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Impact of the TCR signal on regulatory T cell homeostasis, function, and trafficking.

Kim JK, Klinger M, Benjamin J, Xiao Y, Erle DJ, Littman DR, Killeen N - PLoS ONE (2009)

Bottom Line: Using an Ox40-cre allele that is prominently expressed in Treg cells, and a conditional allele of the gene encoding p56(Lck), we have examined the importance of TCR signaling in Treg cells.Inactivation of p56(Lck) resulted in abnormal Treg homeostasis characterized by impaired turnover, preferential redistribution to the lymph nodes, loss of suppressive function, and striking changes in gene expression.Abnormal Treg cell homeostasis and function did not reflect the involvement of p56(Lck) in CD4 function because these effects were not observed when CD4 expression was inactivated by Ox40-cre.The results make clear multiple aspects of Treg cell homeostasis and phenotype that are dependent on a sustained capacity to signal through the TCR.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA, USA.

ABSTRACT
Signaling through the T cell antigen receptor (TCR) is important for the homeostasis of naïve and memory CD4(+) T cells. The significance of TCR signaling in regulatory T (Treg) cells has not been systematically addressed. Using an Ox40-cre allele that is prominently expressed in Treg cells, and a conditional allele of the gene encoding p56(Lck), we have examined the importance of TCR signaling in Treg cells. Inactivation of p56(Lck) resulted in abnormal Treg homeostasis characterized by impaired turnover, preferential redistribution to the lymph nodes, loss of suppressive function, and striking changes in gene expression. Abnormal Treg cell homeostasis and function did not reflect the involvement of p56(Lck) in CD4 function because these effects were not observed when CD4 expression was inactivated by Ox40-cre.The results make clear multiple aspects of Treg cell homeostasis and phenotype that are dependent on a sustained capacity to signal through the TCR.

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Related in: MedlinePlus

Gene expression in Lck-mutant regulatory T cells.A. The graphs show normalized log2 ratios of hybridization signals (Lck/Control) versus average hybridization intensity for all spots on the microarrays. Ratios corresponding to greater than 1.5-fold changes in spot intensity (dotted lines) are colored black instead of grey, and the numbers of these are indicated at the top and bottom right of the graphs. RNA was purified from flow-sorted Treg cells (CD4+CD25+) labeled differentially according to its origin (Lck mutant vs. control) and hybridized to microarrays spotted with 70-mer oligos from the MEEBO collection as described in Methods and Materials. B. Bivariate plot of Lck/Control spot ratios in memory versus regulatory T cells. Numbers of spots with vectors greater than 1.5 (colored black instead of grey) in the indicated parts of the four quadrants are shown. C. Venn diagram showing overlap between genes that are differentially expressed in control versus Lck memory and/or Treg cells and the Treg signature gene set identified by Hill et al. [40].
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pone-0006580-g006: Gene expression in Lck-mutant regulatory T cells.A. The graphs show normalized log2 ratios of hybridization signals (Lck/Control) versus average hybridization intensity for all spots on the microarrays. Ratios corresponding to greater than 1.5-fold changes in spot intensity (dotted lines) are colored black instead of grey, and the numbers of these are indicated at the top and bottom right of the graphs. RNA was purified from flow-sorted Treg cells (CD4+CD25+) labeled differentially according to its origin (Lck mutant vs. control) and hybridized to microarrays spotted with 70-mer oligos from the MEEBO collection as described in Methods and Materials. B. Bivariate plot of Lck/Control spot ratios in memory versus regulatory T cells. Numbers of spots with vectors greater than 1.5 (colored black instead of grey) in the indicated parts of the four quadrants are shown. C. Venn diagram showing overlap between genes that are differentially expressed in control versus Lck memory and/or Treg cells and the Treg signature gene set identified by Hill et al. [40].

Mentions: We identified a collection of genes that changed significantly in their expression in regulatory and/or memory T cells as a consequence of p56Lck deficiency (Figure 6A and B, Table S1). 20% of these genes increased in expression in both types of p56Lck-deficient T cells (Figure 6B top right quadrant). An even smaller proportion (13%) registered an increase in one or the other, but not both populations (Figure 6B). In marked contrast, the dominant consequence of the deficiency (in 67% of cases) was a reduction in expression in both types of T cell (Figure 6B bottom left quadrant). In general, therefore, the data showed that p56Lck, and thus the TCR signal, is more important for maintaining gene expression than for repressing it.


