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WASP regulates suppressor activity of human and murine CD4(+)CD25(+)FOXP3(+) natural regulatory T cells.

Marangoni F, Trifari S, Scaramuzza S, Panaroni C, Martino S, Notarangelo LD, Baz Z, Metin A, Cattaneo F, Villa A, Aiuti A, Battaglia M, Roncarolo MG, Dupré L - J. Exp. Med. (2007)

Bottom Line: Moreover, WAS(-/-) nTreg cells failed to proliferate and to produce transforming growth factor beta upon T cell receptor (TCR)/CD28 triggering.Compared with WT nTreg cells, WAS(-/-) nTreg cells showed reduced in vitro suppressor activity on both WT and WAS(-/-) effector T cells.Similarly, peripheral nTreg cells were present at normal levels in WAS patients but failed to suppress proliferation of autologous and allogeneic CD4(+) effector T cells in vitro.

View Article: PubMed Central - PubMed

Affiliation: San Raffaele Telethon Institute for Gene Therapy (HSR-TIGET), 20132 Milan, Italy.

ABSTRACT
A large proportion of Wiskott-Aldrich syndrome (WAS) patients develop autoimmunity and allergy. CD4(+)CD25(+)FOXP3(+) natural regulatory T (nTreg) cells play a key role in peripheral tolerance to prevent immune responses to self-antigens and allergens. Therefore, we investigated the effect of WAS protein (WASP) deficiency on the distribution and suppressor function of nTreg cells. In WAS(-/-) mice, the steady-state distribution and phenotype of nTreg cells in the thymus and spleen were normal. However, WAS(-/-) nTreg cells engrafted poorly in immunized mice, indicating perturbed homeostasis. Moreover, WAS(-/-) nTreg cells failed to proliferate and to produce transforming growth factor beta upon T cell receptor (TCR)/CD28 triggering. WASP-dependent F-actin polarization to the site of TCR triggering might not be involved in WAS(-/-) nTreg cell defects because this process was also inefficient in wild-type (WT) nTreg cells. Compared with WT nTreg cells, WAS(-/-) nTreg cells showed reduced in vitro suppressor activity on both WT and WAS(-/-) effector T cells. Similarly, peripheral nTreg cells were present at normal levels in WAS patients but failed to suppress proliferation of autologous and allogeneic CD4(+) effector T cells in vitro. Thus, WASP appears to play an important role in the activation and suppressor function of nTreg cells, and a dysfunction or incorrect localization of nTreg cells may contribute to the development of autoimmunity in WAS patients.

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Cell count and immunophenotype of nTreg cells in the spleens of WAS−/− mice. (a) Immunophenotype of CD4+ splenocytes from representative WT and WAS−/− mice. Numbers indicate the percentages and MFI of CD25+ cells. (b) Percentage, absolute count, and MFI of CD25+ cells among CD4+ splenocytes. Mean ± SD of 13 mice per group is shown. *, P < 0.05, Student's t test. (c) Foxp3 and CD25 expression in CD4+ splenocytes. Numbers indicate the percentage of cells in the respective region. (d) Absolute count of the indicated splenocyte populations. Mean ± SD of 13 mice per group is shown. *, P < 0.05, Student's t test. (e) Immunophenotype of nTreg cells from WT and WAS−/− mice. Expression of CD25 is shown together with the expression of CTLA-4, GITR, CD69, CD62L, and CD45RB. Negative control staining resulted in signal below the value of 10. Numbers indicate the percentages of cells in the respective regions. Data are representative of six to eight mice per group analyzed in two independent experiments.
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fig3: Cell count and immunophenotype of nTreg cells in the spleens of WAS−/− mice. (a) Immunophenotype of CD4+ splenocytes from representative WT and WAS−/− mice. Numbers indicate the percentages and MFI of CD25+ cells. (b) Percentage, absolute count, and MFI of CD25+ cells among CD4+ splenocytes. Mean ± SD of 13 mice per group is shown. *, P < 0.05, Student's t test. (c) Foxp3 and CD25 expression in CD4+ splenocytes. Numbers indicate the percentage of cells in the respective region. (d) Absolute count of the indicated splenocyte populations. Mean ± SD of 13 mice per group is shown. *, P < 0.05, Student's t test. (e) Immunophenotype of nTreg cells from WT and WAS−/− mice. Expression of CD25 is shown together with the expression of CTLA-4, GITR, CD69, CD62L, and CD45RB. Negative control staining resulted in signal below the value of 10. Numbers indicate the percentages of cells in the respective regions. Data are representative of six to eight mice per group analyzed in two independent experiments.

