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A multifactorial mechanism in the superior antimalarial activity of alpha-C-GalCer.

Schmieg J, Yang G, Franck RW, Tsuji M - J. Biomed. Biotechnol. (2009)

Bottom Line: We have previously shown that the C-glycoside analog of alpha-galactosylceramide (alpha-GalCer), alpha-C-GalCer, displays a superior inhibitory activity against the liver stages of the rodent malaria parasite Plasmodium yoelii than its parental glycolipid, alpha-GalCer.In this study, we demonstrate that NK cells, as well as IL-12, are a key contributor for the superior activity displayed by alpha-C-GalCer.Surprisingly, the diminished production of Th2 cytokines, including IL-4, by alpha-C-GalCer has no affect on its superior therapeutic activity relative to alpha-GalCer.

View Article: PubMed Central - PubMed

Affiliation: Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.

ABSTRACT
We have previously shown that the C-glycoside analog of alpha-galactosylceramide (alpha-GalCer), alpha-C-GalCer, displays a superior inhibitory activity against the liver stages of the rodent malaria parasite Plasmodium yoelii than its parental glycolipid, alpha-GalCer. In this study, we demonstrate that NK cells, as well as IL-12, are a key contributor for the superior activity displayed by alpha-C-GalCer. Surprisingly, the diminished production of Th2 cytokines, including IL-4, by alpha-C-GalCer has no affect on its superior therapeutic activity relative to alpha-GalCer. Finally, we show that the in vivo administration of alpha-C-GalCer induces prolonged maturation of dendritic cells (DCs), as well as an enhanced proliferative response of mouse invariant Valpha14 (Valpha14i) NKT cells, both of which may also contribute to some degree to the superior activity of alpha-C-GalCer in vivo.

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Related in: MedlinePlus

TCRβ usage does not affect in vivo Vα14i NKT cell activation stimulated by α-GalCer or α-C-GalCer. Groups of 2 WT C57BL/6 were injected i.p. with 1 μg of α-GalCer or α-C-GalCer, or with nothing, and 72 hours later splenocytes and hepatic lymphocytes were isolated and stained for Vα14i NKT cells using α-GalCer-loaded mouse CD1d-IgG1 dimers, as well as for Vβ8.1/8.2, Vβ7, and Vβ2. Vα14i NKT cells were gated, and FACS analyzed for the three different Vβ gene segments. The numbers shown represent the percentage of cells expressing the indicated Vβ segment. The data shown comes from one of two independent experiments with similar results.
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fig6: TCRβ usage does not affect in vivo Vα14i NKT cell activation stimulated by α-GalCer or α-C-GalCer. Groups of 2 WT C57BL/6 were injected i.p. with 1 μg of α-GalCer or α-C-GalCer, or with nothing, and 72 hours later splenocytes and hepatic lymphocytes were isolated and stained for Vα14i NKT cells using α-GalCer-loaded mouse CD1d-IgG1 dimers, as well as for Vβ8.1/8.2, Vβ7, and Vβ2. Vα14i NKT cells were gated, and FACS analyzed for the three different Vβ gene segments. The numbers shown represent the percentage of cells expressing the indicated Vβ segment. The data shown comes from one of two independent experiments with similar results.

Mentions: Two recent studies show that TCRβ usage by Vα14i NKT cells affects the avidity of Vα14i TCRs for CD1d-glycolipid complexes [22, 23]. In particular, they indicate that TCRβ chains encoded by the Vβ8.2 gene segment confer higher avidity to Vα14i TCRs than Vβ7 or Vβ2, and that glycolipid ligands preferentially stimulate these higher avidity cells. Despite these findings, our data showing a complete disappearance of Vα14i NKT cells by 24 hours post-α-GalCer or α-C-GalCer injection (Figure 5(a)) suggests that in vivo both glycolipids stimulate all Vα14i NKT cells regardless of their TCRβ usage. To confirm this suspicion, we treated WT mice with α-GalCer, α-C-GalCer, or with nothing, and 72 hours later obtained splenocytes and liver lymphocytes for staining with CD1d-IgG1 dimer loaded with α-GalCer. In addition to dimer staining, we also stained the cells for Vβ8.1/8.2, Vβ7, and Vβ2 to see if the distribution Vα14i NKT cells changes after glycolipid-mediated stimulation. More specifically, if α-GalCer or α-C-GalCer preferentially stimulates the higher avidity Vβ8.2-containing NKT cells in vivo, then there should be an increase in the proportions of these cells in the expanded NKT cell population that results after glycolipid-induced proliferation. We found that there was no difference in the proportions of TCRβ usage by Vα14i NKT cells before or after stimulation with α-GalCer or α-C-GalCer (Figure 6). Prior to glycolipid administration about 50% of Vα14i NKT cells in the livers and spleens of mice expressed Vβ8.1/8.2, while about 15% expressed Vβ7 and 3-4% expressed Vβ2. These proportions did not change after α-GalCer- or α-C-GalCer-induced proliferation (Figure 6). In all, these results suggest that TCRβ usage does not affect in vivo Vα14i NKT cell activation stimulated by α-GalCer or α-C-GalCer.


