Cat allergen peptide immunotherapy reduces CD4+ T cell responses to cat allergen but does not alter suppression by CD4+ CD25+ T cells: a double‐blind placebo …

TRF Smith, C Alexander, AB Kay, M Larche… - Allergy, 2004 - Wiley Online Library
TRF Smith, C Alexander, AB Kay, M Larche, DS Robinson
Allergy, 2004Wiley Online Library
Background: We have previously described both modification of allergen immunotherapy
using peptide fragments, and reduced regulation of allergen stimulated T cells by CD4+
CD25+ T cells from allergic donors when compared with nonallergic controls. It has been
suggested that allergen immunotherapy induces regulatory T cell activity: we hypothesized
that allergen peptide immunotherapy might increase suppressive activity of CD4+ CD25+ T
cells. Objective: To examine cat allergen‐stimulated CD4 T cell responses and their …
Background:  We have previously described both modification of allergen immunotherapy using peptide fragments, and reduced regulation of allergen stimulated T cells by CD4+ CD25+ T cells from allergic donors when compared with nonallergic controls. It has been suggested that allergen immunotherapy induces regulatory T cell activity: we hypothesized that allergen peptide immunotherapy might increase suppressive activity of CD4+ CD25+ T cells.
Objective:  To examine cat allergen‐stimulated CD4 T cell responses and their suppression by CD4+ CD25+ T cells before and after cat allergen peptide immunotherapy in a double‐blind placebo‐controlled study.
Methods:  Peripheral blood was obtained and stored before and after peptide immunotherapy or placebo treatment. CD4+ and CD4+ CD25+ were then isolated by immunomagnetic beads and cultured with allergen in vitro.
Results:  Comparing cells from blood taken before with that after peptide immunotherapy there was a significant reduction in both proliferation and IL‐13 production by allergen‐stimulated CD4+ T cells, whereas no change was seen after placebo. CD4+ CD25+ T cells suppressed both proliferation and IL‐13 production by CD4+ CD25 T cells before and after therapy but peptide therapy was not associated with any change in suppressive activity of these cells.
Conclusion:  Allergen peptide immunotherapy alters T cell response to allergen through mechanisms other than changes in CD4+ CD25+ T cell suppression.
Wiley Online Library