The Experts below are selected from a list of 909 Experts worldwide ranked by ideXlab platform
S Kollnberger - One of the best experts on this subject based on the ideXlab platform.
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the leukocyte immunoglobulin like receptor family member lilrb5 binds to hla class i heavy chains
PLOS ONE, 2015Co-Authors: Zhiyong Zhang, Hiroko Hatano, J Shaw, Marloes Olde Nordkamp, Guosheng Jiang, S KollnbergerAbstract:Objective The leukocyte immunoglobulin-like receptor (LILR) family includes inhibitory and stimulatory members which bind to classical and non-classical HLA-class I. The ligands for many LILR including LILRB5 have not yet been identified. Methods We generated C-terminal eGFP and N-terminal FLAG-tagged fusion constructs for monitoring LILR expression. We screened for LILR binding to HLA-class I by tetramer staining of 293T cells transfected with LILRA1, A4, A5 A6 and LILRB2 and LILRB5. We also studied HLA class I tetramer binding to LILRB5 on peripheral monocyte cells. LILRB5 binding to HLA-class I heavy chains was confirmed by co-immunoprecipitation. Results HLA-B27 (B27) free heavy chain (FHC) dimer but not other HLA-class I stained LILRB5-transfected 293T cells. B27 dimer binding to LILRB5 was blocked with the class I heavy chain antibody HC10 and anti-LILRB5 antisera. B27 dimers also bound to LILRB5 on peripheral monocytes. HLA-B7 and B27 heavy chains co-immunoprecipitated with LILRB5 in transduced B and rat basophil RBL cell lines. Conclusions Our findings show that class I free heavy chains are ligands for LILRB5. The unique binding specificity of LILRB5 for HLA-class I heavy chains probably results from differences in the D1 and D2 immunoglobulin-like binding domains which are distinct from other LILR which bind to β2m-associated HLA-class I.
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HLA-B27 free heavy chain dimers bind to LILRB5.
2015Co-Authors: Zhiyong Zhang, Hiroko Hatano, Marloes Olde Nordkamp, Guosheng Jiang, S KollnbergerAbstract:FACS staining of 293 T cells transfected with eGFP and FLAG-tagged constructs of LILRA1, LILRA4, LILRA5, LILRA6, LILRB2 and LILRB5 stained with Extravidin-PE (left panels) or Extravidin PE-conjugated HLA-B27 free heavy chain dimer tetramers (centre panels). FACS plots show PE fluorescence from tetramer or Extravidin staining plotted against eGFP expression of each of the fusion experiments. (Right panels) FACS staining of 293 T cells transfected with eGFP and FLAG-tagged constructs of LILRA1, LILRA4, LILRA5, LILRA6, and LILRB5 stained with allophycocyanin (APC) conjugated anti-FLAG antibody. FACS plots show APC fluorescence from anti-FLAG staining plotted against eGFP expression of each of the fusion constructs. Representative FACS stain from 1 of 4 independent experiments.
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The Leukocyte Immunoglobulin-Like Receptor Family Member LILRB5 Binds to HLA-Class I Heavy Chains - Fig 2
2015Co-Authors: Zhiyong Zhang, Hiroko Hatano, J Shaw, Marloes Olde Nordkamp, Guosheng Jiang, S KollnbergerAbstract:LILRB5 binds specifically to HLA-B27 free heavy chain dimers but does not bind to β2m and peptide associated HLA-A3, HLA-B7 and HLA-B27 heterodimers A. FACS staining of 293 T cells transfected with eGFP and FLAG-tagged constructs of LILRB2 and LILRB5 and stained with Extravidin-PE, orExtravidin-PE conjugated tetramers of HLA-A3, HLA-B7, and HLA-B27 heterodimer or HLA-B27 free heavy chain (FHC) dimers. FACS plots show PE fluorescence from tetramer or Extravidin staining plotted against eGFP expression of each of the fusion experiments. Representative FACS stain from 1 of 3 independent experiments B. FACS staining of LILRB5 transfected 293T cells with HLA-B27 FHC dimer tetramer or Extravidin PE with or without isotype control antibody (IgG2a) or free heavy chain antibody HC10 as indicated. FACS plots show PE fluorescence from tetramer or Extravidin staining plotted against eGFP expression of each of the fusion experiments. Representative FACS stain from 1 of 3 independent experiments.
