Resumo
The aim of the present study was to evaluate the activity of macrophages, and the production of TNF- and antibodies against experimental infection by Leptospira serovar Pomona in mice genetically selected for High (H) or Low (L) humoral immune response. To evaluate macrophagic activity, peritoneal and splenic lavages were performed for determination of oxygen (H2O2) and nitrogen (NO) intermediates. The production of the tumor necrosis factor (TNF-) was investigated through bioassays in serum and homogenates of splenic and hepatic cells of control and infected animals, as was as specific antibodies production. The immune response against serovar Pomona in those lines, was characterized by high antibody production, especially in later periods of the infectious process, whereas values of bacterial recovery in culture medium were lower. The production of reactives oxygen and nitrogen intermediate, also helped to eliminate Leptospira Pomona in both lines; H2O2 production an important factor in H IV-A, as well as NO production in L IV-A, especially in later post-inoculation periods. The same was detected for TNF-. Results suggest that such lines could be an important model to investigate the pathogenesis and the immune response of animals against the several Leptospira serovars.
Resumo
Mice genetically selected for high (H) and low (L) antibody production (Selection IV-A) were used as murine experimental model. The aim of the present work was to evaluate the macrophagic activity and to characterize the immune response in Mycobacterium bovis-AN5 infected mice (3X10(7) bacteria). The response profile previously observed in such strains was not similar to that obtained during M. bovis infection; however, it corroborated works carried out using Selection I, which is very similar to Selection IV-A regarding infection by M. tuberculosis and Bacillus Calmette-Guérin (BCG). Considering bacterial recovery, L IV-A mice showed higher control of the infectious process in the lungs than in the spleen, whereas H IV-A mice presented more resistance in the spleen. With respect to macrophagic activity, hydrogen peroxide (H2O2) was probably not involved in the infection control since there was an inhibition in the production of this metabolite. Nitric oxide (NO) and TNF-alpha production seemed to be important in the control of bacterial replication and varied according to the strain, period and organ. Evaluation of the antibody production indicated that the multi-specific effect commonly observed in these strains was not the same in the response to M. bovis. Antibody concentrations were higher in L IV-A than in H IV-A mice at the beginning of the infection, being similar afterwards. Such data were compared with delayed-type hypersensitivity (DTH), which was more intense in H IV-A than in L IV-A mice, indicating that antibody production is independent of the capability to trigger DTH reactions and that cellular and humoral responses to M. bovis antigens show a polygenic control and an independent quantitative genetic regulation. Differences were observed among organs and metabolites, suggesting that different mechanisms play an important role in this infection in natural heterogeneous populations, indicating that NO, TNF-alpha and Th1 cytokines are involved in the infection control.
Resumo
Mice genetically selected for high (H) and low (L) antibody production (Selection IV-A) were used as murine experimental model. The aim of the present work was to evaluate the macrophagic activity and to characterize the immune response in Mycobacterium bovis-AN5 infected mice (3X107 bacteria). The response profile previously observed in such strains was not similar to that obtained during M. bovis infection; however, it corroborated works carried out using Selection I, which is very similar to Selection IV-A regarding infection by M. tuberculosis and Bacillus Calmette-Guérin (BCG). Considering bacterial recovery, LIV-A mice showed higher control of the infectious process in the lungs than in the spleen, whereas HIV-A mice presented more resistance in the spleen. With respect to macrophagic activity, hydrogen peroxide (H2O2) was probably not involved in the infection control since there was an inhibition in the production of this metabolite. Nitric oxide (NO) and TNF-a production seemed to be important in the control of bacterial replication and varied according to the strain, period and organ. Evaluation of the antibody production indicated that the multi-specific effect commonly observed in these strains was not the same in the response to M. bovis. Antibody concentrations were higher in LIV-A than in HIV-A mice at the beginning of the infection, being similar afterwards. Such data were compared with delayed-type hypersensitivity (DTH), which was more intense in HIV-A than in LIV-A mice, indicating that antibody production is independent of the capability to trigger DTH reactions and that cellular and humoral responses to M. bovis antigens show a polygenic control and an independent quantitative genetic regulation. Differences were observed among organs and metabolites, suggesting that different mechanisms play an important role in this infection in natural heterogeneous populations, indicating that NO, TNF-a and Th1 cytokines are involved in the infection control.(AU)
Assuntos
Animais , Camundongos , Imunidade , Formação de Anticorpos , Mycobacterium bovis , Peróxido de HidrogênioResumo
The spleen, during a long time was considered an organ without a definite function. Nowadays it is considered an elaborate defense system, mainly of phagocitosis. The present study intends to present the influence of total splenectomy on total phagocytic capacity. Twenty-six male mice were used, 180 days old with medium weight of 289.5 g, which were divided in 3 groups: control ( n=10), sham (n=8) and experiment (n=8). The animals from control group were used to provide the phagocytosis standard. The sham group were submitted to median laparotomy under general anesthesia with peritoneal sodium-thiopental. The experiment group suffered the same process and total splenectomy. After 7 days, blood samples were taken and iron solution was injected (2mg/kg). New blood samples were collected after 5 minutes, and 15 minutes of injection. The serum iron from the samples were dosed and the phagocytosis index were calculated from the equation of Biozzi et al. The phagocytosis index were similar in control and sham groups (p=0,143086) and lower in experiment group (p=0,000685). The total phagocytic capacity is diminished after splenectomy in rats.
