Displaying publications 61 - 80 of 109 in total

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  1. Fulltext Sero-prevalence study of IgE responses to allergens from Malaysian house dust (HDM) and storage mites (SM)
    Chong KT, Wong SF, Mak JW, Loh LC, Ho TM
    Trop Biomed, 2015 Sep;32(3):524-39.
    PMID: 26695214 MyJurnal
    Allergens of Dermatophagoides and Blomia species are well-characterized but not for other species. This study was conducted to determine the prevalence of allergic sensitization to house dust (HDM) and storage mites (SM). One hundred adult subjects (aged ≥ 18) were recruited. The mite specific IgE of all allergic subjects were higher compared with healthy subjetcs despite being not statistically significant except for D. farinae and G. malaysiensis. The mean serum IgE levels against HDM and SM for allergic subjects were significantly higher compared with those in healthy subjects. They were mainly sensitized to Dermatophagoides farinae (35%) and Glycycometus malaysiensis (37%). Immunoblots revealed not all allergic subjects showed positive immuno-reactivity against the mites tested. Single or multiple bands were observed for different species. The subjects were commonly sensitized to Group 2 (9-12 kDa), 10 (38 kDa) and 18 (40-48 kDa) allergens. Twenty-one out of 60 allergic subjects were sensitized to either one or more species. The majority of them (71%) were sensitized to single species. The allergic subjects were mainly sensitized to D. pteronyssinus, followed by Tyrophagus putrecentiae and Aleuroglyphus ovatus. Seven were solely sensitized to HDM while 10 were solely sensitized to SM. Four subjects were sensitized to both. Pre-adsorption study revealed no cross-reactivity. There was difference between the prevalence and reactivity to allergens of HDM and SM in these subjects. Both ELISA and immunoblot did not correlate well but can complement each other in improving the detection of mite allergens to the species level.
    Matched MeSH terms: Immunoglobulin E/blood*
  2. Fulltext Identification of tropomyosin and arginine kinase as major allergens of Portunus pelagicus (blue swimming crab)
    Rosmilah M, Shahnaz M, Zailatul HM, Noormalin A, Normilah I
    Trop Biomed, 2012 Sep;29(3):467-78.
    PMID: 23018510
    Crab is an important source of food allergen. Tropomyosin represents the main crab allergen and is responsible for IgE cross-reactivity between various species of crustaceans. Recently, other new crab allergens including arginine kinase have been identified. However, information on allergens of the local Portunidcrab is not available. Thus, the aim of this study was to identify the major allergens of Portunus pelagicus (blue swimming crab) using the allergenomics approach. Raw and cooked extracts of the crab were prepared from the crab meat. Protein profile and IgE binding pattern were demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting using sera from 30 patients with crab allergy. The major allergens of the crab were then identified by two-dimensional electrophoresis (2-DE), followed by mass spectrometry analysis of the peptide digests. The SDS-PAGE of raw extract revealed approximately 20 protein fractions over a wide molecular weight range, while cooked extract demonstrated fewer protein bands. The raw extract also demonstrated a higher number of IgE reactive bands than the cooked extract. A heat-resistant protein of 36 kDa has been identified as the major allergen in both raw and cooked extracts. In addition, a heat-sensitive protein of 41 kDa was also recognized as a major allergen in raw crab. The 2-DE gel profile of the raw extract demonstrated about >100 distinct proteins spots and immunoblotting of the 2-DE profile demonstrated at least 12 different major IgE reactive spots with molecular masses between 13 to 250 kDa and isoelectric point (pI) values ranging from 4.0 to 7.0. The 36 and 41 kDa proteins were identified as the crab tropomyosin and arginine kinase, respectively by mass spectrometry. Therefore, this study confirmed that tropomyosin and arginine kinase are the major allergens of the local Portunid crab, P. pelagicus.
    Matched MeSH terms: Immunoglobulin E/immunology
  3. Optimizing Protein Harvest From Nasal Brushings for Determining Local Allergy Responses
    Saricilar EC, Hamizan A, Alvarado R, Rimmer J, Sewell W, Tatersall J, et al.
    Am J Rhinol Allergy, 2018 Jul;32(4):244-251.
    PMID: 29785855 DOI: 10.1177/1945892418777668
    Background Rhinitis is a highly prevalent yet often misdiagnosed condition. Patients who have local allergic rhinitis are regularly mislabeled as having a nonallergic etiology. Thus, a highly accurate, reproducible, and noninvasive assessment, which can be performed quickly and with minimal discomfort to the patient, is required. Objective The aim of this research was to identify the efficiency of various nasal brushes as tools for harvest and collection of epithelial proteins and its suitability for identification of rhinitis. Methods Nasal epithelial mucosa samples were taken from patients undergoing turbinate surgery using a cytology brush, a dental brush, and a nasal curette in random order. After washing in phosphate-buffered saline, the suspended cells were sonicated. Total protein content was assessed for all samples by bicinchoninic acid assay measured using a Nanodrop machine. Identification of nasal-specific immunoglobulin E (spIgE) was then assessed using immunoassay and compared to the patient's allergic status from epicutaneous and serum testing. The lower threshold limit for the spIgE in nasal brushings was determined using the results of serum spIgE tests as the reference. The diagnostic accuracy of this new established cutoff value was determined. Results The cytology brush was found to be the optimal tool for maximal nasal mucosa protein collection followed by dental brush and nasal curette (0.75 ± 0.45 mg/mL vs 0.43 ± 0.24 mg/mL vs 0.071 ± 0.55 mg/mL, respectively; P 
    Matched MeSH terms: Immunoglobulin E/metabolism*
  4. Fulltext Tropical eosinophilia. A human model of parasitic immunopathology, with observations on serum IgE levels before and after treatment
    Neva FA, Kaplan AP, Pacheco G, Gray L, Danaraj TJ
    J Allergy Clin Immunol, 1975 Jun;55(5):422-9.
    PMID: 1138016
    The diverse clinical syndromes characterized by asthmatic symptoms, transient pulmonary infiltrates, and eosinophilia have tended to obscure the specific association of one such entity with filarial infections. Serum IgE levels were determined before and after therapy in a group of well-characterized patients with tropical eosinophilia (TE), studied earlier in Singapore. The mean serum IgE level in 14 cases before treatment with diethylcarbamazine was 2,355 ng. per milliliter, with a trend but statistically nonsignificant decrease in levels to 600-1,000 ng. occurring 8 to 12 weeks after therapy. Leukocyte and eosinophil counts showed a rapid reduction after treatment, and although mean complement-fixing (cf) titers to Dirofilarial antigen tended to decrease, they were not significantly reduced until 5 to 6 weeks. The historical development of evidence supporting the filarial etiology of TE was reviewed. Many basic questions engendered by the clinical syndrome of tropical eosinophilia make it an excellent model for study of the immunopathology of parasitic infections.
