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Inhibition of T cell and promotion of natural killer cell development by the dominant negative helix loop helix factor Id3.

Heemskerk MH, Blom B, Nolan G, Stegmann AP, Bakker AQ, Weijer K, Res PC, Spits H - J. Exp. Med. (1997)

Bottom Line: The natural dominant negative HLH factor Id3, which blocks transcriptional activity of a number of known bHLH factors, was expressed in CD34+ progenitor cells by retrovirus-mediated gene transfer.In contrast, development into NK cells in an FTOC is enhanced.Our results identify a molecular switch for lineage specification in early lymphoid precursors of humans.

View Article: PubMed Central - PubMed

Affiliation: Division of Immunology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.

ABSTRACT
Bipotential T/natural killer (NK) progenitor cells are present in the human thymus. Despite their bipotential capacity, these progenitors develop predominantly to T cells in the thymus. The mechanisms controlling this developmental choice are unknown. Here we present evidence that a member(s) of the family of basic helix loop helix (bHLH) transcription factors determines lineage specification of NK/T cell progenitors. The natural dominant negative HLH factor Id3, which blocks transcriptional activity of a number of known bHLH factors, was expressed in CD34+ progenitor cells by retrovirus-mediated gene transfer. Constitutive expression of Id3 completely blocks development of CD34+ cells into T cells in a fetal thymic organ culture (FTOC). In contrast, development into NK cells in an FTOC is enhanced. Thus, the activity of a bHLH transcription factor is necessary for T lineage differentiation of bipotential precursors, in the absence of which a default pathway leading to NK cell development is chosen. Our results identify a molecular switch for lineage specification in early lymphoid precursors of humans.

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Related in: MedlinePlus

Enforced expression of Id3 in  CD1a−CD34+ thymocytes blocks T cell  development and promotes NK development in an FTOC. CD1a−CD34+ thymocytes were isolated from a thymic fragment of a 6-mo-old child, transduced and  incubated in a FTOC for 4 wk at 104 cells/ lobe. Cell recoveries were 5 × 104 and 6 ×  104 cells/lobe for the Id3- and the control-transduced cells, respectively. Percentages of  GFP+ cells 2 d after transduction were 9% in  both samples. Percentages of GFP+ cells,  harvested from the FTOC, were 7.2% in  the control and 2.4% in the Id3-transduced  samples.
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Figure 4: Enforced expression of Id3 in CD1a−CD34+ thymocytes blocks T cell development and promotes NK development in an FTOC. CD1a−CD34+ thymocytes were isolated from a thymic fragment of a 6-mo-old child, transduced and incubated in a FTOC for 4 wk at 104 cells/ lobe. Cell recoveries were 5 × 104 and 6 × 104 cells/lobe for the Id3- and the control-transduced cells, respectively. Percentages of GFP+ cells 2 d after transduction were 9% in both samples. Percentages of GFP+ cells, harvested from the FTOC, were 7.2% in the control and 2.4% in the Id3-transduced samples.

Mentions: TCR-β rearrangements are initiated in the CD1a+ CD3−CD4−CD8−CD34+ cells (25, 26). Moreover, CD1a+ cells are unable to develop into NK cells (2). This suggests that upregulation of CD1a is correlated with T cell commitment. If this is correct and if overexpression of Id3 inhibits T cell commitment, we should expect that CD1a− CD34+ cells transduced with Id3 fail to develop into T cells in an FTOC. Purified CD1a−CD34+ cells were cultured with SCF and IL-7, transduced, and incubated in an FTOC for 3 wk. Fig. 4 demonstrates that the control-transduced cells developed normally. By contrast, the proportion of CD3+ cells that developed from Id3-transduced CD1a− CD34+ cells is strongly reduced, whereas the proportion of NK cells is dramatically increased. The absolute numbers of GFP+ NK cells in the Id3-transduced samples was 10-fold higher than in the GFP+ cells in the control-transduced samples. The inhibition of generation of CD3+ by Id3 is underscored by the almost complete absence of CD4+ and CD4+CD8+ in the cells expressing Id3-GFP. The CD8+ cells observed in these cultures are CD3−CD56+ cells. The Id3-IRES-GFP+CD3−CD56+ could be expanded with a feeder cell mixture and displayed cytolytic activity against K562 cells (results not shown).


