SCHISTOSOMA - ANALYSIS OF MONOCLONAL-ANTIBODIES REACTIVE WITH THE CIRCULATING ANTIGENS CAA AND CCA

Using spleen cells of mice infected or immunized respectively with cer cariae or antigen preparations of Schistosoma mansoni, S. haematobium or S. japonicum monoclonal antibodies (mAbs) were produced against the schistosome gut-associated antigens CAA (circulating anodic antigen) and CCA (circulating cathodic antigen). Fusions nearly exclusively pro duced either anti-CAA (n = 25) or anti-CCA mAbs (n = 55) with a strong isotype restriction (IgM, IgG1 and IgG3) against both antigens, the m ajority of anti-CAA mAbs being IgG1 and the majority of anti-CCA mAbs being IgM. The mAbs, which on the basis of their selection were reacti ve with multiple carbohydrate epitopes of CAA or CCA, were applied in different immunological techniques including immunofluorescence, a dot immunobinding assay and immunoelectrophoresis to study the epitope re pertoire. Anti-CAA mAbs were found to be reactive with 5 different epi topes, none of which occurred as multiple epitopes on eggs. Anti-CCA m Abs, on the other hand, recognized at least 10 different epitopes, whi le 44% of anti-CCA mAbs recognized epitopes common to the adult worm a nd the egg. Both CAA- and CCA-epitopes were found to be developmentall y expressed at the level of the tegument in cercariae, schistosomula a nd 5-day-old lung worms, but in the adult worm were primarily found in the gut. Thus, the production of panels of mAbs has not only resulted in the selection of reagents optimally performing in diagnostic immun oassays, but also allowed a more detailed study of the epitope reperto ire of these important schistosome antigens.