Mentions: We next investigated if WASP deficiency may influence the steady-state distribution of nTreg cells into the spleen. The overall splenocyte count was comparable in WT and WAS−/− mice (not depicted). Normal percentages and numbers of CD4+CD25+ T cells were found in the spleens of WAS−/− mice, although the expression of CD25 was reduced as compared with WT mice (Fig. 3, a and b). As in the thymus, the absolute count of CD4+CD25−Foxp3+ T cells increased in the spleens of WAS−/− mice. Conversely, the numbers of splenic CD4+CD25+Foxp3+ nTreg cells were comparable to those of normal mice, whereas an increased number of splenic CD4+CD25+Foxp3− T cells was observed (Fig. 3, c and d). Expression of the nTreg cell markers CTLA-4 and GITR on CD4+CD25+ splenic T cells was in the normal range, indicating that WAS−/− nTreg cells have a normal phenotype (Fig. 3 e). WAS−/− CD4+CD25+ T cells also expressed normal levels of the activation markers CD69, CD62L, and CD45RB (Fig. 3 e). These data indicate that splenic nTreg cells are present in WAS−/− mice in a similar amount to those present in WT mice, albeit CD25 expression is reduced.


WASP regulates suppressor activity of human and murine CD4(+)CD25(+)FOXP3(+) natural regulatory T cells.

Marangoni F, Trifari S, Scaramuzza S, Panaroni C, Martino S, Notarangelo LD, Baz Z, Metin A, Cattaneo F, Villa A, Aiuti A, Battaglia M, Roncarolo MG, Dupré L - J. Exp. Med. (2007)

Cell count and immunophenotype of nTreg cells in the spleens of WAS−/− mice. (a) Immunophenotype of CD4+ splenocytes from representative WT and WAS−/− mice. Numbers indicate the percentages and MFI of CD25+ cells. (b) Percentage, absolute count, and MFI of CD25+ cells among CD4+ splenocytes. Mean ± SD of 13 mice per group is shown. *, P < 0.05, Student's t test. (c) Foxp3 and CD25 expression in CD4+ splenocytes. Numbers indicate the percentage of cells in the respective region. (d) Absolute count of the indicated splenocyte populations. Mean ± SD of 13 mice per group is shown. *, P < 0.05, Student's t test. (e) Immunophenotype of nTreg cells from WT and WAS−/− mice. Expression of CD25 is shown together with the expression of CTLA-4, GITR, CD69, CD62L, and CD45RB. Negative control staining resulted in signal below the value of 10. Numbers indicate the percentages of cells in the respective regions. Data are representative of six to eight mice per group analyzed in two independent experiments.
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Related In: Results  -  Collection

