Effects of bacterial products on granulopoiesis.

Methylated endotoxin and Freeman-type polysaccharide each stimulate granulopoiesis and the production of CSF in mice. These same preparations also protect pretreated mice from lethal X-irradiation. The role of CSF in stimulating granulopoiesis in vivo was shown by the ability of anti-CSF to reduce the number of CFUc in endotoxin-treated mice. C3H/HeJ low responder mice cannot be protected against lethal X-irradiation by pretreatment with endotoxin and they fail to produce CSF in response to phenol water extracted endotoxin and the Freeman-type polysaccharide, but do respond to trichloroacetic acid endotoxin with elevated serum CF levels.