Eplaced with 10 FCS in DMEM. SeAP expression was measured 24 hours later

Eplaced with 10 FCS in DMEM. SeAP expression was measured 24 hours later using the chemiluminescent substrate (CSPD), from the PhosphaLightTM kit (Tropix Cat No T1016, Applied Biosystems, Bedford, MA) without heat inactivation. Light emission (relative light units, RLU) was monitored 45 minutes after the addition of the CSPD substrate, using the Envision 2102 Multi-label reader (Perkin Elmer, Waltham, MA).Statistical analysisSurvival data for vaccine groups vs. controls were compared by Log-Rank analysis and the Bonferroni Method using PRISM (GraphPad Software, Inc., La Jolla, CA).Results Expression of influenza proteins from PanAd3 vectorsThe PanAd3-NPM1 construct was designed using two conserved influenza antigens important in human immunity, NP and M1. To analyze the level of transgene expression, HeLa cells were infected with PanAd3-NPM1 at various MOI, and Triton extracts prepared. Western blot analysis of the extracts was performed using a mouse hyperimmune serum raised against the NPM1 antigen. The 80 kD major band seen is consistent with the fusion NPM1 protein (Fig. 2). The 80 kD 18325633 band was also detected if the Western blot was developed with a monoclonal antibody to NP (data not shown).Detailed characterization of immune responses to mucosally administered PanAd3 recombinantGiven the superiority of i.n. administration for inducing T cell responses in the lungs, we further explored the immune responses to vaccination by this mucosal route, using PanAd3-NPM1 or as a control PanAd3 with an irrelevant RSV insert. Mice were immunized with doses of 109,107, or 105 vp per mouse. Antibody responses. Serum and BAL were analyzed for IgG and IgA antibodies to NP and M1. Figure 4A shows results for IgG antibodies to NP in serum and BAL. At the highest vaccine dose, 109 vp per mouse, GSK864 strong IgG responses were seen for PanAd3-NPM1. If the vaccine dose given to the mice was reduced to 107 vp per mouse, antibody responses were greatly reduced in serum and absent in BAL. The IgA antibody GSK2879552 response to PanAd3-NPM1 was undetectable in serum and marginal in BAL (Fig. 4B). As in Figure 3, a reagent control provided by BAL from A/NP-rAd5 immunized mice showed that the assay could detect IgA antibodies if present. The antibody response to the M1 component of PanAd3-NPM1 did not include IgA (data not shown) and the IgG response to M1 was only substantial in the serum (Fig. 4C). T cell responses. T cell responses were again measured by IFN-c ELISPOT. At a dose of 109 vp, PanAd3-NPM1 induced a strong T cell response in the lungs to the dominant NP147?55 epitope. Both PanAd3-NPM1 and the PanAd3-RSV controlFigure 2. Detection of influenza antigens expressed by vectors in cultured cells. Western blot analysis of HeLa extracts prepared as described after 48 hours infection with PanAd3NPM1 at 50, 250, 1250 MOI (ni = not infected). The blotted proteins were revealed with a mouse hyperimmune serum raised against the NPM1 antigen. The 80 kD major band is consistent with the fusion NPM1 protein. doi:10.1371/journal.pone.0055435.gHighly Immunogenic Simian Adenovirus VectorFigure 3. Antibody and T cell responses to PanAd3NPM1. Mice were vaccinated with 109 or 107 total vp/mouse. Immunizations were by either the i.n. or i.m. route, as indicated. Four weeks later mice were sacrificed, and serum and BAL were collected for antibody analysis. Lung T cells were also collected for IFN-c ELISPOT analysis. Error bars indicate mean 6 SEM. a) ELISA for IgG antibodies to rNP in.Eplaced with 10 FCS in DMEM. SeAP expression was measured 24 hours later using the chemiluminescent substrate (CSPD), from the PhosphaLightTM kit (Tropix Cat No T1016, Applied Biosystems, Bedford, MA) without heat inactivation. Light emission (relative light units, RLU) was monitored 45 minutes after the addition of the CSPD substrate, using the Envision 2102 Multi-label reader (Perkin Elmer, Waltham, MA).Statistical analysisSurvival data for vaccine groups vs. controls were compared by Log-Rank analysis and the Bonferroni Method using PRISM (GraphPad Software, Inc., La Jolla, CA).Results Expression of influenza proteins from PanAd3 vectorsThe PanAd3-NPM1 construct was designed using two conserved influenza antigens important in human immunity, NP and M1. To analyze the level of transgene expression, HeLa cells were infected with PanAd3-NPM1 at various MOI, and Triton extracts prepared. Western blot analysis of the extracts was performed using a mouse hyperimmune serum raised against the NPM1 antigen. The 80 kD major band seen is consistent with the fusion NPM1 protein (Fig. 2). The 80 kD 18325633 band was also detected if the Western blot was developed with a monoclonal antibody to NP (data not shown).Detailed characterization of immune responses to mucosally administered PanAd3 recombinantGiven the superiority of i.n. administration for inducing T cell responses in the lungs, we further explored the immune responses to vaccination by this mucosal route, using PanAd3-NPM1 or as a control PanAd3 with an irrelevant RSV insert. Mice were immunized with doses of 109,107, or 105 vp per mouse. Antibody responses. Serum and BAL were analyzed for IgG and IgA antibodies to NP and M1. Figure 4A shows results for IgG antibodies to NP in serum and BAL. At the highest vaccine dose, 109 vp per mouse, strong IgG responses were seen for PanAd3-NPM1. If the vaccine dose given to the mice was reduced to 107 vp per mouse, antibody responses were greatly reduced in serum and absent in BAL. The IgA antibody response to PanAd3-NPM1 was undetectable in serum and marginal in BAL (Fig. 4B). As in Figure 3, a reagent control provided by BAL from A/NP-rAd5 immunized mice showed that the assay could detect IgA antibodies if present. The antibody response to the M1 component of PanAd3-NPM1 did not include IgA (data not shown) and the IgG response to M1 was only substantial in the serum (Fig. 4C). T cell responses. T cell responses were again measured by IFN-c ELISPOT. At a dose of 109 vp, PanAd3-NPM1 induced a strong T cell response in the lungs to the dominant NP147?55 epitope. Both PanAd3-NPM1 and the PanAd3-RSV controlFigure 2. Detection of influenza antigens expressed by vectors in cultured cells. Western blot analysis of HeLa extracts prepared as described after 48 hours infection with PanAd3NPM1 at 50, 250, 1250 MOI (ni = not infected). The blotted proteins were revealed with a mouse hyperimmune serum raised against the NPM1 antigen. The 80 kD major band is consistent with the fusion NPM1 protein. doi:10.1371/journal.pone.0055435.gHighly Immunogenic Simian Adenovirus VectorFigure 3. Antibody and T cell responses to PanAd3NPM1. Mice were vaccinated with 109 or 107 total vp/mouse. Immunizations were by either the i.n. or i.m. route, as indicated. Four weeks later mice were sacrificed, and serum and BAL were collected for antibody analysis. Lung T cells were also collected for IFN-c ELISPOT analysis. Error bars indicate mean 6 SEM. a) ELISA for IgG antibodies to rNP in.