Inhibition of T cell and promotion of natural killer cell development by the dominant negative helix loop helix factor Id3.

Heemskerk MH, Blom B, Nolan G, Stegmann AP, Bakker AQ, Weijer K, Res PC, Spits H - J. Exp. Med. (1997)

Enforced expression of Id3 in  CD1a−CD34+ thymocytes blocks T cell  development and promotes NK development in an FTOC. CD1a−CD34+ thymocytes were isolated from a thymic fragment of a 6-mo-old child, transduced and  incubated in a FTOC for 4 wk at 104 cells/ lobe. Cell recoveries were 5 × 104 and 6 ×  104 cells/lobe for the Id3- and the control-transduced cells, respectively. Percentages of  GFP+ cells 2 d after transduction were 9% in  both samples. Percentages of GFP+ cells,  harvested from the FTOC, were 7.2% in  the control and 2.4% in the Id3-transduced  samples.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2199115&req=5

Figure 4: Enforced expression of Id3 in CD1a−CD34+ thymocytes blocks T cell development and promotes NK development in an FTOC. CD1a−CD34+ thymocytes were isolated from a thymic fragment of a 6-mo-old child, transduced and incubated in a FTOC for 4 wk at 104 cells/ lobe. Cell recoveries were 5 × 104 and 6 × 104 cells/lobe for the Id3- and the control-transduced cells, respectively. Percentages of GFP+ cells 2 d after transduction were 9% in both samples. Percentages of GFP+ cells, harvested from the FTOC, were 7.2% in the control and 2.4% in the Id3-transduced samples.
Mentions: TCR-β rearrangements are initiated in the CD1a+ CD3−CD4−CD8−CD34+ cells (25, 26). Moreover, CD1a+ cells are unable to develop into NK cells (2). This suggests that upregulation of CD1a is correlated with T cell commitment. If this is correct and if overexpression of Id3 inhibits T cell commitment, we should expect that CD1a− CD34+ cells transduced with Id3 fail to develop into T cells in an FTOC. Purified CD1a−CD34+ cells were cultured with SCF and IL-7, transduced, and incubated in an FTOC for 3 wk. Fig. 4 demonstrates that the control-transduced cells developed normally. By contrast, the proportion of CD3+ cells that developed from Id3-transduced CD1a− CD34+ cells is strongly reduced, whereas the proportion of NK cells is dramatically increased. The absolute numbers of GFP+ NK cells in the Id3-transduced samples was 10-fold higher than in the GFP+ cells in the control-transduced samples. The inhibition of generation of CD3+ by Id3 is underscored by the almost complete absence of CD4+ and CD4+CD8+ in the cells expressing Id3-GFP. The CD8+ cells observed in these cultures are CD3−CD56+ cells. The Id3-IRES-GFP+CD3−CD56+ could be expanded with a feeder cell mixture and displayed cytolytic activity against K562 cells (results not shown).

Bottom Line: The natural dominant negative HLH factor Id3, which blocks transcriptional activity of a number of known bHLH factors, was expressed in CD34+ progenitor cells by retrovirus-mediated gene transfer.In contrast, development into NK cells in an FTOC is enhanced.Our results identify a molecular switch for lineage specification in early lymphoid precursors of humans.

View Article: PubMed Central - PubMed

Affiliation: Division of Immunology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.

ABSTRACT
Bipotential T/natural killer (NK) progenitor cells are present in the human thymus. Despite their bipotential capacity, these progenitors develop predominantly to T cells in the thymus. The mechanisms controlling this developmental choice are unknown. Here we present evidence that a member(s) of the family of basic helix loop helix (bHLH) transcription factors determines lineage specification of NK/T cell progenitors. The natural dominant negative HLH factor Id3, which blocks transcriptional activity of a number of known bHLH factors, was expressed in CD34+ progenitor cells by retrovirus-mediated gene transfer. Constitutive expression of Id3 completely blocks development of CD34+ cells into T cells in a fetal thymic organ culture (FTOC). In contrast, development into NK cells in an FTOC is enhanced. Thus, the activity of a bHLH transcription factor is necessary for T lineage differentiation of bipotential precursors, in the absence of which a default pathway leading to NK cell development is chosen. Our results identify a molecular switch for lineage specification in early lymphoid precursors of humans.

Show MeSH
Related in: MedlinePlus