PRODUCTION AND CHARACTERIZATION OF MURINE MONOCLONAL-ANTIBODIES TO BLASTOCYSTIS-HOMINIS

Several hybridomas producing antibodies detected by enzyme-linked immu nosorbent assay (ELISA) were established by fusions of mouse myeloma P 3.X63.Ag8.U1 with spleen cells from BALB/c mice immunized against an i solate of Blastocystis hominis. Five strongly positive hybrids (6B6, 1 D5, 1E7, 4F7 and 4G11) were cloned and all were found to secrete IgM m onoclonal antibodies. Four MAbs (6B6, 1E7, 4F7 and 4G11) reacted in im munoblots with a number of B. hominis antigens (mel. wt ranging from 2 5,000 to 220,000) which were likely to be repeating oligosaccharide ep itopes located on glycoproteins, as indicated by pronase and periodate treatment. Another MAb (1D5) reacted with a single antigenic band (me l. wt 30,5000). Similar results were obtained in immunoblots using 4 o ther B. hominis isolates. Indirect fluorescent-antibody assay (IFA) us ing MAbs showed 3 patterns of reactivity. 1D5 showed patchy fluorescen ce, 4F7 showed peripheral fluorescence and 6B6, 1E7 and 4G11 shelved b right diffuse fluorescence. These patterns were observed for all 5 hum an Blastocystis isolates. The MAbs exhibited some cross-reactivity wit h 2 reptilian Blastocystis isolates but not with Giardia intestinalis, Trichomonas vaginalis or Entamoeba histolytica. Copyright (C) 1996 Au stralian Society for Parasitology.