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The Wiskott-Aldrich syndrome protein is required for the function of CD4(+)CD25(+)Foxp3(+) regulatory T cells.

Maillard MH, Cotta-de-Almeida V, Takeshima F, Nguyen DD, Michetti P, Nagler C, Bhan AK, Snapper SB - J. Exp. Med. (2007)

Bottom Line: Preincubation of WKO nTreg cells with exogenous interleukin (IL)-2, combined with antigen receptor-mediated activation, substantially rescues the suppression defects.WKO nTreg cells are also defective in the secretion of the immunomodulatory cytokine IL-10.Overall, our data reveal a critical role for WASP in nTreg cell function and implicate nTreg cell dysfunction in the autoimmunity associated with WASP deficiency.

View Article: PubMed Central - PubMed

Affiliation: Gastrointestinal Unit, Massachusetts General Hospital, Boston, MA 02114, USA.

ABSTRACT
The Wiskott-Aldrich syndrome, a primary human immunodeficiency, results from defective expression of the hematopoietic-specific cytoskeletal regulator Wiskott-Aldrich syndrome protein (WASP). Because CD4(+)CD25(+)Foxp3(+) naturally occurring regulatory T (nTreg) cells control autoimmunity, we asked whether colitis in WASP knockout (WKO) mice is associated with aberrant development/function of nTreg cells. We show that WKO mice have decreased numbers of CD4(+)CD25(+)Foxp3(+) nTreg cells in both the thymus and peripheral lymphoid organs. Moreover, we demonstrate that WKO nTreg cells are markedly defective in both their ability to ameliorate the colitis induced by the transfer of CD45RB(hi) T cells and in functional suppression assays in vitro. Compared with wild-type (WT) nTreg cells, WKO nTreg cells show significantly impaired homing to both mucosal (mesenteric) and peripheral sites upon adoptive transfer into WT recipient mice. Suppression defects may be independent of antigen receptor-mediated actin rearrangement because both WT and WKO nTreg cells remodeled their actin cytoskeleton inefficiently upon T cell receptor stimulation. Preincubation of WKO nTreg cells with exogenous interleukin (IL)-2, combined with antigen receptor-mediated activation, substantially rescues the suppression defects. WKO nTreg cells are also defective in the secretion of the immunomodulatory cytokine IL-10. Overall, our data reveal a critical role for WASP in nTreg cell function and implicate nTreg cell dysfunction in the autoimmunity associated with WASP deficiency.

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WKO nTreg cells are defective in suppressing T cell proliferation in vitro. CD4+CD25− cells were isolated from the spleens of WT (A) and WKO (B) mice and were cocultured with mitomycin-treated T cell–depleted splenocytes and 0.5 μg/ml anti-CD3ɛ for 3 d in the presence of varying numbers of CD4+CD25+ regulatory T cells (nTreg cells) coming from the spleen of WT (black full line, dots) or WKO (gray dashed curve, squares) mice. Proliferation was measured by [3H]thymidine uptake (y axis). Ratios of CD25+/CD25− T cells are indicated on the x axis. Shown is one representative of five (left) and three (right) independent experiments performed in triplicate.
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fig4: WKO nTreg cells are defective in suppressing T cell proliferation in vitro. CD4+CD25− cells were isolated from the spleens of WT (A) and WKO (B) mice and were cocultured with mitomycin-treated T cell–depleted splenocytes and 0.5 μg/ml anti-CD3ɛ for 3 d in the presence of varying numbers of CD4+CD25+ regulatory T cells (nTreg cells) coming from the spleen of WT (black full line, dots) or WKO (gray dashed curve, squares) mice. Proliferation was measured by [3H]thymidine uptake (y axis). Ratios of CD25+/CD25− T cells are indicated on the x axis. Shown is one representative of five (left) and three (right) independent experiments performed in triplicate.

Mentions: We next sought to extend our in vivo findings by using an in vitro suppression assay (29). WT CD4+CD25− T cells were cocultured with mitomycin-treated WT APCs in the presence of anti-CD3ɛ antibodies and WT or WKO nTreg cells. Suppression of proliferation by WT or WKO nTreg cells was assessed by [3H]thymidine incorporation. As expected, WT nTreg cells efficiently suppressed proliferation, readily apparent at a CD25+/CD25− cell ratio of 1:16 (Fig. 4 A) (29). In contrast, even at a 1:1 CD25+/CD25− cell ratio, WKO nTreg cells failed to suppress the proliferation of WT CD25− cells (Fig. 4 A). Moreover, consistent with these findings, preliminary data suggest that WT but not WKO nTreg cells suppress the secretion of IFN-γ by WT CD25− T cells in this coculture system (unpublished data).