O baço, durante muito tempo considerado um órgão sem função definida, é hoje considerado um elaborado sistema de defesa, principalmente de fagocitose. O presente estudo visa conhecer a influência da esplenectomia total sobre a capacidade fagocitária total. Utilizaram-se 26 ratos machos com 180 dias de idade, divididos em 3 grupos: controle (n=10), sham (n=8) e esplenectomizados (n=8). Submetreram-se os animais do grupo sham à laparotomia mediana sob anestesia geral intra-peritoneal de tiopental sódico e os do grupo esplenectomia à laparotomia e esplenectomia total. Após 7 dias colheram-se amostras de sangue. Em seguida injetou-se ferro na dose de 2mg/kg de ferro e colheram-se novas amostras após 5 e 15 minutos da injeção. Dosou-se o ferro sérico nas amostras coletas e calculou-se o índice de fagocitose pela equação de Biozzi e col. O índice de fagocitose foi semelhante nos grupos controle e sham (p=0,143086) e menor no grupo dos esplenectomizados (p=0,0006850). Observou-se que a capacidade fagocitária total está diminuída após esplenectomia, em ratos.
Resumo
The spleen, during a long time was considered an organ without a definite function. Nowadays it is considered an elaborate defense system, mainly of phagocitosis. The present study intends to present the influence of total splenectomy on total phagocytic capacity. Twenty-six male mice were used, 180 days old with medium weight of 289.5 g, which were divided in 3 groups: control ( n=10), sham (n=8) and experiment (n=8). The animals from control group were used to provide the phagocytosis standard. The sham group were submitted to median laparotomy under general anesthesia with peritoneal sodium-thiopental. The experiment group suffered the same process and total splenectomy. After 7 days, blood samples were taken and iron solution was injected (2mg/kg). New blood samples were collected after 5 minutes, and 15 minutes of injection. The serum iron from the samples were dosed and the phagocytosis index were calculated from the equation of Biozzi et al. The phagocytosis index were similar in control and sham groups (p=0,143086) and lower in experiment group (p=0,000685). The total phagocytic capacity is diminished after splenectomy in rats.
O baço, durante muito tempo considerado um órgão sem função definida, é hoje considerado um elaborado sistema de defesa, principalmente de fagocitose. O presente estudo visa conhecer a influência da esplenectomia total sobre a capacidade fagocitária total. Utilizaram-se 26 ratos machos com 180 dias de idade, divididos em 3 grupos: controle (n=10), sham (n=8) e esplenectomizados (n=8). Submetreram-se os animais do grupo sham à laparotomia mediana sob anestesia geral intra-peritoneal de tiopental sódico e os do grupo esplenectomia à laparotomia e esplenectomia total. Após 7 dias colheram-se amostras de sangue. Em seguida injetou-se ferro na dose de 2mg/kg de ferro e colheram-se novas amostras após 5 e 15 minutos da injeção. Dosou-se o ferro sérico nas amostras coletas e calculou-se o índice de fagocitose pela equação de Biozzi e col. O índice de fagocitose foi semelhante nos grupos controle e sham (p=0,143086) e menor no grupo dos esplenectomizados (p=0,0006850). Observou-se que a capacidade fagocitária total está diminuída após esplenectomia, em ratos.