCP-7, might have a prominent proinflammatory role in experimental colitis. The dextran sodium sulfate (DSS) and trinitrobenzene sulfonic acid (TNBS) colitis models were used to evaluate the differences between C57BL/6 (B6) mouse lines that differ in their expression of mMCP-6 and mMCP-7 with regard to weight loss, colon histopathology, and endoscopy scores. Microarray analyses were performed, and confirmatory real-time PCR, ELISA, and/or immunohistochemical analyses were carried out on a number of differentially expressed cytokines, chemokines, and matrix metalloproteinases (MMPs). The mMCP-6–null mice that had been exposed to DSS had significantly less weight loss as well as significantly lower pathology and endoscopy scores than similarly treated mMCP-6–expressing mice. This difference in colitis severity was confirmed endoscopically in the TNBS-treated mice. Evaluation of the distal colon segments revealed that numerous proinflammatory cytokines, chemokines that preferentially attract neutrophils, and MMPs that participate in the remodeling of the ECM were all markedly increased in the colons of DSS-treated WT mice relative to untreated WT mice and DSS-treated mMCP-6–null mice. Collectively, our data show that mMCP-6 (but not mMCP-7) is an essential MC-restricted mediator in chemically induced colitis and that this Tryptase acts upstream of many of the factors implicated in IBD.
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mast cells contribute to autoimmune inflammatory arthritis via their Tryptase heparin complexes
Journal of Immunology, 2009Co-Authors: Ki Chul Shin, Peter A Nigrovic, James F Crish, Eric Boilard, Patrick H Mcneil, Katherine Larabee, Roberto Adachi, Michael F Gurish, Reuben Gobezie, R L StevensAbstract:Although mast cells (MCs) often are abundant in the synovial tissues of patients with rheumatoid arthritis, the contribution of MCs to joint inflammation and cartilage loss remains poorly understood. MC-restricted Tryptase/heparin complexes have proinflammatory activity, and significant amounts of human Tryptase β (hTryptase-β) are present in rheumatoid arthritis synovial fluid. Mouse MC protease-6 (mMCP-6) is the ortholog of hTryptase-β, and this serine protease is abundant in the synovium of arthritic mice. We now report that C57BL/6 (B6) mice lacking their Tryptase/heparin complexes have attenuated arthritic responses, with mMCP-6 as the dominant Tryptase responsible for augmenting neutrophil infiltration in the K/BxN mouse serum-transfer arthritis model. While inflammation in this experimental arthritis model was not dependent on protease-activated receptor-2, it was dependent on the chemokine receptor CXCR2. In support of the latter data, exposure of synovial fibroblasts to hTryptase-β/heparin or mMCP-6/heparin complexes resulted in expression of the neutrophil chemotactic factors CXCL1/KC, CXCL5/LIX, and CXCL8/IL-8. Our proteomics, histochemistry, and immunohistochemistry data also revealed substantial loss of cartilage-derived aggrecan proteoglycans in the arthritic joints of wild-type B6 mice but not mMCP-6-null B6 mice. These observations demonstrate the functional contribution of MC-restricted Tryptase/heparin complexes in the K/BxN mouse arthritis model and connect our mouse findings with rheumatoid arthritis pathophysiology.
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protease proteoglycan complexes of mouse and human mast cells and importance of their β Tryptase heparin complexes in inflammation and innate immunity
Immunological Reviews, 2007Co-Authors: R L Stevens, Roberto AdachiAbstract:Summary: Approximately 50% of the weight of a mature mast cell (MC) consists of varied neutral proteases stored in the cell’s secretory granules ionically bound to serglycin proteoglycans that contain heparin and/or chondroitin sulfate E/diB chains. Mouse MCs express the exopeptidase carboxypeptidase A3 and at least 15 serine proteases [designated as mouse MC protease (mMCP) 1–11, transmembrane Tryptase/Tryptase γ/protease serine member S (Prss) 31, cathepsin G, granzyme B, and neuropsin/Prss19]. mMCP-6, mMCP-7, mMCP-11/Prss34, and Prss31 are the four members of the chromosome 17A3.3 family of Tryptases that are preferentially expressed in MCs. One of the challenges ahead is to understand why MCs express so many different protease–proteoglycan macromolecular complexes. MC-like cells that contain Tryptase–heparin complexes in their secretory granules have been identified in the Ciona intestinalis and Styela plicata urochordates that appeared approximately 500 million years ago. Because sea squirts lack B cells and T cells, it is likely that MCs and their Tryptase–proteoglycan granule mediators initially appeared in lower organisms as part of their innate immune system. The conservation of MCs throughout evolution suggests that some of these protease–proteoglycan complexes are essential to our survival. In support of this conclusion, no human has been identified that lacks MCs. Moreover, transgenic mice lacking the β-Tryptase mMCP-6 are unable to combat a Klebsiella pneumoniae infection effectively. Here we summarize the nature and function of some of the Tryptase–serglycin proteoglycan complexes found in mouse and human MCs.
