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Galectin-9 controls CD40 signaling through a Tim-3 independent mechanism and redirects the cytokine profile of pathogenic T cells in autoimmunity.

Vaitaitis GM, Wagner DH - PLoS ONE (2012)

Bottom Line: Galectins interact with carbohydrates on proteins to effect such signaling alterations.Studying autoimmune prone NOD and non-autoimmune BALB/c mice, here we reveal that in-vivo CD40 signals alter the glycosylation status of non-autoimmune derived CD4 T cells to resemble that of autoimmune derived CD4 T cells.Interestingly, galectin-9, at lower concentrations, alters the surface expression of CD3, CD4, and TCR, regulating access to those molecules and thereby redirects the inflammatory cytokine phenotype and CD3 induced proliferation of autoimmune CD4(lo)CD40(+) T cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine and Webb-Waring Center, University of Colorado Denver, Aurora, Colorado, United States of America.

ABSTRACT
While it has long been understood that CD40 plays a critical role in the etiology of autoimmunity, glycobiology is emerging as an important contributor. CD40 signaling is also gaining further interest in transplantation and cancer therapies. Work on CD40 signaling has focused on signaling outcomes and blocking of its ligand, CD154, while little is known about the actual receptor itself and its control. We demonstrated that CD40 is in fact several receptors occurring as constellations of differentially glycosylated forms of the protein that can sometimes form hybrid receptors with other proteins. An enticing area of autoimmunity is differential glycosylation of immune molecules leading to altered signaling. Galectins interact with carbohydrates on proteins to effect such signaling alterations. Studying autoimmune prone NOD and non-autoimmune BALB/c mice, here we reveal that in-vivo CD40 signals alter the glycosylation status of non-autoimmune derived CD4 T cells to resemble that of autoimmune derived CD4 T cells. Galectin-9 interacts with CD40 and, at higher concentrations, prevents CD40 induced proliferative responses of CD4(lo)CD40(+) effector T cells and induces cell death through a Tim-3 independent mechanism. Interestingly, galectin-9, at lower concentrations, alters the surface expression of CD3, CD4, and TCR, regulating access to those molecules and thereby redirects the inflammatory cytokine phenotype and CD3 induced proliferation of autoimmune CD4(lo)CD40(+) T cells. Understanding the dynamics of the CD40 receptor(s) and the impact of glycosylation status in immunity will gain insight into how to maintain useful CD40 signals while shutting down detrimental ones.

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Related in: MedlinePlus

CD40 and CD3 induced cytokine phenotypes differ and galectin-9 alters the production level.CD4loCD40+ T cells were sorted from 7–20 weeks old female NOD spleens. Cells were either isotype treated, CD40- or CD3-stimulated in the absence/presence of indicated concentrations of galectin-9 (gal-9; µg/ml) for 3 days then cytokines were measured. Bar graphs depict means with SEM. Asterisks denote significant differences determined by one-way Anova; * – P between 0.01 and 0.05; ** – P <0.01; *** – P <0.001. Measurements were done on four individual mice of different ages.
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pone-0038708-g006: CD40 and CD3 induced cytokine phenotypes differ and galectin-9 alters the production level.CD4loCD40+ T cells were sorted from 7–20 weeks old female NOD spleens. Cells were either isotype treated, CD40- or CD3-stimulated in the absence/presence of indicated concentrations of galectin-9 (gal-9; µg/ml) for 3 days then cytokines were measured. Bar graphs depict means with SEM. Asterisks denote significant differences determined by one-way Anova; * – P between 0.01 and 0.05; ** – P <0.01; *** – P <0.001. Measurements were done on four individual mice of different ages.

Mentions: Considering the impact of galectin-9 on proliferative responses of CD4loCD40+ T cells to CD3-stimulation we determined whether galectin-9 could also impact the production of cytokines by these cells. We determined the level of production of IL-2, IL-4, IL-5, IL-6, IL-10, IL-17, and IFNγ. Regardless of the presence of galectin-9, the cytokine production was very different depending on whether CD40 or CD3 was stimulated (Fig. 6 and S1). CD40 induced more IL-6 (Fig. 6) and IL-10 (Fig. S1) while CD3 induced more IL-17 (more than double the amount compared to CD40; Fig. S1) and IL-2 (Fig. 6) after 3 days of stimulation. IFNγ production was similar between the two treatments (Fig. 6). CD40-induced IFNγ and IL-6 production was affected by the addition of galectin-9 where production was down-regulated in a dose dependent manner (IFNγ, P<0.05; IL-6, P<0.01). Conversely, CD3 induced IL-2 production was increased by the addition of galectin-9 (P<0.001). CD40 did not induce any IL-4 or IL-5 in these cells and while CD3 induced some, the levels were very low (Fig. S1).


