Phagocytosis and killing of salmonella typhimurium by peritoneal exudate cells

Normal peritoneal cells from conventional, germfree, or nu/nu mice readily killed opsonized salmonellae, an observation that suggests that this activity in the normal peritoneal cavity may not be dependent on either environmental antigenic stimulation or T-cell mediation. In contrast, peritoneal cells elicited 4 days after injection with thioglycolate medium failed to kill opsonized salmonellae but appeared to be highly phagocytic. Peritoneal cells from thioglycolate-treated mice could be induced to kill opsonized salmonellae by giving the mice a primary footpad injection and a secondary intraperitoneal injection of Corynebacterium parvum. This activation by C. parvum appeared to be thymus dependent, since it did not occur in nu/nu mice.