title: Expression of interleukin (IL)-2 and IL-7 receptors discriminates between human regulatory and activated T cells.
abstract: Abnormalities in CD4(+)CD25(+)Foxp3(+) regulatory T (T reg) cells have been implicated in susceptibility to allergic, autoimmune, and immunoinflammatory conditions. However, phenotypic and functional assessment of human T reg cells has been hampered by difficulty in distinguishing between CD25-expressing activated and regulatory T cells. Here, we show that expression of CD127, the alpha chain of the interleukin-7 receptor, allows an unambiguous flow cytometry-based distinction to be made between CD127(lo) T reg cells and CD127(hi) conventional T cells within the CD25(+)CD45RO(+)RA(-) effector/memory and CD45RA(+)RO(-) naive compartments in peripheral blood and lymph node. In healthy volunteers, peripheral blood CD25(+)CD127(lo) cells comprised 6.35 +/- 0.26% of CD4(+) T cells, of which 2.05 +/- 0.14% expressed the naive subset marker CD45RA. Expression of FoxP3 protein and the CD127(lo) phenotype were highly correlated within the CD4(+)CD25(+) population. Moreover, both effector/memory and naive CD25(+)CD127(lo) cells manifested suppressive activity in vitro, whereas CD25(+)CD127(hi) cells did not. Cell surface expression of CD127 therefore allows accurate estimation of T reg cell numbers and isolation of pure populations for in vitro studies and should contribute to our understanding of regulatory abnormalities in immunopathic diseases.
authors.affiliation: Centenary Institute of Cancer Medicine and Cell Biology, Faculty of Medicine, University of Sydney, Newtown, NSW 2042, Australia.
authors.forename: Nabila
authors.initials: N
authors.lastname: Seddiki
authors.forename: Brigitte
authors.initials: B
authors.lastname: Santner-Nanan
authors.forename: Jeff
authors.initials: J
authors.lastname: Martinson
authors.forename: John
authors.initials: J
authors.lastname: Zaunders
authors.forename: Sarah
authors.initials: S
authors.lastname: Sasson
authors.forename: Alan
authors.initials: A
authors.lastname: Landay
authors.forename: Michael
authors.initials: M
authors.lastname: Solomon
authors.forename: Warwick
authors.initials: W
authors.lastname: Selby
authors.forename: Stephen I
authors.initials: SI
authors.lastname: Alexander
authors.forename: Ralph
authors.initials: R
authors.lastname: Nanan
authors.forename: Anthony
authors.initials: A
authors.lastname: Kelleher
authors.forename: Barbara
authors.initials: B
authors.lastname: Fazekas de St Groth
mesh_terms: D000328:Adult; D006801:Humans; D007231:Infant, Newborn; D008213:Lymphocyte Activation / Q000276:immunology*; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis* / Q000235:genetics; D020395:Receptors, Interleukin-7 / Q000096:biosynthesis* / Q000235:genetics; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism*
chemical_list: D015375:Receptors, Interleukin-2; D020395:Receptors, Interleukin-7