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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

(A) B4 and St8 knockouts in pathways of ganglioside biosynthesis. Gangliosides previously shown or shown here to function as MuPyV receptors are outlined. Modified from U. Neu and T. Stehle. (B) High performance TLC on acidic lipid fractions from kidneys of wild-type and B4 knockout mice. Lane 1 –standards for GM1, GD1a, GD1b and GT1b; lane 2 –standards for GM1 and GD1a loaded at 50% volume of lane 1; lane 3 –B4 -/-; lane 4—B4 +/-; lane 5 –B4 +/+; lane 6 –GM3 standard; lane 7 –GM2 standard; lane 8 –GD3 standard. (C) St8 KO MEFs retain a-series gangliosides. GD1a staining of WT and St8 KO MEFs show that both cell lines express GD1a. B4 KO and B4St8 KO MEFs do not express GD1a.
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ppat.1005175.g001: (A) B4 and St8 knockouts in pathways of ganglioside biosynthesis. Gangliosides previously shown or shown here to function as MuPyV receptors are outlined. Modified from U. Neu and T. Stehle. (B) High performance TLC on acidic lipid fractions from kidneys of wild-type and B4 knockout mice. Lane 1 –standards for GM1, GD1a, GD1b and GT1b; lane 2 –standards for GM1 and GD1a loaded at 50% volume of lane 1; lane 3 –B4 -/-; lane 4—B4 +/-; lane 5 –B4 +/+; lane 6 –GM3 standard; lane 7 –GM2 standard; lane 8 –GD3 standard. (C) St8 KO MEFs retain a-series gangliosides. GD1a staining of WT and St8 KO MEFs show that both cell lines express GD1a. B4 KO and B4St8 KO MEFs do not express GD1a.

Mentions: Previous studies have used ganglioside-deficient cell lines (i.e., rat glioma C6 cells, R- mouse cells) to evaluate the importance of ganglioside receptors for MuPyV infection [2, 9]. These cell lines are often from a heterologous-host for MuPyV, and are not genetically defined. Thus, we generated ganglioside-deficient mice with known ganglioside composition to clearly identify the role of specific gangliosides in MuPyV infection. The B4 KO mouse is blocked in a β1–4 GalNAc transferase (GM2/GD2 synthase) and is expected to lack the previously identified MuPyV ganglioside receptors, GD1a and GT1b, while maintaining expression of GM3 and GD3 (Fig 1A). We validated the ganglioside composition in B4 KO mice by analyzing total acidic lipid fractions from kidneys, a major site of replication and tissue destruction by MuPyV. High performance thin layer chromatography of kidney lipid fractions from uninfected wild type and B4 KO mice confirmed that only GD3 and its precursor GM3 are made in B4 KO mice (Fig 1B, lane 3). B4 heterozygous (+/-) mice showed decreased levels of gangliosides compared to wild-type mice (Fig 1B, lane 4). Immunofluorescence staining also showed that B4 KO mice lack a-series gangliosides such as GD1a (Fig 1C).


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)

(A) B4 and St8 knockouts in pathways of ganglioside biosynthesis. Gangliosides previously shown or shown here to function as MuPyV receptors are outlined. Modified from U. Neu and T. Stehle. (B) High performance TLC on acidic lipid fractions from kidneys of wild-type and B4 knockout mice. Lane 1 –standards for GM1, GD1a, GD1b and GT1b; lane 2 –standards for GM1 and GD1a loaded at 50% volume of lane 1; lane 3 –B4 -/-; lane 4—B4 +/-; lane 5 –B4 +/+; lane 6 –GM3 standard; lane 7 –GM2 standard; lane 8 –GD3 standard. (C) St8 KO MEFs retain a-series gangliosides. GD1a staining of WT and St8 KO MEFs show that both cell lines express GD1a. B4 KO and B4St8 KO MEFs do not express GD1a.
© Copyright Policy
Related In: Results  -  Collection

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

ppat.1005175.g001: (A) B4 and St8 knockouts in pathways of ganglioside biosynthesis. Gangliosides previously shown or shown here to function as MuPyV receptors are outlined. Modified from U. Neu and T. Stehle. (B) High performance TLC on acidic lipid fractions from kidneys of wild-type and B4 knockout mice. Lane 1 –standards for GM1, GD1a, GD1b and GT1b; lane 2 –standards for GM1 and GD1a loaded at 50% volume of lane 1; lane 3 –B4 -/-; lane 4—B4 +/-; lane 5 –B4 +/+; lane 6 –GM3 standard; lane 7 –GM2 standard; lane 8 –GD3 standard. (C) St8 KO MEFs retain a-series gangliosides. GD1a staining of WT and St8 KO MEFs show that both cell lines express GD1a. B4 KO and B4St8 KO MEFs do not express GD1a.
Mentions: Previous studies have used ganglioside-deficient cell lines (i.e., rat glioma C6 cells, R- mouse cells) to evaluate the importance of ganglioside receptors for MuPyV infection [2, 9]. These cell lines are often from a heterologous-host for MuPyV, and are not genetically defined. Thus, we generated ganglioside-deficient mice with known ganglioside composition to clearly identify the role of specific gangliosides in MuPyV infection. The B4 KO mouse is blocked in a β1–4 GalNAc transferase (GM2/GD2 synthase) and is expected to lack the previously identified MuPyV ganglioside receptors, GD1a and GT1b, while maintaining expression of GM3 and GD3 (Fig 1A). We validated the ganglioside composition in B4 KO mice by analyzing total acidic lipid fractions from kidneys, a major site of replication and tissue destruction by MuPyV. High performance thin layer chromatography of kidney lipid fractions from uninfected wild type and B4 KO mice confirmed that only GD3 and its precursor GM3 are made in B4 KO mice (Fig 1B, lane 3). B4 heterozygous (+/-) mice showed decreased levels of gangliosides compared to wild-type mice (Fig 1B, lane 4). Immunofluorescence staining also showed that B4 KO mice lack a-series gangliosides such as GD1a (Fig 1C).

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