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Allelic exclusion of the T cell receptor beta locus requires the SH2 domain-containing leukocyte protein (SLP)-76 adaptor protein.

Aifantis I, Pivniouk VI, Gärtner F, Feinberg J, Swat W, Alt FW, von Boehmer H, Geha RS - J. Exp. Med. (1999)

Bottom Line: The adaptor protein SH2 domain-containing leukocyte protein (SLP)-76 has been shown to play a crucial role in thymic development, because thymocytes of SLP-76(-/-) mice are arrested at the CD25(+)CD44(-) DN stage.Here we show that SLP-76(-/-) DN thymocytes express the pre-TCR on their surfaces and that introduction of a TCR-alpha/beta transgene into the SLP-76(-/-) background fails to cause expansion of DN thymocytes or developmental progression to the DP stage.Moreover, analysis of TCR-beta rearrangement in SLP-76(-/-) TCR-transgenic mice or in single CD25(+)CD44(-) DN cells from SLP-76(-/-) mice indicates an essential role of SLP-76 in TCR-beta allelic exclusion.

View Article: PubMed Central - PubMed

Affiliation: Institut National de la Santé et Recherche Medicale (INSERM) U373, Hôpital Necker Enfants-Malades, Paris cedex 15, France.

ABSTRACT
Signaling via the pre-T cell receptor (TCR) is required for the proliferative expansion and maturation of CD4(-)CD8(-) double-negative (DN) thymocytes into CD4(+)CD8(+) double-positive (DP) cells and for TCR-beta allelic exclusion. The adaptor protein SH2 domain-containing leukocyte protein (SLP)-76 has been shown to play a crucial role in thymic development, because thymocytes of SLP-76(-/-) mice are arrested at the CD25(+)CD44(-) DN stage. Here we show that SLP-76(-/-) DN thymocytes express the pre-TCR on their surfaces and that introduction of a TCR-alpha/beta transgene into the SLP-76(-/-) background fails to cause expansion of DN thymocytes or developmental progression to the DP stage. Moreover, analysis of TCR-beta rearrangement in SLP-76(-/-) TCR-transgenic mice or in single CD25(+)CD44(-) DN cells from SLP-76(-/-) mice indicates an essential role of SLP-76 in TCR-beta allelic exclusion.

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Intracellular TCR-β expression in CD4−CD8− DN cells from WT (B6), pTα−/−, and SLP-76−/− mice. DN cells were surface stained for CD25 and subsequently cytoplasmically labeled with TCR-β antibodies. Results are representative of three mice in each group.
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Figure 3: Intracellular TCR-β expression in CD4−CD8− DN cells from WT (B6), pTα−/−, and SLP-76−/− mice. DN cells were surface stained for CD25 and subsequently cytoplasmically labeled with TCR-β antibodies. Results are representative of three mice in each group.

Mentions: We next examined intracellular TCR-β protein expression in SLP-76−/− thymocytes. Fig. 3 shows that SLP-76–deficient CD25+ thymocytes expressed lower levels of intracellular TCR-β protein than WT CD25+ thymocytes (Fig. 3). Decreased levels of expression of intracellular TCR-β protein were also observed in CD25+ thymocytes from pTα−/− mice, which are also blocked at the CD25+CD44− DN stage 2. The CD25−TCR-β+ cells in SLP-76−/− mice may represent γ/δ cells that express cytoplasmic TCR-β chain, as has been shown recently in pTα−/− mice 32. These results suggest that SLP-76 is not required for assembly and surface expression of TCR-β chains. However, it is required for the generation of CD25+ DN cells that express high levels of TCR-β protein intracellularly.


Allelic exclusion of the T cell receptor beta locus requires the SH2 domain-containing leukocyte protein (SLP)-76 adaptor protein.

Aifantis I, Pivniouk VI, Gärtner F, Feinberg J, Swat W, Alt FW, von Boehmer H, Geha RS - J. Exp. Med. (1999)

Intracellular TCR-β expression in CD4−CD8− DN cells from WT (B6), pTα−/−, and SLP-76−/− mice. DN cells were surface stained for CD25 and subsequently cytoplasmically labeled with TCR-β antibodies. Results are representative of three mice in each group.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2195661&req=5

Figure 3: Intracellular TCR-β expression in CD4−CD8− DN cells from WT (B6), pTα−/−, and SLP-76−/− mice. DN cells were surface stained for CD25 and subsequently cytoplasmically labeled with TCR-β antibodies. Results are representative of three mice in each group.
Mentions: We next examined intracellular TCR-β protein expression in SLP-76−/− thymocytes. Fig. 3 shows that SLP-76–deficient CD25+ thymocytes expressed lower levels of intracellular TCR-β protein than WT CD25+ thymocytes (Fig. 3). Decreased levels of expression of intracellular TCR-β protein were also observed in CD25+ thymocytes from pTα−/− mice, which are also blocked at the CD25+CD44− DN stage 2. The CD25−TCR-β+ cells in SLP-76−/− mice may represent γ/δ cells that express cytoplasmic TCR-β chain, as has been shown recently in pTα−/− mice 32. These results suggest that SLP-76 is not required for assembly and surface expression of TCR-β chains. However, it is required for the generation of CD25+ DN cells that express high levels of TCR-β protein intracellularly.

Bottom Line: The adaptor protein SH2 domain-containing leukocyte protein (SLP)-76 has been shown to play a crucial role in thymic development, because thymocytes of SLP-76(-/-) mice are arrested at the CD25(+)CD44(-) DN stage.Here we show that SLP-76(-/-) DN thymocytes express the pre-TCR on their surfaces and that introduction of a TCR-alpha/beta transgene into the SLP-76(-/-) background fails to cause expansion of DN thymocytes or developmental progression to the DP stage.Moreover, analysis of TCR-beta rearrangement in SLP-76(-/-) TCR-transgenic mice or in single CD25(+)CD44(-) DN cells from SLP-76(-/-) mice indicates an essential role of SLP-76 in TCR-beta allelic exclusion.

View Article: PubMed Central - PubMed

Affiliation: Institut National de la Santé et Recherche Medicale (INSERM) U373, Hôpital Necker Enfants-Malades, Paris cedex 15, France.

ABSTRACT
Signaling via the pre-T cell receptor (TCR) is required for the proliferative expansion and maturation of CD4(-)CD8(-) double-negative (DN) thymocytes into CD4(+)CD8(+) double-positive (DP) cells and for TCR-beta allelic exclusion. The adaptor protein SH2 domain-containing leukocyte protein (SLP)-76 has been shown to play a crucial role in thymic development, because thymocytes of SLP-76(-/-) mice are arrested at the CD25(+)CD44(-) DN stage. Here we show that SLP-76(-/-) DN thymocytes express the pre-TCR on their surfaces and that introduction of a TCR-alpha/beta transgene into the SLP-76(-/-) background fails to cause expansion of DN thymocytes or developmental progression to the DP stage. Moreover, analysis of TCR-beta rearrangement in SLP-76(-/-) TCR-transgenic mice or in single CD25(+)CD44(-) DN cells from SLP-76(-/-) mice indicates an essential role of SLP-76 in TCR-beta allelic exclusion.

Show MeSH
Related in: MedlinePlus