Allergen immunotherapy increases suppressive activity by CD4+CD25-, IL-10 producing T cells, but does not affect suppression by CD4+CD25+ T cells*1

• DOI: 10.1016/j.jaci.2003.12.381
• Publication Date: 2004-02-05T10:34:35Z
• Authors: E LING
• Keywords: Affect

Abstract Rationale Allergen immunotherapy (AI) is associated with modulation of Th2-type T cell responses to allergen, and has previously been described as resulting in induction of IL-10 producing T cells. We have previously reported less suppression by CD4+CD25+ regulatory T cells in patients with allergic rhinitis than non-atopics. We asked whether AI- induced regulation of allergen-driven T cell responses resulted from increased activity of naturally occurring CD4+CD25+ or was due to a separate regulatory population of IL-10 producing T cells. Methods During the UK pollen season, peripheral blood CD4+CD25+ and CD4+CD25- T cells were isolated by immunomagnetic columns from patients who had received AI for severe summer hay fever for at least one year and from a control group of rhinitic patients who had not received AI. CD4+CD25- T cells were separated after overnight incubation into IL-10 producing cells and non-IL-10 T cells by a further immunomagnetic step. The ability of CD4+CD25+ or CD4+CD25- IL-10+ T cells to suppress grass pollen allergen-driven cultures of CD4+CD25- T cells was compared between groups. Results Suppression of grass pollen (whole allergen extract and PhlPV) driven proliferation was greater by CD4+CD25- IL-10 producing T cells from patients who had received AI when compared to those who had not (median percent suppression 75% vs 20%, p Conclusions Allergen immunotherapy induces a population of IL-10 producing regulatory T cells, which are distinct from the naturally occurring CD4+CD25+ subset.