    Matched MeSH terms: Immunoglobulin E/analysis
  5. The detection of house dust mite Dermatophagoides farinae, Der f 2 and Zen-1 allergen-specific immunoglobulin E antibodies in dogs with atopic Dermatitis in Malaysia
    Chan WY, Selvarajah GT, Ajat M, Suzuki R, Tsukui T
    Vet Immunol Immunopathol, 2019 Jun;212:43-49.
    PMID: 31213251 DOI: 10.1016/j.vetimm.2019.05.002
    Canine atopic dermatitis (AD) is a chronic, inflammatory and pruritic allergic skin disease in dogs. House dust mites such as Dermatophagoides farinae are one of the known causative agents for the induction of canine AD worldwide. D. farinae protein Der f 2 is known as an important allergen involved in canine AD and recently, Zen-1 has also been identified as an allergenic protein. There is limited information on the prevalence and role of allergen sensitization to crude D. farinae extract (CDF), Der f 2 and Zen-1 among dogs diagnosed with AD in Malaysia. The aim of this study was to determine the proportion of CDF-, Der f 2- and Zen-1-specific reactive sera among dogs diagnosed with AD in Malaysia using an enzyme-linked immunosorbent assay (ELISA). Serum samples were collected from dogs diagnosed with AD from several veterinary clinics in Malaysia. The canine case records were retrieved and information on signalment, dermatological and non-dermatological histories, clinical presentation, food allergies, and exclusion of ectoparasitic, microbial and fungal skin infections were obtained through a survey form. All serum samples were evaluated to quantify the CDF-, Der f 2- and Zen-1-specific immunoglobulin E (IgE) levels. A total of 24.6%, 48.4% and 29.8% of dogs diagnosed with AD were positive for CDF-, Der f 2- and Zen-1-specific IgE, respectively. These results suggest that CDF-, Der f 2- and Zen-1 are important allergens that can contribute to AD in dogs in Malaysia, and serological testing can be performed to provide additional treatment options involving specific immunotherapies.
    Matched MeSH terms: Immunoglobulin E/blood*
  6. Fulltext Diagnostic Potential of an IgE-ELISA in Detecting Strongyloidiasis
    Ahmad H, Balachandra D, Arifin N, Nolan TJ, Lok JB, Hayat Khan A, et al.
    Am J Trop Med Hyg, 2020 12;103(6):2288-2293.
    PMID: 32996454 DOI: 10.4269/ajtmh.20-0265
    Strongyloides stercoralis infection is prevalent worldwide and can cause lifelong infection in immunocompetent individuals, and potentially death in immunosuppressed patients. The diagnosis is hindered by the low sensitivity of microscopic examination, thus making serology an important complementary test to improve the detection rate. However, there were reports that some Strongyloides-infected individuals were negative with specific IgG and IgG4 assays, and other helminth infections were positive with commercial Strongyloides IgG-ELISAs. Thus, there is a need to develop better serodiagnostic methods for strongyloidiasis. We investigated the diagnostic potential of IgE-ELISAs using Strongyloides larval lysate. Sera from two groups infected with Strongyloides served as the positive reference, that is, 1) positive by commercial IgG-ELISAs and IgG4 rapid test, and stool samples positive by microscopy and/or PCR (group IA; n = 20); and 2) negative by IgG-ELISAs and IgG4 rapid test, but stool samples were PCR positive (group IB sera; n = 11). Sera from another two groups served as negative reference (controls), that is, 1) infected with other parasites (group II; n = 73) and 2) healthy donors (group III; n = 22). Results showed a 100% diagnostic sensitivity in detecting sera from groups IA and IB. The latter group of individuals probably had early infection because their IgG and IgG4 assays were negative. The optical density values of group IB sera were also significantly lower than those of group IA (P < 0.003). The IgE-ELISA was 100% specific when tested against sera from groups II and III. This study highlights the diagnostic potential of IgE-ELISA using larval lysate to detect strongyloidiasis, especially those with probable early infection.
    Matched MeSH terms: Immunoglobulin E/immunology*
  7. Fulltext Conformational IgE Epitope Mapping of Der p 2 and the Evaluations of Two Candidate Hypoallergens for Immunotherapy
    Reginald K, Chew FT
    Sci Rep, 2018 02 21;8(1):3391.
    PMID: 29467434 DOI: 10.1038/s41598-018-21792-1
    Epitope mapping of Der p 2, a clinically important dust-mite allergen is the first step in designing immunotherapy hypoallergen vaccine candidates. Twenty-one single alanine mutants of Der p 2 were generated and their secondary structure was analysed using circular dichroism spectra. Only one mutant, K96A resulted in a misfolded protein. All mutants were tested for serum IgE reactivity using serum from dust mite allergic individuals by immuno dot-blots. Mutations to five residues, N10, E25, K77, K96 and E102 consistently showed reduced IgE reactions compared to wild-type Der p 2, and therefore these residues constitute the major IgE epitopes of Der p 2. Two mutants with consistent low IgE binding, K96A and E102A, were subsequently evaluated as hypoallergen candidates. IgG antibodies raised in mice against both mutants could inhibit human IgE-binding to WT Der p 2. Both mutants had intact T-cell epitopes as they were able to stimulate peripheral blood mononuclear cell proliferation similar to WT Der p 2. However, a switch in Th1:Th2 cytokine profile was not observed. In summary, we have identified the major conformational epitopes of Der p 2, and evaluated two Der p 2 hypoallergen vaccine candidates for immunotherapy.
    Matched MeSH terms: Immunoglobulin E/immunology*
  8. Clinacanthus nutans aqueous leaves extract exerts anti-allergic activity in preclinical anaphylactic models via alternative IgG pathway
    Kow ASF, Khoo LW, Tan JW, Abas F, Lee MT, Israf DA, et al.
    J Ethnopharmacol, 2023 Mar 01;303:116003.
    PMID: 36464074 DOI: 10.1016/j.jep.2022.116003
    ETHNOPHARMACOLOGICAL RELEVANCE: Allergy is mediated by the crosslinking of immunoglobulins (Ig) -E or -G to their respective receptors, which degranulates mast cells, macrophages, basophils, or neutrophils, releasing allergy-causing mediators. The removal of these mediators such as histamine, platelet-activating factor (PAF) and interleukins (ILs) released by effector cells will alleviate allergy. Clinacanthus nutans (C. nutans), an herbal plant in Southeast Asia, is used traditionally to treat skin rash, an allergic symptom. Previously, we have reported that C. nutans aqueous leaves extract (CNAE) was able to suppress the release of β-hexosaminidase and histamine but not interleukin-4 (IL-4) and tumor necrosis factor-alpha (TNF-α) in the IgE-induced mast cell degranulation model at 5 mg/mL and above. We also found that CNAE could protect rats against ovalbumin-challenged active systemic anaphylaxis (OVA-ASA) through the downregulation and upregulation of certain metabolites using proton nuclear magnetic resonance (1H-NMR) metabolomics approach.