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B27 dimer binding to LILRB5 is inhibited by LILRB5 specific antiserum.
2015Co-Authors: Zhiyong Zhang, Hiroko Hatano, Marloes Olde Nordkamp, Guosheng Jiang, S KollnbergerAbstract:A. FACS staining of LILRB5, LILRA1 and B2 transfected 293T cells with HLA-B27 FHC dimer tetramer or Extravidin PE with or without isotype control antisera (ISOT) or anti-LILRB5 antisera (αLILRB5) as indicated. FACS plots show PE fluorescence from tetramer or Extravidin staining plotted against eGFP expression of each of the respective fusion constructs. Representative FACS stain from 1 of 3 independent experiments. B. Representative FACS staining of 293T cells transfected with the indicated LILR constructs and stained with anti-LILRB5 or normal goat antisera (NGS). Representative stain from 1 of 3 independent experiments.
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LILRB5 is expressed on the surface of peripheral monocytes.
2015Co-Authors: Zhiyong Zhang, Hiroko Hatano, Marloes Olde Nordkamp, Guosheng Jiang, S KollnbergerAbstract:B27 heavy chain dimers bind to monocyte LILRB5. A. Forward scatter (FSC-A) and side scatter (SSC-A) FACS plot of peripheral blood mononuclear cells (PBMC) showing gating strategy for monocytes (Mθ) and lymphocyte (Lθ) populations. The relative proportions of monocyte and lymphocyte populations are indicated to the side of each gate. B. FACS staining of peripheral CD14+ (CD3-, CD19-, CD56-) monocytes with anti-LILRB5 antiserum (bold line) or normal goat serum (NGS, shaded histogram). C. FACS staining of (left panel) CD19+ (CD3-,CD14-CD56-) peripheral B, (centre panel) CD56+ (CD3-,CD14-,CD19-) natural killer (NK) or (right panel) CD3+ (CD14-,CD19-) T cell populations with anti-LILRB5 antiserum (bold line) or NGS (shaded histogram). Representative staining from 1 of 3 independent experiments. D. B27 dimer tetramer staining of peripheral monocytes without antiserum (dashed line) or in the presence of NGS (light line) or LILRB5 antiserum (bold line). FACS staining with extravidin PE (ExPE, shaded histogram) is included as a background staining control. The respective geometric mean fluorescent intensities (MFI) for staining without antiserum, with NGS and with anti-LILRB5 antiserum were 2498, 2827 and 881 respectively. The geometric MFI for staining with extravidin PE was 236. Representative staining from 1 of 3 independent experiments.
Mathias Lichterfeld - One of the best experts on this subject based on the ideXlab platform.
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Stable LILRB1 expression on T cells after “bystander activation”.
2013Co-Authors: Ilona Toth, Florencia Pereyra, Julian Schulze Zur Wiesch, Jennifer Rychert, Eric S. Rosenberg, Jan Van Lunzen, Mathias LichterfeldAbstract:(A) Representative dot plots demonstrating proportions of LILRB1-expressing Vβ13.1+ and Vβ13.1− T cells after activation with SEB over indicated time course. (B): Fold change of LILRB1 expression on Vβ13.1+ or Vβ13.1− T cells at indicated time points. Mean and standard error from 7 different HIV-1 negative donors are shown. Significance was tested by paired T test.
