TY - JOUR

T1 - Regulation of NKG2D-ligand cell surface expression by intracellular calcium after HDAC-inhibitor treatment

AU - Jensen, Helle

AU - Hagemann-Jensen, Michael Henrik

AU - Lauridsen, Felicia Kathrine Bratt

AU - Skov, Søren

N1 - Copyright © 2012 Elsevier Ltd. All rights reserved.

PY - 2013

Y1 - 2013

N2 - In this study we demonstrate that histone deacetylase (HDAC)-inhibitor mediated cell surface expression of the structural different NKG2D-ligands MICA/B and ULBP2 is calcium-dependent. Treatment with the calcium chelator EGTA inhibited constitutive as well as HDAC-inhibitor induced MICA/B and ULBP2 cell surface expression on melanoma cells and Jurkat T-cells. A NKG2D-dependent cytolytic assay and staining with a recombinant NKG2D-Fc fusion protein showed that calcium chelation impaired the functional ability of NKG2D-ligands induced by HDAC-inhibitor treatment. The HDAC-inhibitor induced cell surface expression of ULBP2, but not MICA/B, was sensitive to treatment calmidazolium and trifluoperazine, two agents known to block calcium signaling. siRNA-mediated knock-down of the calcium-regulated proteins calmodulin or calpain did however not affect NKG2D-ligand cell surface expression on Jurkat T-cells. We further show that secretion and cell surface binding of the calcium-regulating protein galectin-1 is enhanced upon HDAC-inhibitor treatment of melanoma cells. However, binding of galectin-1 to cell surface glycoproteins was not critical for constitutive or HDAC-inhibitor induced MICA/B and ULBP2 cell surface expression. We provide evidence that MICA/B and ULBP2 cell surface expression is controlled differently by calcium, which adds to the increasing perception that cell surface expression of MICA/B and ULBP2 is controlled by distinct signal transduction pathways.

AB - In this study we demonstrate that histone deacetylase (HDAC)-inhibitor mediated cell surface expression of the structural different NKG2D-ligands MICA/B and ULBP2 is calcium-dependent. Treatment with the calcium chelator EGTA inhibited constitutive as well as HDAC-inhibitor induced MICA/B and ULBP2 cell surface expression on melanoma cells and Jurkat T-cells. A NKG2D-dependent cytolytic assay and staining with a recombinant NKG2D-Fc fusion protein showed that calcium chelation impaired the functional ability of NKG2D-ligands induced by HDAC-inhibitor treatment. The HDAC-inhibitor induced cell surface expression of ULBP2, but not MICA/B, was sensitive to treatment calmidazolium and trifluoperazine, two agents known to block calcium signaling. siRNA-mediated knock-down of the calcium-regulated proteins calmodulin or calpain did however not affect NKG2D-ligand cell surface expression on Jurkat T-cells. We further show that secretion and cell surface binding of the calcium-regulating protein galectin-1 is enhanced upon HDAC-inhibitor treatment of melanoma cells. However, binding of galectin-1 to cell surface glycoproteins was not critical for constitutive or HDAC-inhibitor induced MICA/B and ULBP2 cell surface expression. We provide evidence that MICA/B and ULBP2 cell surface expression is controlled differently by calcium, which adds to the increasing perception that cell surface expression of MICA/B and ULBP2 is controlled by distinct signal transduction pathways.

KW - Base Sequence

KW - Calcium Signaling

KW - Calmodulin

KW - Calpain

KW - Cell Line, Tumor

KW - Cell Membrane

KW - Depsipeptides

KW - GPI-Linked Proteins

KW - Galectin 1

KW - Gene Knockdown Techniques

KW - Histone Deacetylase Inhibitors

KW - Humans

KW - Imidazoles

KW - Intercellular Signaling Peptides and Proteins

KW - Jurkat Cells

KW - Ligands

KW - Melanoma

KW - RNA, Small Interfering

KW - Trifluoperazine

KW - NKG2D-ligand

KW - ULBP2

KW - Calcium

KW - Galectin-1

KW - HDAC-inhibitor

KW - Cancer

U2 - 10.1016/j.molimm.2012.08.011

DO - 10.1016/j.molimm.2012.08.011

M3 - Journal article

C2 - 22964480

VL - 53

SP - 255

EP - 264

JO - Molecular Immunology

JF - Molecular Immunology

SN - 0161-5890

IS - 3

ER -