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Inhibitory receptors bind ANGPTLs and support blood stem cells and leukaemia development.

Zheng J, Umikawa M, Cui C, Li J, Chen X, Zhang C, Huynh H, Hyunh H, Kang X, Silvany R, Wan X, Ye J, Cantó AP, Chen SH, Wang HY, Ward ES, Zhang CC - Nature (2012)

Bottom Line: Angiopoietin-like proteins (ANGPTLs), a family of seven secreted glycoproteins, are known to support the activity of haematopoietic stem cells (HSCs) in vitro and in vivo.ANGPTLs also have important roles in lipid metabolism, angiogenesis and inflammation, but were considered 'orphan ligands' because no receptors were identified.In mouse transplantation acute myeloid leukaemia models, a deficiency in intracellular signalling of PIRB resulted in increased differentiation of leukaemia cells, revealing that PIRB supports leukaemia development.

View Article: PubMed Central - PubMed

Affiliation: Departments of Physiology and Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.

ABSTRACT
How environmental cues regulate adult stem cell and cancer cell activity through surface receptors is poorly understood. Angiopoietin-like proteins (ANGPTLs), a family of seven secreted glycoproteins, are known to support the activity of haematopoietic stem cells (HSCs) in vitro and in vivo. ANGPTLs also have important roles in lipid metabolism, angiogenesis and inflammation, but were considered 'orphan ligands' because no receptors were identified. Here we show that the immune-inhibitory receptor human leukocyte immunoglobulin-like receptor B2 (LILRB2) and its mouse orthologue paired immunoglobulin-like receptor (PIRB) are receptors for several ANGPTLs. LILRB2 and PIRB are expressed on human and mouse HSCs, respectively, and the binding of ANGPTLs to these receptors supported ex vivo expansion of HSCs. In mouse transplantation acute myeloid leukaemia models, a deficiency in intracellular signalling of PIRB resulted in increased differentiation of leukaemia cells, revealing that PIRB supports leukaemia development. Our study indicates an unexpected functional significance of classical immune-inhibitory receptors in maintenance of stemness of normal adult stem cells and in support of cancer development.

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Cell surface LILRB2 binds to Angptlsa, Flow cytometry analysis of GST-Angptl5-FLAG binding to uninfected BAF3 cells or MSCV-GFP, MSCV-Tie2-GFP, or MSCV-LILRB2-GFP stably infected BAF3 cells. MFIs were indicated. b, Flow cytometry analysis of indicated FLAG-tagged Angptls binding to LILRB2 transfected 293T cells. c, Angptl2 and Angptl5 bound to the extracellular domain of LILRB2 but not Tie-2 in conditioned medium (CM) of co-transfected 293T cells (IB, immunoblotting; IP, immunoprecipitation). d–e, Concentration dependent specific (d) and competitive (e) 125I-GST-Angptl5 binding to LILRB2 stably expressed BAF3 cells (n = 3). Error bars, s.e.m.
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Figure 1: Cell surface LILRB2 binds to Angptlsa, Flow cytometry analysis of GST-Angptl5-FLAG binding to uninfected BAF3 cells or MSCV-GFP, MSCV-Tie2-GFP, or MSCV-LILRB2-GFP stably infected BAF3 cells. MFIs were indicated. b, Flow cytometry analysis of indicated FLAG-tagged Angptls binding to LILRB2 transfected 293T cells. c, Angptl2 and Angptl5 bound to the extracellular domain of LILRB2 but not Tie-2 in conditioned medium (CM) of co-transfected 293T cells (IB, immunoblotting; IP, immunoprecipitation). d–e, Concentration dependent specific (d) and competitive (e) 125I-GST-Angptl5 binding to LILRB2 stably expressed BAF3 cells (n = 3). Error bars, s.e.m.

Mentions: We used multiple approaches, including expression cloning, to identify the receptor(s) for Angptls. Human LILRB2, when ectopically expressed on BAF3 cells, enabled the cells to specifically bind GST-Angptl5 as determined by flow cytometry (Fig. 1a). LILRB2 is a member of the immune inhibitory B type subfamily of LILR receptors 13 and contains four Ig-domains and three immunoreceptor tyrosine-based inhibitory motifs. Using flow cytometry analysis, we further demonstrated that LILRB2-overexpressing 293T cells had enhanced binding to several Angptls, especially Angptl2 and GST-Angptl5 (Fig. 1b, Supplementary Fig. 1a–b). Angptl2 and GST-Angptl5 also bound to LILRB3- and LILRB5-overexpressing cells, though with a lower affinity than to LILRB2-expressing cells (Supplementary Table 1). In addition, Angptl1 and Angptl7 bound to LAIR1 14 -overexpressing 293T cells (Supplementary Table 1, Supplementary Fig. 2). Angptls did not bind to LILRAs, LILRB1, or LILRB4 (Supplementary Table 1).