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soluble hla g inhibits myeloid dendritic cell function in hiv 1 infection by interacting with leukocyte immunoglobulin like receptor b2
Journal of Virology, 2010Co-Authors: Jinghe Huang, Patrick S Burke, Thai Duong Hong Cung, Florencia Pereyra, Ildiko Toth, Yue Yang, Katherine Seiss, Jill Beamon, Mathias LichterfeldAbstract:Dendritic cells represent a specialized class of professional antigen-presenting cells that are responsible for priming and maintaining antigen-specific effector cell responses and regulating immune activation by cytokine secretion. In HIV-1 infection, myeloid dendritic cells are highly dysfunctional, but mechanisms contributing to their functional alterations are not well defined. Here, we show that soluble molecules of the nonclassical major histocompatibility complex class Ib (MHC-Ib) antigen HLA-G are highly upregulated in the plasma during progressive HIV-1 infection, while levels of membrane-bound HLA-G surface expression on dendritic cells, monocytes, and T cells only slightly differ among HIV-1 progressors, HIV-1 elite controllers, and HIV-1-negative persons. These elevated levels of soluble HLA-G in progressive HIV-1 infection likely result from increased secretion of intracellularly stored HLA-G molecules in monocytes and dendritic cells and contribute to a functional disarray of dendritic cells by inhibiting their antigen-presenting properties, while simultaneously enhancing their secretion of proinflammatory cytokines. Interestingly, we observed that these immunoregulatory effects of soluble HLA-G were mainly mediated by interactions with the myelomonocytic HLA class I receptor leukocyte immunoglobulin-like receptor B2 (LILRB2; ILT4), while binding of soluble HLA-G to its alternative high-affinity receptor, LILRB1 (ILT2), appeared to be less relevant for its immunomodulatory functions on dendritic cells. Overall, these results demonstrate a critical role for soluble HLA-G in modulating the functional characteristics of professional antigen-presenting cells in progressive HIV-1 infection and suggest that soluble HLA-G might represent a possible target for immunotherapeutic interventions in HIV-1-infected persons.
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leukocyte immunoglobulin like receptors maintain unique antigen presenting properties of circulating myeloid dendritic cells in hiv 1 infected elite controllers
Journal of Virology, 2010Co-Authors: Jinghe Huang, Luis Borges, Patrick S Burke, Thai Duong Hong Cung, Florencia Pereyra, Ildiko Toth, Bruce D Walker, Mathias LichterfeldAbstract:Elite controllers maintain undetectable levels of HIV-1 replication in the absence of antiretroviral therapy, but the correlates of immune protection in this patient population are ill defined. Here, we demonstrate that in comparison to patients with progressive HIV-1 infection or healthy persons not infected with HIV-1, elite controllers have circulating myeloid dendritic cells with significantly increased antigen-presenting properties, while their ability to secrete proinflammatory cytokines is substantially diminished. This unique functional profile is associated with a distinct surface expression pattern of immunomodulatory leukocyte-immunoglobulin-like receptors (LILR) and a strong and selective upregulation of LILRB1 and LILRB3. Blockade of these two receptors by monoclonal antibodies or short interfering RNA (siRNA) abrogated the specific antigen-presenting properties of dendritic cells, implying an important regulatory role of these molecules. These data reveal previously unrecognized innate components of immune protection against HIV-1 in elite controllers and offer novel perspectives for the manipulation of host immunity for the prevention and treatment of HIV-1 infection.
William S. B. Yeung - One of the best experts on this subject based on the ideXlab platform.
