bluuebunny/crossref_metadata_2025 huggingface dataset:
A Sib-Pair Regression Model of Linkage Disequilibrium for Quantitative Traits
Authors: Cardon Lon R.
Published: April 2003

A multiple-regression model is described for the detection of linkage disequilibrium in quantitative trait loci. The model is developed for application to large numbers of single nucleotide polymorphism (SNP) markers genotyped on small nuclear families. Parental data are not required by the method, although it provides a direct means to test quantitative trait locus-marker allele association and to determine whether any such association is attributable to linkage disequilibrium or population admixture. Analytical expectations for the regression coefficients are derived, allowing direct interpretation of the parameter estimates. Simulation studies indicate a substantial improvement in power over classical linkage studies of sibling pairs and show the effects of population admixture on the model outcomes.
Identification of mtDNA Mutation in a Pedigree with Gestational Diabetes, Deafness, Wolff-Parkinson-White Syndrome and Placenta accreta
Authors: Aggarwal P. , Gill-Randall R. , Wheatley T. , Buchalter M.B. , Metcalfe J. , Alcolado J.C.
Published: April 2003

Mitochondrial DNA (mtDNA) defects are associated with a number of human disorders. Although many occur sporadically, maternal transmission is the hallmark of diseases due to mtDNA point mutations. The same mutation may manifest strikingly different phenotypes; for example, the A to G substitution at np 3243 was first reported in patients with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (the MELAS syndrome), but is also found in patients with diabetes and deafness. Here we present a case of gestational diabetes, deafness, premature greying, placenta accreta and Wolff-Parkinson-White (WPW) syndrome associated with a mtDNA mutation. Although this is the first report of such an association, study of 27 other patients with WPW syndrome failed to confirm that this mtDNA mutation is a common cause of such pre-excitation disorders.
Ascertainment and Anticipation in Family Studies
Authors: Hoh Josephine , Heitjan Daniel F. , Mérette Chantal , Ott Jürg
Published: April 2003

Many human diseases show anticipation; that is, disease occurs earlier (or with greater severity) in successive generations. In a computer simulation, we assessed the degree of anticipation that one would expect to see in two-generation breast cancer families. Under reasonable assumed distributions for age at cancer onset, number of children, and mortality, we find a consistent earlier mean age at diagnosis in daughters than in mothers, but the same mean age at diagnosis in affected aunts and nieces. We compare these results with published pedigree data for familial breast cancer that show substantial anticipation in affected daughters compared to their mothers. We find that at least some anticipation is expected in human disease families even when the disease is stable and families are ascertained without obvious sampling bias. We further demonstrate that such anticipation is reduced when comparing affected children to the parents’ affected siblings.
Consanguinity in South America: Demographic Aspects
Authors: Liascovich Rosa , Rittler Mónica , Castilla Eduardo E.
Published: April 2003

A sample of 53,552 nonmalformed liveborn infants was ascertained by the Latin-American Collaborative Study of Congenital Malformations between 1967 and 1996. The mean consanguinity rate was 0.96%, with significantly higher values in Brazil and Venezuela, and lower in Argentina. Low paternal education and occupation levels were positively associated with consanguinity. First-cousin matings represented almost half of all consanguineous couples. The consanguinity was mainly of more closely related types in Brazil, while in Venezuela more remote types predominated. This could reflect differences in migration patterns and rates between these two countries.
The C677T Mutation of the Methylenetetrahydrofolate Reductase Gene Is Not Associated with the Risk of Coronary Artery Disease or Venous Thrombosis among Chinese in Taiwan
Authors: Hsu Lung-An , Ko Yu-Lin , Wang Shu-Mei , Chang Chi-Jen , Hsu Tsu-Shiu , Chiang Cheng-Wen , Lee Ying-Shiung
Published: April 2003

Objectives: We sought to investigate the association between the methylenetetrahydrofolate reductase (MTHFR) gene C677T mutation and the risk of coronary artery disease (CAD), myocardial infarction (MI) and venous thrombosis (VT) in a Chinese population in Taiwan. Methods: The subjects included 218 CAD patients, 107 VT patients, and their age- and sex-matched controls. DNA was extracted from the blood and genotypes were determined by polymerase chain reaction, restriction mapping with HinfI and gel electrophoresis. Results: The distribution of MTHFR genotypes was similar in the CAD cases and controls; the genotype TT was present in 6.0% of CAD patients, as compared to 6.9% of CAD control subjects (p = 0.165; odds ratio = 0.86; 95% confidence interval = 0.40–1.85). The frequency of the T allele was also similar in CAD cases and controls (25.5% vs. 24.8%; p = 0.788). There was no significant association between TT homozygosity and the risk of MI. The genotype distributions and the frequency of the T allele were also similar in VT cases and controls. Conclusions: Our data suggest that there is no association between the C677T mutation of the human MTHFR gene and the risk of CAD or VT among Chinese in Taiwan.
Association Tests for Traits with Variable Age at Onset
Authors: Mokliatchouk Oksana , Blacker Deborah , Rabinowitz Daniel
Published: April 2003

