Regulation of nickel-induced T-cell responsiveness by CD4+CD25+ cells in contact allergic patients and healthy individuals.
In this study, we investigated the capacity of CD4+CD25+ regulatory T cells to suppress nickel-specific effector T cells, both in nickel-allergic patients and healthy controls. CD4+ cells isolated from allergic patients showed an increased proliferative response to nickel, whereas CD4+ cells from negative controls did not respond to allergen. When CD4+CD25+ cells were depleted, nickel-specific responsiveness was strongly increased both in allergic and in non-allergic individuals, with the most pronounced effect in allergic patients. These regulatory T cells were anergic to nickel but inhibited nickel-specific CD4+CD25- effector T cells in coculture experiments. CD4+CD25+ cells from nickel-allergic patients showed only a limited capacity to suppress effector T-cell responsiveness, because an increased nickel reactivity could still be detected in these cocultures. None of the isolated CD4+CD25+ cells, either isolated from healthy controls or allergic patients, produced IL-10 in response to nickel. Overall, these results support the view that CD4+CD25+ cells can control the activation of nickel-specific effector T cells in non-allergic individuals, whereas this regulatory capacity is impaired in allergic patients. To investigate the presence of allergen-specific regulatory T cells in truly naïve, non-sensitized individuals, T-cell reactivity should also be studied with non-environmental contact allergens, such as para-phenylenediamine.
Moed
H
H
Department of Dermatology, VU University Medical Center Amsterdam, the Netherlands.
von Blomberg
B M E
BM
Bruynzeel
D P
DP
Scheper
R J
RJ
Gibbs
S
S
Rustemeyer
T
T
D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D016022:Case-Control Studies; D049109:Cell Proliferation; D018920:Coculture Techniques; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D016753:Interleukin-10 / Q000097:blood; D009532:Nickel / Q000276:immunology*; D015375:Receptors, Interleukin-2 / Q000276:immunology*
D015375:Receptors, Interleukin-2; D016753:Interleukin-10; D009532:Nickel