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Soluble human leukocyte antigen-g5 activates extracellular signal-regulated protein kinase www.frontiersin.org December 2014
2016Co-Authors: Yifan Guo, Cheuk-lun Lee, Jing Gao, William S. B. Yeung, Yuanqing YaoAbstract:Soluble human leukocyte antigen-G (HLA-G) is a non-classical class Ib HLA molecule that is secreted from blastocysts. Soluble HLA-G modulates the immune tolerance of the mother and can be used as a prognostic factor for the clinical pregnancy rate. However, the underlying mechanism of how soluble HLA-G5 affects pregnancy remains largely unknown. We hypothesized that soluble HLA-G5 promotes successful implantation and pregnancy by modulating trophoblast invasion through receptor binding and activation of extracellular signal-regulated protein kinase (ERK) signaling pathway. Recombinant HLA-G5 protein over-expressed in E. coli BL21 was purified to near homogeneity. We studied the expression of HLA-G5 and its receptors, the leukocyte immunoglobulin-like receptor subfamily B1 (LILRB1) and killer cell immunoglobulin-like receptor 2DL4 (KIR2DL4), in primary trophoblasts and trophoblastic (JAr and JEG-3) cell lines by florescence-labeled HLA-G5. HLA-G5 was detected in the primary trophoblasts and JEG-3 cells. The LILRB1 and KIR2DL4 receptors were expressed in both primary trophoblasts and trophoblastic cell lines. HLA-G5 stimulated cell invasion (p,0.05) and increased urokinase (uPA) and matrix metalloproteinases (MMPs) transcripts and their activity (p,0.05) in trophoblastic cells. HLA-G5 activated the ERK signaling pathway and induced ERK1/2 phosphorylation in the trophoblastic cell lines. Addition of ERK inhibitors (U0126 and PD98059) nullified the stimulatory effect of HLA-G5 on trophoblastic cell invasion. Taken together, HLA-G5 induced trophoblast invasion by binding to KIR2DL4 and LILRB1, by increasing uPA and MMPs expressions and b
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Soluble human leukocyte antigen-g5 activates extracellular signal-regulated protein kinase signaling and stimulates trophoblast invasion.
PloS one, 2013Co-Authors: Yifan Guo, Cheuk-lun Lee, Jing Gao, William S. B. Yeung, Yuanqing Yao, Kai-fai LeeAbstract:Soluble human leukocyte antigen-G (HLA-G) is a non-classical class Ib HLA molecule that is secreted from blastocysts. Soluble HLA-G modulates the immune tolerance of the mother and can be used as a prognostic factor for the clinical pregnancy rate. However, the underlying mechanism of how soluble HLA-G5 affects pregnancy remains largely unknown. We hypothesized that soluble HLA-G5 promotes successful implantation and pregnancy by modulating trophoblast invasion through receptor binding and activation of extracellular signal-regulated protein kinase (ERK) signaling pathway. Recombinant HLA-G5 protein over-expressed in E. coli BL21 was purified to near homogeneity. We studied the expression of HLA-G5 and its receptors, the leukocyte immunoglobulin-like receptor subfamily B1 (LILRB1) and killer cell immunoglobulin-like receptor 2DL4 (KIR2DL4), in primary trophoblasts and trophoblastic (JAr and JEG-3) cell lines by florescence-labeled HLA-G5. HLA-G5 was detected in the primary trophoblasts and JEG-3 cells. The LILRB1 and KIR2DL4 receptors were expressed in both primary trophoblasts and trophoblastic cell lines. HLA-G5 stimulated cell invasion (p
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soluble human leukocyte antigen g5 activates extracellular signal regulated protein kinase signaling and stimulates trophoblast invasion
PLOS ONE, 2013Co-Authors: Kamhei So, William S. B. YeungAbstract:Soluble human leukocyte antigen-G (HLA-G) is a non-classical class Ib HLA molecule that is secreted from blastocysts. Soluble HLA-G modulates the immune tolerance of the mother and can be used as a prognostic factor for the clinical pregnancy rate. However, the underlying mechanism of how soluble HLA-G5 affects pregnancy remains largely unknown. We hypothesized that soluble HLA-G5 promotes successful implantation and pregnancy by modulating trophoblast invasion through receptor binding and activation of extracellular signal-regulated protein kinase (ERK) signaling pathway. Recombinant HLA-G5 protein over-expressed in E. coli BL21 was purified to near homogeneity. We studied the expression of HLA-G5 and its receptors, the leukocyte immunoglobulin-like receptor subfamily B1 (LILRB1) and killer cell immunoglobulin-like receptor 2DL4 (KIR2DL4), in primary trophoblasts and trophoblastic (JAr and JEG-3) cell lines by florescence-labeled HLA-G5. HLA-G5 was detected in the primary trophoblasts and JEG-3 cells. The LILRB1 and KIR2DL4 receptors were expressed in both primary trophoblasts and trophoblastic cell lines. HLA-G5 stimulated cell invasion (p<0.05) and increased urokinase (uPA) and matrix metalloproteinases (MMPs) transcripts and their activity (p<0.05) in trophoblastic cells. HLA-G5 activated the ERK signaling pathway and induced ERK1/2 phosphorylation in the trophoblastic cell lines. Addition of ERK inhibitors (U0126 and PD98059) nullified the stimulatory effect of HLA-G5 on trophoblastic cell invasion. Taken together, HLA-G5 induced trophoblast invasion by binding to KIR2DL4 and LILRB1, by increasing uPA and MMPs expressions and by activating the ERK signaling pathway.
