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Ganglioside and Non-ganglioside Mediated Host Responses to the Mouse Polyomavirus.

You J, O'Hara SD, Velupillai P, Castle S, Levery S, Garcea RL, Benjamin T - PLoS Pathog. (2015)

Bottom Line: Specificity is determined by recognition of carbohydrate moieties on the ganglioside by the major viral capsid protein VP1.Ganglioside-deficient fibroblasts responded rapidly to virus exposure with a transient induction of c-fos as an early manifestation of a mitogenic response.Thus, while gangliosides are essential for infection in the animal, gangliosides are not required for mitogenic responses and innate immune responses to the virus.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, United States of America.

ABSTRACT
Gangliosides serve as receptors for internalization and infection by members of the polyomavirus family. Specificity is determined by recognition of carbohydrate moieties on the ganglioside by the major viral capsid protein VP1. For the mouse polyomavirus (MuPyV), gangliosides with terminal sialic acids in specific linkages are essential. Although many biochemical and cell culture experiments have implicated gangliosides as MuPyV receptions, the role of gangliosides in the MuPyV-infected mouse has not been investigated. Here we report results of studies using ganglioside-deficient mice and derived cell lines. Knockout mice lacking complex gangliosides were completely resistant to the cytolytic and pathogenic effects of the virus. Embryo fibroblasts from these mice were likewise resistant to infection, and supplementation with specific gangliosides restored infectibility. Although lacking receptors for viral infection, cells from ganglioside-deficient mice retained the ability to respond to the virus. Ganglioside-deficient fibroblasts responded rapidly to virus exposure with a transient induction of c-fos as an early manifestation of a mitogenic response. Additionally, splenocytes from ganglioside-deficient mice responded to MuPyV by secretion of IL-12, previously recognized as a key mediator of the innate immune response. Thus, while gangliosides are essential for infection in the animal, gangliosides are not required for mitogenic responses and innate immune responses to the virus.

No MeSH data available.


Related in: MedlinePlus

Induction of c-fos in wild-type and B4St8 KO MEFs.Purified virus in serum-free medium was used to infect wild-type and B4St8 KO MEFs. Cell extracts were made at the indicated times post-infection and subjected to western blot analysis with anti-fos antibody.
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ppat.1005175.g006: Induction of c-fos in wild-type and B4St8 KO MEFs.Purified virus in serum-free medium was used to infect wild-type and B4St8 KO MEFs. Cell extracts were made at the indicated times post-infection and subjected to western blot analysis with anti-fos antibody.

Mentions: An earlier study demonstrated the ability of MuPyV to induce expression of c-fos and other ‘early response’ genes in established mouse fibroblasts [30]. This response, measured by mRNA synthesis, is biphasic. A rapid but transient response occurs within the first hour followed by a second sustained wave of expression beginning around 12 hrs post-infection. The second wave requires early viral gene expression, while the initial transient phase can be induced by empty capsids or recombinant VP1. To determine if the induction of an immediate early response depends on recognition of gangliosides or other virus receptors, wild-type and B4St8 KO MEFs were exposed to purified virus in serum-free medium (Fig 6). Extracts were analyzed for c-fos protein by western blot. The double KO MEFs responded indistinguishably from wild-type MEFs with a clear induction at 1 hr post-infection. At 6 hrs post-infection, the response was diminished but showed the slower migrating form(s) of the c-fos protein indicative of phosphorylation which is known to accompany activation of mitogen receptors (Fig 6) [31]. We conclude that the rapid induction of c-fos in ganglioside-deficient cells results from virus binding to non-ganglioside receptor(s).


Ganglioside and Non-ganglioside Mediated Host Responses to the Mouse Polyomavirus.

You J, O'Hara SD, Velupillai P, Castle S, Levery S, Garcea RL, Benjamin T - PLoS Pathog. (2015)

Induction of c-fos in wild-type and B4St8 KO MEFs.Purified virus in serum-free medium was used to infect wild-type and B4St8 KO MEFs. Cell extracts were made at the indicated times post-infection and subjected to western blot analysis with anti-fos antibody.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4608836&req=5

ppat.1005175.g006: Induction of c-fos in wild-type and B4St8 KO MEFs.Purified virus in serum-free medium was used to infect wild-type and B4St8 KO MEFs. Cell extracts were made at the indicated times post-infection and subjected to western blot analysis with anti-fos antibody.
Mentions: An earlier study demonstrated the ability of MuPyV to induce expression of c-fos and other ‘early response’ genes in established mouse fibroblasts [30]. This response, measured by mRNA synthesis, is biphasic. A rapid but transient response occurs within the first hour followed by a second sustained wave of expression beginning around 12 hrs post-infection. The second wave requires early viral gene expression, while the initial transient phase can be induced by empty capsids or recombinant VP1. To determine if the induction of an immediate early response depends on recognition of gangliosides or other virus receptors, wild-type and B4St8 KO MEFs were exposed to purified virus in serum-free medium (Fig 6). Extracts were analyzed for c-fos protein by western blot. The double KO MEFs responded indistinguishably from wild-type MEFs with a clear induction at 1 hr post-infection. At 6 hrs post-infection, the response was diminished but showed the slower migrating form(s) of the c-fos protein indicative of phosphorylation which is known to accompany activation of mitogen receptors (Fig 6) [31]. We conclude that the rapid induction of c-fos in ganglioside-deficient cells results from virus binding to non-ganglioside receptor(s).

Bottom Line: Specificity is determined by recognition of carbohydrate moieties on the ganglioside by the major viral capsid protein VP1.Ganglioside-deficient fibroblasts responded rapidly to virus exposure with a transient induction of c-fos as an early manifestation of a mitogenic response.Thus, while gangliosides are essential for infection in the animal, gangliosides are not required for mitogenic responses and innate immune responses to the virus.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, United States of America.

ABSTRACT
Gangliosides serve as receptors for internalization and infection by members of the polyomavirus family. Specificity is determined by recognition of carbohydrate moieties on the ganglioside by the major viral capsid protein VP1. For the mouse polyomavirus (MuPyV), gangliosides with terminal sialic acids in specific linkages are essential. Although many biochemical and cell culture experiments have implicated gangliosides as MuPyV receptions, the role of gangliosides in the MuPyV-infected mouse has not been investigated. Here we report results of studies using ganglioside-deficient mice and derived cell lines. Knockout mice lacking complex gangliosides were completely resistant to the cytolytic and pathogenic effects of the virus. Embryo fibroblasts from these mice were likewise resistant to infection, and supplementation with specific gangliosides restored infectibility. Although lacking receptors for viral infection, cells from ganglioside-deficient mice retained the ability to respond to the virus. Ganglioside-deficient fibroblasts responded rapidly to virus exposure with a transient induction of c-fos as an early manifestation of a mitogenic response. Additionally, splenocytes from ganglioside-deficient mice responded to MuPyV by secretion of IL-12, previously recognized as a key mediator of the innate immune response. Thus, while gangliosides are essential for infection in the animal, gangliosides are not required for mitogenic responses and innate immune responses to the virus.

No MeSH data available.


Related in: MedlinePlus