Maturation of Human Monocyte-derived Dendritic Cells Studied by Microarray Hybridization

Allan B. Dietz, Peggy A. Bulur, Gaylord J. Knutson, Richard Matasic and Stanimir Vuk-Pavlovic (2000) BBRC 275, 731-738

Abstract

We compared the transcript profiles of human myeloid immature dendritic (IDC) cells and mature dendritic cells (MDC) by hybridization of cell-derived cDNA to DNA probes immobilized on microarrays. The microarrays contained probes for 4110 known genes. We report maturation–dependent changes in transcription of clusters of differentiation, cytokines, cytokine receptors, chemokines, chemokine receptors, neuropeptides, adhesion molecules and other genes. We identified 1124 transcripts expressed in IDC and 1556 transcripts expressed in MDC. Maturation increased the levels of 291 transcripts twofold or more and reduced the levels of 78 transcripts to one half or less than in IDC. We identified a concerted maturation–stage dependent transcription of the variable chains of the members of the -chain–cytokine receptor family IL-4R, IL-7R, and IL-15R. Also, we found the reversal of the ratio of transcripts for galectin-3 and galectin-9 upon maturation. We identified maturation–dependent changes in the levels of transcripts for numerous genes encoding proteins previously undetected in dendritic cells such as indoleamine 2,3-deoxygenase, Epstein-Barr virus induced protein 3 and kinesin-2. Moreover, MDC transcribed and translated insulin like growth factor-1 receptor, transforming growth factor , and neuropeptide Y.

Introduction

Dendritic cell function is regulated by stimulatory signals originating from infection (1-3), tissue damage or other "danger" signals (4), and inhibitory signals such as interleukin-10 (5), corticosteroids (6, 7), or vascular endothelial growth factor (8). Immature dendritic cells (IDC) reside at sentinel locations, e.g., skin and mucous membranes, where they detect regulatory signals. When a stimulatory threshold is reached, IDC terminally differentiate (mature) into mature dendritic cells (MDC) that migrate to lymph nodes where they recruit and stimulate naive T cells (cf. refs. 9 and 10). Consequently, maturation of dendritic cells is critical to the initiation of the immune response (11, 12).

Dendritic cells are characterized by antigen uptake, presentation, directional migration, and stimulation of T-cell responses (reviewed in Refs. 9 and 10). These functional characteristics, best described in dendritic cells of myeloid origin, are profoundly affected by maturation of IDC to MDC (9, 10). Maturation reduces the high rate of antigen uptake and increases cell surface expression of antigen presenting molecules, costimulatory molecules, and the secretion of cytokines and chemokines. Likewise, maturation alters the expression of adhesion molecules and receptors involved in migration, homing and cell–cell interactions of dendritic cells. These features have been intensely studied by immunological, cell biology and biochemical techniques; however, a comprehensive understanding of dendritic cell maturation based on a global analysis of changes in gene expression is still lacking.

Insight into global changes in gene expression has been made possible through the use of sequential analysis of gene expression (SAGE) (13) and hybridization to DNA immobilized on solid-state microarrays (14-16). The power of microarray analysis has been demonstrated in studies of the effects of serum on transcription dynamics in serum-starved fibroblasts (17), in characterizing transcription patterns in human tumors (18, 19) and chronically inflamed tissues in rheumatoid arthritis and inflammatory bowel disease (20). Recently, SAGE was applied to the

transformation of human monocytes into IDC (21), but the critical terminal differentiation of IDC into MDC has not been characterized. Consequently, we analyzed global changes in transcription that accompany this final maturation step. We report the results of probing 4110 transcripts for known genes with cDNA from IDC and MDC. We classified the data by the function or serologic characteristics of the respective gene products. The transcript levels correlated well with the published data for expression of cluster of differentiation (CD) proteins as well as with the reports for maturation stage-dependent transcription of chemokine receptors. We describe transcription of genes hitherto undetected in dendritic cells as well as genes not previously associated with dendritic cell maturation. Also, we demonstrate coordinated changes in transcription that indicate novel features and functions in dendritic cell maturation.