This paper is concerned with testing association between marker genotypes and traits with variable age at onset. Two methods are proposed, one which makes use of both age-at-ascertainment and age-at-onset information, and one which may be applied when only age-at-ascertainment information is available. (Here, by age-at-ascertainment, is meant the subject’s age when presence of onset and age at onset are determined; for subjects who have died or are otherwise censored before ascertainment, the censoring time should be used instead). Adjustment for confounding due to population stratification is carried out by conditioning on observed traits and parental genotypes, or, if complete parental genotypes are not available, by conditioning on observed traits and the minimal sufficient statistics under the null hypothesis for the parental genotypes. Proportional hazards regression models and logistic regression models are used to motivate the methods, but correct type I error rates result even if the models are not correct. An illustrative example is described.
Ric c 1 and Ric c 3, the Allergenic 2S Albumin Storage Proteins of Ricinus communis: Complete Primary Structures and Phylogenetic Relationships
Authors: Bashir Mohamed Elfatih H. , Hubatsch Ina , Leinenbach Hans Peter , Zeppezauer Michael , Panzani Raphael C. , Hussein Ismail H.
Published: April 2003

The 2S albumin storage protein of Ricinus communis consists of the two heterodimeric proteins Ric c 1 and Ric c 3 each of which is composed of a small and a large subunit linked together by disulphide bridges. The complete primary structures of both heterodimeric proteins were determined by enzymatic degradation and automated Edman degradation. The sequences of all four chains correspond to the known cDNA sequence of the gene of a presumed precursor molecule and to the previously determined partial sequences for Ric c 1 and Ric c 3. In addition, few differences in amino acid positions were found which seem to be related to different varieties of R. communis. Sequence comparisons with 2S albumin from other plant genera revealed high degrees of homology and support the view of a common genetic origin of this protein family. Ric c 1 and Ric c 3 which have 11,212 and 12,032 daltons, respectively, share a similar molecular size, biological function and allergenicity with the 2S albumins from Brassica juncea (Bra j 1E) and Sinapis alba L (Sin a 1). Ric c 1 and Ric c 3 may be classified as isoallergens if, additionally, the high degree of similarity in the position of polar residues is taken into account.
Recombinant Aspergillus fumigatus Allergens: From the Nucleotide Sequences to Clinical Applications
Authors: Crameri Reto
Published: April 2003

Members of the genus Aspergillus are opportunistic pathogens for cold- and warm- blooded animals. They are associated with an impressive spectrum of diseases in humans, ranging from benign colonization of the lung to life-threatening diseases such as invasive aspergillosis or allergic bronchopulmonary aspergillosis (ABPA). Aspergillus fumigatus is the etiological agent identified in most of the Aspergillus-related human diseases and is therefore of particular clinical relevance. A major problem in the diagnosis of A. fumigatus-related complications arises from the lack of standardized fungal extracts. The allergenicity of commercial A. fumigatus extracts depends on many factors including the strain used, growth conditions, harvesting and extraction procedures hampering the development of diagnostic reagents suitable for the discrimination between A. fumigatus-related diseases. Molecular DNA/RNA technologies and biotechnological procedures allow cloning, characterization and production of large amounts of single, highly pure allergens. The development of phage surface display technologies for cloning cDNAs has speeded up the isolation of candidate cDNAs encoding allergens. Screening of an A. fumigatus cDNA library displayed on the surface of phage M13 allowed characterization and production of a panel of allergens identified as proteins with known biological function or as allergens without sequence homology to known proteins. They belong to two functional categories: secreted and cytoplasmic proteins. Secreted allergens are recognized by serum IgE of A. fumigatus-sensitized individuals with or without ABPA, whereas nonsecreted allergens are exclusively recognized by serum IgE of ABPA patients. The dissection of IgE-mediated immune responses to single A. fumigatus allergens allows a discrimination between ABPA and A. fumigatus sensitization with high specificity and sensitivity demonstrating the power of recombinant allergens for the differential diagnosis of A. fumigatus-related pulmonary complications.
Specificity of the Human IgE Response to the Different Purified Caseins in Allergy to Cow’s Milk Proteins
Authors: Bernard Hervé , Créminon Christophe , Yvon Mireille , Wal Jean-Michel
Published: April 2003

Background: Cow’s milk is one of the most frequent food allergens. Whole casein appears to be highly allergenic. It corresponds to an association of four different proteins, αs1-, αs2-, β- and *-caseins in approximate proportions of 40, 10, 40, and 10%, respectively. Methods: These different components were thus purified and used as immobilized antigens in an original enzyme immunoassay to measure specific serum IgE response in a population of 58 children (median age 11 months) allergic to cow’s milk who were sensitive to whole casein. Results: A great variability was observed in the affinity and specificity of specific IgE responses in milk-allergic patients’ sera. 85% of the patients presented IgE against each of the four caseins. Statistically higher amounts of specific IgE were found to be directed against the most abundant fractions (αs1- and β-casein). Co- and/or cross-sensitization to the different caseins were seen in most of the patients sensitive to whole casein. Conclusion: These results suggest that both distinct and common epitopes may occur on these different caseins. The major site of phosphorylation which is the most conserved domain in three caseins could be involved in the IgE response to casein and in immunocross-reactivity between these proteins.
Biochemical Characterization of Pru a 2, a 23-kD Thaumatin-Like Protein Representing a Potential Major Allergen in Cherry (Prunus avium)
Authors: Inschlag Claudia , Hoffmann-Sommergruber Karin , O’Riordain Gabriel , Ahorn Horst , Ebner Christof , Scheiner Otto , Breiteneder Heimo
Published: April 2003