    AIM OF THE STUDY: As allergy could be mediated by both IgE and IgG, we further evaluated the anti-allergy potential of CNAE in both in vitro model of IgG-induced macrophage activation and in vivo anaphylaxis models to further dissect the mechanism of action underlying the anti-allergic properties of CNAE.

    MATERIAL & METHODS: The anti-allergy potential of CNAE was evaluated in in vivo anaphylaxis models of ovalbumin-challenged active systemic anaphylaxis (OVA-ASA) and IgE-challenged passive systemic anaphylaxis (PSA) using Sprague Dawley rats as well as IgG-challenged passive systemic anaphylaxis (IgG-PSA) using C57BL/6 mice. Meanwhile, in vitro model of IgG-induced macrophage activation model was performed using IC-21 macrophages. The release of soluble mediators from both IgE and IgG-mediated pathways were measured using enzyme-linked immunosorbent assay (ELISA). The signaling molecules targeted by CNAE were identified by performing Western blot.

    RESULTS: IgG, platelet-activating factor (PAF) and IL-6 was suppressed by CNAE in OVA-ASA, but not IgE. In addition, CNAE significantly suppressed PAF and IL-6 in IgG-PSA but did not suppress histamine, IL-4 and leukotrienes C4 (LTC4) in IgE-PSA. CNAE also inhibited IL-6 and TNF-α by inhibiting the phosphorylation of ERK1/2 in the IgG-induced macrophage activation model.

    CONCLUSION: Overall, our findings supported that CNAE exerts its anti-allergic properties by suppressing the IgG pathway and its mediators by inhibiting ERK1/2 phosphorylation, thus providing scientific evidence supporting its traditional use in managing allergy.

