The basophil activation test by flow cytometry: recent developments in clinical studies, standardization and emerging perspectives

BACKGROUND: Beauveria bassiana is an important entomopathogenic fungus currently under development as a bio-control agent for a variety of insect pests. Although reported to be non-toxic to vertebrates, the potential allergenicity of Beauveria species has not been widely studied. METHODS: IgE-reactivity studies were performed using sera from patients displaying mould hypersensitivity by immunoblot and immunoblot inhibition. Skin reactivity to B. bassiana extracts was measured using intradermal skin testing. RESULTS: Immunoblots of fungal extracts with pooled as well as individual sera showed a distribution of IgE reactive proteins present in B. bassiana crude extracts. Proteinase K digestion of extracts resulted in loss of IgE reactive epitopes, whereas EndoH and PNGaseF (glycosidase) treatments resulted in minor changes in IgE reactive banding patterns as determined by Western blots. Immunoblot inhibitions experiments showed complete loss of IgE-binding using self protein, and partial inhibition using extracts from common allergenic fungi including; Alternaria alternata, Aspergillus fumigatus, Cladosporium herbarum, Candida albicans, Epicoccum purpurascens, and Penicillium notatum. Several proteins including a strongly reactive band with an approximate molecular mass of 35 kDa was uninhibited by any of the tested extracts, and may represent B. bassiana specific allergens. Intradermal skin testing confirmed the in vitro results, demonstrating allergenic reactions in a number of individuals, including those who have had occupational exposure to B. bassiana. CONCLUSIONS: Beauveria bassiana possesses numerous IgE reactive proteins, some of which are cross-reactive among allergens from other fungi. A strongly reactive potential B. bassiana specific allergen (35 kDa) was identified. Intradermal skin testing confirmed the allergenic potential of B. bassiana.     

Prostaglandin Endoperoxide H Synthase-2 (PGHS-2) Variants and Risk of Obesity and Microvascular Dysfunction Among Tunisians: Relevance of rs5277 (306G/C) and rs5275 (8473T/C) Genetic Markers

The purpose of this study was to determine the impact of six PGHS-2 genetic variants on obesity development and microvascular dysfunction. The study included 305 Tunisian subjects (186 normal weights, 35 overweights and 84 obeses). PCR analyses were used for allelic discrimination between polymorphisms. Prostaglandin (PGE2, PGI2), leptin, and matrix metalloproteinase (MMP1, 2, 3, 9) levels were evaluated by ELISA. Fatty acid composition was performed by gas chromatography–mass spectrometry. Our results revealed that subjects carrying the PGHS-2 306CC (rs5277) and 8473CC (rs5275) genotypes present higher anthropometric values compared to wild-type genotypes (306GG, BMI (Kg/m²): 27.11?±?0.58; WC (cm): 93.09?±?1.58; 306CC, BMI: 33.83?±?2.46; WC: 109.93?±?5.41; 8473TT, BMI: 27.75?±?0.68; WC: 93.96?±?1.75; 8473CC, BMI: 33.72?±?2.2; WC: 117.89?±?2.94). A reduced microvascular reactivity and a higher PGE2 level were also found in individuals with the 306CC and 8473CC genotypes in comparison to 306GG and 8473TT carriers (306GG, Peak Ach-CVC (PU/mmHg): 0.46?±?0.03; PGE2 (pg/ml): 7933.1?±?702; 306CC, Peak Ach-CVC: 0.24?±?0.01; PGE2: 13,380.3?±?966.2; 8473TT, Peak Ach-CVC: 0.48?±?0.05; PGE2: 7086.41?±?700.31; 8473CC, Peak Ach-CVC: 0.23?±?0.01; PGE2: 13,175.7?±?1165.8). Fatty acid analysis showed a significant increase of palmitic acid (PA) (34.2?±?2.09 vs. 16.82%?±?1.76, P?<?0.001), stearic acid (SA) (25.76?±?3.29 vs. 9.05%?±?2.53, P?<?0.001), and linoleic acid (LA) (5.25?±?1.18 vs. 0.5%?±?0.09, P?<?0.001) levels in individuals carrying the PGHS-2 306CC genotype when compared to GG genotype individuals. Subjects with the 8473CC genotype showed also a significant increase of PA, SA ,and LA levels when compared to TT genotype carriers (PA: 38.02?±?1.51 vs. 12.65%?±?1.54, P?<?0.001; SA: 32.96?±?1.87 vs. 1.38%?±?0.56, P?<?0.001; LA: 26.84?±?2.09 vs. 3.7%?±?1.54, P?<?0.001). Logistic regression analysis revealed that PGHS-2 306CC and 8473CC variants are significantly associated with obesity status (OR 6.25, CI (1.8–21.6), P?=?0.004; OR 3.01, CI (1.13–8.52), P?=?0.03, respectively). Haplotypes containing the C₃₀₆:T₈₄₇₃ (OR 2.91; P?=?0.01) and G_306:C₈₄₇₃ (OR 5.25; P?=?0.002) combinations were associated with an enhanced risk for obesity development in the studied population. In conclusion, our results highlight that PGHS-2 306G/C and 8473T/C variants could be useful indicators of obesity development, inflammation, and microvascular dysfunction among Tunisians.