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An A2B Adenosine Receptor Agonist Promotes Th17 Autoimmune Responses in Experimental Autoimmune Uveitis (EAU) via Dendritic Cell Activation.

Chen M, Liang D, Zuo A, Shao H, Kaplan HJ, Sun D - PLoS ONE (2015)

Bottom Line: We have recently reported that, although adenosine receptor (AR) agonists have a suppressive effect on Th1 autoreactive T cells, their effect on Th17 autoreactive T cells and γδ T cells is stimulatory and this effect is mainly mediated via A2A adenosine receptors (A2ARs).In the present study, we showed that exposure of DCs to A2BR agonist facilitated γδ T cell activation, leading to augmented Th17 responses and progressive EAU development.Our results further support our previous finding that AR agonists have distinct effects on Th1 and Th17 autoimmune responses.

View Article: PubMed Central - PubMed

Affiliation: Doheny Eye Institute and Department of Ophthalmology, University of California, Los Angeles, CA90033, United States of America.

ABSTRACT
We have recently reported that, although adenosine receptor (AR) agonists have a suppressive effect on Th1 autoreactive T cells, their effect on Th17 autoreactive T cells and γδ T cells is stimulatory and this effect is mainly mediated via A2A adenosine receptors (A2ARs). In this study, we further demonstrate that treatment of C57BL/6 (B6) mice with a selective A2B adenosine receptor (A2BR) agonist greatly enhanced the development of experimental autoimmune uveitis (EAU), whereas treatment with an A2BR antagonist significantly ameliorated severity of EAU. The A2BR agonist-treated mice showed augmented Th17, but not Th1, responses. Mechanistic studies showed that the A2BR agonist-induced enhancement of the Th17 response was significantly lower when TCR-δ-/- mice received the same treatment and that transfer of γδ T cells into TCR-δ-/- mice partially restored this effect. We also showed that dendritic cells (DCs) from A2BR agonist-treated mice showed a significantly increased ability to activate γδ T cells and Th17 autoreactive T cells. Thus, our previous studies have shown that, in EAU, activated γδ T cells possess greatly increased ability to enhance Th17 autoimmune responses. In the present study, we showed that exposure of DCs to A2BR agonist facilitated γδ T cell activation, leading to augmented Th17 responses and progressive EAU development. Our results further support our previous finding that AR agonists have distinct effects on Th1 and Th17 autoimmune responses.

No MeSH data available.


Related in: MedlinePlus

A2BR agonist does not directly stimulate γδ T cells.A and B) γδ T cells isolated from immunized B6 mice at day 13 post-immunization were cultured in the presence or absence of A2BR agonist for 48 h. then IL-17 levels in the supernatants were measured by ELISA (A) and expression of IL-17 and CD44 on the cells was examined by staining and FACS analysis (B). C) Adenosine binding assay showing that γδ T cells do not bind adenosine via A2BR. In 96-well plates, γδ T cells (1x105/well) isolated from IRBP1-20-immunized mice at day 13 post-immunization were incubated for 30 min with vehicle (Control) or an antagonist of the A1AR (DPCPX, 50 nM), A2AR (SCH 58261, 100 nM), A2BR (MRS 1754, 100 nM), or A3AR (MRS1220, 5 μM), then for 1 h with radiolabeled adenosine (3H-adenosine, 100 nM). The amount of labeled adenosine bound was measured **P<0.01.
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pone.0132348.g005: A2BR agonist does not directly stimulate γδ T cells.A and B) γδ T cells isolated from immunized B6 mice at day 13 post-immunization were cultured in the presence or absence of A2BR agonist for 48 h. then IL-17 levels in the supernatants were measured by ELISA (A) and expression of IL-17 and CD44 on the cells was examined by staining and FACS analysis (B). C) Adenosine binding assay showing that γδ T cells do not bind adenosine via A2BR. In 96-well plates, γδ T cells (1x105/well) isolated from IRBP1-20-immunized mice at day 13 post-immunization were incubated for 30 min with vehicle (Control) or an antagonist of the A1AR (DPCPX, 50 nM), A2AR (SCH 58261, 100 nM), A2BR (MRS 1754, 100 nM), or A3AR (MRS1220, 5 μM), then for 1 h with radiolabeled adenosine (3H-adenosine, 100 nM). The amount of labeled adenosine bound was measured **P<0.01.

Mentions: To determine whether BAY 60–6583 had a direct activating effect on γδ T cells, we isolated γδ T cells from immunized B6 mice and incubated them in vitro with and without BAY 60–6583 for 48 h, then measured cytokine levels in the culture supernatants and the expression of CD44 on the γδ T cells. The results showed that neither IL-17 production (Fig 5A) nor CD44 expression (Fig 5B) was significantly altered by exposure to BAY 60–6583. In addition, a competitive adenosine binding assay using AR subtype-specific antagonists revealed that γδ T cells did not bind adenosine via any ARs except A2AR and would therefore not bind BAY 60–6583 (Fig 5C).


