Granulocyte-macrophage colony-stimulating factor (
GM-CSF) produced by splenic lymphocytes obtained from Schistosoma japonicum-infected mice was partially purified by a combination of
DEAE anion-exchange chromatography,
concanavalin A-Sepharose affinity chromatography, and high-pressure liquid chromatography. When this partially purified
GM-CSF was added to the culture of isolated intact
granulomas, eosinophil
chemotactic factor (ECF) lymphokine production by
granulomas was significantly enhanced. The partially purified
GM-CSF also enhanced ECF lymphokine production by
granuloma T cells cocultured with syngeneic macrophages and specific
antigen. The partially purified
GM-CSF itself had neither ECF activity nor a synergistic effect with ECF lymphokine. When normal splenic macrophages were preincubated with the partially purified
GM-CSF, they potentiated the ECF production by
granuloma T cells under the presence of specific
antigen. Augmentation of ECF lymphokine production by partially purified
GM-CSF was further confirmed by using T-cell clones that were established from
granuloma T cells. These results suggest that T-cell-derived
GM-CSF primarily activate macrophages so that these activated macrophages can cooperate more effectively with T lymphocytes to produce ECF. Such potentiation of macrophage-T-cell interaction by
GM-CSF may be important in the mechanisms of
granuloma formation during an acute stage of
schistosomiasis.