Three Phases of Phagocyte Contribution to Resistance against Listeria monocytogenes

Abstract

The contribution of phagocytes to protection against LiJteria monocytogenes was analysed in outbred ddN mice. Most of the bacteria injected intravenously at a dose of 3 x lo3 to 4 x lo3 were trapped in the liver within 10 min. There was a transient 10-fold decrease in the number of bacteria by 6 h. Anti-listeria activity in the initial phase was resistant to X-irradiation but was inhibited by carrageenan, and was not influenced by immunization. The protection in this very early stage of infection seemed to be attributable to the function of fixed macrophages. Viable bacteria in the organs increased progressively but slowly from 6 h to 72 h to reach maximum numbers. Bacterial growth during this period was markedly enhanced by X-irradiation or treatment with carrageenan. Accumulation of free phagocytes seemed to suppress the bacterial growth in this phase. The number of bacteria began to decrease from day 4 and became undetectable by day 9. The suppressive effect on bacterial growth in this last phase may be dependent on immunologically activated macrophages and was reversed by X-irradiation and carrageenan. The course of local infection was similar to that of systemic infection except for the lack of initial decrease. We conclude that the course of infection with L. monocytogenes can be divided into three phases with regard to the roles of phagocytes in resistance.

Suppressive effect of 1-methyladenosine on the generation of chemiluminescence by mouse peritoneal macrophages stimulated with opsonized zymosan.

“…It is already known that Mss play an important role in the elimination of Listeria in mice (Mitsuyama et al 1978). In confirmation of this, the suppressive effect of m1Ado on the resistance of mice to Listeria infection was demonstrated ), the mechanism being partly explained by the impaired migration of Mss to the peritoneal cavity.…”

Virulence of Listeria spp.: Course of infection in resistant and susceptible mice

“…1988. 1984). Three clear-cut stages are seen when this organism is injected intravenously into mice (Mitsuyama et al, 1978). Firstly, 90% of the inoculum is cleared from the blood by liver Kupffer cells and, within 6 h, 90% of these bacteria are killed.…”

Protective Mechanisms against Pulmonary Infection with Influenza Virus. I. Relative Contribution of Polymorphonuclear Leukocytes and of Alveolar Macrophages to Protection during the Early Phase of Intranasal Infection

“…Both blood monocytes and tissue macrophages are selectively sensitive to carrageenan, yet tissue macrophages, except for monocytes, are resistant to X-irradiation (Benacerraf et al, 1959;Kornfeld & Greenman, 1966;Volkman & Collins, 1971;Gillette & Lance, 1973). The relative contribution of the two series of phagocytes, PMN and macrophages, to early protection against bacterial infection has been investigated using their differential susceptibility to X-irradiation and carrageenan (Mitsuyama et al, 1978 ;Tatsukawa et al, 1979;Tsuru et al, 1981). In contrast, little is known of the protective role of such phagocytes in the early phase of generalized virus infection prior to the development of specific immune responses.…”