A multifactorial mechanism in the superior antimalarial activity of alpha-C-GalCer.

Schmieg J, Yang G, Franck RW, Tsuji M - J. Biomed. Biotechnol. (2009)

TCRβ usage does not affect in vivo Vα14i NKT cell activation stimulated by α-GalCer or α-C-GalCer. Groups of 2 WT C57BL/6 were injected i.p. with 1 μg of α-GalCer or α-C-GalCer, or with nothing, and 72 hours later splenocytes and hepatic lymphocytes were isolated and stained for Vα14i NKT cells using α-GalCer-loaded mouse CD1d-IgG1 dimers, as well as for Vβ8.1/8.2, Vβ7, and Vβ2. Vα14i NKT cells were gated, and FACS analyzed for the three different Vβ gene segments. The numbers shown represent the percentage of cells expressing the indicated Vβ segment. The data shown comes from one of two independent experiments with similar results.
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2801455&req=5

fig6: TCRβ usage does not affect in vivo Vα14i NKT cell activation stimulated by α-GalCer or α-C-GalCer. Groups of 2 WT C57BL/6 were injected i.p. with 1 μg of α-GalCer or α-C-GalCer, or with nothing, and 72 hours later splenocytes and hepatic lymphocytes were isolated and stained for Vα14i NKT cells using α-GalCer-loaded mouse CD1d-IgG1 dimers, as well as for Vβ8.1/8.2, Vβ7, and Vβ2. Vα14i NKT cells were gated, and FACS analyzed for the three different Vβ gene segments. The numbers shown represent the percentage of cells expressing the indicated Vβ segment. The data shown comes from one of two independent experiments with similar results.
Mentions: Two recent studies show that TCRβ usage by Vα14i NKT cells affects the avidity of Vα14i TCRs for CD1d-glycolipid complexes [22, 23]. In particular, they indicate that TCRβ chains encoded by the Vβ8.2 gene segment confer higher avidity to Vα14i TCRs than Vβ7 or Vβ2, and that glycolipid ligands preferentially stimulate these higher avidity cells. Despite these findings, our data showing a complete disappearance of Vα14i NKT cells by 24 hours post-α-GalCer or α-C-GalCer injection (Figure 5(a)) suggests that in vivo both glycolipids stimulate all Vα14i NKT cells regardless of their TCRβ usage. To confirm this suspicion, we treated WT mice with α-GalCer, α-C-GalCer, or with nothing, and 72 hours later obtained splenocytes and liver lymphocytes for staining with CD1d-IgG1 dimer loaded with α-GalCer. In addition to dimer staining, we also stained the cells for Vβ8.1/8.2, Vβ7, and Vβ2 to see if the distribution Vα14i NKT cells changes after glycolipid-mediated stimulation. More specifically, if α-GalCer or α-C-GalCer preferentially stimulates the higher avidity Vβ8.2-containing NKT cells in vivo, then there should be an increase in the proportions of these cells in the expanded NKT cell population that results after glycolipid-induced proliferation. We found that there was no difference in the proportions of TCRβ usage by Vα14i NKT cells before or after stimulation with α-GalCer or α-C-GalCer (Figure 6). Prior to glycolipid administration about 50% of Vα14i NKT cells in the livers and spleens of mice expressed Vβ8.1/8.2, while about 15% expressed Vβ7 and 3-4% expressed Vβ2. These proportions did not change after α-GalCer- or α-C-GalCer-induced proliferation (Figure 6). In all, these results suggest that TCRβ usage does not affect in vivo Vα14i NKT cell activation stimulated by α-GalCer or α-C-GalCer.

Bottom Line: We have previously shown that the C-glycoside analog of alpha-galactosylceramide (alpha-GalCer), alpha-C-GalCer, displays a superior inhibitory activity against the liver stages of the rodent malaria parasite Plasmodium yoelii than its parental glycolipid, alpha-GalCer.In this study, we demonstrate that NK cells, as well as IL-12, are a key contributor for the superior activity displayed by alpha-C-GalCer.Surprisingly, the diminished production of Th2 cytokines, including IL-4, by alpha-C-GalCer has no affect on its superior therapeutic activity relative to alpha-GalCer.

View Article: PubMed Central - PubMed

Affiliation: Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.

ABSTRACT
We have previously shown that the C-glycoside analog of alpha-galactosylceramide (alpha-GalCer), alpha-C-GalCer, displays a superior inhibitory activity against the liver stages of the rodent malaria parasite Plasmodium yoelii than its parental glycolipid, alpha-GalCer. In this study, we demonstrate that NK cells, as well as IL-12, are a key contributor for the superior activity displayed by alpha-C-GalCer. Surprisingly, the diminished production of Th2 cytokines, including IL-4, by alpha-C-GalCer has no affect on its superior therapeutic activity relative to alpha-GalCer. Finally, we show that the in vivo administration of alpha-C-GalCer induces prolonged maturation of dendritic cells (DCs), as well as an enhanced proliferative response of mouse invariant Valpha14 (Valpha14i) NKT cells, both of which may also contribute to some degree to the superior activity of alpha-C-GalCer in vivo.

Show MeSH
Related in: MedlinePlus