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soluble human leukocyte antigen g5 activates extracellular signal regulated protein kinase signaling and stimulates trophoblast invasion
PLOS ONE, 2013Co-Authors: Yifan Guo, Cheuk-lun Lee, Jing Gao, William S. B. Yeung, Yuanqing Yao, Kai-fai LeeAbstract:Soluble human leukocyte antigen-G (HLA-G) is a non-classical class Ib HLA molecule that is secreted from blastocysts. Soluble HLA-G modulates the immune tolerance of the mother and can be used as a prognostic factor for the clinical pregnancy rate. However, the underlying mechanism of how soluble HLA-G5 affects pregnancy remains largely unknown. We hypothesized that soluble HLA-G5 promotes successful implantation and pregnancy by modulating trophoblast invasion through receptor binding and activation of extracellular signal-regulated protein kinase (ERK) signaling pathway. Recombinant HLA-G5 protein over-expressed in E. coli BL21 was purified to near homogeneity. We studied the expression of HLA-G5 and its receptors, the leukocyte immunoglobulin-like receptor subfamily B1 (LILRB1) and killer cell immunoglobulin-like receptor 2DL4 (KIR2DL4), in primary trophoblasts and trophoblastic (JAr and JEG-3) cell lines by florescence-labeled HLA-G5. HLA-G5 was detected in the primary trophoblasts and JEG-3 cells. The LILRB1 and KIR2DL4 receptors were expressed in both primary trophoblasts and trophoblastic cell lines. HLA-G5 stimulated cell invasion (p<0.05) and increased urokinase (uPA) and matrix metalloproteinases (MMPs) transcripts and their activity (p<0.05) in trophoblastic cells. HLA-G5 activated the ERK signaling pathway and induced ERK1/2 phosphorylation in the trophoblastic cell lines. Addition of ERK inhibitors (U0126 and PD98059) nullified the stimulatory effect of HLA-G5 on trophoblastic cell invasion. Taken together, HLA-G5 induced trophoblast invasion by binding to KIR2DL4 and LILRB1, by increasing uPA and MMPs expressions and by activating the ERK signaling pathway.
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Expression of HLA-G5 and its receptors LILRB1 and KIR2DL4 in trophoblasts. (
2013Co-Authors: Yifan Guo, Cheuk-lun Lee, Jing Gao, William S. B. Yeung, Yuanqing Yao, Kai-fai LeeAbstract:A) Western blot analysis of the total cell lysate showed HLA-G5 was expressed in human choriocarcinoma JEG-3 cells but not in JAr or human natural killer NK92mi cells. JEG-3, JAr and NK92mi cells expressed both LILRB1 and KIR2DL4 receptors. The β-actin protein was used as loading control. (B) Immunofluorescent staining (green) showed the LILRB1 and KIR2DL4 receptors were expressed in the JAr and JEG-3 cells mainly in the cytoplasm and membrane areas. Representative images are from three sets of individual experiments. (C) Human primary trophoblastic cells stained for HLA-G5, LILRB1 and KIR2DL4 receptors. The nuclei of the cells were counterstained with DAPI. 100x Magnification.
Kai-fai Lee - One of the best experts on this subject based on the ideXlab platform.
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Soluble human leukocyte antigen-g5 activates extracellular signal-regulated protein kinase signaling and stimulates trophoblast invasion.
