The Leukocyte Integrin Gene CD11d Is Repressed by Gut-enriched Kruppel-like Factor 4 in Myeloid Cells

Jill D. Dillon,John D. Noti,Andrew K. Johnson

doi:10.1074/jbc.m412627200

Abstract

The myeloid-specific leukocyte integrin CD11d encodes the alphaD subunit for the alphaDbeta2 receptor. A yeast one-hybrid screen showed that a longer isoform of gut-enriched Kruppel-like factor 4 (GKLF) we term GKLFa interacts with the CD11d promoter. Purified GST-GKLFa protein was shown to bind within the -61 to -44 region that overlaps a binding site for the CD11d transcriptional activators Sp1 and transforming growth factor beta-inducible early gene-1 (TIEG1). Transfection of GKLF/GKLFa in myeloid cells reduced CD11d promoter activity, whereas, down-regulation of GKLF/GKLFa with small interfering RNAs led to up-regulation of CD11d expression. Differentiation of myeloid cells with phorbol ester led to activation of the CD11d promoter and reduced occupancy of the promoter by GKLF/GKLFa but an increased occupancy by TIEG1 in vivo. Binding of GKLF/GKLFa, Sp1, and TIEG1 to the CD11d promoter in vivo is dependent on their zinc finger DNA binding domains. GKLFa physically associates with the histone deacetylases (HDAC) 1 and 2, and both HDACs are bound to the CD11d promoter in vivo but released after exposure of myeloid cells to phorbol ester suggesting that GKLF/GKLFa recruits HDACs to effect repression.

Highlights

The four members of the leukocyte integrin family are composed of distinct ␣-subunits encoded by the CD11a [8], CD11b [9], CD11c [10], and CD11d [11] genes that non-covalently associate with a common ␤-subunit, encoded by the CD18 gene [12]
GKLFa physically associates with the histone deacetylases (HDAC) 1 and 2, and both HDACs are bound to the CD11d promoter in vivo but released after exposure of myeloid cells to phorbol ester suggesting that gut-enriched Kruppel-like factor 4 (GKLF)/GKLFa recruits HDACs to effect repression
We show using chromatin immunoprecipitation assays (ChIP) that the up-regulation of CD11d in phorbol-12-myristate 13-acetate (PMA)-stimulated myeloid cells correlates with reduced occupancy of the CD11d promoter by GKLF/GKLFa and histone deacetylases (HDAC) 1 and 2 in vivo

Summary

Introduction

The four members of the leukocyte integrin family are composed of distinct ␣-subunits encoded by the CD11a [8], CD11b [9], CD11c [10], and CD11d [11] genes that non-covalently associate with a common ␤-subunit, encoded by the CD18 gene [12]. ChIP analysis revealed that the amount of GKLF/ GKLFa bound to the Ϫ200 to Ϫ20 region of the CD11d promoter in PMA-stimulated THP1 and HL60 cells was significantly reduced compared with the amount bound in unstimulated cells (Fig. 5, A and C).

Results

Conclusion