Blastomyces dermatitidis :

Abstract

A hybridoma cell line was isolated which produced monoclonal antibody to one protein component of a yeast-phase cytoplasmic antigen of B.dermatitidis. The IgM antibody product was characterized by immunodiffusion, autoradiography of polyacrylamide gels, and cellulose acetate electrophoresis. By attaching the antibody to an affinity gel, one major protein band was identified as the antigen for which the antibody was specific. The usefulness of this approach to serologic analysis of fungal pathogens is discussed.

A purified "A" antigen preparation of Blastomyces dermatitidis was determined to be composed of five major glycoprotein bands, visible with Coomassie blue and periodic acid-Schiff staining of polyacrylamide gels. A minimum of 20 additional protein bands were detected using a silver stain which is 100 times more sensitive than the Coomassie method. Two components of this mixture were determined to be associated with the A antigenic activity of B. dermatitidis. Of several antigen preparations examined in Ouchterlony precipitation tests, those reactive with a reference anti-A antiserum contained the slowest moving of the "Coomassie blue" bands. The antigen preparations without precipitin reactivity lacked this protein band. Two protein bands were shown to disappear from an antigen preparation after incubation with an affinity gel linked to the reference anti-A serum. One of the bands was the slowest "Coomassie blue" band and the other was a fast-migrating protein detectable only with the silver stain. The characterization of the components responsible for the A antigenic activity has important applications in the production and standardization of serologic reagents for the diagnosis of blastomycosis.

In addition, a comprehensive review of the antigens and chemical composition of B. dermatitidis introduces the work.