PloS one, 2013Co-Authors: Yifan Guo, Cheuk-lun Lee, Jing Gao, William S. B. Yeung, Yuanqing Yao, Kai-fai LeeAbstract:Soluble human leukocyte antigen-G (HLA-G) is a non-classical class Ib HLA molecule that is secreted from blastocysts. Soluble HLA-G modulates the immune tolerance of the mother and can be used as a prognostic factor for the clinical pregnancy rate. However, the underlying mechanism of how soluble HLA-G5 affects pregnancy remains largely unknown. We hypothesized that soluble HLA-G5 promotes successful implantation and pregnancy by modulating trophoblast invasion through receptor binding and activation of extracellular signal-regulated protein kinase (ERK) signaling pathway. Recombinant HLA-G5 protein over-expressed in E. coli BL21 was purified to near homogeneity. We studied the expression of HLA-G5 and its receptors, the leukocyte immunoglobulin-like receptor subfamily B1 (LILRB1) and killer cell immunoglobulin-like receptor 2DL4 (KIR2DL4), in primary trophoblasts and trophoblastic (JAr and JEG-3) cell lines by florescence-labeled HLA-G5. HLA-G5 was detected in the primary trophoblasts and JEG-3 cells. The LILRB1 and KIR2DL4 receptors were expressed in both primary trophoblasts and trophoblastic cell lines. HLA-G5 stimulated cell invasion (p
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soluble human leukocyte antigen g5 activates extracellular signal regulated protein kinase signaling and stimulates trophoblast invasion
PLOS ONE, 2013Co-Authors: Yifan Guo, Cheuk-lun Lee, Jing Gao, William S. B. Yeung, Yuanqing Yao, Kai-fai LeeAbstract:Soluble human leukocyte antigen-G (HLA-G) is a non-classical class Ib HLA molecule that is secreted from blastocysts. Soluble HLA-G modulates the immune tolerance of the mother and can be used as a prognostic factor for the clinical pregnancy rate. However, the underlying mechanism of how soluble HLA-G5 affects pregnancy remains largely unknown. We hypothesized that soluble HLA-G5 promotes successful implantation and pregnancy by modulating trophoblast invasion through receptor binding and activation of extracellular signal-regulated protein kinase (ERK) signaling pathway. Recombinant HLA-G5 protein over-expressed in E. coli BL21 was purified to near homogeneity. We studied the expression of HLA-G5 and its receptors, the leukocyte immunoglobulin-like receptor subfamily B1 (LILRB1) and killer cell immunoglobulin-like receptor 2DL4 (KIR2DL4), in primary trophoblasts and trophoblastic (JAr and JEG-3) cell lines by florescence-labeled HLA-G5. HLA-G5 was detected in the primary trophoblasts and JEG-3 cells. The LILRB1 and KIR2DL4 receptors were expressed in both primary trophoblasts and trophoblastic cell lines. HLA-G5 stimulated cell invasion (p<0.05) and increased urokinase (uPA) and matrix metalloproteinases (MMPs) transcripts and their activity (p<0.05) in trophoblastic cells. HLA-G5 activated the ERK signaling pathway and induced ERK1/2 phosphorylation in the trophoblastic cell lines. Addition of ERK inhibitors (U0126 and PD98059) nullified the stimulatory effect of HLA-G5 on trophoblastic cell invasion. Taken together, HLA-G5 induced trophoblast invasion by binding to KIR2DL4 and LILRB1, by increasing uPA and MMPs expressions and by activating the ERK signaling pathway.
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Expression of HLA-G5 and its receptors LILRB1 and KIR2DL4 in trophoblasts. (
2013Co-Authors: Yifan Guo, Cheuk-lun Lee, Jing Gao, William S. B. Yeung, Yuanqing Yao, Kai-fai LeeAbstract:A) Western blot analysis of the total cell lysate showed HLA-G5 was expressed in human choriocarcinoma JEG-3 cells but not in JAr or human natural killer NK92mi cells. JEG-3, JAr and NK92mi cells expressed both LILRB1 and KIR2DL4 receptors. The β-actin protein was used as loading control. (B) Immunofluorescent staining (green) showed the LILRB1 and KIR2DL4 receptors were expressed in the JAr and JEG-3 cells mainly in the cytoplasm and membrane areas. Representative images are from three sets of individual experiments. (C) Human primary trophoblastic cells stained for HLA-G5, LILRB1 and KIR2DL4 receptors. The nuclei of the cells were counterstained with DAPI. 100x Magnification.
