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World J Diabetes. Apr 15, 2017; 8(4): 130-134
Published online Apr 15, 2017. doi: 10.4239/wjd.v8.i4.130
Syndecan-1-coating of interleukin-17-producing natural killer T cells provides a specific method for their visualization and analysis
Anil Kumar Jaiswal, Mohanraj Sadasivam, Abdel Rahim A Hamad
Anil Kumar Jaiswal, Mohanraj Sadasivam, Abdel Rahim A Hamad, Department of Pathology, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, United States
Author contributions: All authors contributed to conception and writing of this article.
Conflict-of-interest statement: Authors declare no coflict of interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Abdel Rahim A Hamad, BVSC, PhD, Associate Professor of Pathology and Medicine, Department of Pathology, Johns Hopkins University, School of Medicine, Ross 66G, 720 Rutland Ave, Baltimore, MD 21205, United States. ahamad@jhmi.edu
Telephone: +1-410-6143021 Fax: +1-410-6143548
Received: November 13, 2016
Peer-review started: November 24, 2016
First decision: January 16, 2017
Revised: January 27, 2017
Accepted: February 18, 2017
Article in press: February 20, 2017
Published online: April 15, 2017
Processing time: 141 Days and 12.3 Hours
Abstract

Natural killer T cells (NKT cells) are innate-like T cells that acquire effector functions while developing in the thymus, polarize into three distinct functional subsets viz. NKT1, NKT2 and NKT17 cells that produce interferon (IFN)-γ, interleukin (IL)-4 and IL-17, respectively. However, there has been no unique surface markers that define each subsets, forcing investigators to use intracellular staining of transcription factors and cytokines in combination of surface markers to distinguish among these subsets. Intracellular staining, however, causes apoptosis and prevents subsequent utilization of NKT cells in functional in vitro and in vivo assays that require viable cells. This limitation has significantly impeded understanding the specific properties of each subset and their interactions with each other. Therefore, there has been fervent efforts to find a specific markers for each NKT cell subset. We have recently identified that syndecan-1 (SDC-1; CD138) as a specific surface marker of NKT17 cells. This discovery now allows visualization of NKT17 in situ and study of their peripheral tissue distribution, characteristics of their TCR and viable sorting for in vitro and in vivo analysis. In addition, it lays the ground working for investigating significance of SDC-1 expression on this particular subset in regulating their roles in host defense and glucose metabolism.

Keywords: Natural killer T cell; NKT17; Syndecan-1 (CD138); Interleukin-17; Body fat

Core tip: Discrete subsets of innate-like Natural killer T (NKT) cells differentially produce three of the most potent and polarizing cytokines, interferon-γ (NKT1), interleukin (IL)-4 (NKT2) and IL-17 (NKT17). But very little is known about how the relationship among the functional subsets of NKT cells is regulated. A major obstacle was the absence of specific single surface markers that reliably identify each subset. Here we highlight our discovery of syndecan-1 as a specific marker of NKT17 subset and its significance for understanding the role of NKT17 in glucose metabolism and autoimmunity.