Regulatory T Cells Protect Against Experimentally-Induced Asthma by Altering the Dendritic Cell Phenotype and Activation State

Neonatal bacillus Calmette–Guérin vaccination inhibits de novo allergic inflammatory response in mice via alteration of CD4+CD25+ T-regulatory cells

“…It has been shown that CD4 + CD25 + Treg cells isolated from hay fever patients have an impaired ability to suppress proliferation and IL-5 production of CD4 + CD25 -T cells compared with healthy controls [19] . Lewkowich et al used an anti-CD25 antibody to deplete CD25 + cells in vivo and showed that the depletion of CD25 + cells before delivery of a house dust mite allergen led to significantly increased Th2 cytokine responses, IgE levels, eosinophilia, and allergen-induced airway hyperresponsiveness (AHR) in allergy-resistant mice [20] . Using a complementary approach, Kearley et al transferred Treg cells to the immunocompetent mice previously sensitized with OVA and thus inhibited AHR, eosinophil recruitment, and Th2 cytokine production [21] .…”

“…There is growing and conflicting evidence concerning the roles of IL-10 and transforming growth factor (TGF)-β [17,18] . A number of studies have shown that CD4 + CD25 + Treg cells play an essential role in limiting the development of immune response in allergy and asthma [19][20][21] . Therapeutic opportunities to exploit the immunosuppressive effects of Treg cells for prophylactic or therapeutic treatment may become feasible.…”

Regulatory T cells and IL-10 in allergic inflammation

“…Two studies in this issue clarify the role of CD4 ϩ CD25 ϩ T reg cells in the regulation of allergic responses and show several similarities to observations made in humans. The study by Lewkowich et al (p. 1549) investigates the impact of depleting CD4 ϩ CD25 ϩ T reg cells on sensitization to allergens in susceptible and resistant strains of immunocompetent mice (18). The study by Kearley et al (p. 1539) examines the effect of adoptively transferring CD4 ϩ CD25 ϩ T reg cells into allergen-sensitized mice before antigen challenge (19).…”

The functional insufficiency of human CD4+CD25high T‐regulatory cells in allergic asthma is subjected to TNF‐α modulation

“…Although the development of AHR is unaffected by altering the number of CD4 + CD25 + Treg cells (12, 13), the development of eosinophilic airway inflammation is reported to be both increased (12), and paradoxically decreased (14), after depletion of naturally occurring CD4 + CD25 + Treg cells. This discrepancy may be due to the different genetic backgrounds of the mice studied (15). However, the factors that influence the functional capacity in Treg cell‐mediated suppression of allergen‐specific immune responses have not been delineated in allergic asthmatic patients.…”