Phagocytosis and killing of salmonella typhimurium by peritoneal exudate cells

Abstract

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.

Histopathological study of protective immunity against murine salmonellosis induced by killed vaccine

“…It is therefore apparent from this study that the control mice die from salmonellosis because they fail to contain the rapid proliferation of the pathogen, despite a massive accumulation of polymorphs at the site of infection, whereas the vaccinated mice are able to eliminate the invading pathogen effectively by the influx of polymorphs, whose antibacterial action at the site of infection is undoubtedly facilitated by opsonic antibodies. This contention is consistent with in vitro observations of the antiphagocytic property of virulent S. typhimurium, the digestive capacity of phagocytes, and the opsonic action of antibodies (4,10,12,13,22,24). Furthermore, the killed vaccine endows the host with an effective capability to localize the pathogens at the site of inoculation and to retard their systemic dissemination, as evidenced by the delayed appearance of lesions in the organs after the initial i.p.…”

Electronmicroscopy studies on the bactericidal action of inflammatory leukocytes in murine salmonellosis

“…It was also evident that virulent salmonellae multiplied extracellularly in the peritoneal cavity of the infected mice. Zwet et d., 1975;Briles et al, 198 I ) as well as within ~.…”

Pathogenesis and immunity in murine salmonellosis.

“…Contrary to the assertion of intracellular multiplication of salmonellae, some in vitro studies showed the innate ability of murine macrophages (11,126) and polymorphs (6) to destroy the pathogen. Consistent with this view, the virulence of salmonellae is directly influenced by their resistance to phagocytosis (120) and is related to the nature of their 0-antigenic structure (101,122).…”

“…In spite of the persistent inference of the intracellular survival and multiplication of salmonellae, a thorough search of the literature will reveal that there has never been indisputable experimental evidence of this organism proliferating within host phagocytes. On the contrary, experimental data from independent workers over the years do show the killing of salmonellae within polymorphs (6) and macrophages (11,126). Also, contrary to the common claim that acquired immunity to the disease is primarily cell mediated, nonviable vaccines, which induce only humoral immunity (19), are shown by many investigators to offer effective protection against subsequent challenges (2,24,30,37,93).…”