Limits...
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.

Show MeSH

Related in: MedlinePlus

WT and WKO nTreg cells inefficiently remodel their actin cytoskeleton upon T cell receptor activation. (A–C) Reduced actin polarization of WT and WKO nTreg cells upon incubation with anti-CD3/anti-CD28–coated beads. Representative examples of cells with nonpolarized (A) and polarized actin (B) are displayed. Left panels represent phase images, and right panels show actin staining. Beads are marked with a cross. Bars, 5 μm. The percentage of CD4+CD25− or nTreg cells (black, WT; white, WKO) with polarized cytoskeleton relative to WT CD4+CD25− is shown in C. For each group, at least 300 conjugated cells have been examined. Shown are averages of three independent experiments ± SD. (D and E) Reduced T cell spreading by WT and WKO nTreg cells. An example of actin staining of WT CD4+CD25− splenocytes 10 min after incubation on anti-CD3/anti-CD28–coated coverslips is shown in D. Examples of spread T cells are indicated by arrowheads, and unspread T cells are represented by arrows. Bar, 5 μm. The percentage of CD4+CD25− or nTreg cells (isolated from WT [black] or WKO [white] mice) that were spread relative to WT CD4+CD25− is shown in E. For each group, at least 300 cells have been examined. Shown are averages of three independent experiments ± SD. NS, Nonsignificant (P > 0.05). *, P < 0.05; **, P < 0.01.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2118715&req=5

fig5: WT and WKO nTreg cells inefficiently remodel their actin cytoskeleton upon T cell receptor activation. (A–C) Reduced actin polarization of WT and WKO nTreg cells upon incubation with anti-CD3/anti-CD28–coated beads. Representative examples of cells with nonpolarized (A) and polarized actin (B) are displayed. Left panels represent phase images, and right panels show actin staining. Beads are marked with a cross. Bars, 5 μm. The percentage of CD4+CD25− or nTreg cells (black, WT; white, WKO) with polarized cytoskeleton relative to WT CD4+CD25− is shown in C. For each group, at least 300 conjugated cells have been examined. Shown are averages of three independent experiments ± SD. (D and E) Reduced T cell spreading by WT and WKO nTreg cells. An example of actin staining of WT CD4+CD25− splenocytes 10 min after incubation on anti-CD3/anti-CD28–coated coverslips is shown in D. Examples of spread T cells are indicated by arrowheads, and unspread T cells are represented by arrows. Bar, 5 μm. The percentage of CD4+CD25− or nTreg cells (isolated from WT [black] or WKO [white] mice) that were spread relative to WT CD4+CD25− is shown in E. For each group, at least 300 cells have been examined. Shown are averages of three independent experiments ± SD. NS, Nonsignificant (P > 0.05). *, P < 0.05; **, P < 0.01.

Mentions: Although remodeling of the actin cytoskeleton and formation of an immunological synapse appear to be important for TCR signaling in peripheral T cells (30–32), a role for actin remodeling and immunological synapse formation has not been described for regulatory T cells. Because WASP has been demonstrated to regulate actin remodeling and immunological synapse formation, we hypothesized that deficiencies in these processes might contribute to WKO nTreg cell dysfunction (2–5). When compared with WT CD4+CD25− cells, both WT and WKO nTreg cells polarized their actin cytoskeleton less efficiently upon stimulation with anti-CD3/anti-CD28–coated beads (Fig. 5, A–C, and Table S1, which is available at http://www.jem.org/cgi/content/full/jem.20061338/DC1). As expected, WKO CD4+CD25− T cells polarized their actin cytoskeleton inefficiently when compared with WT CD4+CD25− cells (2–5).


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)

WT and WKO nTreg cells inefficiently remodel their actin cytoskeleton upon T cell receptor activation. (A–C) Reduced actin polarization of WT and WKO nTreg cells upon incubation with anti-CD3/anti-CD28–coated beads. Representative examples of cells with nonpolarized (A) and polarized actin (B) are displayed. Left panels represent phase images, and right panels show actin staining. Beads are marked with a cross. Bars, 5 μm. The percentage of CD4+CD25− or nTreg cells (black, WT; white, WKO) with polarized cytoskeleton relative to WT CD4+CD25− is shown in C. For each group, at least 300 conjugated cells have been examined. Shown are averages of three independent experiments ± SD. (D and E) Reduced T cell spreading by WT and WKO nTreg cells. An example of actin staining of WT CD4+CD25− splenocytes 10 min after incubation on anti-CD3/anti-CD28–coated coverslips is shown in D. Examples of spread T cells are indicated by arrowheads, and unspread T cells are represented by arrows. Bar, 5 μm. The percentage of CD4+CD25− or nTreg cells (isolated from WT [black] or WKO [white] mice) that were spread relative to WT CD4+CD25− is shown in E. For each group, at least 300 cells have been examined. Shown are averages of three independent experiments ± SD. NS, Nonsignificant (P > 0.05). *, P < 0.05; **, P < 0.01.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2118715&req=5

fig5: WT and WKO nTreg cells inefficiently remodel their actin cytoskeleton upon T cell receptor activation. (A–C) Reduced actin polarization of WT and WKO nTreg cells upon incubation with anti-CD3/anti-CD28–coated beads. Representative examples of cells with nonpolarized (A) and polarized actin (B) are displayed. Left panels represent phase images, and right panels show actin staining. Beads are marked with a cross. Bars, 5 μm. The percentage of CD4+CD25− or nTreg cells (black, WT; white, WKO) with polarized cytoskeleton relative to WT CD4+CD25− is shown in C. For each group, at least 300 conjugated cells have been examined. Shown are averages of three independent experiments ± SD. (D and E) Reduced T cell spreading by WT and WKO nTreg cells. An example of actin staining of WT CD4+CD25− splenocytes 10 min after incubation on anti-CD3/anti-CD28–coated coverslips is shown in D. Examples of spread T cells are indicated by arrowheads, and unspread T cells are represented by arrows. Bar, 5 μm. The percentage of CD4+CD25− or nTreg cells (isolated from WT [black] or WKO [white] mice) that were spread relative to WT CD4+CD25− is shown in E. For each group, at least 300 cells have been examined. Shown are averages of three independent experiments ± SD. NS, Nonsignificant (P > 0.05). *, P < 0.05; **, P < 0.01.
Mentions: Although remodeling of the actin cytoskeleton and formation of an immunological synapse appear to be important for TCR signaling in peripheral T cells (30–32), a role for actin remodeling and immunological synapse formation has not been described for regulatory T cells. Because WASP has been demonstrated to regulate actin remodeling and immunological synapse formation, we hypothesized that deficiencies in these processes might contribute to WKO nTreg cell dysfunction (2–5). When compared with WT CD4+CD25− cells, both WT and WKO nTreg cells polarized their actin cytoskeleton less efficiently upon stimulation with anti-CD3/anti-CD28–coated beads (Fig. 5, A–C, and Table S1, which is available at http://www.jem.org/cgi/content/full/jem.20061338/DC1). As expected, WKO CD4+CD25− T cells polarized their actin cytoskeleton inefficiently when compared with WT CD4+CD25− cells (2–5).

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