Early protection events in swine immunized with an experimental live attenuated classical swine fever marker vaccine, FlagT4G

Figures

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  Fig 1. Mortality in FlagT4Gv-infected animals challenged at different times post-infection with virulent BICv. Groups of animals (n = 5) were IM inoculated with 105 TCID50 of FlagT4Gv and IN challenged with BICv 1, 2, 3, 5 or 7 days later. Animals were clinically observed for 21 days post-challenge.

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  Fig 2. Viremia in FlagT4Gv-infected animals challenged at different times post-infection with virulent BICv. Data represent average titers and SD of 5 animals in each time point. Titers, expressed as TCID50/mL, correspond exclusively to presence of BICv that was determined by immunocytochemistry using mAbs WH303 which specifically detects BICv. Sensitivity of virus detection: ≥1.8 TCID50/mL.

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  Fig 3. In vitro growth of FlagT4G virus. Primary cell cultures of swine macrophages were infected (MOI = 0.01) with FlagT4G or BIC viruses and virus yield titrated at the indicated times post-infection in SK6 cells. Data represent means and standard deviations from two independent experiments. Sensitivity of virus detection: ≥1.8 TCID50/mL.

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  Fig 4. Localization of BICv and FlagT4Gv in tissue samples. (A) Localization of BICv and FlagT4Gv in frozen sections of tonsil tissues from pigs either IM infected with FlagT4Gv or IN with BICv. Cryosectioned tissues from the tonsils were processed for immunofluorescence and confocal microscopy using monoclonal antibodies WH303 (specific for BICv) or anti-Flag (Specific for FlagT4Gv), respectively. The virus was visualized with Alexa Fluor 563 (red). Sections were counterstained with TOPRO-iodide 642/661 (blue) to reveal the nuclei. (B) Co-expression of CSFV E2 303 epitope (specific for BICv) or Flag epitope (specific for FlagT4v) along with Monocyte/Graculocyte cell marker in tonsil sections of FlagT4Gv or BICv infected pigs. Cryosectioned tissues were labeled for immunofluorescence and confocal microscopy with monoclonal antibody WH303 or anti-Flag monoclonal antibody along with anti-Monocyte/Granulocyte marker antibodies. Viral antigens were visualized with Alexa Fluor 563 (red), Monocyte /Granulocyte was visualized with Alexa Fluor 488 (green). Sections were counterstained with TOPRO 642/661 (blue) to reveal the nuclei. (C) Co-expression of CSFV E2 303 epitope (specific for BICv) or…

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  Fig 5. Evaluation of the systemic levels of different host cytokines in swine. Samples were taken on the third day after inoculation with FlagT4G virus (FlagT4Gv), or mock infection (naïve control). Data represent individual animal determinations. Values are expressed as concentration per mL of serum determined as described in Material and Methods.