PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-6 (6)
 

Clipboard (0)
None

Select a Filter Below

Journals
Year of Publication
Document Types
1.  Structural studies of novel glycoconjugates from polymerized allergens (allergoids) and mannans as allergy vaccines 
Glycoconjugate Journal  2015;33:93-101.
Immunotherapy for treating IgE-mediated allergies requires high doses of the corresponding allergen. This may result in undesired side effects and, to avoid them, hypoallergenic allergens (allergoids) polymerized with glutaraldehyde are commonly used. Targeting allergoids to dendritic cells to enhance cell uptake may result in a more effective immunotherapy. Allergoids coupled to yeast mannan, as source of polymannoses, would be suitable for this purpose, since mannose-binding receptors are expressed on these cells. Conventional conjugation procedures of mannan to proteins use oxidized mannan to release reactive aldehydes able to bind to free amino groups in the protein; yet, allergoids lack these latter because their previous treatment with glutaraldehyde. The aim of this study was to obtain allergoids conjugated to mannan by an alternative approach based on just glutaraldehyde treatment, taking advantage of the mannoprotein bound to the polymannose backbone. Allergoid-mannan glycoconjugates were produced in a single step by treating with glutaraldehyde a defined mixture of allergens derived from Phleum pratense grass pollen and native mannan (non-oxidized) from Saccharomyces cerevisae. Analytical and structural studies, including 2D-DOSY and 1H-13C HSQC nuclear magnetic resonance spectra, demonstrated the feasibility of such an approach. The glycoconjugates obtained were polymers of high molecular weight showing a higher stability than the native allergen or the conventional allergoid without mannan. The allergoid-mannan glycoconjugates were hypoallergenic as detected by the IgE reactivity with sera from grass allergic patients, even with lower reactivity than conventional allergoid without mannan. Thus, stable hypoallergenic allergoids conjugated to mannan suitable for using in immunotherapy can be achieved using glutaraldehyde. In contrast to mannan oxidation, the glutaraldehyde approach allows to preserve mannoses with their native geometry, which may be functionally important for its receptor-mediated recognition.
doi:10.1007/s10719-015-9640-4
PMCID: PMC4722057  PMID: 26603537
Mannan; Allergen; Allergoid; Glutaraldehyde; Conjugation; Vaccine
2.  Identification of Der p 23, a Peritrophin-like Protein, as a New Major Dermatophagoides pteronyssinus Allergen Associated with the Peritrophic Matrix of Mite Fecal Pellets 
The house dust mite (HDM) Dermatophagoides pteronyssinus is one of most important allergen sources and a major elicitor of allergic asthma. We screened a D. pteronyssinus expression cDNA library with IgE Abs from HDM allergic patients. A cDNA coding for a new major allergen was isolated, which showed sequence homology to peritrophins, which contain chitin-binding domains and are part of the peritrophic matrix lining the gut of arthropods. The mature Der p 23 allergen was expressed in Escherichia coli as an 8-kDa protein without its hydrophobic leader sequence and purified to homogeneity. It reacted with IgE Abs from 74% of D. pteronyssinus allergic patients (n = 347) at levels comparable to the two major HDM allergens, Der p 1 and Der p 2. Thus, Der p 23 represents a new major D. pteronyssinus allergen. Furthermore, rDer p 23 exhibited high allergenic activity as demonstrated by upregulation of CD203c expression on basophils from D. pteronyssinus allergic patients. Immunogold electron microscopy localized the allergen in the peritrophic matrix lining the midgut of D. pteronyssinus as well as on the surface of the fecal pellets. Thus, we identified a new major D. pteronyssinus allergen as peritrophin-like protein. The high allergenic activity of Der p 23 and its frequent recognition as respiratory allergen may be explained by the fact that it becomes airborne and respirable through its association with mite feces. Der p 23 may be an essential component for diagnosis and specific immunotherapy of HDM allergy.
doi:10.4049/jimmunol.1202288
PMCID: PMC4582595  PMID: 23460742
3.  Sensitization to Indigenous Pollen and Molds and Other Outdoor and Indoor Allergens in Allergic Patients From Saudi Arabia, United Arab Emirates, and Sudan 
Background
Airborne allergens vary from one climatic region to another. Therefore, it is important to analyze the environment of the region to select the most prevalent allergens for the diagnosis and treatment of allergic patients.