    Matched MeSH terms: Immunoglobulin E/metabolism
  9. Fulltext Pulmonary nocardiosis in a child with hyperimmunoglobulin E syndrome
    Lee WS, Boey CC, Goh AY
    Singapore Med J, 1999 Apr;40(4):278-80.
    PMID: 10487085
    Hyperimmunoglobulin E syndrome (HIE) is a rare condition characterised by marked elevation of serum IgE level, chronic dermatitis, intense pruritus, and recurrent serious infection. The major organism is usually S aureus. We report a case of an infant with HIE, who had pulmonary nocardiosis. The clinical features, immunological abnormalities, and radiological features of the condition are described. The child finally succumbed to the complications of pulmonary nocardiosis.
    Matched MeSH terms: Immunoglobulin E/immunology
  10. Fulltext Blo t 2: Group 2 allergen from the dust mite Blomia tropicalis
    Reginald K, Pang SL, Chew FT
    Sci Rep, 2019 Aug 22;9(1):12239.
    PMID: 31439916 DOI: 10.1038/s41598-019-48688-y
    Blomia tropicalis has been recognized as a cause of allergic diseases in the tropical and subtropical regions. Here we report the immuno-characterization of its group 2 allergen, Blo t 2. Allergen Blo t 2 was amplified from the cDNA of B. tropicalis using degenerate primers, expressed in Escherichia coli as a recombinant protein and purified to homogeneity. The mature protein of Blo t 2 was 126 amino acids long with 52% sequence identity to Der p 2 and apparent molecular mass of 15 kDa. Circular dichroism spectroscopy showed that Blo t 2 is mainly a beta-sheeted protein. We confirmed the presence of three disulfide bonds in recombinant (r) Blo t 2 protein using electrospray mass spectrometry. Thirty-four percent of dust-mite allergic individuals from the Singapore showed specific IgE binding to rBlo t 2 as tested using immuno dot-blots. IgE-cross reactivity assays showed that Blo t 2 had between 20-50% of unique IgE-epitopes compared to Der p 2. IgE binding of native and recombinant forms of Blo t 2 were highly concordant (r2 = 0.77, p 
    Matched MeSH terms: Immunoglobulin E/immunology
  11. Expression of a codon-optimised recombinant Ara h 2.02 peanut allergen in Escherichia coli
    Lew MH, Lim RL
    Appl Microbiol Biotechnol, 2016 Jan;100(2):661-71.
    PMID: 26411458 DOI: 10.1007/s00253-015-6953-y
    Current diagnostic tools for peanut allergy using crude peanut extract showed low predictive value and reduced specificity for detection of peanut allergen-specific immunoglobulin E (IgE). The Ara h 2.02, an isoform of the major peanut allergen Ara h 2, contains three IgE epitope recognition sequence of 'DPYSPS' and may be a better reagent for component resolve diagnosis. This research aimed to generate a codon-optimised Ara h 2.02 gene for heterologous expression in Escherichia coli and allergenicity study of this recombinant protein. The codon-optimised gene was generated by PCR using overlapping primers and cloned into the pET-28a (+) expression vector. Moderate expression of a 22.5 kDa 6xhistidine-tagged recombinant Ara h 2.02 protein (6xHis-rAra h 2.02) in BL21 (DE3) host cells was observed upon induction with 1 mM isopropyl β-D-1-thiogalactopyranoside (IPTG). The insoluble recombinant protein was purified under denaturing condition using nickel-nitrilotriacetic acid (Ni-NTA) affinity chromatography and refolded by dialysis in decreasing urea concentration, amounting to a yield of 74 mg/l of expression culture. Matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) and immunoblot analysis confirmed the production of the recombinant 6xHis-rAra h 2.02. The refolded recombinant 6xHis-rAra h 2.02, with or without adjuvant, was able to elicit comparable level of allergen-specific IgE and IgG1 in sensitised Balb/c mice. In addition, the specific IgE antibodies raised against the recombinant protein were able to recognise the native Ara h 2 protein, demonstrating its allergenicity and potential as a reagent for diagnosis and therapeutic study.
    Matched MeSH terms: Immunoglobulin E/blood; Immunoglobulin E/immunology
  12. Nuclear magnetic resonance structure and IgE epitopes of Blo t 5, a major dust mite allergen
    Chan SL, Ong TC, Gao YF, Tiong YS, Wang de Y, Chew FT, et al.
    J Immunol, 2008 Aug 15;181(4):2586-96.
    PMID: 18684949
    A high incidence of sensitization to Blomia tropicalis, the predominant house dust mite species in tropical regions, is strongly associated with allergic diseases in Singapore, Malaysia, and Brazil. IgE binding to the group 5 allergen, Blo t 5, is found to be the most prevalent among all B. tropicalis allergens. The NMR structure of Blo t 5 determined represents a novel helical bundle structure consisting of three antiparallel alpha-helices. Based on the structure and sequence alignment with other known group 5 dust mite allergens, surface-exposed charged residues have been identified for site-directed mutagenesis and IgE binding assays. Four charged residues, Glu76, Asp81, Glu86, and Glu91 at around the turn region connecting helices alpha2 and alpha3 have been identified to be involved in the IgE binding. Using overlapping peptides, we have confirmed that these charged residues are located on a major putative linear IgE epitope of Blo t 5 from residues 76-91 comprising the sequence ELKRTDLNILERFNYE. Triple and quadruple mutants have been generated and found to exhibit significantly lower IgE binding and reduced responses in skin prick tests. The mutants induced similar PBMC proliferation as the wild-type protein but with reduced Th2:Th1 cytokines ratio. Mass screening on a quadruple mutant showed a 40% reduction in IgE binding in 35 of 42 sera of atopic individuals. Findings in this study further stressed the importance of surface-charged residues on IgE binding and have implications in the cross-reactivity and use of Blo t 5 mutants as a hypoallergen for immunotherapy.
    Matched MeSH terms: Immunoglobulin E/metabolism; Immunoglobulin E/chemistry*
  13. Minimal agreement between basophil activation test and immunoassay in diagnosis of penicillin allergy
    Leecyous B, Bakhtiar F, Tang MM, Yadzir ZHM, Abdullah N
    Allergol Immunopathol (Madr), 2020 06 09;48(6):626-632.
    PMID: 32532468 DOI: 10.1016/j.aller.2020.01.006
    INTRODUCTION: Basophil activation test (BAT) and immunoassays are the most widely used in vitro tests to diagnose IgE-mediated allergic reactions to penicillin. However, studies to determine if one test is interdependent from another are limited.

