Figure 1.
In vivo antibody mediated neutralization of IFN-γ protects from lethal SEB-induced TSS.
Age-matched HLA-DR3 transgenic mice were challenged with SEB (50 µg) immediately followed by indicated amounts of monoclonal rat anti-mouse IFN-γ or isotype control. Mice were closely monitored for symptoms of TSS.
Figure 2.
Effect of antibody mediated neutralization of IFN-γ on SEB-induced cytokine and chemokine responses in vivo.
Age-matched HLA-DR3 transgenic mice were challenged with SEB (5 µg) immediately followed by 100 µg of goat anti-mouse IFN-γ or control goat antibodies. Mice were bled 3 hrs later and serum cytokine levels were determined using a multiplex suspension array system (Bio-Plex, Bio-Rad). Each bar represents the mean±SE of 4–6 mice.
Figure 3.
Effect of antibody mediated neutralization of IFN-γ on SEB-induced splenic T cell expansion and thymocyte deletion.
Age-matched HLA-DR3 transgenic mice were challenged with SEB (5 µg) immediately followed by 100 µg of goat anti-mouse IFN-γ or control goat antibodies. Mice were killed 3 days later and distribution of different T cell subsets in the spleen (A and B) and thymus (C and D) was determined by flow cytometry. Each bar represents the mean±SE of 4–6 mice.
Figure 4.
Effect of IFN-γ deficiency on SEB-induced TSS.
Age-matched HLA-DR3.IFN-γ+/+ and HLA-DR3.IFN-γ−/− transgenic mice were challenged with SEB (50 µg) and monitored closely. Data from 6–13 mice in each group.
Figure 5.
Effect of IFN-γ deficiency on SEB-induced cytokine responses in vivo.
Age-matched HLA-DR3.IFN-γ+/+ and HLA-DR3.IFN-γ−/− transgenic mice were challenged with SEB (10 µg). Mice were bled at 3 hrs and serum cytokine levels were determined using a multiplex suspension array system (Bio-Plex, Bio-Rad).
Figure 6.
Effect of IFN-γ deficiency on SEB-induced chemokine responses in vivo.
Age-matched HLA-DR3.IFN-γ+/+ and HLA-DR3.IFN-γ−/− transgenic mice were challenged with SEB (10 µg). Mice were bled at 3 hrs and serum chemokine levels were determined using a multiplex suspension array system (Bio-Plex, Bio-Rad).
Figure 7.
Effect of IFN-γ deficiency on SEB-induced splenic T cell expansion and thymocyte deletion.
Age-matched HLA-DR3.IFN-γ+/+ and HLA-DR3.IFN-γ−/− transgenic mice were challenged with SEB (10 µg). Mice were killed 3 days later and distribution of different T cell subsets in the spleen (A and B) and thymus (C and D) was determined by flow cytometry. Each bar represents the mean±SE of 4–6 mice.
Figure 8.
Effect of IFN-γ deficiency on SEB-induced pulmonary immunopathology.
Age-matched HLA-DR3.IFN-γ+/+ (A and C) and HLA-DR3.IFN-γ−/− (B and D) transgenic mice were left untreated (A and B) or challenged with SEB (50 µg, C and D). Mice were killed 48 hrs later, lungs were collected in buffered formalin and processed for H&E. The bar corresponds to 100 µM.
Figure 9.
Effect of IFN-γ deficiency on SEB-induced hepatic immunopathology.
Age-matched HLA-DR3.IFN-γ+/+ (A to D) and HLA-DR3.IFN-γ−/− (E and H) transgenic mice were challenged with PBS (A, B and E, F) or challenged with SEB (50 µg) (C, D and G, H). Mice were killed 48 hrs later, livers were collected in buffered formalin and processed for H&E. The bar corresponds to 100 µM.
Figure 10.
Effect of IFN-γ deficiency on SEB-induced intestinal immunopathology.
Age-matched HLA-DR3.IFN-γ+/+ (D, E and F) and HLA-DR3.IFN-γ−/− (G, H and I) transgenic mice were challenged with SEB (50 µg). Mice were killed 48 hrs later, intestinal segments were collected in buffered formalin and processed for H&E. Panels A, B and C – sections from naïve HLA-DR3.IFN-γ+/+ mice shown for comparison. The bar corresponds to 100 µM.
Figure 11.
Effect of IFN-γ deficiency on SEB-induced duodenal immunopathology.
Age-matched HLA-DR3.IFN-γ+/+ (A, C and E) and HLA-DR3.IFN-γ−/− (B, D and F) transgenic mice were challenged with SEB (50 µg). Mice were killed at 24, 48 and 72 hrs, duodenal segments were collected in buffered formalin and processed for H&E. The bar corresponds to 100 µM.
Figure 12.
Effect of IFN-γ deficiency on SEB-induced alteration in gut permeability.
Age-matched HLA-DR3.IFN-γ+/+ and HLA-DR3.IFN-γ−/− transgenic mice were challenged with SEB (50 µg). Mice were gavaged with FITC-dextran as indicated in methods. Three hours after gavage, mice were killed, sera collected and the fluorescence in the sera were determined at 490 nm excitation and 525 nm emission.