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The developmentally regulated expression of Twisted gastrulation reveals a role for bone morphogenetic proteins in the control of T cell development.

Graf D, Nethisinghe S, Palmer DB, Fisher AG, Merkenschlager M - J. Exp. Med. (2002)

Bottom Line: The evolutionarily conserved, secreted protein Twisted gastrulation (Tsg) modulates morphogenetic effects of decapentaplegic (dpp) and its orthologs, the bone morphogenetic proteins 2 and 4 (BMP2/4), in early Drosophila and vertebrate embryos.We have uncovered a role for Tsg at a much later stage of mammalian development, during T cell differentiation in the thymus.BMP4 is expressed by thymic stroma and inhibits the proliferation of CD4(-)CD8(-) double-negative (DN) thymocytes and their differentiation to the CD4(+)CD8(+) double-positive (DP) stage in vitro.

View Article: PubMed Central - PubMed

Affiliation: Lymphocyte Development Group, Medical Research Council Clinical Sciences Centre, Imperial College of Medicine, London W12 0NN, United Kingdom.

ABSTRACT
The evolutionarily conserved, secreted protein Twisted gastrulation (Tsg) modulates morphogenetic effects of decapentaplegic (dpp) and its orthologs, the bone morphogenetic proteins 2 and 4 (BMP2/4), in early Drosophila and vertebrate embryos. We have uncovered a role for Tsg at a much later stage of mammalian development, during T cell differentiation in the thymus. BMP4 is expressed by thymic stroma and inhibits the proliferation of CD4(-)CD8(-) double-negative (DN) thymocytes and their differentiation to the CD4(+)CD8(+) double-positive (DP) stage in vitro. Tsg is expressed by thymocytes and up-regulated after T cell receptor signaling at two developmental checkpoints, the transition from the DN to the DP and from the DP to the CD4(+) or CD8(+) single-positive stage. Tsg can synergize with the BMP inhibitor chordin to block the BMP4-mediated inhibition of thymocyte proliferation and differentiation. These data suggest that the developmentally regulated expression of Tsg may allow thymocytes to temporarily withdraw from inhibitory BMP signals.

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Tsg synergizes with chordin to block the effects of exogenous BMP4 on thymocyte developmental progression. (a) Top panel; Rag1o/o organ cultures were treated with the anti-CD3ε antibody 2C11 for 3 d (1 μg/ml) with the addition of BMP4 (100 ng/ml), chordin (2 μg/ml), and/or Tsg (1 μg/ml). Thymocytes were analyzed as in Fig. 3. Note the restoration of DP thymocyte development by the combination of chordin and Tsg. Bottom panel; suspension cultures of wild-type E15.5 thymi cultured overnight with the same additions as in top panel. (b) Suspension cultures of wild-type E15.5 thymi were cultured overnight and analyzed as in a. (c) E15.5 thymus suspensions were treated with BMP4 (100 ng/ml, left diagonal pattern), chordin (2 μg/ml, right diagonal pattern), or BMP4 plus chordin (cross-hatched) with or without Tsg (0.03 to 3,000 ng/ml) and analyzed as in Fig. 3. The percentage of DP thymocytes generated after 24 h is given (mean ± SD, n = 4).
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fig5: Tsg synergizes with chordin to block the effects of exogenous BMP4 on thymocyte developmental progression. (a) Top panel; Rag1o/o organ cultures were treated with the anti-CD3ε antibody 2C11 for 3 d (1 μg/ml) with the addition of BMP4 (100 ng/ml), chordin (2 μg/ml), and/or Tsg (1 μg/ml). Thymocytes were analyzed as in Fig. 3. Note the restoration of DP thymocyte development by the combination of chordin and Tsg. Bottom panel; suspension cultures of wild-type E15.5 thymi cultured overnight with the same additions as in top panel. (b) Suspension cultures of wild-type E15.5 thymi were cultured overnight and analyzed as in a. (c) E15.5 thymus suspensions were treated with BMP4 (100 ng/ml, left diagonal pattern), chordin (2 μg/ml, right diagonal pattern), or BMP4 plus chordin (cross-hatched) with or without Tsg (0.03 to 3,000 ng/ml) and analyzed as in Fig. 3. The percentage of DP thymocytes generated after 24 h is given (mean ± SD, n = 4).

Mentions: As described in Fig. 3 c, BMP4 inhibited the developmental progression from the DN to DP stage in Rag1o/o organ cultures treated with CD3ε. In the presence of BMP4 (100 ng/ml) the BMP inhibitor chordin restored the generation of DP cells only partially, even when added in threefold molar excess (2 μg/ml). We used this system to assess the functional effects of Tsg. On its own (not shown) or in combination with BMP4 (100 ng/ml), Tsg (1 μg/ml, ∼40 nM) had little effect. In combination with chordin, however, TSG was able to reverse the inhibitory effects of BMP4 on the generation of DP thymocytes in anti-CD3ε–treated Rag1o/o organ cultures (Fig. 5 a, top panel). Rescue of DP differentiation from BMP4-mediated inhibition by chordin and Tsg was also seen in trypsinized suspension cultures of E15.5 thymi. Again, chordin antagonized BMP4 only partially, Tsg on its own was without effect, but the combination of chordin and Tsg rescued DP thymocyte development effectively (Fig. 5 a, bottom panel). A representative experiment is shown in Fig. 5 b.