Galectin-9 controls CD40 signaling through a Tim-3 independent mechanism and redirects the cytokine profile of pathogenic T cells in autoimmunity.

Vaitaitis GM, Wagner DH - PLoS ONE (2012)

CD40 and CD3 induced cytokine phenotypes differ and galectin-9 alters the production level.CD4loCD40+ T cells were sorted from 7–20 weeks old female NOD spleens. Cells were either isotype treated, CD40- or CD3-stimulated in the absence/presence of indicated concentrations of galectin-9 (gal-9; µg/ml) for 3 days then cytokines were measured. Bar graphs depict means with SEM. Asterisks denote significant differences determined by one-way Anova; * – P between 0.01 and 0.05; ** – P <0.01; *** – P <0.001. Measurements were done on four individual mice of different ages.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3369903&req=5

pone-0038708-g006: CD40 and CD3 induced cytokine phenotypes differ and galectin-9 alters the production level.CD4loCD40+ T cells were sorted from 7–20 weeks old female NOD spleens. Cells were either isotype treated, CD40- or CD3-stimulated in the absence/presence of indicated concentrations of galectin-9 (gal-9; µg/ml) for 3 days then cytokines were measured. Bar graphs depict means with SEM. Asterisks denote significant differences determined by one-way Anova; * – P between 0.01 and 0.05; ** – P <0.01; *** – P <0.001. Measurements were done on four individual mice of different ages.
Mentions: Considering the impact of galectin-9 on proliferative responses of CD4loCD40+ T cells to CD3-stimulation we determined whether galectin-9 could also impact the production of cytokines by these cells. We determined the level of production of IL-2, IL-4, IL-5, IL-6, IL-10, IL-17, and IFNγ. Regardless of the presence of galectin-9, the cytokine production was very different depending on whether CD40 or CD3 was stimulated (Fig. 6 and S1). CD40 induced more IL-6 (Fig. 6) and IL-10 (Fig. S1) while CD3 induced more IL-17 (more than double the amount compared to CD40; Fig. S1) and IL-2 (Fig. 6) after 3 days of stimulation. IFNγ production was similar between the two treatments (Fig. 6). CD40-induced IFNγ and IL-6 production was affected by the addition of galectin-9 where production was down-regulated in a dose dependent manner (IFNγ, P<0.05; IL-6, P<0.01). Conversely, CD3 induced IL-2 production was increased by the addition of galectin-9 (P<0.001). CD40 did not induce any IL-4 or IL-5 in these cells and while CD3 induced some, the levels were very low (Fig. S1).

Bottom Line: Galectins interact with carbohydrates on proteins to effect such signaling alterations.Studying autoimmune prone NOD and non-autoimmune BALB/c mice, here we reveal that in-vivo CD40 signals alter the glycosylation status of non-autoimmune derived CD4 T cells to resemble that of autoimmune derived CD4 T cells.Interestingly, galectin-9, at lower concentrations, alters the surface expression of CD3, CD4, and TCR, regulating access to those molecules and thereby redirects the inflammatory cytokine phenotype and CD3 induced proliferation of autoimmune CD4(lo)CD40(+) T cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine and Webb-Waring Center, University of Colorado Denver, Aurora, Colorado, United States of America.

ABSTRACT
While it has long been understood that CD40 plays a critical role in the etiology of autoimmunity, glycobiology is emerging as an important contributor. CD40 signaling is also gaining further interest in transplantation and cancer therapies. Work on CD40 signaling has focused on signaling outcomes and blocking of its ligand, CD154, while little is known about the actual receptor itself and its control. We demonstrated that CD40 is in fact several receptors occurring as constellations of differentially glycosylated forms of the protein that can sometimes form hybrid receptors with other proteins. An enticing area of autoimmunity is differential glycosylation of immune molecules leading to altered signaling. Galectins interact with carbohydrates on proteins to effect such signaling alterations. Studying autoimmune prone NOD and non-autoimmune BALB/c mice, here we reveal that in-vivo CD40 signals alter the glycosylation status of non-autoimmune derived CD4 T cells to resemble that of autoimmune derived CD4 T cells. Galectin-9 interacts with CD40 and, at higher concentrations, prevents CD40 induced proliferative responses of CD4(lo)CD40(+) effector T cells and induces cell death through a Tim-3 independent mechanism. Interestingly, galectin-9, at lower concentrations, alters the surface expression of CD3, CD4, and TCR, regulating access to those molecules and thereby redirects the inflammatory cytokine phenotype and CD3 induced proliferation of autoimmune CD4(lo)CD40(+) T cells. Understanding the dynamics of the CD40 receptor(s) and the impact of glycosylation status in immunity will gain insight into how to maintain useful CD40 signals while shutting down detrimental ones.

Show MeSH
Related in: MedlinePlus