    OBJECTIVE: The present study aimed to measure the agreement between BAT and immunoassay in diagnosis of penicillin allergy.

    METHOD: BAT was performed using penicillin G (Pen G), penicillin V (Pen V), penicilloyl-polylysine (PPL), minor determinant mix (MDM), amoxicillin (Amx) and ampicillin (Amp) in 25 patients. Immunoassay of total IgE (tIgE) and specific IgE (sIgE) antibodies to Pen G, Pen V, Amx and Amp were quantified. Skin prick test (SPT) using PPL-MDM, Amx, Amp and Clavulanic acid were also performed.

    RESULTS: Minimal agreement was observed between BAT and immunoassay (k=0.25). Of two BAT-positive patients, one patient is positive to Amx (59.27%, SI=59) and Amp (82.32%, SI=82) but sIgE-negative to all drug tested. This patient is also SPT-positive to both drugs. Another patient is BAT-positive to Pen G (10.18%, SI=40), Pen V (25.07%, SI=100) and Amp (19.52%, SI=79). In sIgE immunoassay, four patients were sIgE-positive to at least one of the drugs tested. The sIgE level of three patients was between low and moderate and they were BAT-negative. One BAT-positive patient had a high level of sIgE antibodies (3.50-17.5kU/L) along with relatively high specific to total IgE ratio ≥0.002 (0.004-0.007).

    CONCLUSIONS: The agreement between BAT and immunoassay is minimal. Performing both tests provides little increase in the sensitivity of allergy diagnosis work-up for immediate reactions to penicillin.