Background: The prevalence of allergy to fruits and vegetables increased with pollinosis over the last 10 years. So far, clusters of hypersensitivity have been established and corroborated by the molecular characterization of individual cross-reacting allergens. Several case studies demonstrated the existence of allergic reactions to fruits of the subfamily Prunoideae (apricots, cherries, plums and peaches). Here, we present the characterization of a major allergen in cherry. Methods: Characterization was performed using IgE immunoblotting and immunoblot inhibition, N-terminal sequencing, mass spectroscopy analysis and PCR-based cDNA cloning. Results: A 23-kD protein was identified as IgE-binding component. As all cherry-extract-reactive sera displayed IgE-binding to this band, it was designated a major allergen from Prunus avium (Pru a 2). Sequencing the corresponding cDNA identified Pru a 2 as a thaumatin-like protein belonging to the group 5 of pathogenesis-related proteins. Conclusions: A thaumatin-like protein in cherry has been identified as a major allergen (Pru a 2). Homologous proteins from the thaumatin family share sequence similarities and should therefore be checked for the capability to elicit an IgE-mediated allergic reaction.
Effects of Anti-IL-5 Monoclonal Antibody on the Murine Model of Nasal Allergy
Authors: Asakura Kohji , Saito Hiroko , Watanabe Masako , Ogasawara Hideki , Matsui Toshinori , Kataura Akikatsu
Published: April 2003

IL-5 is known to be closely related to the infiltration, activation and proliferation of eosinophils. In this study, we evaluated the in vivo effects of anti-IL-5 monoclonal antibody (mAb) in the murine model of nasal allergy. The mAb treatment inhibited the antigen-induced late phase eosinophilia, but had no effects on the number of basophilic cells. It also inhibited early phase nasal symptoms, and tended to inhibit histamine hypersensitivity. These findings suggest that IL-5 plays an important role in the pathogenesis of allergic nasal disorders.
Inhibitory Effects of Lodoxamide on Eosinophil Activation
Authors: Capron M. , Loiseau S. , Papin J.P. , Robertson S. , Capron A.
Published: April 2003

Recent reports describe the beneficial use of lodoxamide, an anti-allergic compound, for the treatment of asthma and allergic conjunctivitis. Lodoxamide is known as a mast cell stabilizer, however, the association of a significant clinical improvement with a specific decrease in eosinophil infiltrate suggested possible direct effects of lodoxamide on eosinophils. The chemotactic response of eosinophils to fMLP as well as to IL-5, in vitro, was very significantly and dose-dependently inhibited by Lodoxamide. Lodoxamide was also able to strongly inhibit the release of eosinophil peroxidase after IgA-dependent activation and, to a lesser extent, the release of eosinophil cationic protein and eosinophil-derived neurotoxin. Moreover, the release of cytotoxic mediators evaluated in an antibody-dependent cytotoxicity assay against parasitic targets was also significantly reduced, not only in the case of human eosinophils but also in a rat eosinophil-mast cell model of cytotoxicity. Taken together, these results indicate that lodoxamide can exert potent inhibitory effects on eosinophil activation in vitro combined with a strong inhibition of eosinophil attraction, leading therefore to a reduction in their pathological potential in vivo.
Inhibition of Neurotensin-Stimulated Mast Cell Secretion and Carboxypeptidase A Activity by the Peptide Inhibitor of Carboxypeptidase A and Neurotensin-Receptor Antagonist SR 48692
Authors: Miller Lisa A. , Cochrane David E. , Feldberg Ross S. , Carraway Robert E.
Published: April 2003

Background: Neurotensin (NT), a peptide found in brain and several peripheral tissues, is a potent stimulus for mast cell secretion and its actions are blocked by the specific NT receptor antagonist, SR 48692. Subsequent to stimulation, NT is rapidly degraded by mast cell carboxypeptidase A (CPA). In the experiments described here, we tested for the involvement of CPA activity in the activation of mast cell secretion by the peptide, NT. Methods: Mast cells were isolated from the peritoneal and pleural cavities of rats, purified over metrizamide gradients and incubated at 37 °C in Locke solution or Locke containing the appropriate inhibitors. For some experiments, media derived from mast cells stimulated by compound 48/80 were used as a source of mast cell CPA activity. Results: Treatment of mast cells with the highly specific peptide inhibitor of CPA derived from potato (PCI) inhibited histamine release in response to NT and NT8–13 (the biologically active region of NT). This inhibition required some 20 min to develop and was only partially reversed by a 20-min wash period. PCI (10 μM) did not inhibit histamine release in response to NT1–12, bardykinin, compound 48/80, the calcium ionophore, A23187, or anti-IgE serum. PCI also inhibited mast cell CPA activity. SR 48692, a highly selective antagonist of the brain NT receptor and of NT-stimulated mast cell secretion, also inhibited mast cell CPA activity as well as bovine pancreatic CPA activity in a concentration-dependent manner. Discussion: It is suggested that the mast cell binding site for NT and the active site for CPA may share similar characteristics. The results are discussed in terms of NT mechanism of action on the mast cell.
Immunohistochemical Study of E–cadherin and ZO–1 in Allergic Nasal Epithelium of the Guinea Pig
Authors: Kobayashi Noriko , Dezawa Mari , Nagata Hiroshi , Yuasa Shigeki , Konno Akiyoshi
Published: April 2003