Impact of the TCR signal on regulatory T cell homeostasis, function, and trafficking.

Kim JK, Klinger M, Benjamin J, Xiao Y, Erle DJ, Littman DR, Killeen N - PLoS ONE (2009)

Gene expression in Lck-mutant regulatory T cells.A. The graphs show normalized log2 ratios of hybridization signals (Lck/Control) versus average hybridization intensity for all spots on the microarrays. Ratios corresponding to greater than 1.5-fold changes in spot intensity (dotted lines) are colored black instead of grey, and the numbers of these are indicated at the top and bottom right of the graphs. RNA was purified from flow-sorted Treg cells (CD4+CD25+) labeled differentially according to its origin (Lck mutant vs. control) and hybridized to microarrays spotted with 70-mer oligos from the MEEBO collection as described in Methods and Materials. B. Bivariate plot of Lck/Control spot ratios in memory versus regulatory T cells. Numbers of spots with vectors greater than 1.5 (colored black instead of grey) in the indicated parts of the four quadrants are shown. C. Venn diagram showing overlap between genes that are differentially expressed in control versus Lck memory and/or Treg cells and the Treg signature gene set identified by Hill et al. [40].
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2719063&req=5

pone-0006580-g006: Gene expression in Lck-mutant regulatory T cells.A. The graphs show normalized log2 ratios of hybridization signals (Lck/Control) versus average hybridization intensity for all spots on the microarrays. Ratios corresponding to greater than 1.5-fold changes in spot intensity (dotted lines) are colored black instead of grey, and the numbers of these are indicated at the top and bottom right of the graphs. RNA was purified from flow-sorted Treg cells (CD4+CD25+) labeled differentially according to its origin (Lck mutant vs. control) and hybridized to microarrays spotted with 70-mer oligos from the MEEBO collection as described in Methods and Materials. B. Bivariate plot of Lck/Control spot ratios in memory versus regulatory T cells. Numbers of spots with vectors greater than 1.5 (colored black instead of grey) in the indicated parts of the four quadrants are shown. C. Venn diagram showing overlap between genes that are differentially expressed in control versus Lck memory and/or Treg cells and the Treg signature gene set identified by Hill et al. [40].
Mentions: We identified a collection of genes that changed significantly in their expression in regulatory and/or memory T cells as a consequence of p56Lck deficiency (Figure 6A and B, Table S1). 20% of these genes increased in expression in both types of p56Lck-deficient T cells (Figure 6B top right quadrant). An even smaller proportion (13%) registered an increase in one or the other, but not both populations (Figure 6B). In marked contrast, the dominant consequence of the deficiency (in 67% of cases) was a reduction in expression in both types of T cell (Figure 6B bottom left quadrant). In general, therefore, the data showed that p56Lck, and thus the TCR signal, is more important for maintaining gene expression than for repressing it.

Bottom Line: Using an Ox40-cre allele that is prominently expressed in Treg cells, and a conditional allele of the gene encoding p56(Lck), we have examined the importance of TCR signaling in Treg cells.Inactivation of p56(Lck) resulted in abnormal Treg homeostasis characterized by impaired turnover, preferential redistribution to the lymph nodes, loss of suppressive function, and striking changes in gene expression.Abnormal Treg cell homeostasis and function did not reflect the involvement of p56(Lck) in CD4 function because these effects were not observed when CD4 expression was inactivated by Ox40-cre.The results make clear multiple aspects of Treg cell homeostasis and phenotype that are dependent on a sustained capacity to signal through the TCR.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA, USA.

ABSTRACT
Signaling through the T cell antigen receptor (TCR) is important for the homeostasis of naïve and memory CD4(+) T cells. The significance of TCR signaling in regulatory T (Treg) cells has not been systematically addressed. Using an Ox40-cre allele that is prominently expressed in Treg cells, and a conditional allele of the gene encoding p56(Lck), we have examined the importance of TCR signaling in Treg cells. Inactivation of p56(Lck) resulted in abnormal Treg homeostasis characterized by impaired turnover, preferential redistribution to the lymph nodes, loss of suppressive function, and striking changes in gene expression. Abnormal Treg cell homeostasis and function did not reflect the involvement of p56(Lck) in CD4 function because these effects were not observed when CD4 expression was inactivated by Ox40-cre.The results make clear multiple aspects of Treg cell homeostasis and phenotype that are dependent on a sustained capacity to signal through the TCR.

Show MeSH
Related in: MedlinePlus