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Flow cytometric analysis of the anti-KIR2DL4/LILRB1 antibody treatments on the binding of pre-labeled HLA-G5 in JAr and JEG-3 cells.
2013Co-Authors: Yifan Guo, Cheuk-lun Lee, Jing Gao, William S. B. Yeung, Yuanqing Yao, Kai-fai LeeAbstract:(A) The binding of pre-labeled HLA-G5 in trophoblastic cells was significantly reduced after treatments with KIR2DL4 or LILRB1 antibodies (N = 4, p
Yifan Guo - One of the best experts on this subject based on the ideXlab platform.
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Soluble human leukocyte antigen-g5 activates extracellular signal-regulated protein kinase www.frontiersin.org December 2014
2016Co-Authors: Yifan Guo, Cheuk-lun Lee, Jing Gao, William S. B. Yeung, Yuanqing YaoAbstract:Soluble human leukocyte antigen-G (HLA-G) is a non-classical class Ib HLA molecule that is secreted from blastocysts. Soluble HLA-G modulates the immune tolerance of the mother and can be used as a prognostic factor for the clinical pregnancy rate. However, the underlying mechanism of how soluble HLA-G5 affects pregnancy remains largely unknown. We hypothesized that soluble HLA-G5 promotes successful implantation and pregnancy by modulating trophoblast invasion through receptor binding and activation of extracellular signal-regulated protein kinase (ERK) signaling pathway. Recombinant HLA-G5 protein over-expressed in E. coli BL21 was purified to near homogeneity. We studied the expression of HLA-G5 and its receptors, the leukocyte immunoglobulin-like receptor subfamily B1 (LILRB1) and killer cell immunoglobulin-like receptor 2DL4 (KIR2DL4), in primary trophoblasts and trophoblastic (JAr and JEG-3) cell lines by florescence-labeled HLA-G5. HLA-G5 was detected in the primary trophoblasts and JEG-3 cells. The LILRB1 and KIR2DL4 receptors were expressed in both primary trophoblasts and trophoblastic cell lines. HLA-G5 stimulated cell invasion (p,0.05) and increased urokinase (uPA) and matrix metalloproteinases (MMPs) transcripts and their activity (p,0.05) in trophoblastic cells. HLA-G5 activated the ERK signaling pathway and induced ERK1/2 phosphorylation in the trophoblastic cell lines. Addition of ERK inhibitors (U0126 and PD98059) nullified the stimulatory effect of HLA-G5 on trophoblastic cell invasion. Taken together, HLA-G5 induced trophoblast invasion by binding to KIR2DL4 and LILRB1, by increasing uPA and MMPs expressions and b
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Soluble human leukocyte antigen-g5 activates extracellular signal-regulated protein kinase signaling and stimulates trophoblast invasion.