Nasal epithelial damage during allergic inflammation was studied by observing the distribution of cell adhesion molecule E–cadherin and tight junction (zonula occludens) cell–cell contact associated protein ZO–1. The guinea pig model of nasal allergy, sensitized with intraperitoneally administered ovalbumin (OA) and subsequently challenged with OA intranasally, was used. In control epithelium, E–cadherin immunoreactivity was detected continuously along neighboring epithelial cell borders. ZO–1 spot–like immunoreactivity was detected in the apicolateral portion of epithelial cells corresponding to the tight junction (TJ) position, but no changes in immunoreactivity were found between control and challenged epithelia. In the challenged epithelium of sensitized animals, marked infiltration of eosinophils and structural changes, such as widening of the intercellular spaces and detachment of adjacent epithelial cells, were observed concurrently. In addition, spots negative for E–cadherin immunoreactivity were noted in the epithelium, associated with the extracellular deposition of eosinophil granule proteins. Immunoelectron microscopy revealed a decrease or disappearance of E–cadherin immunoreactivity, which took place not only in regions where intercellular spaces were wide and adjacent epithelial cells were detached, but also at the point of contact between infiltrating eosinophils and epithelial cells. Approximately 87% of eosinophils observed in the challenged epithelium were associated with such loss of E–cadherin immunoreactivity. These results suggest that the intimate epithelial cell contact mediated by E–cadherin is loosened as a consequence of eosinophil infiltration, which may trigger the initial step of subsequent epithelial destruction in allergic states.
Identification of Allergens in Oilseed Rape (Brassica napus) Pollen
Authors: Focke M. , Hemmer W. , Hayek B. , Götz M. , Jarisch R.
Published: April 2003

Background: Pollen from oilseed rape (OSR), Brassica napus, an increasingly cultivated oilplant from the Brassicaceae, has been recognized as a potential cause of allergic sensitization. Allergens have been hardly investigated. Methods: We characterized IgE binding proteins in OSR pollen by immunoblot, immunoblot inhibition and specific monoclonal antibodies using sera from 89 patients sensitized to OSR. Results: Two low–molecular–weight allergens of 6/8 kD and 14 kD as well as a high molecular–weight cluster (27–69 kD) comprising six cross–reactive peptides could be identified. The three allergens were recognized by 50, 34 and 80% of patients, respectively. Immunoblot IgE binding to OSR could be totally inhibited by rye pollen and moderately by birch pollen (6/8 and 14 kD) while mugwort had little effect. An anti–profilin–specific monoclonal antibody bound specifically to a 14–kD protein in OSR. Binding to the 6/8–kD rape allergen could be effectively inhibited by rAln g 2, a calcium–binding protein from alder. Periodate treatment led to a significant reduction in IgE binding to the 27 to 69–kD OSR allergens indicating that carbohydrate determinants are involved in IgE binding. OSR proteins were capable to quench IgE binding to timothy grass pollen proteins of ≥60 kD suggesting that grass pollen group 4 allergens cross–react with the 27 to 69–kD cluster in OSR. Conclusions: The data demonstrate that OSR pollen is allergenic and indicate that the identified allergens represent cross–reacting homologues of well–known pollen allergens, i.e. calcium–binding proteins, profilins, and high–molecular–weight glycoproteins. Via cross–reactivity, exposure to OSR pollen may be a prolonging and aggravating factor in underlying birch and grass pollen allergy.
Exogenous Interleukin–3 Enhances IL–4 Production by Splenic CD4+ Cells during the Early Stages of a Trichinella spiralis Infection
Authors: Korenaga Masataka , Akimaru Yoko , Hashiguchi Yoshihisa
Published: April 2003

Treatment with recombinant interleukin–3 (rIL–3) augmented IL–4 production of spleen cells in mice infected with Trichinella spiralis. In a previous report, we showed that treatment with rIL–3 accelerated IgE responsiveness in mice. We have examined IL–4 and interferon (IFN)–γ production by spleen cells from both rIL–3–treated and untreated mice during the early stages of infection. The results indicated that IL–4 production was enhanced in rIL–3–treated mice compared to that in untreated mice. In contrast, there was no difference in IFN–γ production between the two groups. Augmentation of IL–4 production was dependent on the dose of rIL–3 injected before infection. To examine if the treatment with rIL–3 affects T cell function, spleen cells from mice treated with various doses of rIL–3 were cultured under the stimulation with anti–CD3 (T cell receptor complex) mAb and then assessed for cytokine production. IL–4 production increased depending on the dose of rIL–3, while IFN–γ production did not. Furthermore, spleen cells were separated by surface markers, Thy1.2, CD4 and CD8. Thy1.2+ cell population responded significantly to produce IL–4 after anti–CD3 stimulation, when compared with IL–4 production of Thy1.2– cell population. A major producer of IL–4 in T cells was CD4+ cell population but not CD8+ cell population. IL–4 production was suppressed in rIL–3–treated mice injected with anti–CD4 mAb. These results suggest that IL–3 might play a role as Th2 amplifier in immune response to parasite infection.
Calcium–Binding Allergens: From Plants to Man
Authors: Valenta Rudolf , Hayek Brigitte , Seiberler Susanne , Bugajska-Schretter Agnes , Niederberger Verena , Twardosz Anna , Natter Susanne , Vangelista Luca , Pastore Annalisa , Spitzauer Susanne , Kraft Dietrich
Published: April 2003

Calcium–binding proteins contain a variable number of motifs, termed EF–hands, which consist of two perpendicularly placed α–helices and an interhelical loop forming a single calcium–binding site. Due to their ability to bind and transport calcium as well as to interact with a variety of ligands in a calcium–dependent manner, they fulfill important biological functions in eukaryotic cells. After parvalbumin, a three EF–hand fish allergen, calcium–binding allergens were discovered in pollens of trees, grasses and weeds and, recently, as autoallergens in man. Although only a small percentage of atopic individuals displays IgE reactivity to calcium–binding allergens, these allergens may be important because of their ability to cross–sensitize allergic individuals. Conformation and stability as well as IgE recognition of calcium–binding allergens greatly depend on the presence of protein–bound calcium ions. It is thus likely that hypoallergenic derivatives of calcium–binding allergens can be engineered by recombinant DNA technology for immunotherapy of sensitized patients.
Role of CD4–Positive T Cells in the Pathogenesis of Nasal Allergy in the Murine Model
Authors: Ogasawara Hideki , Asakura Kohji , Saito Hiroko , Kataura Akikatsu
Published: April 2003

