Suppression of the immune response in C3H/HeJ mice by protein-free lipopolysaccharides

The experiments described herein demonstrate the plaque-forming cell response of C3H/HeJ mice can be suppressed by a Boivin type lipopolysaccharide (LPS) and a deproteinized glycolipid. Suppression was observed both in vivo and in vitro, and could be transferred to normal cells in coculture experiments. This newly discovered effect of LPS in C3H/HeJ mice indicates that the adjuvant and inhibitory action of LPS may be distinct phenomena which are under different genetic regulation. Thus, the C3H/HeJ strain provides a convenient animal model for study of immunosuppression independent of the adjuvant effect.