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BACKGROUND: Pollen of grasses in Chloridoideae and Panicoideae subfamilies is a major source of grass group-1 allergens in tropical/subtropical areas. Previously, most studies of subtropical grass pollen allergens have focused on Cynodon dactylon (Bermuda grass-Chloridoideae) and Sorghum halepense (Johnson grass-Panicoideae). However, little information is available about allergenicity of pollen from Zoysia matrella (Manila grass or Zoysia grass-Chloridoideae), which is among the most popular turfgrasses in tropical/subtropical areas. OBJECTIVE: This study aimed to investigate the IgE reactivity and cross-reactivity of grass group-1 allergen from Z. matrella. In addition, the clinical relevance of Z. matrella in comparison with other species was assessed. METHODS: IgE reactivity and cross-reactivity between recombinant proteins of group-1 allergen from Z. matrella (Zoy m 1) and C. dactylon (Cyn d 1) were determined by ELISA and immunoblot assays. Clinical relevance of Z. matrella pollen in Thai atopic patients was assessed using its pollen crude extract for skin-prick test, in comparison with extracts from four other pollen species. RESULTS: The Zoy m 1 had high IgE binding and could interfere with binding to C. dactylon crude extract. In addition, Z. matrella pollen extract elicited positive skin-prick test results comparable to previously reported allergenic species. Group-1 grass pollen allergen was confirmed to be a major allergen from Z. matrella among Thai atopic patients and was officially designated Zoy m 1.0101. CONCLUSIONS: Zoy m 1 allergen is a major allergen from Z. matrella that cross-reacts with other group-1 grass pollen allergens in the tropical/subtropical region.
RESUMEN
Background and objectives: Group-1 grass allergens or beta-expansins (EXPBs) are major allergens from pollen of all grass species. Previous studies showed that they are highly conserved (64-85%) in Pooideae species, which are found mostly in the temperate regions. However, the information about group-1 allergens from common grass species in subtropical areas is still lacking. This study aimed to assess the sequence diversity of group-1 grass pollen allergens in subtropical areas, especially in Southeast Asia. Materials and Methods: Group-1 allergens were cloned from pollen of eight grass species using a single set of primers. Sequences were analyzed and IgE and IgG4 binding regions were compared to the previously reported epitopes in homologous EXPBs. The phylogenetic analysis was used to assess the relationship between sequences of these species and previously characterized EXPBs. Moreover, three-dimensional structure of the EXPB was modeled based on homology to Zea m 1. Results: Sequences from eight grass species were nearly identical. It is conceivable that the primers used for cDNA amplification detected the same isoform in different species. In fact, the deduced amino acid sequences shared 97.79-100% identity with each other and 15/819 polymorphic nucleotide positions were identified. The predicted structure showed that the IgE and IgG4 epitopes and polymorphic residues were located in both domains 1 and 2. The dendrogram presents clustering of class A EXPBs into four groups corresponding to the grass subfamilies. Conclusions: This study identified the allergens with near-identical sequences from different grass species. This isoform could be the major cross-reacting allergenic protein from commonly found grass species.
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Alérgenos/inmunología , Poaceae/inmunología , Polen/inmunología , Biodiversidad , Humanos , TailandiaRESUMEN
The present study aimed to investigate the hepatotoxicity of zederone isolated from Curcuma elata in mice. Adult male mice were intraperitoneally injected with a single dose of zederone (50-300 mg/kg body weight [BW]). Twenty-four hours after the injection, zederone induced liver enlargement with scattered white foci over the organ. The medium lethal dose (LD50) value at 24 hours of zederone was approximately 223 mg/kg BW. Hepatic centrilobular necrosis with marked increases in plasma alanine transaminase activity and total bilirubin levels was observed. Zederone at a dose of 200 mg/kg BW markedly decreased the activity of superoxide dismutase and the hepatic glutathione content, whereas the activity of catalase was not altered. The compound at this dose also increased the messenger RNA (mRNA) expression of Cyp2b10 and Cyp3a11, which are the main drug-metabolizing enzymes in the liver. The mRNA expression of proinflammatory cytokine tumor necrosis factor α was increased. The nuclear factor-E2-related factor 2 protein, which is the transcription factor regulating the antioxidant gene expression, was decreased. The histopathology of massive hepatic centrilobular necrosis with an increase in the expression of cytochrome P450 (Cyp) suggests that the possible potentiation of zederone-induced hepatotoxicity implicated the induction of Cyps, which leads to the formation of biological reactive metabolites and that cause the oxidative stress and liver cell injuries.