Background: Antigen–induced upregulation of cytokines, especially Th2–type cytokines, has been proven to be closely related to allergic inflammation in nasal allergy. CD4–positive T cells are supposed to play an important role not only in the induction of allergy but also in allergic inflammation. Methods: The anti–CD4 mAb was administered to the murine model of nasal allergy either at the beginning of sensitization, just before antigen challenge or during a topical booster sensitization. Then, the effects on the antigen–induced nasal responses and the serum level of antigen–specific IgE antibody were evaluated. Results: When the mAb was applied at the beginning of sensitization, the early–phase nasal symptoms and the late–phase nasal eosinophilia were significantly inhibited, and the 8–day passive cutaneous anaphylaxis (PCA) titer tended to be inhibited. When the mAb was applied just before the challenge, there were no differences in the nasal symptoms, the nasal eosinophilia or the 8–day PCA titer between the mAb–treated animals and the control animals. When the mAb was applied during a topical booster sensitization, the nasal eosinophilia, the 8–day PCA titer and histamine hypersensitivity were significantly suppressed in the treated animals. Conclusion: CD4–positive T cells play an important role in the induction of IgE–mediated nasal allergy, occurrence of late–phase allergic inflammation and histamine hypersensitivity, but not in antigen–induced early–phase nasal symptoms in the murine model. In cases of chronic topical antigen exposure, however, the suppressive effects of a single application of the anti–CD4 mAb are not remarkable.
T Cells and Chronic Asthma
Authors: Kon Onn M. , Kay A.B.
Published: April 2003

There is increasing evidence that the asthma process is 'driven’ and maintained by persistence of a subset of chronically activated T memory cells, sensitized against allergenic, occupational or viral antigens which 'home’ to the lung after antigen exposure or viral infection. In general, allergens induce a CD4 T helper (Th) cell response, whereas viruses recognize CD8+ cytotoxic (Tc) T cells. In the asthmatic airways, there are CD4+ and, to a lesser number CD8+ cells with a type 2 cytokine phenotype (i.e., Th–2 and Tc–2 type). These cells produce interleukin (IL) 3 and 5 and granulocyte–macrophage colony–stimulating factor which recruit, mobilize and activate eosinophils for subsequent mucosal damage, as well as IL–4, an essential cofactor for local or generalized IgE production. This leads to epithelial shedding, mucus hypersecretion and bronchial muscle contraction. Thus, although the eosinophil may damage the mucosal surfaces in asthma, its function appears to be under T cell control. Support for this hypothesis includes: (1) activated T cells and their products can be identified in biopsies from the major variants of the disease (atopic, non–atopic and occupational asthma); (2) colocalization of mRNA for type 2 cytokines to CD4+ and CD8+ cells in atopic and non–atopic asthma; (3) the presence of activated cytokine–producing T cells in corticosteroid–resistant asthma; (4) the association of disease severity with type 2 cytokines, especially IL–5; and (5) the efficacy of cyclosporin A and a monoclonal anti–CD4 in chronic steroid–dependent disease. Inhibitors and/or antagonists directed against more precise T cell associated molecular targets hold promise for the future treatment of chronic asthma.
gp49B1 and Its Related Family of Counterregulatory Receptors of the Immunoglobulin Superfamily
Authors: Katz Howard R.
Published: April 2003

Cross–linking of FcεRI on mast cells elicits positive signal transduction cascades that lead to the release of a variety of proinflammatory mediators. Mouse mast cells also express gp49B1 on their surface, an immunoglobulin superfamily member that bears two immunoreceptor tyrosine–based inhibitory motifs in its cytoplasmic domain and inhibits FcεRI–induced release of secretory granule mediators and the cysteinyl leukotriene, LTC4. gp49B1 belongs to a growing family of inhibitory receptors expressed in mouse and man. Thus, FcεRI–induced mast cell activation is counterregulated by several receptors belonging to the same superfamily as FcεRI itself.
Implications of the Grass Group I Allergens on the Sensitization and Provocation Process
Authors: Petersen A. , Grobe K. , Schramm G. , Vieths S. , Altmann F. , Schlaak M. , Becker W.-M.
Published: April 2003

Grass pollen allergens of group I are particularly important because of their high IgE prevalence and occurrence in all grass species. Four independent IgE–binding regions and one continous epitope were identified. The posttranslational modifications on the molecule increased allergenicity. Phl p 1 is a cysteine protease, as determined by specific substrates, inhibitors and consensus sequence motifs. In analogy to other allergens and/or proteases, we deduce that Phl p 1 might enhance the permeability of the epithelium, influence T helper cells to bias Th2, and increase the IgE production of plasma cells. Thus, the group I allergens seem to be the crucial components in a pollen extract which can mediate sensitization and enhance the triggering of symptoms leading to the persistence of a grass pollen allergy.
Cytoplasmic Lipid Bodies in Eosinophils: Central Roles in Eicosanoid Generation
Authors: Weller Peter F. , Bozza Patricia T. , Yu Wengui , Dvorak Ann M.
Published: April 2003

