MONOCLONAL-ANTIBODIES AGAINST A 97-KILODALTON ANTIGEN FROM ASPERGILLUS-FLAVUS

We prepared a panel of five monoclonal antibodies (MAbs) directed agai nst Aspergillus flavus that all reacted against one 97-KDa antigen by Western blot (immunoblot). Flow cytometry demonstrated that these anti bodies bound (in increasing degrees) to all morphologic stages of A. f lavus growth: conidia, swollen conidia, and hyphae. Cross-reactivity a mong species was examined by enzyme-linked immunosorbent assay of fung al culture filtrates. Four MAbs reacted with 10 of 11 A. flavus isolat es, and the fifth one reacted with 9 of them. One MAb also reacted wit h A. fumigatus, two reacted with A. niger, A. wentii, and A. nidulans, and all five reacted with A. ochraceus. None reacted with A. ter reus , A. glaucus, A. versicolor, or a Penicillium species. Each MAb bound to A. flavus hyphae in formalin-fixed paraffin sections of a muscle bi opsy from a confirmed human case of invasive aspergillosis. In summary , these MAbs identified a 97-kDa antigen found on A. flavus that is bo th surface bound and an exoantigen. Either the same or a cross-reactin g antigen is present in A. fumigatus and other Aspergillus species.