Characterization of new Alternaria alternata--specific rat monoclonal antibodies.

In this study, three different rat hybridoma cell lines secreting monoclonal antibodies (mAbs) recognizing the spores from Alternaria alternata, a plant pathogenic fungus, contaminant of food products and important cause of both allergic rhinitis and asthma, have been characterized. These three mAbs are all of IgM isotype. Two antibodies, A1 and F10, were cross-reactive antibodies recognizing spores from Alternaria, Cladosporium, Penicillium, Aspergillus and Stachybotrys genera, but not the yeasts Saccharomyces cerevisiae or Candida albicans. Competitive and sandwich assays demonstrated that these two mAbs were directed against the same or very close repetitive(s) epitope(s). A1-based sandwich ELISA efficiently detected this epitope in various mould (but not yeast)-soluble extracts prepared from strains grown in the laboratory. Moreover, this A1-based sandwich ELISA detected its cognate epitope in air and dust samples obtained from dwellings. The third antibody, E5, recognized only the spores of Alternaria and the phylogenetically very close Ulocladium botrytis. This E5 antibody is directed against a repetitive epitope found in Alternaria and Ulocladium laboratory extracts and can be used in a sandwich assay for the quantification of these moulds. Therefore, E5 antibody is a promising tool for the development of Alternaria-Ulocladium-specific immunoassays, while A1 and F10 could be interesting tools for the quantification of the total mould biomass.

Benzisothiazolinone as a useful template for the design of new monoacylglycerol lipase inhibitors: investigation of the target residues and comparison with octhilinone.

The regulation of 2-arachidonoylglycerol (2-AG) levels is a major issue as 2-AG has been proven to participate in numerous physiopathological phenomena such as neuroprotection or analgesia. Octhilinone, a cysteine-reagent compound, has recently been shown to inhibit in the nanomolar range monoacylglycerol lipase (MAGL), the major enzyme responsible for the degradation of 2-AG. Here, we further investigate the mechanism by which octhilinone and its benzisothiazolinone analog inhibit human MAGL. We also provide new information on the structural requirements for MAGL inhibition by these compounds. Finally, we describe for N-octylbenzisothiazolinone a mode of inhibition which is partially different from that described for octhilinone, especially with regard to the targeted cysteine residues in the vicinity of the catalytic site.