Specific IgE to propolis extracts among pollen allergic patients

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Double One-Dimensional Electrophoresis (D1-DE) Adapted for Immunoproteomics

International audienceThe classical proteomics approach for the identification of allergen candidates consists on the separation of proteins by high-resolution two-dimensional electrophoresis (2-DE) with subsequent IgE immunoblotting and further analysis of IgE-reactive protein spots with mass spectrometry. In this approach at least two gels most be run. One gel is used for staining and the other is for immunoblotting by antibodies labeled with specific immunostains. Additional functional characterizations require either protein purification or 2-DE replicates and appear to be time- and reagent-consuming. Here we described a modified double one-dimensional electrophoresis (D1-DE) allowing the conversion of a protein spot previously visualized by 2-DE into an extended protein band. In D1-DE, the purity of the protein of interest is similar to 2-DE spots, but its abundance is many times higher than what can be found in a 2-DE single spot allowing many other functional analyses from a single D1-DE separation

The Use of Combinatorial Hexapeptide Ligand Library (CPLL) in Allergomics

International audienceThe recent progress of proteomic protocols led to more efficient protein extraction and concentration procedures to remove nonprotein interfering compounds present in the starting material and to increase the concentration of underrepresented proteins. Combinatorial hexapeptide ligand libraries (CPLL) were recently applied to both plant- and animal-derived tissues for capturing the low- and very low-abundance allergens. Several IgE-binding proteins which were previously absent or poorly represented by using conventional proteomics tools have been detected and characterized through a CPLL-based approach. In the present chapter, a protocol based on improved protein extraction and enrichment by CPLL, allowing the immunochemical characterization of several “hidden allergens” in cypress pollen, is described in detail

Contamination of milk and dairy products by Brucella species: A global systematic review and meta-analysis

Brucellosis is known as an influential zoonosis in different regions worldwide, with significant effects on the reproductive performance of livestock. Considering the high incidence of brucellosis in dairy products and further negative impacts on food safety, the present study was aimed to systematically investigate prevalence worldwide among published data regarding the identification of Brucella spp. in dairy products. In this regard, some databases, i.e., Scopus, PubMed, Embase, and Web of Science have been searched to retrieve all related articles regarding the incidence of Brucella contaminations in dairy products from 1 January 1983 to 1 April 2019. The prevalence of Brucella spp. in unpasteurized dairy products based on countries, WHO regions, and dairy product subgroups were evaluated and statistically compared. Based on the findings, the prevalence of Brucella spp. in dairy products increased while the GDP (C = 0.17, P-value Eastern Mediterranean (2.41) > Region of America (1.65) > European Region (1.54) > Africa region (1.46) > Western Pacific (reference). The results of this study showed that decreasing poverty and an increase in the level of education in societies could reduce the prevalence of Brucella spp. in dairy products. The outcome of the current investigation can be used for the implementation of sustainable intervention and prevention strategies in affected regions128sem informaçãosem informaçã

Kinetic of NO₂ uptake by Phleum pratense pollen: Chemical and allergenic implications

Phleum pratense pollen was exposed to NO2 in a reactor allowing a continuous analysis of NO2 concentration by FTIR. The uptake coefficient of NO2 on pollen was calculated postulating a first order kinetic reaction and a value of (1.1 ± 0.1) × 10−7 was determined. NO2 uptake was faster when the pollen water content was increased and when the pollen was pre-treated with ozone. The effect of NO2 exposure on pollen allergic properties was investigated by quantifying Th2- and Th1-associated chemokines in a model of human dendritic cells. Cellular analysis clearly showed that cells exposed to fumigated pollen favored the production of chemokines known to promote Th2-cell responses. Altogether these data demonstrate that NO2 uptake by pollen directly correlates with increased Th2 response in human cells, and are in favor of the involvement of NO2 pollution in the increase of allergic diseases

Allergomic study of cypress pollen via combinatorial peptide ligand libraries

Although Cupressus sempervirens (Cups) pollen represents one of the main aeroallergens in southern Europe, only two Cups allergens have yet been identified and reported: Cup s 1 and Cup s 3.The aim of this study was to identify allergens in cypress pollen using an immuno-proteomic approach. A sequential pollen protein extn. was developed and supplemented by a combinatorial peptide ligand library (CPLL) treatment to select low-abundance species. Control exts. and CPLL eluates have then been resolved by 1-DE and 2-DE gel electrophoresis, blotted and confronted with sera from cypress allergic patients. Extd. proteins including IgE-binding components were identified using nanoLC-MS/MS anal. A total of 108 unique gene products were identified analyzing the eluates and control loaded onto 1-DE SDS-PAGE. Forty proteins were identified in control samples and 68 supplementary species upon CPLL treatment. Out of the 12 IgE-binding proteins characterized in 2-DE gels, 9 were already reported as allergens in various sources including the two major known allergens of Cupressaceae (groups 1 and 2). Three IgE-binding proteins, not previously reported as allergens, are newly described. The improvement in protein extn. combined with the enrichment of low-abundance species allowed us to extend the repertoire of potential cypress pollen allergen