CULTURE OF CELLS FROM JUVENILE WORMS OF SCHISTOSOMA-MANSONI

Tissue disruption methods were developed and serum-free cell culture m edia formulated for the maintenance in vitro of cells from juvenile wo rms (day 18 after infection) of Schistosoma mansoni. Cultures maintain ed viability for up to 6 mo when plated on a feeder layer of irradiate d rat liver cells and survived primarily as clusters of small (2.5-4 m u m diameter) cells with a high nuclear-to-cytoplasmic ratio and relat ively few organelles identified by electron microscopy. Cultures synth esized a protein profile similar to that of intact worms, and the cell clusters maintained a time- and concentration-dependent contractile r esponse to serotonin. Cells synthesizing DNA were detected by precurso r incorporation and flow cytometry in cultures initially and also afte r several weeks in vitro, although the percentage of cells synthesizin g DNA decreased with time. Efforts to identify peptide growth factor-r esponsive tyrosine phosphorylation were negative, and the overall amou nt of S. mansoni phosphotyrosine-containing proteins identified by wes tern blot with anti-phosphotyrosine monoclonal antibody was much less than that found in a peptide growth factor-responsive mouse cell line.