Schistosoma mansoni: comparison of the killing effect of granulocytes and complement with or without antibody on fresh and cultured schistosomula in vitro.

The efficiency of human granulocytes from patients infected with Schistosoma mansoni in killing either 2-hour or 24-hour schistosomula in the presence of complement was 43.0 +/- 5.0% and 22.7 +/- 1.8%, respectively. Granulocyte, antibody, and complement killed 61.1 +/- 1.7% of 2-hour schistosomula and 13.9 +/- 1.9% of schistosomula previously incubated for 24 hours in complex medium. The resistance of 24-hour schistosomula was less marked when they were incubated in defined medium (20.0 +/- 1.5%). When the 24-hour incubation was performed in the presence of puromycin, however, the death of schistosomula remained high: 51.9 +/- 5.7% with cells plus complement or 48.7 +/- 4.8% with cells, antibody, and complement. The increase in eosinophil percentage in granulocyte suspensions did not enhance their ability to kill 24-hour schistosomula, but it was associated with a slight increase in the degree of damage inflicted on the 2-hour schistosomula.