[Effect of Phytolacca acinosa polysaccharides I on production of colony-stimulating factors of mouse splenocytes in vitro].

Phytolacca acinose polysaccharides I (PAP-I), M(r) = 10,000, activated mouse splenocytes to produce colony-stimulating factors (CSF) in vitro. The level of CSF was tested by [3H]TdR uptaken by bone marrow cells and rmGM-CSF was used as standard. PAP-I (10-500 micrograms.ml-1) increased CSF production of the splenocytes treated with or without concanavalin A. When the concentration of PAP-I was 100 micrograms.ml-1, the level of CSF was about equivalent to that of rmGM-CSF 11.8 +/- 1.8 ng.ml-1. After a 3-d incubation of PAP-I with the splenocytes, CSF was assayed. The longer the incubation, the higher were the CSF concentrations. The CSF type in supernants of splenocytes induced by PAP-I was determined by IL-3 McAb, GM-CSF McAb, and M-CSF PcAb. The type of CSF was found to be interleukin-3.