    Matched MeSH terms: Immunoglobulin E/blood; Immunoglobulin E/immunology
  14. Fulltext Mast cell stabilizing effect of a geranyl acetophenone in dengue virus infection using in vitro model of DENV3-induced RBL-2H3 cells
    Tan JW, Wan Zahidi NF, Kow ASF, Soo KM, Shaari K, Israf DA, et al.
    Biosci Rep, 2019 06 28;39(6).
    PMID: 31110077 DOI: 10.1042/BSR20181273
    Mast cells (MCs), a type of immune effector cell, have recently become recognized for their ability to cause vascular leakage during dengue virus (DENV) infection. Although MC stabilizers have been reported to attenuate DENV induced infection in animal studies, there are limited in vitro studies on the use of MC stabilizers against DENV induced MC degranulation. 2,4,6-trihydroxy-3-geranyl acetophenone (tHGA) has been reported to be a potential MC stabilizer by inhibiting IgE-mediated MC activation in both cellular and animal models. The present study aims to establish an in vitro model of DENV3-induced RBL-2H3 cells using ketotifen fumarate as a control drug, as well as to determine the effect of tHGA on the release of MC mediators upon DENV infection. Our results demonstrated that the optimal multiplicities of infection (MOI) were 0.4 × 10-2 and 0.8 × 10-2 focus forming units (FFU)/cell. Ketotifen fumarate was proven to attenuate DENV3-induced RBL-2H3 cells degranulation in this in vitro model. In contrast, tHGA was unable to attenuate the release of both β-hexosaminidase and tumor necrosis factor (TNF)-α. Nonetheless, our study has successfully established an in vitro model of DENV3-induced RBL-2H3 cells, which might be useful for the screening of potential MC stabilizers for anti-dengue therapies.
    Matched MeSH terms: Immunoglobulin E/immunology; Immunoglobulin E/metabolism
  15. An orally active geranyl acetophenone attenuates airway remodeling in a murine model of chronic asthma
    Lee YZ, Shaari K, Cheema MS, Tham CL, Sulaiman MR, Israf DA
    Eur J Pharmacol, 2017 Feb 15;797:53-64.
    PMID: 28089919 DOI: 10.1016/j.ejphar.2017.01.011
    2,4,6-Trihydroxy-3-geranyl acetophenone (tHGA) is a synthetic compound that is naturally found in Melicope ptelefolia. We had previously demonstrated that parenteral administration of tHGA reduces pulmonary inflammation in OVA-sensitized mice. In this study, we evaluated the effect of orally administered tHGA upon airway remodeling in a murine model of chronic asthma. Female BALB/C mice were sensitized intraperitoneally with ovalbumin (OVA) on day 0, 7 and 14, followed by aerosolized 1% OVA 3 times per week for 6 weeks. Control groups were sensitized with saline. OVA sensitized animals were either treated orally with vehicle (saline with 1% DMSO and Tween 80), tHGA (80, 40, 20mg/kg) or zileuton (30mg/kg) 1h prior to each aerosolized OVA sensitization. On day 61, mice underwent methacholine challenge to determine airway hyperresponsiveness prior to collection of bronchoalveolar lavage (BAL) fluid and lung samples. BAL fluid inflammatory cell counts and cytokine concentrations were evaluated while histological analysis and extracellular matrix protein concentrations were determined on collected lung samples. Oral tHGA treatment attenuated airway hyperresponsiveness and inhibited airway remodeling in a dose-dependent fashion. tHGA's effect on airway remodeling could be attributed to the reduction of inflammatory cell infiltration and decreased expression of cytokines associated with airway remodeling. Oral administration of tHGA attenuates airway hyperresponsiveness and remodeling in OVA-induced BALB/c mice. tHGA is an interesting compound that should be evaluated further for its possible role as an alternative non-steroidal pharmacological approach in the management of asthma.
    Matched MeSH terms: Immunoglobulin E/blood; Immunoglobulin E/immunology
  16. Fulltext Topical Lyogel Containing Corticosteroid Decreases IgE Expression and Enhances the Therapeutic Efficacy Against Atopic Eczema
    Ng SF, Anuwi NA, Tengku-Ahmad TN
    AAPS PharmSciTech, 2015 Jun;16(3):656-63.
    PMID: 25511806 DOI: 10.1208/s12249-014-0248-y