Wolfgang R. Sperr - One of the best experts on this subject based on the ideXlab platform.
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the serum Tryptase test an emerging robust biomarker in clinical hematology
Expert Review of Hematology, 2014Co-Authors: Peter Valent, Wolfgang R. Sperr, Cem Akin, Karl Sotlar, Andreas Reiter, Jason Gotlib, Hanspeter Horny, Michel ArockAbstract:During the past few years, a number of molecular markers have been developed in clinical hematology, most of them related to specific gene defects. However, there is also an unmet need to develop novel serologic parameters to improve diagnostics and prognostication in daily practice. Among these, the serum Tryptase appears to be a most reliable biomarker of myeloid neoplasms. Elevated Tryptase levels are found in subgroups of patients with mastocytosis, myelodysplastic syndrome, myeloproliferative neoplasm, acute myeloid leukemia, chronic myeloid leukemia and chronic eosinophilic leukemia. In these patients, the Tryptase level is of diagnostic and/or prognostic significance. In mastocytosis, an elevated Tryptase level is a minor criterion of systemic disease and in BCR-ABL1+ chronic myeloid leukemia, elevated Tryptase at diagnosis correlates with treatment responses and overall survival. In patients with elevated Tryptase, the enzyme also serves as follow-up parameter and can be employed to measure treatm...
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elevated Tryptase levels selectively cluster in myeloid neoplasms a novel diagnostic approach and screen marker in clinical haematology
European Journal of Clinical Investigation, 2009Co-Authors: Wolfgang R. Sperr, Michael Kundi, A Elsamahi, Michael Girschikofsky, Susanne Winkler, D Lutz, Georg Endler, H Rumpold, Hermine Agis, Christian SillaberAbstract:Background Recent data suggest that Tryptase, a mast cell enzyme, is expressed in neoplastic cells in myeloid leukaemias. In several of these patients, increased serum Tryptase levels are detectable. Materials and methods We have determined serum Tryptase levels in 914 patients with haematological malignancies, including myeloproliferative disorders (n = 156), myelodysplastic syndromes (MDS, n = 241), acute myeloid leukaemia (AML, n = 317), systemic mastocytosis (SM, n = 81), non-Hodgkin′s lymphoma (n = 59) and acute lymphoblastic leukaemia (n = 26). Moreover, Tryptase was measured in 136 patients with non-neoplastic haematological disorders, 102 with non-haematological disorders and 164 healthy subjects. Results In healthy subjects, the median serum Tryptase was 5·2 ng mL−1. Elevated serum Tryptase levels were found to cluster in myeloid neoplasm, whereas almost all patients with lymphoid neoplasms exhibited normal Tryptase. Among myeloid neoplasms, elevated Tryptase levels (> 15 ng mL−1) were recorded in > 90% of patients with SM, 38% with AML, 34% with CML and 25% with MDS. The highest Tryptase levels, often > 1000 ng mL−1, were found in advanced SM and core-binding-factor leukaemias. In most patients with non-neoplastic haematological disorders and non-haematological disorders analysed in our study, Tryptase levels were normal, the exception being a few patients with end-stage kidney disease and helminth infections, in whom a slightly elevated Tryptase was found. Conclusions In summary, Tryptase is a new diagnostic marker of myeloid neoplasms and a useful test in clinical haematology.
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Tryptase a Novel Biochemical Marker of Acute Myeloid Leukemia
Leukemia & Lymphoma, 2002Co-Authors: Wolfgang R. Sperr, Alexander W. Hauswirth, Peter ValentAbstract:Despite maturation arrest, blast cells in acute myeloid leukemia (AML) are often capable of expressing lineage-restricted (granulomonocytic or myelomastocytic) differentiation antigens. Tryptases are lineage-associated serine proteases primarily expressed in mast cells, and less abundantly in blood basophils. We have recently shown that myeloblasts in a group of patients with AML (approximately 40%) produce significant amounts of Tryptase(s). In these patients, serum Tryptase levels are elevated (>15 ng/ml) and reflect the total burden of leukemic cells. In most cases, myeloblasts express α -Tryptase mRNA in excess over β -Tryptase mRNA, and secrete the respective protein (=pro- α -Tryptase) in a constitutive manner. It was also found that these AML blasts frequently co-express Tryptase with additional mast cell lineage- and/or basophil-related differentiation antigens including KIT (CD117), histamine, and 2D7. We hypothesize that Tryptase-positive AMLs arise from a leukemic progenitor that exhibits a lim...
