Progress 10/01/09 to 07/01/13
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? The project provided training for a PhD student who graduated successfully. How have the results been disseminated to communities of interest? Publication in peer reviewed journals. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Prostaglandin E2 (PGE2) is an arachidonic acid (AA)-derived signaling molecule that can influence host immune responses to infection or vaccination. To determine whether PGE2 is produced in response to infection by the poxvirus vaccine strain, modified vaccinia Ankara virus (MVA), experiments were conducted in vitro. Various cell types were investigated, which included human THP-1 cells, murine bone marrow-derived dendritic cells, murine C3HA fibroblasts, and monkey B-S-C1 cells. PGE2 production was evaluated in each cell type during a time-course of virus infection. These experiments were analyzed, and the findings and conclusions were disseminated by publication in a peer-reviewed journal. Modified vaccinia Ankara virus (MVA) is an effective vaccine that protects against virulent poxvirus infection, and also is a promising vaccine-vector. But, there is a need to better-characterize the host response to MVA in order to better understand the immune response that it generates. The results of these in vitro experiments showed that MVA infection caused PGE2 production and secretion by human THP-1 cells, murine bone marrow-derived dendritic cells, and murine C3HA fibroblasts. MVA induced the release of arachidonic acid (AA), a PGE2 precursor, from infected cells, and this was, most unusually, independent of host cytosolic phospholipase A2 activity. The accumulation of AA and PGE2 was dependent on viral gene expression, but independent of canonical NF-kappaB signaling via p65/RelA. The production of PGE2 required host cyclooxygenase-2 (COX-2) activity, and COX-2 protein accumulated during MVA infection. The results of this study provided insight into a novel aspect of MVA biology that may affect the efficacy of MVA-based vaccines.
Publications
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Progress 10/01/11 to 09/30/12
Outputs
OUTPUTS: Prostaglandin E2 (PGE2) is an arachidonic acid (AA)-derived signaling molecule that can influence host immune responses to infection or vaccination. To determine whether PGE2 is produced in response to infection by the poxvirus vaccine strain, modified vaccinia Ankara virus (MVA), experiments were conducted in vitro. Various cell types were investigated, which included human THP-1 cells, murine bone marrow-derived dendritic cells, murine C3HA fibroblasts, and monkey B-S-C1 cells. PGE2 production was evaluated in each cell type during a time-course of virus infection. These experiments were analyzed, and the findings and conclusions were disseminated by publication in a peer-reviewed journal. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Modified vaccinia Ankara virus (MVA) is an effective vaccine that protects against virulent poxvirus infection, and also is a promising vaccine-vector. But, there is a need to better-characterize the host response to MVA in order to better understand the immune response that it generates. The results of these in vitro experiments showed that MVA infection caused PGE2 production and secretion by human THP-1 cells, murine bone marrow-derived dendritic cells, and murine C3HA fibroblasts. MVA induced the release of arachidonic acid (AA), a PGE2 precursor, from infected cells, and this was, most unusually, independent of host cytosolic phospholipase A2 activity. The accumulation of AA and PGE2 was dependent on viral gene expression, but independent of canonical NF-kappaB signaling via p65/RelA. The production of PGE2 required host cyclooxygenase-2 (COX-2) activity, and COX-2 protein accumulated during MVA infection. The results of this study provided insight into a novel aspect of MVA biology that may affect the efficacy of MVA-based vaccines.
Publications
- Pollara, J.J, Spesock, A.H., Pickup, D.J., Laster, S.M., Petty, I.T.D. (2012). Production of prostaglandin E2 in response to infection with modified vaccinia Ankara virus. Virology 428:146-155.
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Progress 10/01/09 to 09/30/10
Outputs
OUTPUTS: Terameprocol (TMP) is a methylated derivative of nordihydroguaiaretic acid, a phenolic antioxidant originally derived from creosote bush extracts. TMP has previously been shown to have anti-inflammatory activity, and to inhibit the growth of certain viruses in vitro. To determine whether TMP might be effective in inhibiting the growth of poxviruses, experiments were conducted in vitro. The effect of TMP on the yield of cowpox virus, or vaccinia virus, was evaluated in both single-step and multi-step growth assays. The ability of TMP to inhibit poxvirus growth in a panel of different mammalian cell lines also was evaluated. These experiments were analyzed, and the findings and conclusions were disseminated by publication in a peer-reviewed journal. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
There is a need to identify new chemotherapeutics that are effective against poxviruses. The results of these experiments showed that TMP could potently inhibit the growth of both cowpox virus and vaccinia virus in a variety of cell lines. Although TMP treatment was highly effective at reducing infectious virus yield in multi-step growth assays, it did not substantially inhibit the synthesis of infectious progeny viruses in individual infected cells. These contrasting results showed that TMP inhibits poxvirus growth in vitro by preventing the efficient spread of virus particles from cell to cell. The canonical mechanism of poxvirus cell-to-cell spread requires morphogenesis of cell-associated, enveloped virions, which then triggers the formation of actin tails to project them from the cell surface. The number of actin tails present at the surface of poxvirus-infected cells was reduced dramatically by treatment with TMP. Whether TMP inhibits poxvirus morphogenesis, or subsequent events required for actin tail formation, remains to be determined. The results of this study, together with the clinical safety record of TMP, support further evaluation of TMP as a poxvirus therapeutic.
Publications
- Pollara, J.J., Laster, S.M., Petty, I.T.D. (2010). Inhibition of poxvirus growth by Terameprocol, a methylated derivative of nordihydroguaiaretic acid. Antiviral Research 88:287-295.
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