    Hydrocortisone cream intended for atopic eczema often produces unwanted side effects after long-term use. These side effects are essentially due to repeated percutaneous administration of the medication for skin dermatitis, as atopic eczema is a relapsing disorder. Hence, there is a need to develop a new hydrocortisone formulation that will deliver the drug more effectively and require a reduced dosing frequency; therefore, the side effects could be minimized. In this study, a hydroxypropyl methylcellulose (HPMC) lyogel system based on 80% organic and 20% aqueous solvents containing 1% hydrocortisone was formulated. The hydrocortisone lyogel physicochemical characteristics, rheological properties, stability profile, and in vitro Franz cell drug release properties, as well as the in vivo therapeutic efficacies and dermal irritancy in Balb/c mice were investigated. The HPMC lyogel appeared clear and soft and was easy to rub on the skin. The lyogel also showed a higher drug release profile compared with commercial hydrocortisone cream. Similar to the cream, HPMC lyogels exhibited pseudoplastic behavior. From the mouse model, the hydrocortisone lyogel showed higher inflammatory suppressive effects than the cream. However, it did not reduce the transepidermal water loss as effectively as the control did. The dermal irritancy testing revealed that the hydrocortisone lyogel caused minimal irritation. In conclusion, HPMC lyogel is a promising vehicle to deliver hydrocortisone topically, as it showed a higher drug release in vitro as well as enhanced therapeutic efficacy in resolving eczematous inflammatory reaction compared with commercial cream.
    Matched MeSH terms: Immunoglobulin E/immunology*
  17. A geranyl acetophenone targeting cysteinyl leukotriene synthesis prevents allergic airway inflammation in ovalbumin-sensitized mice
    Ismail N, Jambari NN, Zareen S, Akhtar MN, Shaari K, Zamri-Saad M, et al.
    Toxicol Appl Pharmacol, 2012 Mar 1;259(2):257-62.
    PMID: 22266348 DOI: 10.1016/j.taap.2012.01.003
    Asthma is associated with increased pulmonary inflammation and airway hyperresponsiveness. The current use of corticosteroids in the management of asthma has recently raised issues regarding safety and lack of responsiveness in 5-10% of asthmatic individuals. The aim of the present study was to investigate the therapeutic effect of a non-steroidal small molecule that has cysteinyl leukotriene (cysLT) inhibitory activity, upon attenuation of allergic lung inflammation in an acute murine model. Mice were sensitized with ovalbumin (OVA) and treated with several intraperitoneal doses (100, 20, 2 and 0.2mg/kg) of 2,4,6,-trihydroxy-3-geranylacetophenone (tHGA). Bronchoalveolar lavage was performed, blood and lung samples were obtained and respiratory function was measured. OVA sensitization increased pulmonary inflammation and pulmonary allergic inflammation was significantly reduced at doses of 100, 20 and 2mg/kg with no effect at the lowest dose of 0.2mg/kg. The beneficial effects in the lung were associated with reduced eosinophilic infiltration and reduced secretion of Th2 cytokines and cysLTs. Peripheral blood reduction of total IgE was also a prominent feature. Treatment with tHGA significantly attenuated altered airway hyperresponsiveness as measured by the enhanced pause (Penh) response to incremental doses of methacholine. These data demonstrate that tHGA, a synthetic non-steroidal small molecule, can prevent acute allergic inflammation. This proof of concept opens further avenues of research and development of tHGA as an additional option to the current armamentarium of anti-asthma therapeutics.
    Matched MeSH terms: Immunoglobulin E/blood
  18. Anaphylaxis to Malaysian meat loaf
    Moritz KB, Kopp T, Stingl G, Bublin M, Breiteneder H, Wöhrl S
    Allergol Immunopathol (Madr), 2011 Jul-Aug;39(4):244-5.
    PMID: 21741147 DOI: 10.1016/j.aller.2010.06.010
    Matched MeSH terms: Immunoglobulin E/blood
  19. Characterization of glutathione S-transferase from dust mite, Der p 8 and its immunoglobulin E cross-reactivity with cockroach glutathione S-transferase
    Huang CH, Liew LM, Mah KW, Kuo IC, Lee BW, Chua KY
    Clin Exp Allergy, 2006 Mar;36(3):369-76.
    PMID: 16499649
    Sensitization to mite and cockroach allergens is common, and diagnosis and therapy of allergy can be further complicated by the presence of allergen isoforms and panallergens. Purified recombinant and native allergens are useful for studies to resolve such problems.
    Matched MeSH terms: Immunoglobulin E/immunology*
  20. Molecular cloning and immunoglobulin E reactivity of a natural rubber latex lecithinase homologue, the major allergenic component of Hev b 4
    Sunderasan E, Bahari A, Arif SA, Zainal Z, Hamilton RG, Yeang HY
    Clin Exp Allergy, 2005 Nov;35(11):1490-5.
    PMID: 16297147 DOI: 10.1111/j.1365-2222.2005.02371.x
    BACKGROUND:
    Hev b 4 is an allergenic natural rubber latex (NRL) protein complex that is reactive in skin prick tests and in vitro immunoassays. On SDS-polyacrylamide gel electrophoresis (SDS-PAGE), Hev b 4 is discerned predominantly at 53-55 kDa together with a 57 kDa minor component previously identified as a cyanogenic glucosidase. Of the 13 NRL allergens recognized by the International Union of Immunological Societies, the 53-55 kDa Hev b 4 major protein is the only candidate that lacks complete cDNA and protein sequence information.

