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T cell receptor-instructed alphabeta versus gammadelta lineage commitment revealed by single-cell analysis.

Kreslavsky T, Garbe AI, Krueger A, von Boehmer H - J. Exp. Med. (2008)

Bottom Line: Two models have been proposed to explain these results.The second model suggests that commitment occurs before TCR expression and that TCR signaling merely confirms the lineage choice.By tracing the fate of single T cell precursors, this study shows that there is no commitment to either the alphabeta or gammadelta lineage before TCR expression and that modulation of TCR signaling in progeny of a single TCR-expressing cell changes lineage commitment.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Lymphocyte Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA.

ABSTRACT
alphabeta and gammadelta T cell lineages develop in the thymus from a common precursor. It is unclear at which stage of development commitment to these lineages takes place and in which way T cell receptor signaling contributes to the process. Recently, it was demonstrated that strong TCR signals favor gammadelta lineage development, whereas weaker TCR signals promote alphabeta lineage fate. Two models have been proposed to explain these results. The first model suggests that commitment occurs after TCR expression and TCR signaling directly instructs lymphocytes to adopt one or the other lineage fate. The second model suggests that commitment occurs before TCR expression and that TCR signaling merely confirms the lineage choice. By tracing the fate of single T cell precursors, this study shows that there is no commitment to either the alphabeta or gammadelta lineage before TCR expression and that modulation of TCR signaling in progeny of a single TCR-expressing cell changes lineage commitment.

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γδ Lineage cells generated in culture home to the IEL compartment. (A and B) TCRγδ+CD25+ thymocytes form Thy1.1 BALB/c mice were sorted and co-cultured with OP9-DL1 in wells coated with anti-TCRγδ antibodies. On day 4, cells were transferred to a fresh OP9-DL1 monolayer in uncoated wells. On day 10, CD45+CD4−CD8− TCRγδ+ cells were sorted from the cultures and 105 cells were transferred intravenously into nude mice (Thy1.2). On day 14 after transfer, recipients were killed and the presence of donor-derived (Thy1.1+) cells among CD45+ cells in LNs, spleen, Peyer's patches (PP), and among IELs was analyzed (A). Expression of TCRγδ and CD4 on the donor-derived IELs is shown (B). (C) 106 of CD4+ splenocytes from Thy1.1 BALB/c mice were transferred intravenously into nude mice. No donor-derived IELs were found 14 d after transfer.
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fig3: γδ Lineage cells generated in culture home to the IEL compartment. (A and B) TCRγδ+CD25+ thymocytes form Thy1.1 BALB/c mice were sorted and co-cultured with OP9-DL1 in wells coated with anti-TCRγδ antibodies. On day 4, cells were transferred to a fresh OP9-DL1 monolayer in uncoated wells. On day 10, CD45+CD4−CD8− TCRγδ+ cells were sorted from the cultures and 105 cells were transferred intravenously into nude mice (Thy1.2). On day 14 after transfer, recipients were killed and the presence of donor-derived (Thy1.1+) cells among CD45+ cells in LNs, spleen, Peyer's patches (PP), and among IELs was analyzed (A). Expression of TCRγδ and CD4 on the donor-derived IELs is shown (B). (C) 106 of CD4+ splenocytes from Thy1.1 BALB/c mice were transferred intravenously into nude mice. No donor-derived IELs were found 14 d after transfer.

Mentions: To further test how well γδ lineage cell development is recapitulated in the cell culture system, we performed adoptive transfer experiments with γδ cells generated in culture. To this end, 105 γδ lineage cells generated from Thy1.1 TCRγδ+ DN3 thymocytes in the presence of TCRγδ antibody were transferred into nude mice (Thy1.2), and their tissue distribution was analyzed 2 wk later. Few, if any, donor-derived cells were found in the spleen, LNs, and Peyer's patches of the recipient (Fig. 3 A). However, Thy1.1 cells were readily detected in the intraepithelial lymphocyte (IEL) compartment of the small intestine (Fig. 3 A). These cells maintained TCRγδ expression and the CD4−CD8− phenotype (Fig. 3 B and not depicted). As many of the γδ lineage cells in the gut are Thy1 negative, it is possible that the detected Thy1.1+ cells represent only a fraction of donor-derived cells. The epithelium of the small intestine is one of the major physiological locations for γδ lineage cells, where they comprise about half of the lymphocytes (21). Migration to the IEL is known to depend on specific chemoattracting signals (22). In accordance with this notion, no donor-derived cells were found among IELs when 106 splenic CD4 cells were used for the transfer Fig. 3 C. It is important to note that endogenous IELs are present in the intestinal epithelium of nude mice, albeit in reduced numbers. Approximately 35% of them are TCRγδ+ (not depicted). Thus, transferred cells are likely to compete for appropriate niches with endogenous γδ lineage IELs. The nude recipient mice contained relatively large numbers of Thy1.2-positive cells in IELs and PP, which may represent thymus-independent T cells or their precursors.


T cell receptor-instructed alphabeta versus gammadelta lineage commitment revealed by single-cell analysis.

