[Immunostimulating activities in vivo of extract from Klebsiella pneumoniae].

The adjuvant and immunostimulating activities of a glycoprotein preparation (GP) extracted from Klebsiella pneumoniae have been studied. When injeted with an ovalbumin in incomplet Freund adjuvant emulsion, the GP induces delayed hypersensitivity to the antigen and increases the level of antibody developed. When it is injected before the antigen to C57Bl/6 mice, the GP provokes an increase of plaque forming cells, rosette forming cells, and antibody responses. With the doses that are used, no mechanism can be detected which could be due to an antigenic activity of the GP. The immunostimulating properties decribed cannot be due to a lipopolysaccharide since the preparation contains less than 1 p. 100 of endotoxin.