MARKED REDUCTION OF MOUSE PERITONEAL CD5(-CELLS BY INTRAPERITONEAL ADMINISTRATION OF LIPOPOLYSACCHARIDE() B)

Intraperitoneal administration of lipopolysaccharide to mice induced a marked reduction of CD5(+) IS cells in the peritoneal cavity. The red uction was not induced by intravenous, subcutaneous, or oral administr ation of lipopolysaccharide. The reduction continued for about 10 days after the injection, and the CD5(+) B-cell count recovered to the nor mal slate about 14 dass after the injection, The reduction of peritone al CD5(+) a cells might be caused by apoptotic tell death, Injection o f lipopolysaccharide did not result In production of antibody to lipop olysaccharide. On the other hand, Intraperitoneal injection of heat-ki lled bacteria aid not induce a reduction of peritoneal CD5(+) B cells and elicited the definite production of antibody to lipopolysaccharide .