Kreslavsky T, Garbe AI, Krueger A, von Boehmer H - J. Exp. Med. (2008)

γδ Lineage cells generated in culture home to the IEL compartment. (A and B) TCRγδ+CD25+ thymocytes form Thy1.1 BALB/c mice were sorted and co-cultured with OP9-DL1 in wells coated with anti-TCRγδ antibodies. On day 4, cells were transferred to a fresh OP9-DL1 monolayer in uncoated wells. On day 10, CD45+CD4−CD8− TCRγδ+ cells were sorted from the cultures and 105 cells were transferred intravenously into nude mice (Thy1.2). On day 14 after transfer, recipients were killed and the presence of donor-derived (Thy1.1+) cells among CD45+ cells in LNs, spleen, Peyer's patches (PP), and among IELs was analyzed (A). Expression of TCRγδ and CD4 on the donor-derived IELs is shown (B). (C) 106 of CD4+ splenocytes from Thy1.1 BALB/c mice were transferred intravenously into nude mice. No donor-derived IELs were found 14 d after transfer.
© Copyright Policy
Related In: Results  -  Collection

License 1 - License 2
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getmorefigures.php?uid=PMC2373848&req=5

fig3: γδ Lineage cells generated in culture home to the IEL compartment. (A and B) TCRγδ+CD25+ thymocytes form Thy1.1 BALB/c mice were sorted and co-cultured with OP9-DL1 in wells coated with anti-TCRγδ antibodies. On day 4, cells were transferred to a fresh OP9-DL1 monolayer in uncoated wells. On day 10, CD45+CD4−CD8− TCRγδ+ cells were sorted from the cultures and 105 cells were transferred intravenously into nude mice (Thy1.2). On day 14 after transfer, recipients were killed and the presence of donor-derived (Thy1.1+) cells among CD45+ cells in LNs, spleen, Peyer's patches (PP), and among IELs was analyzed (A). Expression of TCRγδ and CD4 on the donor-derived IELs is shown (B). (C) 106 of CD4+ splenocytes from Thy1.1 BALB/c mice were transferred intravenously into nude mice. No donor-derived IELs were found 14 d after transfer.
Mentions: To further test how well γδ lineage cell development is recapitulated in the cell culture system, we performed adoptive transfer experiments with γδ cells generated in culture. To this end, 105 γδ lineage cells generated from Thy1.1 TCRγδ+ DN3 thymocytes in the presence of TCRγδ antibody were transferred into nude mice (Thy1.2), and their tissue distribution was analyzed 2 wk later. Few, if any, donor-derived cells were found in the spleen, LNs, and Peyer's patches of the recipient (Fig. 3 A). However, Thy1.1 cells were readily detected in the intraepithelial lymphocyte (IEL) compartment of the small intestine (Fig. 3 A). These cells maintained TCRγδ expression and the CD4−CD8− phenotype (Fig. 3 B and not depicted). As many of the γδ lineage cells in the gut are Thy1 negative, it is possible that the detected Thy1.1+ cells represent only a fraction of donor-derived cells. The epithelium of the small intestine is one of the major physiological locations for γδ lineage cells, where they comprise about half of the lymphocytes (21). Migration to the IEL is known to depend on specific chemoattracting signals (22). In accordance with this notion, no donor-derived cells were found among IELs when 106 splenic CD4 cells were used for the transfer Fig. 3 C. It is important to note that endogenous IELs are present in the intestinal epithelium of nude mice, albeit in reduced numbers. Approximately 35% of them are TCRγδ+ (not depicted). Thus, transferred cells are likely to compete for appropriate niches with endogenous γδ lineage IELs. The nude recipient mice contained relatively large numbers of Thy1.2-positive cells in IELs and PP, which may represent thymus-independent T cells or their precursors.

Bottom Line: Two models have been proposed to explain these results.The second model suggests that commitment occurs before TCR expression and that TCR signaling merely confirms the lineage choice.By tracing the fate of single T cell precursors, this study shows that there is no commitment to either the alphabeta or gammadelta lineage before TCR expression and that modulation of TCR signaling in progeny of a single TCR-expressing cell changes lineage commitment.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Lymphocyte Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA.

ABSTRACT
alphabeta and gammadelta T cell lineages develop in the thymus from a common precursor. It is unclear at which stage of development commitment to these lineages takes place and in which way T cell receptor signaling contributes to the process. Recently, it was demonstrated that strong TCR signals favor gammadelta lineage development, whereas weaker TCR signals promote alphabeta lineage fate. Two models have been proposed to explain these results. The first model suggests that commitment occurs after TCR expression and TCR signaling directly instructs lymphocytes to adopt one or the other lineage fate. The second model suggests that commitment occurs before TCR expression and that TCR signaling merely confirms the lineage choice. By tracing the fate of single T cell precursors, this study shows that there is no commitment to either the alphabeta or gammadelta lineage before TCR expression and that modulation of TCR signaling in progeny of a single TCR-expressing cell changes lineage commitment.

Show MeSH