Background: Lipid bodies are lipid–rich cytoplasmic inclusions which form in diverse cell types, including eosinophils. Lipid body numbers increase in vivo in leukocytes participating in inflammatory processes. Our interest in lipid bodies relates to the roles that these structures play in arachidonate metabolism by eosinophils and other leukocytes involved in inflammation. Methods: Specific agonists, platelet–activating factor (PAF), two cis–unsaturated fatty acids (arachidonic and oleic acids) and a diglyceride (1–oleyl–2–acetyl–glycerol (OAG)), were used to stimulate lipid body formation in human eosinophils. Lipid bodies were enumerated and eosinophils were stimulated with submaximal calcium ionophore to generate leukotriene C4 (LTC4), which was quantitated by immunoassay. Results: Lipid body formation was rapidly inducible in eosinophils by specific intracellular signaling pathways. PAF, the two cis–unsaturated fatty acids and OAG each stimulated lipid body formation in eosinophils. Increased numbers of lipid bodies correlated quantitatively with the ‘priming’ response of eosinophils to form enhanced amounts of the 5–lipoxygenase–derived eicosanoid, LTC4. Conclusion: Lipid bodies in eosinophils function as intracellular domains that are both depots of esterified arachidonate and sites at which regulated enymatic events relevant to arachidonate metabolism can occur. In conjunction with our findings that key eicosanoid–forming enzzymes, including cyclooxygenase, 5– and 15–lipoxygenase and LTC4 synthase, are localized at lipid bodies in eosinophils, the finding that induction of lipid body formation correlated quantitatively with enhanced LTC4 production indicate that lipid bodies are structurally distinct, inducible, non–nuclear sites for enhanced synthesis of paracrine eicosanoid mediators of inflammation.
The Respiratory Burst Activity of Activated Eosinophils in Atopic Asthmatics
Authors: Tsai Jaw-Ji , Kao Mau-Han , Han Shou-Hwa
Published: April 2003

Although activated eosinophils in peribronchial tissue and peripheral blood are increased in patients with asthma, the mechanisms contributing to their presence and causing airway hyperreactivity are not well established. Recently, the respiratory burst activity on activated eosinophils can be evaluated by dual staining with monoclonal antibody EG2 and 2,7–dichlorofluorescein diacetate, which can be analyzed with the FACS analyzer. The severity of allergy and airway hyperreactivity can be evaluated by allergen–specific IgE and airway hyperresponsiveness to methacholine. In this study we evaluated the cell numbers with respiratory burst activity on activated eosinophils and correlated these cell numbers with the allergen–specific IgE and airway hyperresponsiveness to methacholine. Results showed that the cell number with respiratory burst activity of activated eosinophils was increased in those patients with more hyperresponsiveness to methacholine and correlated with PD20 of methacholine with r = –0.643 and p = 0.01. The number of activated eosinophils was also correlated with allergen–specific IgE with r = 0.641 and p = 0.025. There were increased cell numbers of activated eosinophils (EG2+/PMN) and cells with respiratory burst activity (DCF+EG2+/PMN) in the unstable asthmatic patients when compared to those of stable asthmatic patients. These results suggest that there is in vivo activation of eosinophils in the asthmatic patients, especially in the unstable patients and patients who have airways more hyperreponsive to methacholine. We concluded that the cell numbers with respiratory burst activity of activated eosinophils cannot only reflect the airway hyperresponsiveness but also the disease severity of asthmatic patients.
Molecular Basis of Drug Recognition by Specific T–Cell Receptors
Authors: von Greyerz Salome , Burkhart Christoph , Pichler Werner J.
Published: April 2003

In recent years the involvement of T cells in allergic reactions to drugs has been well established. However, several molecular aspects of drug recognition by specific T cells remain still unclear. This review will discuss the known pathways of drug presentations by antigen presenting cells, the recognition of MHC/peptide/drug complexes by specific T–cell receptors, and the activation mechanism of drug–specific T cells.
Peptide Specificity, HLA Class II Restriction, and T–Cell Subsets of the T–Cell Clones Specific to Either Cry j 1 or Cry j 2, the Major Allergens of Japanese Cedar (Cryptomeria japonica) Pollen
Authors: Sone Toshio , Morikubo Keiko , Shimizu Kimiko , Komiyama Naoki , Tsunoo Hajime , Kino Kohsuke
Published: April 2003

Background: Cry j 1 and Cry j 2 are thought to be the major allergens of Japanese cedar pollen. HLA class II types capable of presenting T–cell epitopes in both allergens and their role in induction of T–cell subsets are not well known. Methods: CD4+ T (Th)–cell clones (TCCs) specific to either Cry j 1 or Cry j 2 were generated. HLA class II restrictions were determined by their reactivity to the T–cell epitope in the presence of antigen presenting cells sharing matched types. Interleukin (IL)–2, interferon–γ, IL–4, and IL–5 contents in the supernatants of TCCs were estimated using enzyme immunoassay. Results: Peripheral blood mononuclear cells (PBMC) from patients induced proliferation with 100 μg/ml Cry j 1 or 3–10 μg/ml rCry j 2 stimulation. T–cell epitopes in Cry j 1 were presented to Th cells by the gene products of DRA1*01/DRB1*0901, DRA1*01/DRB5*0101, DQA1* 0102/DQB1*0602, and DPA1*01/DPB1*0501; those in Cry j 2 were restricted by DRA1*01/DRB1*0901, DRA1* 01/DRB1*1501, DRA1*01/DRB4*01, DRA1*01/DRB5* 0101, DQA1*0102/DQB1*0602, DPA1*01/DPB1*0201, and DPA1*01 and *0202/DPB1*0501. Type 2–like cells were preferentially induced in Cry j 1 stimulation, while an almost equal number of type 2– and type 1–like cells was induced in rCry j 2. Conclusions: No clear correlation existed between peptide specificity, HLA class II restriction and induction of Th–cell subsets, suggesting that the requirement of different dose of Cry j 1 or Cry j 2 to induce proliferation in PBMC may lead to distinguishable difference in induction of Th subsets between TCCs specific to Cry j 1 and Cry j 2.
Protein and Allergen Analysis of Latex Mattresses
Authors: Chardin H. , Desvaux F.X. , Mayer C. , Sénéchal H. , Peltre G.
Published: April 2003