Inhibitory receptors bind ANGPTLs and support blood stem cells and leukaemia development.

Zheng J, Umikawa M, Cui C, Li J, Chen X, Zhang C, Huynh H, Hyunh H, Kang X, Silvany R, Wan X, Ye J, Cantó AP, Chen SH, Wang HY, Ward ES, Zhang CC - Nature (2012)

Cell surface LILRB2 binds to Angptlsa, Flow cytometry analysis of GST-Angptl5-FLAG binding to uninfected BAF3 cells or MSCV-GFP, MSCV-Tie2-GFP, or MSCV-LILRB2-GFP stably infected BAF3 cells. MFIs were indicated. b, Flow cytometry analysis of indicated FLAG-tagged Angptls binding to LILRB2 transfected 293T cells. c, Angptl2 and Angptl5 bound to the extracellular domain of LILRB2 but not Tie-2 in conditioned medium (CM) of co-transfected 293T cells (IB, immunoblotting; IP, immunoprecipitation). d–e, Concentration dependent specific (d) and competitive (e) 125I-GST-Angptl5 binding to LILRB2 stably expressed BAF3 cells (n = 3). Error bars, s.e.m.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3367397&req=5

Figure 1: Cell surface LILRB2 binds to Angptlsa, Flow cytometry analysis of GST-Angptl5-FLAG binding to uninfected BAF3 cells or MSCV-GFP, MSCV-Tie2-GFP, or MSCV-LILRB2-GFP stably infected BAF3 cells. MFIs were indicated. b, Flow cytometry analysis of indicated FLAG-tagged Angptls binding to LILRB2 transfected 293T cells. c, Angptl2 and Angptl5 bound to the extracellular domain of LILRB2 but not Tie-2 in conditioned medium (CM) of co-transfected 293T cells (IB, immunoblotting; IP, immunoprecipitation). d–e, Concentration dependent specific (d) and competitive (e) 125I-GST-Angptl5 binding to LILRB2 stably expressed BAF3 cells (n = 3). Error bars, s.e.m.
Mentions: We used multiple approaches, including expression cloning, to identify the receptor(s) for Angptls. Human LILRB2, when ectopically expressed on BAF3 cells, enabled the cells to specifically bind GST-Angptl5 as determined by flow cytometry (Fig. 1a). LILRB2 is a member of the immune inhibitory B type subfamily of LILR receptors 13 and contains four Ig-domains and three immunoreceptor tyrosine-based inhibitory motifs. Using flow cytometry analysis, we further demonstrated that LILRB2-overexpressing 293T cells had enhanced binding to several Angptls, especially Angptl2 and GST-Angptl5 (Fig. 1b, Supplementary Fig. 1a–b). Angptl2 and GST-Angptl5 also bound to LILRB3- and LILRB5-overexpressing cells, though with a lower affinity than to LILRB2-expressing cells (Supplementary Table 1). In addition, Angptl1 and Angptl7 bound to LAIR1 14 -overexpressing 293T cells (Supplementary Table 1, Supplementary Fig. 2). Angptls did not bind to LILRAs, LILRB1, or LILRB4 (Supplementary Table 1).

Bottom Line: Angiopoietin-like proteins (ANGPTLs), a family of seven secreted glycoproteins, are known to support the activity of haematopoietic stem cells (HSCs) in vitro and in vivo.ANGPTLs also have important roles in lipid metabolism, angiogenesis and inflammation, but were considered 'orphan ligands' because no receptors were identified.In mouse transplantation acute myeloid leukaemia models, a deficiency in intracellular signalling of PIRB resulted in increased differentiation of leukaemia cells, revealing that PIRB supports leukaemia development.

View Article: PubMed Central - PubMed

Affiliation: Departments of Physiology and Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.

ABSTRACT
How environmental cues regulate adult stem cell and cancer cell activity through surface receptors is poorly understood. Angiopoietin-like proteins (ANGPTLs), a family of seven secreted glycoproteins, are known to support the activity of haematopoietic stem cells (HSCs) in vitro and in vivo. ANGPTLs also have important roles in lipid metabolism, angiogenesis and inflammation, but were considered 'orphan ligands' because no receptors were identified. Here we show that the immune-inhibitory receptor human leukocyte immunoglobulin-like receptor B2 (LILRB2) and its mouse orthologue paired immunoglobulin-like receptor (PIRB) are receptors for several ANGPTLs. LILRB2 and PIRB are expressed on human and mouse HSCs, respectively, and the binding of ANGPTLs to these receptors supported ex vivo expansion of HSCs. In mouse transplantation acute myeloid leukaemia models, a deficiency in intracellular signalling of PIRB resulted in increased differentiation of leukaemia cells, revealing that PIRB supports leukaemia development. Our study indicates an unexpected functional significance of classical immune-inhibitory receptors in maintenance of stemness of normal adult stem cells and in support of cancer development.

Show MeSH
Related in: MedlinePlus