Identification of whole pathogenic cells by monoclonal antibodies generated against a specific peptide from an immunogenic cell wall protein.

Journal of microbiological methods

PubMedID: 25451457

Kaba HE, Maier N, Schliebe-Ohler N, Mayer Y, Müller PP, van den Heuvel J, Schuchhardt J, Hanack K, Bilitewski U. Identification of whole pathogenic cells by monoclonal antibodies generated against a specific peptide from an immunogenic cell wall protein. J Microbiol Methods. 2014;.
Rapid diagnosis of pathogens is one of the most challenging topics in medical microbiology. We used a new strategy for easy and rapid identification of whole pathogen cells by staining a specific microbial cell surface protein. Using Candida albicans, one of the major causes of nosocomial bloodstream infections, as a model, we selected the abundant immunogenic cell wall ß-(1,3)-glucosyltransferase Bgl2p as a target protein. Based on sequence homologies and on a model of the 3D-structure of Bgl2p, we identified a unique peptide sequence of C. albicans Bgl2p of 14 amino acids (Bgl2a10), which showed significant differences to sequences from the same region of Bgl2p orthologues from related pathogenic yeasts, such as Candida glabrata. We used Bgl2a10 for immunization of mice and finally obtained hybridoma cell lines for the production of monoclonal anti-C. albicans Bgl2p antibodies. Antibodies in the supernatants of these cell cultures bound recombinant purified Bgl2p. Antibodies released particularly by the cell clone C25HD4A8 even bound to whole C. albicans cells in a manner that was dependent on Bgl2p. Moreover, these antibodies were able to distinguish C. albicans from C. glabrata as determined by flow cytometric analysis. Thus the generation of antibodies against a specific peptide epitope from the surface of an immunogenic cell surface protein avoided tedious selection procedures of suitable antibodies for the specific detection of pathogens without further sample pretreatment.