An A2B Adenosine Receptor Agonist Promotes Th17 Autoimmune Responses in Experimental Autoimmune Uveitis (EAU) via Dendritic Cell Activation.

Chen M, Liang D, Zuo A, Shao H, Kaplan HJ, Sun D - PLoS ONE (2015)

A2BR agonist does not directly stimulate γδ T cells.A and B) γδ T cells isolated from immunized B6 mice at day 13 post-immunization were cultured in the presence or absence of A2BR agonist for 48 h. then IL-17 levels in the supernatants were measured by ELISA (A) and expression of IL-17 and CD44 on the cells was examined by staining and FACS analysis (B). C) Adenosine binding assay showing that γδ T cells do not bind adenosine via A2BR. In 96-well plates, γδ T cells (1x105/well) isolated from IRBP1-20-immunized mice at day 13 post-immunization were incubated for 30 min with vehicle (Control) or an antagonist of the A1AR (DPCPX, 50 nM), A2AR (SCH 58261, 100 nM), A2BR (MRS 1754, 100 nM), or A3AR (MRS1220, 5 μM), then for 1 h with radiolabeled adenosine (3H-adenosine, 100 nM). The amount of labeled adenosine bound was measured **P<0.01.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4492970&req=5

pone.0132348.g005: A2BR agonist does not directly stimulate γδ T cells.A and B) γδ T cells isolated from immunized B6 mice at day 13 post-immunization were cultured in the presence or absence of A2BR agonist for 48 h. then IL-17 levels in the supernatants were measured by ELISA (A) and expression of IL-17 and CD44 on the cells was examined by staining and FACS analysis (B). C) Adenosine binding assay showing that γδ T cells do not bind adenosine via A2BR. In 96-well plates, γδ T cells (1x105/well) isolated from IRBP1-20-immunized mice at day 13 post-immunization were incubated for 30 min with vehicle (Control) or an antagonist of the A1AR (DPCPX, 50 nM), A2AR (SCH 58261, 100 nM), A2BR (MRS 1754, 100 nM), or A3AR (MRS1220, 5 μM), then for 1 h with radiolabeled adenosine (3H-adenosine, 100 nM). The amount of labeled adenosine bound was measured **P<0.01.
Mentions: To determine whether BAY 60–6583 had a direct activating effect on γδ T cells, we isolated γδ T cells from immunized B6 mice and incubated them in vitro with and without BAY 60–6583 for 48 h, then measured cytokine levels in the culture supernatants and the expression of CD44 on the γδ T cells. The results showed that neither IL-17 production (Fig 5A) nor CD44 expression (Fig 5B) was significantly altered by exposure to BAY 60–6583. In addition, a competitive adenosine binding assay using AR subtype-specific antagonists revealed that γδ T cells did not bind adenosine via any ARs except A2AR and would therefore not bind BAY 60–6583 (Fig 5C).

Bottom Line: We have recently reported that, although adenosine receptor (AR) agonists have a suppressive effect on Th1 autoreactive T cells, their effect on Th17 autoreactive T cells and γδ T cells is stimulatory and this effect is mainly mediated via A2A adenosine receptors (A2ARs).In the present study, we showed that exposure of DCs to A2BR agonist facilitated γδ T cell activation, leading to augmented Th17 responses and progressive EAU development.Our results further support our previous finding that AR agonists have distinct effects on Th1 and Th17 autoimmune responses.

View Article: PubMed Central - PubMed

Affiliation: Doheny Eye Institute and Department of Ophthalmology, University of California, Los Angeles, CA90033, United States of America.

ABSTRACT
We have recently reported that, although adenosine receptor (AR) agonists have a suppressive effect on Th1 autoreactive T cells, their effect on Th17 autoreactive T cells and γδ T cells is stimulatory and this effect is mainly mediated via A2A adenosine receptors (A2ARs). In this study, we further demonstrate that treatment of C57BL/6 (B6) mice with a selective A2B adenosine receptor (A2BR) agonist greatly enhanced the development of experimental autoimmune uveitis (EAU), whereas treatment with an A2BR antagonist significantly ameliorated severity of EAU. The A2BR agonist-treated mice showed augmented Th17, but not Th1, responses. Mechanistic studies showed that the A2BR agonist-induced enhancement of the Th17 response was significantly lower when TCR-δ-/- mice received the same treatment and that transfer of γδ T cells into TCR-δ-/- mice partially restored this effect. We also showed that dendritic cells (DCs) from A2BR agonist-treated mice showed a significantly increased ability to activate γδ T cells and Th17 autoreactive T cells. Thus, our previous studies have shown that, in EAU, activated γδ T cells possess greatly increased ability to enhance Th17 autoimmune responses. In the present study, we showed that exposure of DCs to A2BR agonist facilitated γδ T cell activation, leading to augmented Th17 responses and progressive EAU development. Our results further support our previous finding that AR agonists have distinct effects on Th1 and Th17 autoimmune responses.

No MeSH data available.


Related in: MedlinePlus