Depletion of CD4(+)CD25(+)CD127(lo) regulatory T cells does not increase allergen-driven T cell activation

作者：Skrindo I^*; Farkas L; Kvale E O; Johansen F E; Jahnsen F L

来源：Clinical and Experimental Allergy, 2008, 38(11): 1752-1759.

DOI：10.1111/j.1365-2222.2008.03081.x

• allergic rhinitis
• allergy
• human
• regulatory T cells
• T cells
• Th2 cytokines

Background It has been suggested that allergic diseases are caused by defective suppression of allergen-specific Th2 cells by CD4(+)CD25(+) regulatory T cells. However, such studies have been hampered by the difficulty in distinguishing regulatory T cells from CD25-expressing activated T cells. Recently, it was shown that conventional T cells expressed high levels of CD127, whereas regulatory T cells were CD127(lo), allowing discrimination between these distinct T cell subpopulations.
Objective The aim of this study was to study whether the putative regulatory subset defined as CD4(+)CD25(+)CD127(lo) was involved in grass pollen-reactive T cell responses.
Methods Peripheral blood mononuclear cells (PBMCs) were obtained from allergic donors and non-atopic controls out of season. Grass pollen-induced cytokine production and proliferation were compared in cultures of undepleted cells and cells depleted of CD4(+)CD25(+), CD4(+)CD25(+)CD127(hi) or CD4(+)CD25(+)CD127(lo) T cells.
Results Undepleted cell cultures from allergic patients showed significantly increased proliferation and Th2 cytokine production compared with non-atopic controls. Depletion of all CD25(+) T cells did not increase cytokine production or proliferation, and more importantly, no increase in Th2 cytokine production or proliferation was observed in cell cultures depleted of CD4(+)CD25(+)CD127(lo) cells (putative regulatory T cells) compared with undepleted PBMCs in both the allergic and the non-atopic group.
Conclusion Our study showed that T cells from grass pollen-allergic patients and non-atopic controls responded very differently to grass pollen extract, but this difference could not be explained by differences in regulatory T cell function. Further studies are needed to understand the importance of regulatory T cells in allergy.

• 出版日期2008-11