EFFECT OF VARIOUS IMMUNOMODULATORS ON THE PRODUCTION OF GRANULOCYTE/MACROPHAGE COLONY-STIMULATING FACTOR (GM-CSF) IN MOUSE SPLEEN CELL CULTURES

Abstract

Among various immunomodulating agents examined, OK-432 (Streptococcus pyogenes cell bodies), BCG (bacillus Calmette-Guerin) and LPS (lipopolysaccharide) were effective in enhancing the production of granulocyte/macrophage colony-stimulating factor (GM-CSF) in the cultures of mouse spleen cells. Control non-stimulated spleen cell cultures accumulated GM-CSF activity maximally on day 3 and lost it subsequently within a few days. On the other hand, a large amount of GM-CSF activity could be detected in the medium until day 9 when OK-432 was added in the culture at the start of incubation, The GM-CSF obtained from OK-432 or LPS stimulated cultures and the GM-CSF obtained from the con trol non-stimulated culture eluted from an Ultro-gel AcA 34 column at a similar position and inactivated similarly at 80°C. However, these three GM-CSFs behaved in slightly different manners upon isoelectrofocusing. These results suggest that the GM-CSFs produced in increasing amounts by the stimulated spleen cells are similar to that produced by the control non-stimulated cells, but slightly different from one another in the extent of sialylation according to the difference of the stimulant.