RESUMO
The role of mononuclear phagocytic cells in extraneural infection of the mouse with Junin virus (JV) was studied. Endpoint susceptibility (4 days of life) was evaluated by intraperitoneal (i.p.) inoculation of suckling mice. By means of immunofluorescence (IF) and C3 receptor assays, it was found that macrophages were permissive to viral replication in vivo and fostered the recruitment of inflammatory cells as evidenced by the absence of C3 marker. In support, in vitro infection failed to induce alterations of this receptor. Throughout, both in vivo and in vitro, there were no signs of C3-mediated phagocytosis. Silica treatment had no effect on either resistance or susceptibility, suggesting that the "macrophage-barrier" failed to hinder or favour the course of disease. Differences with other JV models are discussed.
Assuntos
Febre Hemorrágica Americana/imunologia , Macrófagos/imunologia , Fatores Etários , Animais , Arenavirus do Novo Mundo/imunologia , Técnicas In Vitro , Antígeno de Macrófago 1 , Camundongos , Camundongos Endogâmicos BALB C , Receptores de Complemento/imunologiaAssuntos
Eritrócitos/imunologia , Hipersensibilidade Tardia/imunologia , Tolerância Imunológica , Animais , Células Apresentadoras de Antígenos/imunologia , Ciclofosfamida/farmacologia , Imunidade Celular/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C/imunologia , Ovinos , Linfócitos T Reguladores/imunologiaRESUMO
The object of this paper was to determine the influence of cyclophosphamide immunosuppression on the mortality of 40-45 day old Balb/c mice infected intracerebrally with a pathogenic strain of Junin virus, using different administration schedules. Up to 200 mg/kg of cyclophosphamide were not toxic. Results show that, unlike in other experimental models, three or four 50 mg/kg cyclophosphamide doses given both before and after viral infection were required to break-down resistance to Junin virus (90-96.5% mortality vs. 8% in controls). Taking into account the effect of cyclophosphamide on the cell populations involved in the immune response, causes likely to lead to the greater susceptibility of the suppressed adult mouse to Junin virus are discussed.
Assuntos
Ciclofosfamida/administração & dosagem , Febre Hemorrágica Americana/imunologia , Imunossupressores/administração & dosagem , Animais , Arenavirus do Novo Mundo , Ciclofosfamida/toxicidade , Esquema de Medicação , Febre Hemorrágica Americana/mortalidade , Imunidade Inata/efeitos dos fármacos , Imunossupressores/toxicidade , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Delayed-type-hypersensitivity (DTH) response "in vivo" is commonly evaluated by the footpad swelling test (FPST). High doses of Sheep Red Blood Cells (SRBC) are known to produce negligible DTH, while low doses lead to optimal sensitization. As expected FPST values obtained in Balb/c mice using 10(6) or 10(8) SRBC as sensitizing doses, showed that in 9 out of 10 batches from individual rams, the former dose resulted in higher values than the latter. However, only 3 out of the above 9 exhibited statistically significant differences between immunizing doses (Table 1). Therefore, in our hands, the accuracy of FPST is highly dependent on the SRBC source. We suggest the need of testing individual SRBC batches at both dilutions before use.
Assuntos
Eritrócitos/imunologia , Hipersensibilidade Tardia/imunologia , Imunidade Celular , Animais , Feminino , Hipersensibilidade Tardia/etiologia , Imunização , Masculino , Camundongos , Camundongos Endogâmicos BALB C/imunologia , Ovinos/sangueRESUMO
Delayed-type-hypersensitivity (DTH) response [quot ]in vivo[quot ] is commonly evaluated by the footpad swelling test (FPST). High doses of Sheep Red Blood Cells (SRBC) are known to produce negligible DTH, while low doses lead to optimal sensitization. As expected FPST values obtained in Balb/c mice using 10(6) or 10(8) SRBC as sensitizing doses, showed that in 9 out of 10 batches from individual rams, the former dose resulted in higher values than the latter. However, only 3 out of the above 9 exhibited statistically significant differences between immunizing doses (Table 1). Therefore, in our hands, the accuracy of FPST is highly dependent on the SRBC source. We suggest the need of testing individual SRBC batches at both dilutions before use.
RESUMO
The object of this paper was to determine the influence of cyclophosphamide immunosuppression on the mortality of 40-45 day old Balb/c mice infected intracerebrally with a pathogenic strain of Junin virus, using different administration schedules. Up to 200 mg/kg of cyclophosphamide were not toxic. Results show that, unlike in other experimental models, three or four 50 mg/kg cyclophosphamide doses given both before and after viral infection were required to break-down resistance to Junin virus (90-96.5
mortality vs. 8
in controls). Taking into account the effect of cyclophosphamide on the cell populations involved in the immune response, causes likely to lead to the greater susceptibility of the suppressed adult mouse to Junin virus are discussed.
RESUMO
The object of this paper was to determine the influence of cyclophosphamide immunosuppression on the mortality of 40-45 day old Balb/c mice infected intracerebrally with a pathogenic strain of Junin virus, using different administration schedules. Up to 200 mg/kg of cyclophosphamide were not toxic. Results show that, unlike in other experimental models, three or four 50 mg/kg cyclophosphamide doses given both before and after viral infection were required to break-down resistance to Junin virus (90-96.5
in controls). Taking into account the effect of cyclophosphamide on the cell populations involved in the immune response, causes likely to lead to the greater susceptibility of the suppressed adult mouse to Junin virus are discussed.