Macrophage-activating T-cell factor(s) produced in an early phase of Legionella pneumophila infection in guinea pigs.
Protective immunity of guinea pigs against Legionella pneumophila was studied by infecting the animals with a sublethal dose (about 2 x 10(4) CFU) of the organism. The bacteria multiplied in the liver, spleen, and lungs up to day 4 after the intraperitoneal infection. The live bacteria in these organs decreased quickly thereafter and were eliminated by day 7. A delayed-type skin reaction and lymphoproliferation of spleen cells to Formalin-killed L. pneumophila were detected from days 5 and 6, respectively, after infection. Peritoneal macrophages obtained from guinea pigs infected 6 days previously inhibited the intracellular growth of L. pneumophila. Antigen-stimulated spleen cell factor prepared from infected guinea pigs inhibited the intracellular growth of the organism in macrophages obtained from uninfected animals. Antigen-stimulated spleen cell factor prepared from spleen cells treated with anti-guinea pig T-cell monoclonal antibody did not inhibit growth. The activity of antigen-stimulated spleen cell factor was labile to pH 2 treatment, and the factor could not be absorbed by L. pneumophila antigen, suggesting that it contains gamma interferon. Our data show that T-cell-mediated immunity begins to work from an early period of infection with L. pneumophila in guinea pigs.
Nikaido
Y
Y
Department of Microbiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
Yoshida
S
S
Goto
Y
Y
Mizuguchi
Y
Y
Kuroiwa
A
A
D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D000917:Antibody Formation; D006168:Guinea Pigs; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007111:Immunity, Cellular; D007875:Legionella / Q000254:growth & development / Q000276:immunology; D007877:Legionnaires' Disease / Q000276:immunology* / Q000382:microbiology; D008099:Liver / Q000382:microbiology; D008168:Lung / Q000382:microbiology; D008222:Lymphokines / Q000502:physiology*; D008262:Macrophage Activation; D008264:Macrophages / Q000276:immunology* / Q000382:microbiology; D012882:Skin Tests; D013154:Spleen / Q000382:microbiology; D013601:T-Lymphocytes / Q000276:immunology*
D000907:Antibodies, Bacterial; D008222:Lymphokines