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2.
Cell ; 179(2): 417-431.e19, 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31585081

RESUMO

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 ß-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 ß-tryptase, which dissociates active tetramers into inactive monomers. A 2.15 Å crystal structure of a ß-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.

3.
Clin Transplant ; 33(5): e13515, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30849195

RESUMO

Lymphocytic bronchitis (LB) precedes chronic lung allograft dysfunction. The relationships of LB (classified here as Endobronchial or E-grade rejection) to small airway (A- and B-grade) pathologies are unclear. We hypothesized that gene signatures common to allograft rejection would be present in LB. We studied LB in two partially overlapping lung transplant recipient cohorts: Cohort 1 included large airway brushes (6 LB cases and 18 post-transplant referents). Differential expression using DESeq2 was used for pathway analysis and to define an LB-associated metagene. In Cohort 2, eight biopsies for each pathology subtype were matched with pathology-free biopsies from the same subject (totaling 48 samples from 24 subjects). These biopsies were analyzed by multiplexed digital counting of immune transcripts. Metagene score differences were compared by paired t tests. Compared to referents in Cohort 1, LB demonstrated upregulation of allograft rejection pathways, and upregulated genes in these cases characterized an LB-associated metagene. We observed statistically increased expression in Cohort 2 for this LB-associated metagene and four other established allograft rejection metagenes in rejection vs paired non-rejection biopsies for both E-grade and A-grade subtypes, but not B-grade pathology. Gene expression-based categorization of allograft rejection may prove useful in monitoring lung allograft health.

4.
Nat Genet ; 48(12): 1564-1569, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27749843

RESUMO

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.


Assuntos
Dor Crônica/genética , Doenças do Tecido Conjuntivo/genética , Variações do Número de Cópias de DNA/genética , Disautonomia Familiar/genética , Gastroenteropatias/genética , Prurido/genética , Dermatopatias/genética , Triptases/sangue , Triptases/genética , Adolescente , Adulto , Idoso , Criança , Dor Crônica/sangue , Dor Crônica/enzimologia , Doenças do Tecido Conjuntivo/sangue , Doenças do Tecido Conjuntivo/enzimologia , Disautonomia Familiar/sangue , Disautonomia Familiar/enzimologia , Feminino , Gastroenteropatias/sangue , Gastroenteropatias/enzimologia , Humanos , Masculino , Pessoa de Meia-Idade , Prurido/sangue , Prurido/enzimologia , Dermatopatias/sangue , Dermatopatias/enzimologia , Adulto Jovem
5.
Exp Dermatol ; 25(6): 434-9, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26706922

RESUMO

Mast cells (MCs) are unique constituents of the human body. While inter-individual differences may influence the ways by which MCs operate in their skin habitat, they have not been surveyed in a comprehensive manner so far. We therefore set out to quantify skin MC variability in a large cohort of subjects. Pathophysiologically relevant key features were quantified and correlated: transcripts of c-kit, FcεRIα, FcεRIß, FcεRIγ, histidine decarboxylase, tryptase, and chymase; surface expression of c-Kit, FcεRIα; activity of tryptase, and chymase; histamine content and release triggered by FcεRI and Ca(2+) ionophore. While there was substantial variability among subjects, it strongly depended on the feature under study (coefficient of variation 33-386%). Surface expression of FcεRI was positively associated with FcεRIα mRNA content, histamine content with HDC mRNA, and chymase activity with chymase mRNA. Also, MC signature genes were co-regulated in distinct patterns. Intriguingly, histamine levels were positively linked to tryptase and chymase activity, whereas tryptase and chymase activity appeared to be uncorrelated. FcεRI triggered histamine release was highly variable and was unrelated to FcεRI expression but unexpectedly tightly correlated with histamine release elicited by Ca(2+) ionophore. This most comprehensive and systematic work of its kind provides not only detailed insights into inter-individual variability in MCs, but also uncovers unexpected patterns of co-regulation among signature attributes of the lineage. Differences in MCs among humans may well underlie clinical responses in settings of allergic reactions and complex skin disorders alike.


Assuntos
Mastócitos/citologia , Pele/citologia , Adolescente , Variação Biológica da População , Criança , Pré-Escolar , Histamina/análise , Humanos , Lactente , Recém-Nascido , Masculino , Mastócitos/química , Mastócitos/enzimologia , Proteínas Proto-Oncogênicas c-kit/análise , Receptores de IgE/análise
6.
J Biol Chem ; 288(15): 10588-98, 2013 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-23447538

RESUMO

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.


Assuntos
Evolução Molecular , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Animais , Células CHO , Bovinos , Cricetinae , Cricetulus , Cobaias , Humanos , Proteínas de Membrana/antagonistas & inibidores , Camundongos , Camundongos Mutantes , Ratos-Toupeira , Mutação , Pan paniscus , Pan troglodytes , Inibidores de Proteases/farmacologia , Ratos , Solubilidade , Especificidade da Espécie
7.
Am J Respir Crit Care Med ; 187(4): 417-23, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23239157

RESUMO

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.


