title: Regulatory T cells dynamically regulate selectin ligand function during multiple challenge contact hypersensitivity.
abstract: Regulatory T cells (Tregs) play critical roles in restricting T cell-mediated inflammation. In the skin, this is dependent on expression of selectin ligands required for leukocyte rolling in dermal microvessels. However, whether there are differences in the molecules used by Tregs and proinflammatory T cells to undergo rolling in the skin remains unclear. In this study, we used spinning disk confocal microscopy in Foxp3-GFP mice to visualize rolling of endogenous Tregs in dermal postcapillary venules. Tregs underwent consistent but low-frequency rolling interactions under resting and inflamed conditions. At the early stage of the response, Treg adhesion was minimal. However, at the peak of inflammation, Tregs made up 40% of the adherent CD4(+) T cell population. In a multiple challenge model of contact hypersensitivity, rolling of Tregs and conventional CD4(+) T cells was mostly dependent on overlapping contributions of P- and E-selectin. However, after a second challenge, rolling of Tregs but not conventional CD4(+) T cells became P-selectin independent, and Tregs showed reduced capacity to bind P-selectin. Moreover, inhibition of E-selectin at this time point resulted in exacerbation of inflammation. These findings demonstrate that in this multiple challenge model of inflammation, Treg selectin binding capacity and the molecular basis of Treg rolling can be regulated dynamically.
authors.affiliation: Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, Clayton, Victoria 3168, Australia;
authors.forename: Latasha D
authors.initials: LD
authors.lastname: Abeynaike
authors.affiliation: Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, Clayton, Victoria 3168, Australia;
authors.forename: James A
authors.initials: JA
authors.lastname: Deane
authors.affiliation: Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, Clayton, Victoria 3168, Australia;
authors.forename: Clare L V
authors.initials: CL
authors.lastname: Westhorpe
authors.affiliation: Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, Clayton, Victoria 3168, Australia;
authors.forename: Zachary
authors.initials: Z
authors.lastname: Chow
authors.affiliation: Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, Clayton, Victoria 3168, Australia;
authors.forename: Maliha A
authors.initials: MA
authors.lastname: Alikhan
authors.affiliation: Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, Clayton, Victoria 3168, Australia; Department of Nephrology, Monash Medical Centre, Clayton, Victoria 3168, Australia; Department of Pediatric Nephrology, Monash Medical Centre, Clayton, Victoria 3168, Australia;
authors.forename: A Richard
authors.initials: AR
authors.lastname: Kitching
authors.affiliation: Department of Pediatrics, Dalhousie University, Halifax, Nova Scotia, Canada B3K 6R8; Department of Microbiology & Immunology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2; and Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2.
authors.forename: Andrew
authors.initials: A
authors.lastname: Issekutz
authors.affiliation: Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, Clayton, Victoria 3168, Australia; michael.hickey@monash.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Hickey
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D002465:Cell Movement; D003877:Dermatitis, Contact / Q000209:etiology / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D019040:E-Selectin / Q000235:genetics / Q000276:immunology*; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000276:immunology; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000276:immunology; D008024:Ligands; D051379:Mice; D008822:Mice, Transgenic; D010080:Oxazoles / Q000494:pharmacology; D019007:P-Selectin / Q000235:genetics / Q000276:immunology*; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D015398:Signal Transduction; D012867:Skin / Q000098:blood supply / Q000276:immunology* / Q000473:pathology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000473:pathology
chemical_list: D019040:E-Selectin; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D008024:Ligands; D010080:Oxazoles; D019007:P-Selectin; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins