RESUMO
Suckling rats infected by ic route with 10(3)LD50 of the XJC13 strain of JV were passively immunized with homologous hyperimmune serum (HIS). Animals treated at 2 days pi with HIS showed a significant increase in survival vs. non-treated infected controls (82% vs 5%). However, at 4 days pi, transfer failed to modify survival. By means of DEAE Sephadex A25 column chromatography, the presence of neutralizing immunoglobulin closely correlated with protective antibodies, but were not restricted to the IgG-containing fraction. Employing Sephadex G200, chromatography demonstrated the absence of neutralizing and protective activity in the high molecular weight protein fraction. Results show that the success of HIS treatment depends on early administration. Besides, it was found that fractions capable of conferring protection exhibited high neutralizing antibody titers.
Assuntos
Febre Hemorrágica Americana/prevenção & controle , Soros Imunes/imunologia , Animais , Anticorpos Antivirais/imunologia , Arenavirus do Novo Mundo , Febre Hemorrágica Americana/imunologia , Soros Imunes/administração & dosagem , Ratos , Fatores de TempoRESUMO
Suckling rats infected by ic route with 10(3)LD50 of the XJC13 strain of JV were passively immunized with homologous hyperimmune serum (HIS). Animals treated at 2 days pi with HIS showed a significant increase in survival vs. non-treated infected controls (82
vs 5
). However, at 4 days pi, transfer failed to modify survival. By means of DEAE Sephadex A25 column chromatography, the presence of neutralizing immunoglobulin closely correlated with protective antibodies, but were not restricted to the IgG-containing fraction. Employing Sephadex G200, chromatography demonstrated the absence of neutralizing and protective activity in the high molecular weight protein fraction. Results show that the success of HIS treatment depends on early administration. Besides, it was found that fractions capable of conferring protection exhibited high neutralizing antibody titers.
RESUMO
The 2-day-old rat is known to be susceptible to infection by ip route with the XJ strain of Junin virus but resists inoculation with XJC13 strain (85% vs 15% mortality). In order to determine whether peritoneal macrophages play a role in modulating the course of infection, viral replication in adherent peritoneal cells infected with either strain was studied. XJ was found to replicate 30-fold as regards XJC13 at day 3 pi. Besides, silica blockage of peritoneal macrophages was also evaluated. Following silica treatment, 60% survival was recorded for XJ-infected animals vs 15% for untreated infected controls. No significant differences were recorded for silica-treated XJC13-infected rats vs untreated infected controls. These preliminary findings indicate that, upon replication within the host's macrophages at the peritoneal inoculation site, virus spreads readily to reach the target organs. Effective silica blockage lends support to this pathway, as shown by significantly greater survival in XJ-infected rats.
Assuntos
Arenaviridae/crescimento & desenvolvimento , Arenavirus do Novo Mundo/crescimento & desenvolvimento , Macrófagos/microbiologia , Replicação Viral , Animais , Movimento Celular/efeitos dos fármacos , Macrófagos/fisiologia , Cavidade Peritoneal/citologia , Ratos , Dióxido de Silício/farmacologiaRESUMO
The 2-day-old rat is known to be susceptible to infection by ip route with the XJ strain of Junin virus but resists inoculation with XJC13 strain (85
mortality). In order to determine whether peritoneal macrophages play a role in modulating the course of infection, viral replication in adherent peritoneal cells infected with either strain was studied. XJ was found to replicate 30-fold as regards XJC13 at day 3 pi. Besides, silica blockage of peritoneal macrophages was also evaluated. Following silica treatment, 60
survival was recorded for XJ-infected animals vs 15
for untreated infected controls. No significant differences were recorded for silica-treated XJC13-infected rats vs untreated infected controls. These preliminary findings indicate that, upon replication within the hosts macrophages at the peritoneal inoculation site, virus spreads readily to reach the target organs. Effective silica blockage lends support to this pathway, as shown by significantly greater survival in XJ-infected rats.
RESUMO
The 2-day-old rat is known to be susceptible to infection by ip route with the XJ strain of Junin virus but resists inoculation with XJC13 strain (85
vs 15
mortality). In order to determine whether peritoneal macrophages play a role in modulating the course of infection, viral replication in adherent peritoneal cells infected with either strain was studied. XJ was found to replicate 30-fold as regards XJC13 at day 3 pi. Besides, silica blockage of peritoneal macrophages was also evaluated. Following silica treatment, 60
survival was recorded for XJ-infected animals vs 15
for untreated infected controls. No significant differences were recorded for silica-treated XJC13-infected rats vs untreated infected controls. These preliminary findings indicate that, upon replication within the hosts macrophages at the peritoneal inoculation site, virus spreads readily to reach the target organs. Effective silica blockage lends support to this pathway, as shown by significantly greater survival in XJ-infected rats.