    OBJECTIVE:
    We sought to clone the transcript encoding the Hev b 4 major protein, and characterize the native protein and its recombinant form in relation to IgE binding.

    METHODS:
    The 5'/3' rapid amplification of cDNA ends method was employed to obtain the complete cDNA of the Hev b 4 major protein. A recombinant form of the protein was over-expressed in Escherichia coli. The native Hev b 4 major protein was deglycosylated by trifluoromethane sulphonic acid. Western immunoblots of the native, deglycosylated and recombinant proteins were performed using both polyclonal antibodies and sera from latex-allergic patients.

    RESULTS:
    The cDNA encoding the Hev b 4 major protein was cloned. Its open reading frame matched lecithinases in the conserved domain database and contained 10 predicted glycosylation sites. Detection of glycans on the Hev b 4 lecithinase homologue confirmed it to be a glycoprotein. The deglycosylated lecithinase homologue was discerned at 40 kDa on SDS-PAGE, this being comparable to the 38.53 kDa mass predicted by its cDNA. Deglycosylation of the lecithinase homologue resulted in the loss of IgE recognition, although reactivity to polyclonal rabbit anti-Hev b 4 was retained. IgE from latex-allergic patients also failed to recognize the non-glycosylated E. coli recombinant lecithinase homologue.

    CONCLUSION:
    The IgE epitopes of the Hev b 4 lecithinase homologue reside mainly in its carbohydrate moiety, which also account for the discrepancy between the observed molecular weight of the protein and the value calculated from its cDNA.
    Matched MeSH terms: Immunoglobulin E/immunology*
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