Assuntos
Brônquios/patologia , Bronquiolite Obliterante/patologia , Transplante de Pulmão/patologia , Linfócitos/patologia , Biópsia , Bronquite/patologia , Broncoscopia/métodos , Feminino , Rejeição de Enxerto/patologia , Humanos , Inflamação/patologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fatores de Risco , Índice de Gravidade de Doença , Síndrome
8.
J Immunol ; 185(9): 5360-8, 2010 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-20889553

RESUMO

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.


Assuntos
Evolução Biológica , Catepsina G/genética , Catepsina G/imunologia , Catepsina G/metabolismo , Primatas/imunologia , Sequência de Aminoácidos , Animais , Humanos , Camundongos , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Primatas/genética , Primatas/metabolismo , Alinhamento de Sequência , Especificidade por Substrato
9.
Am J Respir Cell Mol Biol ; 42(3): 257-67, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19933375

RESUMO

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.


Assuntos
Interações Hospedeiro-Patógeno/imunologia , Imunidade Inata/imunologia , Mastócitos/enzimologia , Mastócitos/imunologia , Peptídeo Hidrolases/imunologia , Animais , Humanos
10.
J Allergy Clin Immunol ; 124(5): 1099-105.e1-4, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19748655

RESUMO

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.


Assuntos
Dosagem de Genes , Mastócitos/enzimologia , Triptases/genética , Alelos , Sequência de Aminoácidos , Linhagem Celular , Frequência do Gene , Genótipo , Haplótipos/genética , Humanos , Hipersensibilidade/enzimologia , Hipersensibilidade/genética , Desequilíbrio de Ligação , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único , Conformação Proteica , Alinhamento de Sequência , Triptases/química , Triptases/deficiência
11.
J Biol Chem ; 283(20): 13943-51, 2008 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-18353771

RESUMO

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.


Assuntos
Quimases/metabolismo , Granzimas/química , Leucina/química , Peptídeo Hidrolases/química , Serina/química , Sequência de Aminoácidos , Animais , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Cobaias , Humanos , Camundongos , Dados de Sequência Molecular , Mutação , Ratos , Homologia de Sequência de Aminoácidos , Especificidade da Espécie
12.
J Allergy Clin Immunol ; 121(5): 1262-8, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18325577

RESUMO

BACKGROUND: Tryptases are serine peptidases stored in mast cell granules. Rodents express 2 soluble tryptases, mast cell proteases (MCPs) 6 and 7. Human alpha- and beta-tryptases are orthologs of MCP-6. However, much of the ancestral MCP-7 ortholog was replaced by parts of other tryptases, creating chimeric delta-tryptase. Human delta-tryptase's limited activity is hypothesized to be due to truncation and processing mutations. OBJECTIVE: We sought to probe the origins and consequences of mutations in primate delta-tryptases. METHODS: Prosimian (lemur), monkey (macaque), great ape (orangutan, gorilla, and chimpanzee), and human delta-tryptase genes were identified by means of data mining and genomic sequencing. Resulting genes were analyzed phylogenetically and structurally. RESULTS: The seminal conversion event generating the delta-tryptase chimera occurred early because all primates studied contain delta-tryptase genes. Truncation, resulting from a nonsense mutation of Trp206, occurred much later, after orangutans and other great apes last shared an ancestor. The Arg-3Gln propeptide mutation occurred most recently, being present in humans and chimpanzees but not in other primates. Surprisingly, the major active tryptase in monkeys is full-length delta-tryptase, not beta-tryptase, which is the main active tryptase in human subjects. Models of macaque delta-tryptase reveal that the segment truncated in human subjects contains antiparallel beta-strands coursing through the substrate-binding cleft, accounting for truncation's drastic effect on activity. CONCLUSIONS: Transformations in the ancestral MCP-7-like gene during primate evolution caused dramatic variations in function. Although delta-tryptases are nearly inactive in humans, they are active and dominant in monkeys.


Assuntos
Quimerismo , Mastócitos/enzimologia , Filogenia , Mutação Puntual , Primatas/genética , Triptases/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Gorilla gorilla , Humanos , Lemur , Macaca , Modelos Moleculares , Dados de Sequência Molecular , Pan troglodytes , Pongo pygmaeus , Estrutura Quaternária de Proteína , Triptases/química
13.
J Immunol ; 179(9): 6072-9, 2007 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-17947681

RESUMO

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.


Assuntos
Membrana Celular/enzimologia , Evolução Molecular , Mastócitos/enzimologia , Triptases/metabolismo , Animais , Sequência de Bases , Éxons/genética , Genoma/genética , Humanos , Íntrons/genética , Dados de Sequência Molecular , Filogenia , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Solubilidade , Fatores de Tempo , Triptases/genética , Vertebrados
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