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Serum Tryptase measurements in patients with myelodysplastic syndromes.
Leukemia & Lymphoma, 2002Co-Authors: Wolfgang R. Sperr, Lawrence B. Schwartz, Stehberger B, Friedrich Wimazal, Mehrdad Baghestanian, Michael Kundi, H. Semper, John-hendrik Jordan, Andreas Chott, Johannes DrachAbstract:Abnormal differentiation and maturation of hemopoietic cells are characteristic features of myelodysplastic syndromes (MDS). Tryptases (α- and β-type) are lineage-restricted serine proteases primarily expressed in mast cells (MC). We have analyzed expression of Tryptase in 89 de novo MDS patients (refractory anemia (RA), n = 30; RA with ringed sideroblasts (RARS), n = 21; RA with excess of blasts (RAEB/RAEB-t), n = 27; chronic myelomonocytic leukemia (CMML), n = 11). Serum levels of total Tryptase (α – proTryptase + β – Tryptase) were measured by FIA. The numbers of Tryptase+ cells were determined in paraffin-embedded bone marrow (bm) sections by immunohistochemistry and morphometry. In healthy individuals, serum total Tryptase levels ranged between 20 ng/ml were detected in 5/22 patients with RA (22.7%), 4/17 with RARS (23.5%), 0/16 with RAEB/RAEB-t, and 3/8 with CMML (37.5%). Thus, serum Tryptase concentrations were higher in RA (16.6 ± 14.3 ng/ml...
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expression of mast cell Tryptase by myeloblasts in a group of patients with acute myeloid leukemia
Blood, 2001Co-Authors: Wolfgang R. Sperr, Alexander W. Hauswirth, Mehrdad Baghestanian, John-hendrik Jordan, Andreas Chott, Hanspeter Kiener, Puchit Samorapoompichit, Hans Semper, Geritholger Schernthaner, Susanne NatterAbstract:α- and β-Tryptase genes encode serine proteases that are abundantly expressed by mast cells. Under physiologic conditions other myeloid cells are virtually Tryptase negative. However, Tryptases are also expressed in several myeloid leukemia cell lines. In this study, serum total Tryptase levels were determined in 150 patients with acute leukemias (de novo acute myeloid leukemia [AML], n = 108; secondary AML, n = 25; acute lymphoid leukemia [ALL], n = 17) by fluoroenzyme immunoassay. In healthy subjects (n = 30), Tryptase levels ranged between 2.0 and 12.6 ng/mL. Elevated Tryptase levels (> 15) were detected in 42 (39%) of 108 patients with de novo AML and in 11 (44%) of 25 patients with secondary AML. No elevated Tryptase levels were found in patients with ALL. In de novo AML, elevated Tryptase levels were frequently detected in patients with French-American-British classification M0 (6 of 9), M2 (9 of 14), M3 (4 of 6), and M4eo (7 of 7), and less frequently in M1 (7 of 20), M4 (6 of 26), M5 (2 of 18), M6 (0 of 5), or M7 (1 of 3). The highest Tryptase levels were found in M4eo. Immunohistochemical staining of bone marrow sections with anti-Tryptase antibody as well as immunoelectron microscopy revealed Tryptase expression in the cytoplasm of myeloblasts. As assessed by Northern blotting and reverse transcriptase–polymerase chain reaction, AML cells expressed α-Tryptase messenger RNA (mRNA) but little or no β-Tryptase mRNA. In AML patients with elevated serum Tryptase before chemotherapy, who entered complete remission, Tryptase levels returned to normal or near normal values. Blast cell persistence or regrowth was associated with a persistently elevated level or recurrent increase of Tryptase. Together, Tryptase is expressed in myeloblasts in a group of AML and may serve as a useful disease-related marker.
Andrew F. Walls - One of the best experts on this subject based on the ideXlab platform.
