title: Effects of IL-7 and dexamethasone: induction of CD25, the high affinity IL-2 receptor, on human CD4+ cells.
abstract: Since we have previously shown that dexamethasone (Dex) enhances the proportion of murine Treg cells, we tested the effect of IL-7, a promoter of T cell survival, together with Dex on human CD4+CD25+ Treg cells in an in vitro setting. The results showed that IL-7 in concert with Dex markedly augmented the generation of CD4+CD25+ T cells. To discern the origin of the induced CD4+CD25+ T cells, MACS-purified CD4+CD25-, and CD4+CD25+ cells were cultured in the presence of Dex and/or IL-7 for 4 days. Although two thirds of CD4+CD25- T cells became CD4+CD25+ T cells, they had no suppressive activity. In contrast, the original CD4+CD25+ T cells maintained suppressive activity after Dex/IL-7 treatment, however, there was not a significant expansion in their cell number. Dex and IL-7 did not induce additional Treg cells, but additively induced the expression of the activation marker CD25 by CD4+CD25- T cells. This combination may provide a novel means of priming CD4 T cells to respond to IL-2 and may prove useful in up-regulation of normal immune responses in immune deficient diseases.
authors.affiliation: Laboratory of Molecular Immunoregulation, Center for Cancer Research, Frederick, MD 21702-1201, USA.
authors.forename: Il Yup
authors.initials: IY
authors.lastname: Chung
authors.forename: Hui Fang
authors.initials: HF
authors.lastname: Dong
authors.forename: Xia
authors.initials: X
authors.lastname: Zhang
authors.forename: Nahed M A
authors.initials: NM
authors.lastname: Hassanein
authors.forename: O M Zack
authors.initials: OM
authors.lastname: Howard
authors.forename: Joost J
authors.initials: JJ
authors.lastname: Oppenheim
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D049109:Cell Proliferation / Q000187:drug effects; D003907:Dexamethasone / Q000494:pharmacology*; D006801:Humans; D015851:Interleukin-7 / Q000494:pharmacology*; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis / Q000187:drug effects* / Q000276:immunology
chemical_list: D015851:Interleukin-7; D015375:Receptors, Interleukin-2; D003907:Dexamethasone