The developmentally regulated expression of Twisted gastrulation reveals a role for bone morphogenetic proteins in the control of T cell development.

Graf D, Nethisinghe S, Palmer DB, Fisher AG, Merkenschlager M - J. Exp. Med. (2002)

Tsg synergizes with chordin to block the effects of exogenous BMP4 on thymocyte developmental progression. (a) Top panel; Rag1o/o organ cultures were treated with the anti-CD3ε antibody 2C11 for 3 d (1 μg/ml) with the addition of BMP4 (100 ng/ml), chordin (2 μg/ml), and/or Tsg (1 μg/ml). Thymocytes were analyzed as in Fig. 3. Note the restoration of DP thymocyte development by the combination of chordin and Tsg. Bottom panel; suspension cultures of wild-type E15.5 thymi cultured overnight with the same additions as in top panel. (b) Suspension cultures of wild-type E15.5 thymi were cultured overnight and analyzed as in a. (c) E15.5 thymus suspensions were treated with BMP4 (100 ng/ml, left diagonal pattern), chordin (2 μg/ml, right diagonal pattern), or BMP4 plus chordin (cross-hatched) with or without Tsg (0.03 to 3,000 ng/ml) and analyzed as in Fig. 3. The percentage of DP thymocytes generated after 24 h is given (mean ± SD, n = 4).
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Related In: Results  -  Collection

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fig5: Tsg synergizes with chordin to block the effects of exogenous BMP4 on thymocyte developmental progression. (a) Top panel; Rag1o/o organ cultures were treated with the anti-CD3ε antibody 2C11 for 3 d (1 μg/ml) with the addition of BMP4 (100 ng/ml), chordin (2 μg/ml), and/or Tsg (1 μg/ml). Thymocytes were analyzed as in Fig. 3. Note the restoration of DP thymocyte development by the combination of chordin and Tsg. Bottom panel; suspension cultures of wild-type E15.5 thymi cultured overnight with the same additions as in top panel. (b) Suspension cultures of wild-type E15.5 thymi were cultured overnight and analyzed as in a. (c) E15.5 thymus suspensions were treated with BMP4 (100 ng/ml, left diagonal pattern), chordin (2 μg/ml, right diagonal pattern), or BMP4 plus chordin (cross-hatched) with or without Tsg (0.03 to 3,000 ng/ml) and analyzed as in Fig. 3. The percentage of DP thymocytes generated after 24 h is given (mean ± SD, n = 4).
Mentions: As described in Fig. 3 c, BMP4 inhibited the developmental progression from the DN to DP stage in Rag1o/o organ cultures treated with CD3ε. In the presence of BMP4 (100 ng/ml) the BMP inhibitor chordin restored the generation of DP cells only partially, even when added in threefold molar excess (2 μg/ml). We used this system to assess the functional effects of Tsg. On its own (not shown) or in combination with BMP4 (100 ng/ml), Tsg (1 μg/ml, ∼40 nM) had little effect. In combination with chordin, however, TSG was able to reverse the inhibitory effects of BMP4 on the generation of DP thymocytes in anti-CD3ε–treated Rag1o/o organ cultures (Fig. 5 a, top panel). Rescue of DP differentiation from BMP4-mediated inhibition by chordin and Tsg was also seen in trypsinized suspension cultures of E15.5 thymi. Again, chordin antagonized BMP4 only partially, Tsg on its own was without effect, but the combination of chordin and Tsg rescued DP thymocyte development effectively (Fig. 5 a, bottom panel). A representative experiment is shown in Fig. 5 b.

Bottom Line: The evolutionarily conserved, secreted protein Twisted gastrulation (Tsg) modulates morphogenetic effects of decapentaplegic (dpp) and its orthologs, the bone morphogenetic proteins 2 and 4 (BMP2/4), in early Drosophila and vertebrate embryos.We have uncovered a role for Tsg at a much later stage of mammalian development, during T cell differentiation in the thymus.BMP4 is expressed by thymic stroma and inhibits the proliferation of CD4(-)CD8(-) double-negative (DN) thymocytes and their differentiation to the CD4(+)CD8(+) double-positive (DP) stage in vitro.

View Article: PubMed Central - PubMed

Affiliation: Lymphocyte Development Group, Medical Research Council Clinical Sciences Centre, Imperial College of Medicine, London W12 0NN, United Kingdom.

ABSTRACT
The evolutionarily conserved, secreted protein Twisted gastrulation (Tsg) modulates morphogenetic effects of decapentaplegic (dpp) and its orthologs, the bone morphogenetic proteins 2 and 4 (BMP2/4), in early Drosophila and vertebrate embryos. We have uncovered a role for Tsg at a much later stage of mammalian development, during T cell differentiation in the thymus. BMP4 is expressed by thymic stroma and inhibits the proliferation of CD4(-)CD8(-) double-negative (DN) thymocytes and their differentiation to the CD4(+)CD8(+) double-positive (DP) stage in vitro. Tsg is expressed by thymocytes and up-regulated after T cell receptor signaling at two developmental checkpoints, the transition from the DN to the DP and from the DP to the CD4(+) or CD8(+) single-positive stage. Tsg can synergize with the BMP inhibitor chordin to block the BMP4-mediated inhibition of thymocyte proliferation and differentiation. These data suggest that the developmentally regulated expression of Tsg may allow thymocytes to temporarily withdraw from inhibitory BMP signals.

Show MeSH
Related in: MedlinePlus