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Alpha Tryptase: Potential Roles in Inflammation Distinct from those of β-Tryptase
The Journal of Allergy and Clinical Immunology, 2010Co-Authors: A. M. Abdelmotelb, M.e. Khedr, Sylvia L.f. Pender, Xiaoying Zhou, Christian P. Sommerhoff, J. W. Holloway, Andrew F. WallsAbstract:RATIONALE: Tryptases are among the most abundant products of the humanmast cell. Beta-Tryptase has emerged as an important mediator of allergicinflammation. The copy number of a-Tryptase has recently beenfound to be associated with the asthma phenotype, but the function ofthis allelic variant to b-Tryptase is unknown.We have investigated potentialactions of a-Tryptase. METHODS: C57BL/6 mice were injected intra-peritoneally with recombinanta or b-Tryptases (0.005 or 0.5 ug/mouse; 12 mice per group). After6, 12 or 24 h, mice were killed and peritoneal lavage performed.Inflammatory cells were enumerated and levels of albumin and total proteindetermined. Gelatine zymography was applied to examine the activityof matrix metalloprotease (MMP)-2 and MMP-9. In separate experiments,cells of the human bronchial epithelial line 16HBE were incubated withTryptases and expression of mRNA for IL-8, IL-6 and TNF-a examinedby quantitative PCR. RESULTS: Injection of a-Tryptase induced the accumulation of neutrophils,eosinophils, macrophages and mast cells (p CONCLUSION: Recombinant a-Tryptase may be a stimulus for the recruitmentof inflammatory cells and altered cytokine gene expressionwith effects different from those of b-Tryptase.
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Elevated serum concentrations of beta-Tryptase, but not alpha-Tryptase, in Sudden Infant Death Syndrome (SIDS). An investigation of anaphylactic mechanisms.
Clinical & Experimental Allergy, 2001Co-Authors: Mark G. Buckley, S. Variend, Andrew F. WallsAbstract:Background Sudden Infant Death Syndrome, (SIDS) or cot death, remains the most common category of post-perinatal death in the UK. By definition, the cause of death is unknown, but a long-standing theory is that some of these deaths could be the result of anaphylaxis. Objective To investigate the potential contribution of anaphylactic mechanisms to deaths in infancy by determining relative levels of ?- and ?-Tryptases and both total and allergen-specific IgE in sera from groups of infants whose deaths were attributed to SIDS or to other causes. Methods Serum samples were collected at the time of post-mortem examination from infants whose death was classed as SIDS (n = 40) and from a comparison group in which cause of death had been established (n = 32). Serum Tryptase concentrations were measured with a radioimmunoassay with monoclonal antibody G5 which detects primarily ?-Tryptase or an ELISA with antibody AA5 which has equal sensitivity for ?- and ?-Tryptases. Levels of total IgE and IgE specific for casein, ?-lactoglobulin, house dust mite and moulds were determined. Results Analysis of the results of the two assays for Tryptase indicated that levels of the ?-like Tryptase (the form secreted on anaphylactic degranulation) were significantly higher in serum from infants with SIDS compared with those whose death was explained. There was no evidence for an increase in serum levels of ?-Tryptase (the variant secreted constitutively from mast cells). Total levels of serum IgE did not differ between the two groups and, reflecting the low circulating IgE concentrations in infancy, an elevation in IgE specific for the panel of allergens was not detected. Conclusions In a proportion of SIDS victims there may be increased serum levels of ?-like Tryptase, a marker for anaphylaxis. The failure to detect an increase in ?-Tryptase would suggest that mast cell hyperplasia is not a feature of cot death. The nature of the inciting agents remains unclear, but anaphylaxis deserves serious consideration as a possible cause of sudden death in infancy.
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A Role for Tryptase in the Activation of Human Mast Cells: Modulation of Histamine Release by Tryptase and Inhibitors of Tryptase
Journal of Pharmacology and Experimental Therapeutics, 1998Co-Authors: Shaoheng He, Marianna D. A. Gaça, Andrew F. WallsAbstract:Tryptase, the most abundant protein product of human mast cells is emerging as an important mediator and target for therapeutic intervention in allergic disease. We have investigated the potential of Tryptase and inhibitors of Tryptase to modulate histamine release from human mast cells. Addition of purified human Tryptase in concentrations ranging from 1 to 100 mU/ml stimulated a concentration-dependent release of histamine from cells dispersed from tonsil, although not from skin tissue. The reaction depended on an intact catalytic site being inhibited by heat inactivation of the enzyme, or by preincubating with the Tryptase inhibitors APC366 or leupeptin or the tryptic substrate N-benzoyl-dl-arginine- p -nitroanilide (BAPNA). Tryptase-induced histamine release took approximately 6 min to reach completion, appeared to require exogenous calcium and magnesium, and on the basis of inhibition by antimycin A and 2-deoxy-d-glucose, seemed to be a noncytotoxic process. Preincubation of cells with Tryptase at concentrations that were suboptimal for histamine release had little effect on their responsiveness to anti-immunoglobulin (Ig) E or to calcium ionophore A23187, but at higher concentrations their subsequent activation was inhibited. APC366 significantly inhibited histamine release induced by anti-IgE or calcium ionophore from both tonsil and skin cells, with up to 90% inhibition being observed at a concentration of 100 μM with skin. IgE-dependent histamine release was inhibited also by leupeptin, benzamidine and BAPNA. Tryptase may act as an amplification signal for mast cell activation, and this could account at least partly for the potent mast cell stabilizing properties of Tryptase inhibitors.