Background: Latex allergy is a well–recognized health problem. The wide use of latex in daily life raised the question whether latex articles could be a source of allergens. The present study was carried out to analyse various latex mattresses for protein and allergen characterization. Methods: Five latex foam mattresses were reduced to powder and proteins were extracted using either water or urea. The protein content of the extracts was analyzed by SDS–PAGE, IEF, 2–D gel electrophoresis and amino acid sequence analysis. The presence of specific IgE, directed toward mattress proteins found in human sera of latex–allergic patients, was tested using ELISA and immunoprints. Results: The results showed that no protein or allergen could be extracted from synthetic foam. However, depending on the type of mattress and extraction procedure, various quantities of proteins could be extracted from mattresses containing natural latex. The ELISA levels of various latex–allergic patients were always more significant against urea extracts than against water extracts, except for one mattress. The protein and allergen patterns were qualitatively similar for all mattresses containing natural latex. Hev b 1 was identified by N–terminal amino acid sequence analysis. Conclusion: Because the natural rubber of the mattresses contains latex allergens, these allergens are a potential source of sensitization and could constitute a risk, at least to allergic individuals.
Distinct Expression of RANTES and GM–CSF by Lipopolysaccharide in Human Nasal Fibroblasts but Not in Other Airway Fibroblasts
Authors: Nonaka Manabu , Pawankar Ruby , Saji Fusako , Yagi Toshiaki
Published: April 2003

Eosinophil infiltration of tissue is a hallmark of nasal polyposis and asthma in both atopic and nonatopic patients. Structural cells like airway fibroblasts are a rich source of cytokines and inflammatory mediators. In order to verify whether airway fibroblasts play a role in eosinophilic infiltration, we investigated the release of eosinophil chemotactic and activating factors from airway fibroblasts when stimulated with nonallergenic exogenous agents such as endotoxin (lipopolysaccharide; LPS). Using a number of primary human airway tissue–derived fibroblast lines, we demonstrated that LPS could induce the gene expression and production of RANTES (regulated and normal T cell expressed and presumably secreted) and granulocyte/macrophage colony–stimulating factor (GM–CSF) only in nasal but not in pharyngeal, tracheal, bronchial, and lung fibroblasts. This selective responsiveness of nasal fibroblasts to LPS was time and dose dependent. These findings suggest that nasal fibroblasts may play an important role in the recruitment and activation of eosinophils into nasal polyps through the release of RANTES and GM–CSF.
Eotaxin and Nitric Oxide Production as Markers of Inflammation in Allergic Cynomolgus Monkeys
Authors: Young Simon S. , Ritacco Gretchen , Skeans Susan , Chapman Richard W.
Published: April 2003

Background: Cynomolgus monkeys have a natural hypersensitivity to Ascaris suum antigen. Inhalation of antigen produces immediate and delayed allergic reactions and an influx of inflammatory cells into the lungs. This study investigated the production of nitric oxide (NO) and the chemokine eotaxin during this allergic response. The effect of bronchoscopy alone on lung inflammatory cells was also investigated along with the time course of the eosinophil influx into the lung. Methods: Allergic cynomolgus monkeys were challenged with antigen. Bronchoalveolar lavage (BAL) was performed before and after challenge, and end–tidal NO was measured before and 24 h after challenge. Eotaxin was measured in the BAL fluid 6, 24 and 72 h after challenge. One group of animals was treated with dexamethasone before challenge to block the influx of cells into the lung. Results: BLA alone induced an influx of neutrophils, but not eosinophils, into the lung 24 h later. A single antigen challenge produced a marked increase in BAL eosinophils that was apparent at 6 h but increased at 72 h after challenge. The increase at 6 h was largely blocked by dexamethasone. Three antigen challenges produced elevated BAL eosinophil levels that persisted for at least 8 weeks. Eotaxin levels rose dramatically 6 h after challenge and remained the same after 24 h. By 72 h, the eotaxin levels had returned to baseline. The increase in eotaxin at 6 h was nonsignificantly reduced by dexamethasone. Exhaled NO levels doubled 24 h after challenge and were not affected by dexamethasone. Conclusions: Eotaxin and NO production were increased after airway challenge in allergic monkeys. The rise in NO was not blocked by dexamethasone. The effects of bronchoscopy on the BAL can be avoided by using alternate lungs on consecutive occasions. Eosinophils persist in the BAL for many weeks after antigen challenge.
Purified and Recombinant Latex Proteins Stimulate Peripheral Blood Lymphocytes of Latex Allergic Patients
Authors: Johnson Bryon D. , Kurup Viswanath P. , Sussman Gordon L. , Arif Siti A.M. , Kelly Kevin J. , Beezhold Donald H. , Fink Jordan N.
Published: April 2003