The Wiskott-Aldrich syndrome protein is required for the function of CD4(+)CD25(+)Foxp3(+) regulatory T cells.

Maillard MH, Cotta-de-Almeida V, Takeshima F, Nguyen DD, Michetti P, Nagler C, Bhan AK, Snapper SB - J. Exp. Med. (2007)

WKO nTreg cells are defective in suppressing T cell proliferation in vitro. CD4+CD25− cells were isolated from the spleens of WT (A) and WKO (B) mice and were cocultured with mitomycin-treated T cell–depleted splenocytes and 0.5 μg/ml anti-CD3ɛ for 3 d in the presence of varying numbers of CD4+CD25+ regulatory T cells (nTreg cells) coming from the spleen of WT (black full line, dots) or WKO (gray dashed curve, squares) mice. Proliferation was measured by [3H]thymidine uptake (y axis). Ratios of CD25+/CD25− T cells are indicated on the x axis. Shown is one representative of five (left) and three (right) independent experiments performed in triplicate.
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Related In: Results  -  Collection

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fig4: WKO nTreg cells are defective in suppressing T cell proliferation in vitro. CD4+CD25− cells were isolated from the spleens of WT (A) and WKO (B) mice and were cocultured with mitomycin-treated T cell–depleted splenocytes and 0.5 μg/ml anti-CD3ɛ for 3 d in the presence of varying numbers of CD4+CD25+ regulatory T cells (nTreg cells) coming from the spleen of WT (black full line, dots) or WKO (gray dashed curve, squares) mice. Proliferation was measured by [3H]thymidine uptake (y axis). Ratios of CD25+/CD25− T cells are indicated on the x axis. Shown is one representative of five (left) and three (right) independent experiments performed in triplicate.
Mentions: We next sought to extend our in vivo findings by using an in vitro suppression assay (29). WT CD4+CD25− T cells were cocultured with mitomycin-treated WT APCs in the presence of anti-CD3ɛ antibodies and WT or WKO nTreg cells. Suppression of proliferation by WT or WKO nTreg cells was assessed by [3H]thymidine incorporation. As expected, WT nTreg cells efficiently suppressed proliferation, readily apparent at a CD25+/CD25− cell ratio of 1:16 (Fig. 4 A) (29). In contrast, even at a 1:1 CD25+/CD25− cell ratio, WKO nTreg cells failed to suppress the proliferation of WT CD25− cells (Fig. 4 A). Moreover, consistent with these findings, preliminary data suggest that WT but not WKO nTreg cells suppress the secretion of IFN-γ by WT CD25− T cells in this coculture system (unpublished data).

Bottom Line: Preincubation of WKO nTreg cells with exogenous interleukin (IL)-2, combined with antigen receptor-mediated activation, substantially rescues the suppression defects.WKO nTreg cells are also defective in the secretion of the immunomodulatory cytokine IL-10.Overall, our data reveal a critical role for WASP in nTreg cell function and implicate nTreg cell dysfunction in the autoimmunity associated with WASP deficiency.

View Article: PubMed Central - PubMed

Affiliation: Gastrointestinal Unit, Massachusetts General Hospital, Boston, MA 02114, USA.

ABSTRACT
The Wiskott-Aldrich syndrome, a primary human immunodeficiency, results from defective expression of the hematopoietic-specific cytoskeletal regulator Wiskott-Aldrich syndrome protein (WASP). Because CD4(+)CD25(+)Foxp3(+) naturally occurring regulatory T (nTreg) cells control autoimmunity, we asked whether colitis in WASP knockout (WKO) mice is associated with aberrant development/function of nTreg cells. We show that WKO mice have decreased numbers of CD4(+)CD25(+)Foxp3(+) nTreg cells in both the thymus and peripheral lymphoid organs. Moreover, we demonstrate that WKO nTreg cells are markedly defective in both their ability to ameliorate the colitis induced by the transfer of CD45RB(hi) T cells and in functional suppression assays in vitro. Compared with wild-type (WT) nTreg cells, WKO nTreg cells show significantly impaired homing to both mucosal (mesenteric) and peripheral sites upon adoptive transfer into WT recipient mice. Suppression defects may be independent of antigen receptor-mediated actin rearrangement because both WT and WKO nTreg cells remodeled their actin cytoskeleton inefficiently upon T cell receptor stimulation. Preincubation of WKO nTreg cells with exogenous interleukin (IL)-2, combined with antigen receptor-mediated activation, substantially rescues the suppression defects. WKO nTreg cells are also defective in the secretion of the immunomodulatory cytokine IL-10. Overall, our data reveal a critical role for WASP in nTreg cell function and implicate nTreg cell dysfunction in the autoimmunity associated with WASP deficiency.

Show MeSH
Related in: MedlinePlus