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potent induction of a neutrophil and eosinophil rich infiltrate in vivo by human mast cell Tryptase selective enhancement of eosinophil recruitment by histamine
Journal of Immunology, 1997Co-Authors: S He, Q Peng, Andrew F. WallsAbstract:Tryptase is the most abundant protein constituent of the secretory granules of human mast cells, but little is known of the contribution of this serine proteinase in acute allergic reactions. We have purified Tryptase from human lung tissue by immunoaffinity procedures, and have investigated its potential to provoke an inflammatory infiltrate in vivo. Within 6 h of injection into the skin of guinea pigs, the accumulation of large numbers of neutrophils and eosinophils was observed, and those eosinophils closest to the injection site were partially degranulated. Similarly, injection of Tryptase into the peritoneum of mice, even in quantities as low as 5 ng, stimulated the ingress of neutrophils. The response was dose dependent at 3, 6, and 16 h, with increases in median numbers of up to 400-fold. At the later time points eosinophil numbers were increased by up to 10-fold, and there were elevations also in the numbers of lymphocytes and macrophages. In both models, the actions of Tryptase appeared to be dependent on an intact catalytic site. Coinjection of heparin with Tryptase had relatively little effect on Tryptase-induced responses. On the other hand, although histamine did not itself stimulate cell accumulation, over a range of concentrations it altered the cellular composition of the infiltrate induced by Tryptase. Addition of histamine to Tryptase provoked selective increases in eosinophil numbers of up to fivefold in the mouse peritoneum. Tryptase may provide an important stimulus for granulocyte recruitment in allergic disease.
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human mast cell Tryptase a stimulus of microvascular leakage and mast cell activation
European Journal of Pharmacology, 1997Co-Authors: Shaoheng He, Andrew F. WallsAbstract:Abstract We have investigated the potential of Tryptase to stimulate an increase in microvascular permeability following injection into the skin of guinea pigs. Tryptase was isolated from high salt extracts of human lung tissue by octyl-agarose and heparin-agarose chromatography. Injection of purified Tryptase (2.5 ng–2.5 μg/site) into the skin of guinea pigs which had been injected intravenously with Evans blue dye provoked a dose-dependent increase in microvascular permeability. The skin reactions elicited by Tryptase were apparent up to 80 min following injection, while histamine-induced microvascular leakage resolved completely by 40 min. Heat-inactivation of Tryptase, or preincubating the proteinase with certain proteinase inhibitors, significantly reduced the extent of microvascular leakage, suggesting dependency on an intact catalytic site. No evidence was found for a synergistic or antagonistic interaction between Tryptase (2.5 ng–2.5 μg/site) and histamine (1–10 μg/site) when these mast cell products were injected together. Addition of heparin to Tryptase (10:1; w/w) prior to injection was without effect on Tryptase-induced microvascular leakage. Pretreatment of guinea pigs with a combination of the histamine H1 receptor antagonist pyrilamine and the histamine H2 receptor antagonist cimetidine (both 10 mg/kg), partially abolished Tryptase-induced microvascular leakage as well as attenuating the reaction to histamine. Reasoning that the microvascular leakage induced by Tryptase is likely to involve the release of histamine, we investigated the ability of Tryptase to stimulate histamine release from dispersed guinea-pig skin and lung cells in vitro. Tryptase was found to induce concentration-dependent histamine release from both sources of tissue. Mast cell activation stimulated by Tryptase in vitro was inhibited by heat treating the enzyme or by addition of proteinase inhibitors, suggesting a requirement for an intact catalytic site. Histamine release was inhibited also by preincubating cells with the metabolic inhibitors antimycin A and 2-deoxy- d -glucose indicating that the mechanism was energy-requiring and non-cytotoxic. We conclude that human mast cell Tryptase may be a potent stimulus of microvascular leakage. The activation of mast cells by this proteinase may represent an amplification process in allergic inflammation.