Background: Natural rubber latex proteins have been implicated in severe allergy in individuals exposed to latex products, particularly health care workers. Until recently, only crude antigens were available to study the immune response in these patients. In recent years a number of relevant allergens have been purified, but few have been used in lymphocyte studies. Hence, to better understand the immunological mechanisms involved in latex allergy, we investigated the response of peripheral blood mononuclear cells (PBMCs) to various purified natural rubber latex allergens. Methods: Using conventional protein purification methods and gene cloning, we have obtained 6 natural rubber latex proteins. We studied allergen–specific IgE levels and PBMC responses to these allergens along with 3 crude latex antigen preparations. Results: Of the 28 latex–allergic health care workers studied, 16 reacted to one or more of the allergens studied, but PBMCs from controls failed to respond to these antigens. Serum IgE to the antigens was detected in 11–90% of the patients. Conclusion: Fifty–seven percent of the latex–allergic patients demonstrated PBMC responses to at least one of the latex allergens tested, but there was no direct correlation between serum IgE levels and PBMC responses. However, since none of the control subjects showed any PBMC stimulation, this may prove useful in determining sensitization to latex. Among the allergens studied, the predominant mononuclear cell responses were directed against Hev b 2, while serum IgE against rHev b 6 was demonstrable in the greatest number of patients. The crude latex allergens were toxic to PBMCs and hence, the purified allergens may be of greater value in demonstrating sensitization of patients to latex allergens.
Interaction of Human IgE with Fc Epsilon RI Alpha Exposes Hidden Epitopes on IgE
Authors: Nechansky Andreas , Ruf Christine , Pursch Edith , Wasserbauer Erich , Stämpfli Martin R. , Pachlopnik Jana M. , Stadler Beda M. , Kricek Franz
Published: April 2003

Background: Binding of human IgE via the heavy–chain constant region domain 3 (Cε3) to the α–chain of its high affinity receptor (FcεRIα) is a key event in mediating allergic reactions. We wanted to identify epitopes within Cε3 that are stable to denaturation and to evaluate whether such structures are involved in receptor binding. The existence of stable epitopes would facilitate the generation of compounds that inhibit the IgE–FcεRIα interaction. Methods: Monoclonal anti–human IgE–antibodies against recombinant bacterially synthesized Cε3, which is known to be partly misfolded, were raised in mice. These antibodies were probed for binding to native, immobilized and receptor–bound IgE, respectively, providing tools for the identification of the indicated stable epitopes. Results: Two of the generated antibodies (8E7, 3G9) discriminate between IgE in solution and IgE attached to FcεRIα, pointing towards a steric rearrangement within Cε3 induced upon receptor binding. The described antibodies represent tools for studying the mechanism of the Fcε–FcεRIα interaction and may be of diagnostic value since serum IgE from various human donors was differently recognized by 8E7, which is indicative for naturally occurring IgE molecules with different steric conformation. Conclusion: The presented data support the hypothesis of a conformational change within IgE Cε3 upon receptor binding by showing that monoclonal antibodies raised against recombinant Cε3 differently recognize soluble and receptor–bound IgE. The presence of an IgE portion in sera of human donors that is recognized by 8E7 indicates the existence of IgE molecules in different steric conformations in human blood, which may be related to pathologic parameters.
Administration of SIN–1 Induces Guinea Pig Airway Hyperresponsiveness through Inactivation of Airway Neutral Endopeptidase
Authors: Kanazawa Hiroshi , Hirata Kazuto , Yoshikawa Junichi
Published: April 2003

Background: Peroxynitrite plays an important role in the pathogenesis of airway inflammation. We have already found that peroxynitrite may contribute to decreased β2–adrenoceptor responses in airway smooth muscle. However, it is not known whether peroxynitrite can alter neutral endopeptidase (EC 3.4.24.11; NEP) activity in the airways. This study was designed to determine whether peroxynitrite induces airway hyperresponsiveness to substance P (SP) and endothelin–1 (ET–1) through the inactivation of airway NEP. Methods: We examined whether the administration of S–morpholinosydnonimine (SIN–1), a compound that releases peroxynitrite, increased bronchoconstrictor responses to SP and ET–1 in anesthetized guinea pigs. In addition, we assayed NEP activity in the airways of SIN–1–exposed guinea pigs. Results: Though SIN–1 (10–7 M) alone had no effect on pulmonary resistance, pretreatment with SIN–1 significantly enhanced SP– and ET–1–induced bronchoconstriction. Pretreatment with phosphoramidon, an NEP inhibitor, also enhanced SP– and ET–1–induced bronchoconstriction. However, simultaneous administration of phosphoramidon and SIN–1 had no additive effect on SP– and ET–1–induced bronchoconstriction. Peroxynitrite formation by SIN–1 was completeley inhibited by N–acetylcysteine (NAC) and glutathione (GSH) in vitro, and pretreatment with NAC and GSH significantly reversed the potentiation by SIN–1 of SP–induced bronchoconstriction. In addition, the NEP activity of the trachea after SIN–1 exposure was significantly reduced compared to the level in control guinea pigs (solvent for SIN–1: 30.0±4.2 fmol·min–1·mg tissue–1; 10–7 M SIN–1; 15.5±4.5 fmol·min–1·mg tissue–1, p<0.05). Conclusions: These findings suggest that peroxynitrite induces airway hyperresponsiveness to SP and ET–1 through the inactivation of airway NEP, and that peroxynitrite is an important mediator of the alterations in airway functions.