Objective
To evaluate the prevalence of positive skin tests to pollen and fungal allergens collected from local indigenous plants or isolated molds, as well as other outdoor and indoor allergens in allergic patients in 6 different geographical areas in the Kingdom of Saudi Arabia (KSA), the United Arab Emirates, and Sudan.
Materials and methods
Four hundred ninety-two consecutive patients evaluated at different Allergy Clinics (276 women and 256 men; mean age, 30 years) participated in this study. The selection of indigenous allergens was based on research findings in different areas from Riyadh and adjoining areas. Indigenous raw material for pollen grains was collected from the desert near the capital city of Riyadh, KSA. The following plants were included: Chenopodium murale, Salsola imbricata, Rumex vesicarius, Ricinus communis, Artiplex nummularia, Amaranthus viridis, Artemisia monosperma, Plantago boissieri, and Prosopis juliflora. Indigenous molds were isolated from air sampling in Riyadh and grown to obtain the raw material. These included the following: Ulocladium spp., Penicillium spp., Aspergillus fumigatus, Cladosporium spp., and Alternaria spp. The raw material was processed under Good Manufacturing Practices for skin testing. Other commercially available outdoor (grass and tree pollens) and indoor (mites, cockroach, and cat dander) allergens were also tested.
Results
The highest sensitization to indigenous pollens was detected to C. murale (32%) in Khartoum (Sudan) and S. imbricata (30%) and P. juliflora (24%) in the Riyadh region. The highest sensitization to molds was detected in Khartoum, especially to Cladosporium spp. (42%), Aspergillus (40%), and Alternaria spp. (38%). Sensitization to mites was also very prevalent in Khartoum (72%), as well as in Abu Dhabi (United Arab Emirates) (46%) and Jeddah (KSA) (30%).
Conclusions
The allergenicity of several indigenous pollens and molds derived from autochthonous sources was demonstrated. Prevalence studies in different regions of KSA and neighbor countries indicate different sensitization rates to these and other outdoor and indoor allergens.
doi:10.1097/WOX.0b013e31825a73cd
PMCID: PMC3651151  PMID: 23283107
allergens; diagnostics; bronchial asthma; allergic rhinitis; Saudi Arabia; Salsola; Prosopis; mites
4.  Mite-induced inflammation: More than allergy 
Allergy & Rhinology  2012;3(1):e25-e29.
Clinical observations have suggested that there is an association of atopic conditions with hypersensitivity reactions to nonsteroidal anti-inflammatory drugs (NSAIDs). This relationship has been especially present in patients allergic to mites. This study was designed to review clinical and experimental evidence linking atopy, mite allergy, and hypersensitivity to aspirin and NSAIDs and discuss the possible mechanisms explaining this association. A review of the medical literature concerning the association of atopic diseases, mite hypersensitivity, and intolerance to NSAIDs using PubMed and other relevant articles is presented. NSAID-sensitive patients are frequently atopic and allergic to mites, and patients who develop oral mite anaphylaxis (OMA) show an increased prevalence of NSAID hypersensitivity. The study of atopic, mite-sensitive patients, who experience urticaria and angioedema when exposed to NSAIDs and patients with OMA suggests an interesting interaction between atopic allergy and disorders of leukotriene synthesis or metabolism. Various mechanisms that could be involved in this interaction are presented, including genetic factors, inhibition of cyclooxygenase-1, and other effects (not related to IgE sensitization) of mite constituents on the immune system. The association of mite hypersensitivity with aspirin/NSAIDs intolerance has been confirmed and provides additional clues to various nonallergic pathways that may contribute to the acute and chronic inflammatory process observed in atopic, mite-allergic, individuals. The clinical relevance of these observations is presently under investigation.
