title: Helios expression is a marker of T cell activation and proliferation.
abstract: Foxp3+ T-regulatory cells (Tregs) normally serve to attenuate immune responses and are key to maintenance of immune homeostasis. Over the past decade, Treg cells have become a major focus of research for many groups, and various functional subsets have been characterized. Recently, the Ikaros family member, Helios, was reported as a marker to discriminate naturally occurring, thymic-derived Tregs from those peripherally induced from naïve CD4+ T cells. We investigated Helios expression in murine and human T cells under resting or activating conditions, using well-characterized molecules of naïve/effector/memory phenotypes, as well as a set of Treg-associated markers. We found that Helios-negative T cells are enriched for naïve T cell phenotypes and vice versa. Moreover, Helios can be induced during T cell activation and proliferation, but regresses in the same cells under resting conditions. We demonstrated comparable findings using human and murine CD4+Foxp3+ Tregs, as well as in CD4+ and CD8+ T cells. Since Helios expression is associated with T cell activation and cellular division, regardless of the cell subset involved, it does not appear suitable as a marker to distinguish natural and induced Treg cells.
authors.affiliation: Division of Transplant Immunology, Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia and University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Akimova
authors.forename: Ulf H
authors.initials: UH
authors.lastname: Beier
authors.forename: Liqing
authors.initials: L
authors.lastname: Wang
authors.forename: Matthew H
authors.initials: MH
authors.lastname: Levine
authors.forename: Wayne W
authors.initials: WW
authors.lastname: Hancock
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006801:Humans; D051740:Ikaros Transcription Factor / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000502:physiology*; D008297:Male; D051379:Mice; D013601:T-Lymphocytes / Q000378:metabolism*; D050378:T-Lymphocytes, Regulatory / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; C111431:IKZF2 protein, human; D014157:Transcription Factors; C491746:Zfpn1a2 protein, mouse; D051740:Ikaros Transcription Factor