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fig3: Cell count and immunophenotype of nTreg cells in the spleens of WAS−/− mice. (a) Immunophenotype of CD4+ splenocytes from representative WT and WAS−/− mice. Numbers indicate the percentages and MFI of CD25+ cells. (b) Percentage, absolute count, and MFI of CD25+ cells among CD4+ splenocytes. Mean ± SD of 13 mice per group is shown. *, P < 0.05, Student's t test. (c) Foxp3 and CD25 expression in CD4+ splenocytes. Numbers indicate the percentage of cells in the respective region. (d) Absolute count of the indicated splenocyte populations. Mean ± SD of 13 mice per group is shown. *, P < 0.05, Student's t test. (e) Immunophenotype of nTreg cells from WT and WAS−/− mice. Expression of CD25 is shown together with the expression of CTLA-4, GITR, CD69, CD62L, and CD45RB. Negative control staining resulted in signal below the value of 10. Numbers indicate the percentages of cells in the respective regions. Data are representative of six to eight mice per group analyzed in two independent experiments.
Mentions: We next investigated if WASP deficiency may influence the steady-state distribution of nTreg cells into the spleen. The overall splenocyte count was comparable in WT and WAS−/− mice (not depicted). Normal percentages and numbers of CD4+CD25+ T cells were found in the spleens of WAS−/− mice, although the expression of CD25 was reduced as compared with WT mice (Fig. 3, a and b). As in the thymus, the absolute count of CD4+CD25−Foxp3+ T cells increased in the spleens of WAS−/− mice. Conversely, the numbers of splenic CD4+CD25+Foxp3+ nTreg cells were comparable to those of normal mice, whereas an increased number of splenic CD4+CD25+Foxp3− T cells was observed (Fig. 3, c and d). Expression of the nTreg cell markers CTLA-4 and GITR on CD4+CD25+ splenic T cells was in the normal range, indicating that WAS−/− nTreg cells have a normal phenotype (Fig. 3 e). WAS−/− CD4+CD25+ T cells also expressed normal levels of the activation markers CD69, CD62L, and CD45RB (Fig. 3 e). These data indicate that splenic nTreg cells are present in WAS−/− mice in a similar amount to those present in WT mice, albeit CD25 expression is reduced.

Bottom Line: Moreover, WAS(-/-) nTreg cells failed to proliferate and to produce transforming growth factor beta upon T cell receptor (TCR)/CD28 triggering.Compared with WT nTreg cells, WAS(-/-) nTreg cells showed reduced in vitro suppressor activity on both WT and WAS(-/-) effector T cells.Similarly, peripheral nTreg cells were present at normal levels in WAS patients but failed to suppress proliferation of autologous and allogeneic CD4(+) effector T cells in vitro.

View Article: PubMed Central - PubMed

Affiliation: San Raffaele Telethon Institute for Gene Therapy (HSR-TIGET), 20132 Milan, Italy.

ABSTRACT
A large proportion of Wiskott-Aldrich syndrome (WAS) patients develop autoimmunity and allergy. CD4(+)CD25(+)FOXP3(+) natural regulatory T (nTreg) cells play a key role in peripheral tolerance to prevent immune responses to self-antigens and allergens. Therefore, we investigated the effect of WAS protein (WASP) deficiency on the distribution and suppressor function of nTreg cells. In WAS(-/-) mice, the steady-state distribution and phenotype of nTreg cells in the thymus and spleen were normal. However, WAS(-/-) nTreg cells engrafted poorly in immunized mice, indicating perturbed homeostasis. Moreover, WAS(-/-) nTreg cells failed to proliferate and to produce transforming growth factor beta upon T cell receptor (TCR)/CD28 triggering. WASP-dependent F-actin polarization to the site of TCR triggering might not be involved in WAS(-/-) nTreg cell defects because this process was also inefficient in wild-type (WT) nTreg cells. Compared with WT nTreg cells, WAS(-/-) nTreg cells showed reduced in vitro suppressor activity on both WT and WAS(-/-) effector T cells. Similarly, peripheral nTreg cells were present at normal levels in WAS patients but failed to suppress proliferation of autologous and allogeneic CD4(+) effector T cells in vitro. Thus, WASP appears to play an important role in the activation and suppressor function of nTreg cells, and a dysfunction or incorrect localization of nTreg cells may contribute to the development of autoimmunity in WAS patients.

Show MeSH
Related in: MedlinePlus