doi:10.2500/ar.2012.3.0025
PMCID: PMC3404474  PMID: 22852126
Aspirin; acetylsalicylic acid; angioedema; cysteinyl-leukotrienes; Dermatophagoides; immunoglobulin E; mites; leukotriene C4 synthase; nonsteroidal anti-inflammatory drugs; NSAIDs
5.  Pancake Syndrome (Oral Mite Anaphylaxis) 
Oral mite anaphylaxis is a new syndrome characterized by severe allergic manifestations occurring in atopic patients shortly after the intake of foods made with mite-contaminated wheat flour. This clinical entity, observed more frequently in tropical/subtropical environments, is more often triggered by pancakes and for that reason it has been designated "pancake syndrome". Because cooked foods are able to induce the symptoms, it has been proposed that thermoresistant allergens are involved in its production. A novel variety of this syndrome occurs during physical exercise and therefore has been named dust mite ingestion-associated exercise-induced anaphylaxis. To prevent mite proliferation and the production of anaphylaxis, it has been recommended that wheat flour be stored at low temperatures in the refrigerator.
doi:10.1186/1939-4551-2-5-91
PMCID: PMC3651046  PMID: 23283016
anaphylaxis; exercise-induced anaphylaxis; food allergy; immunoglobulin E; mites
6.  Usefulness of manufactured tomato extracts in the diagnosis of tomato sensitization: Comparison with the prick-prick method 
Background
Commercial available skin prick test with fruits can be negative in sensitized or allergic patients due to a reduction in biological activity during the manufacturing process. Prick-prick tests with fresh foods are often preferred, but they are a non-standardized procedure. The usefulness of freeze-dried extracts of Canary Islands tomatoes, comparing the wheal sizes induced by prick test with the prick-prick method in the diagnosis of tomato sensitization has been analyzed.
The objective of the study was to assess the potential diagnostic of freeze-dried extracts of Canary Islands tomatoes, comparing the wheal sizes induced by prick test with the prick-prick method.
Methods
Two groups of patients were analyzed: Group I: 26 individuals reporting clinical symptoms induced by tomato contact or ingestion. Group II: 71 control individuals with no symptoms induced by tomato: 12 of them were previously skin prick test positive to a tomato extract, 39 were atopic and 20 were non-atopic. All individuals underwent prick-prick with fresh ripe peel Canary tomatoes and skin prick tested with freeze-dried peel and pulp extracts obtained from peel and pulp of Canary tomatoes at 10 mg/ml. Wheal sizes and prick test positivity (≥ 7 mm2) were compared between groups.
Results
In group I, 21 (81%) out of 26 patients were prick-prick positive. Twenty patients (77%) had positive skin prick test to peel extracts and 12 (46%) to pulp extracts. Prick-prick induced a mean wheal size of 43.81 ± 40.19 mm2 compared with 44.25 ± 36.68 mm2 induced by the peel extract (Not significant), and 17.79 ± 9.39 mm2 induced by the pulp extract (p < 0.01).
In group II, 13 (18%) out of 71 control patients were prick-prick positive. Twelve patients (all of them previously positive to peel extract) had positive skin prick test to peel and 3 to pulp. Prick-prick induced a mean wheal size of 28.88 ± 13.12 mm2 compared with 33.17 ± 17.55 mm2 induced by peel extract (Not significant), and 13.33 ± 4.80 mm2 induced by pulp extract (p < 0.05 with peel extract and prick-prick).
Conclusion
Canary peel tomato extract seems to be as efficient as prick-prick tests with ripe tomatoes to diagnose patients sensitized to tomato. The wheal sizes induced by prick-prick and peel extracts were very similar and showed a high correlation coefficient.
doi:10.1186/1476-7961-6-1
PMCID: PMC2263074  PMID: 18184431

Results 1-6 (6)