Anti‐ Schistosomular Activity of Human Monocytes/Macrophagesin Response to Interleukin‐3 and Granulocyte‐Macrophage Colonystimulating Factor Stimulation

Abstract

Human monocytes, co-incubated for 7 days in culture with GM-CSF or IL-3 but not with IFN-γ, exerted a variable schistosotnulicidal effect on Schistosoma mansoni parasites when grown in 96-well round-bottomed plates but not in flat-bottomed plates. Addition of LPS or IFN-γ or both, for the last 48 h did not enhance the cidal effect. Addition of LPS but not IFN-γ to the pre-incubated cells with GM-CSF or IL-3 markedly stimulated TNF-α production by the cells but not their cidal activity. The variable cidal effects obtained with the monocytes/macrophages from different donors suggest that these effects may be genetically predetermined and are possibly linked to blood group markers or to MHC class I or II antigens.

Assessment of the viability of Schistosoma mansoni schistosomula by comparative uptake of various vital dyes

“…The viability of incubated schistosomula was initially assessed by observation of the organisms without any prior staining as mentioned elsewhere (Hsü and Hsü 1975;Gold et al 1994) and on the basis of body motility and granularity as well as the flickering movement of flame cells. Many of the assessments of the viability of schistosomula following staining were performed with the organisms remaining in the wells.…”

“…This assessment is usually achieved by observation of the mobility of the whole organism and/ or flickering movement of its flame cells as well as of differential dye uptake by nonviable or damaged schistosomula (Howells et al 1975;Chung et al 1982;James et al 1982;Gold et al 1994).…”

Influence of mechanical tail-detachment techniques of schistosome cercariae on the production, viability, and infectivity of resultant schistosomula: a comparative study

“…The schistosomulum has frequently been used for assessment of the antischistosome activity of humoral and cell-mediated immune-response components and for immunization experiments (Anwar et al 1979;Chung et al 1982;James et al 1982;Dessein et al 1983;Cottrell et al 1989;Gold et al 1994). Many of the methods used to transform schistosome cercariae into schistosomules are unsuitable for large-scale production.…”