Identification and Characterization of DC-SCRIPT, a Novel Dendritic Cell-Expressed Member of the Zinc Finger Family of Transcriptional Regulators 1 Vassilis Triantis,* Dagmar Eleveld Trancikova,* Maaike W. G. Looman,* Franca C. Hartgers, † Richard A. J. Janssen, ‡ and Gosse J. Adema 2 * Dendritic cells (DC) compose a heterogeneous population of cells that hold a leading role in initiating and directing immune responses. Although their function in recognizing, capturing, and presenting Ags is well defined, the molecular mechanisms that control their differentiation and immune functions are still largely unknown. In this study, we report the isolation and charac- terization of DC-SCRIPT, a novel protein encoded by an 8-kb mRNA that is preferentially expressed in DC. DC-SCRIPT is expressed in multiple DC subsets in vivo, including myeloid DC, plasmacytoid DC, and Langerhans cells. At the protein level, DC-SCRIPT consists of a proline-rich region, 11 C 2 H 2 -type zinc fingers, and an acidic region. Localization studies reveal that DC-SCRIPT resides in the nucleus and that nuclear localization is critically dependent on the zinc fingers. The protein displays no transcriptional activation properties according to assorted transactivation assays, but interacts with the corepressor C-terminal binding protein 1. Taken together, our results show that we have isolated a novel DC marker that could be involved in tran- scriptional repression. In contrast to other DC molecules, DC-SCRIPT identifies all DC subsets tested to date. The Journal of Immunology, 2006, 176: 1081–1089. D endritic cells (DC) 3 play a pivotal role in adaptive im- munity, because they are the initiators of immune re- sponses. DC are APC that capture Ags in the periphery, process them, and present their peptides in the context of MHC molecules to T cells (1). To activate naive T cells, DC must be activated. Different stimuli such as bacterial or viral products (LPS and dsRNA) (2– 4), cell-to-cell interactions (CD40-CD40L) (5), or soluble factors (TNF-) (6) are able to activate DC, a process referred to as DC maturation. Upon maturation, DC undergo sev- eral functional and morphological changes, such as up-regulation of costimulatory molecules, enhanced peptide loading of MHC classes I and II, and dendrite formation, and migrate to T cell areas of secondary lymphoid tissue where they can launch immune re- sponses (1). DC are the most potent APC, and they are involved in immunity and tolerance (7). There are two main subsets described (type I IFN- producing plasmacytoid DC (PDC) and myeloid DC (MDC)) that originate from different hemopoietic lineages, but also a certain sub- set, Langerhans cells (LC), that resides exclusively at the skin. Dis- tinct subsets may exert diverse functions, such as modulating the type of immune response (8, 9). Even though their functional capacity has been well demonstrated, and DC have already been used in clinical trials, the molecular mechanisms that lie beneath their potency are still, to a great extent, unknown. There have been several DC-specific molecules described, and many of them relate to their immunological capacity, such as DC-specific ICAM-3 grabbing nonintegrin (DC- SIGN), DC-chemokine 1, DC-specific transmembrane protein (DC- STAMP), and langerin (10 –13), yet the molecular basis for their de- velopment and unique function remains largely unknown. Surely, DC induction of immune responses or tolerance must be fine-tuned, and a network of transcription factors has been implicated in DC develop- ment and immunobiology, including PU.1, SpiB, Id2, and RelB (14 – 17). For example, SpiB promotes plasmacytoid DC development while blocking T, B, and NK cell development from hemopoietic precursors. Cross-talk between C/EBP transcription factors and PU.1 is required for myeloid DC development and differentiation. PU.1 is expressed in multiple hemopoietic lineages as well as CD34 + cells, and PU.1-null mice were unable to generate MHC class II high CD11c + MDC in vitro. Id2 is induced by TGF- and was also shown to or- chestrate LC development by repressing B cell genes in DC, whereas RelB, a component of the NF-B complex of transcription factors, is a critical regulator of DC differentiation. In mice, the lack of RelB impairs DC derived from bone marrow in both number and function. Thus, a balanced network of transcription factors governs the devel- opment and function of DC. To characterize more genes entangled in DC immunobiology, we previously applied differential display PCR (DD-PCR) to DC. We report the identification of a novel putative transcription re- pressor expressed in DC, DC-SCRIPT. DC-SCRIPT encodes for a unique protein with a putative DNA binding domain flanked by domains that could be involved in gene regulation. The gene is expressed by several DC subsets, both in vitro and in vivo, *Department of Tumor Immunology, Nijmegen Center for Molecular Life Sciences, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands; † Depart- ment of Parasitology, Leiden University Medical Center, Leiden, The Netherlands; and ‡ Gala ´deno, Leiden, The Netherlands Received for publication April 27, 2005. Accepted for publication October 31, 2005. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. 1 This work was supported by Grants 901-10-092 and 912-02-034 from the Dutch Foundation for Scientific Research. 2 Address correspondence and reprint requests to Dr. Gosse J. Adema, Department of Tumor Immunology 187, Nijmegen Center for Molecular Life Sciences, Radboud University Nijmegen Medical Center, P.O. Box 9101, 6500 HB Nijmegen, The Neth- erlands. For express deliveries: Geert Grooteplein Zuid 28, 6525 GA Nijmegen, The Netherlands. E-mail: g.adema@ncmls.ru.nl 3 Abbreviations used in this paper: DC, dendritic cell; DD-PCR, differential display PCR; HEK, human embryonic kidney; LC, Langerhans cell; MDC, myeloid DC; NLS, nuclear localization sequence; PDC, plasmacytoid DC; ORF, open reading frame; YFP, yellow fluorescence protein; DC-SIGN, DC-specific ICAM-3 grabbing nonintegrin; DC-STAMP, DC-specific transmembrane protein; CtBP1, C-terminal binding protein 1. The Journal of Immunology Copyright © 2006 by The American Association of Immunologists, Inc. 0022-1767/06/$02.00