PloS one, 2013Co-Authors: Yifan Guo, Cheuk-lun Lee, Jing Gao, William S. B. Yeung, Yuanqing Yao, Kai-fai LeeAbstract:Soluble human leukocyte antigen-G (HLA-G) is a non-classical class Ib HLA molecule that is secreted from blastocysts. Soluble HLA-G modulates the immune tolerance of the mother and can be used as a prognostic factor for the clinical pregnancy rate. However, the underlying mechanism of how soluble HLA-G5 affects pregnancy remains largely unknown. We hypothesized that soluble HLA-G5 promotes successful implantation and pregnancy by modulating trophoblast invasion through receptor binding and activation of extracellular signal-regulated protein kinase (ERK) signaling pathway. Recombinant HLA-G5 protein over-expressed in E. coli BL21 was purified to near homogeneity. We studied the expression of HLA-G5 and its receptors, the leukocyte immunoglobulin-like receptor subfamily B1 (LILRB1) and killer cell immunoglobulin-like receptor 2DL4 (KIR2DL4), in primary trophoblasts and trophoblastic (JAr and JEG-3) cell lines by florescence-labeled HLA-G5. HLA-G5 was detected in the primary trophoblasts and JEG-3 cells. The LILRB1 and KIR2DL4 receptors were expressed in both primary trophoblasts and trophoblastic cell lines. HLA-G5 stimulated cell invasion (p
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soluble human leukocyte antigen g5 activates extracellular signal regulated protein kinase signaling and stimulates trophoblast invasion
PLOS ONE, 2013Co-Authors: Yifan Guo, Cheuk-lun Lee, Jing Gao, William S. B. Yeung, Yuanqing Yao, Kai-fai LeeAbstract:Soluble human leukocyte antigen-G (HLA-G) is a non-classical class Ib HLA molecule that is secreted from blastocysts. Soluble HLA-G modulates the immune tolerance of the mother and can be used as a prognostic factor for the clinical pregnancy rate. However, the underlying mechanism of how soluble HLA-G5 affects pregnancy remains largely unknown. We hypothesized that soluble HLA-G5 promotes successful implantation and pregnancy by modulating trophoblast invasion through receptor binding and activation of extracellular signal-regulated protein kinase (ERK) signaling pathway. Recombinant HLA-G5 protein over-expressed in E. coli BL21 was purified to near homogeneity. We studied the expression of HLA-G5 and its receptors, the leukocyte immunoglobulin-like receptor subfamily B1 (LILRB1) and killer cell immunoglobulin-like receptor 2DL4 (KIR2DL4), in primary trophoblasts and trophoblastic (JAr and JEG-3) cell lines by florescence-labeled HLA-G5. HLA-G5 was detected in the primary trophoblasts and JEG-3 cells. The LILRB1 and KIR2DL4 receptors were expressed in both primary trophoblasts and trophoblastic cell lines. HLA-G5 stimulated cell invasion (p<0.05) and increased urokinase (uPA) and matrix metalloproteinases (MMPs) transcripts and their activity (p<0.05) in trophoblastic cells. HLA-G5 activated the ERK signaling pathway and induced ERK1/2 phosphorylation in the trophoblastic cell lines. Addition of ERK inhibitors (U0126 and PD98059) nullified the stimulatory effect of HLA-G5 on trophoblastic cell invasion. Taken together, HLA-G5 induced trophoblast invasion by binding to KIR2DL4 and LILRB1, by increasing uPA and MMPs expressions and by activating the ERK signaling pathway.
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Expression of HLA-G5 and its receptors LILRB1 and KIR2DL4 in trophoblasts. (
2013Co-Authors: Yifan Guo, Cheuk-lun Lee, Jing Gao, William S. B. Yeung, Yuanqing Yao, Kai-fai LeeAbstract:A) Western blot analysis of the total cell lysate showed HLA-G5 was expressed in human choriocarcinoma JEG-3 cells but not in JAr or human natural killer NK92mi cells. JEG-3, JAr and NK92mi cells expressed both LILRB1 and KIR2DL4 receptors. The β-actin protein was used as loading control. (B) Immunofluorescent staining (green) showed the LILRB1 and KIR2DL4 receptors were expressed in the JAr and JEG-3 cells mainly in the cytoplasm and membrane areas. Representative images are from three sets of individual experiments. (C) Human primary trophoblastic cells stained for HLA-G5, LILRB1 and KIR2DL4 receptors. The nuclei of the cells were counterstained with DAPI. 100x Magnification.
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Flow cytometric analysis of the anti-KIR2DL4/LILRB1 antibody treatments on the binding of pre-labeled HLA-G5 in JAr and JEG-3 cells.
2013Co-Authors: Yifan Guo, Cheuk-lun Lee, Jing Gao, William S. B. Yeung, Yuanqing Yao, Kai-fai LeeAbstract:(A) The binding of pre-labeled HLA-G5 in trophoblastic cells was significantly reduced after treatments with KIR2DL4 or LILRB1 antibodies (N = 4, p