Tolerance induced by inhaled antigen involves CD4+ T cells expressing membrane-bound TGF-β and FOXP3
Marina Ostroukhova, … , Timothy E. Corcoran, Anuradha Ray
Marina Ostroukhova, … , Timothy E. Corcoran, Anuradha Ray
Published July 1, 2004
Citation Information: J Clin Invest. 2004;114(1):28-38. https://doi.org/10.1172/JCI20509.
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Article Immunology

Tolerance induced by inhaled antigen involves CD4+ T cells expressing membrane-bound TGF-β and FOXP3

Abstract

Under normal circumstances, the respiratory tract maintains immune tolerance in the face of constant antigen provocation. Using a murine model of tolerance induced by repeated exposure to a low dose of aerosolized antigen, we show an important contribution by CD4+ T cells in the establishment and maintenance of tolerance. The CD4+ T cells expressed both cell surface and soluble TGF-β and inhibited the development of an allergic phenotype when adoptively transferred to naive recipient mice. While cells expressing cell surface TGF-β were detectable in mice with inflammation, albeit at a lower frequency compared with that in tolerized mice, only those from tolerized mice expressed FOXP3. Blockade of TGF-β in vitro and in vivo interfered with immunosuppression. Although cells that expressed TGF-β on the cell surface (TGF-β+), as well as the ones that did not (TGF-β–), secreted equivalent levels of soluble TGF-β, only the former were able to blunt the development of an allergic phenotype in mice. Strikingly, separation of the TGF-β+ cells from the rest of the cells allowed the TGF-β– cells to proliferate in response to antigen. We propose a model of antigen-induced tolerance that involves cell-cell contact with regulatory CD4+ T cells that coexpress membrane-bound TGF-β and FOXP3.

Authors

Marina Ostroukhova, Carole Seguin-Devaux, Timothy B. Oriss, Barbara Dixon-McCarthy, Liyan Yang, Bill T. Ameredes, Timothy E. Corcoran, Anuradha Ray

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Suppressive function of CD4+ T cells from tolerized mice. (A) Mice were ...
Suppressive function of CD4+ T cells from tolerized mice. (A) Mice were exposed to PBS (airway inflammation) or 1% OVA (tolerance) and subsequently immunized with OVA and alum on days 21 and 27 after the initiation of OVA/PBS exposure. Splenic CD4+ T cells isolated from mice on day 34 were stimulated in vitro with different concentrations of OVA (0.01–100 ∝g/ml) and mitomycin C–treated, T cell–depleted APCs at equivalent cell numbers (105 cells each per well). After 72 hours of incubation, small samples of culture supernatants were removed for cytokine determination, and the remaining cells were pulsed for measurement of [3H]-thymidine incorporation. *P < 0.025 compared with proliferation of cells from mice immunized for inflammation. The proliferative response of CD4+ T cells from naive mice (open diamonds) is shown as a negative control. An additional control used was a mixture of cells from the inflammation group and from naive mice used in a 1:2 ratio. Each data point represents the mean plus or minus SEM of triplicate wells. Shown is a representative experiment of three. (B) As described above, CD4+ T cells isolated after day 34 were subjected to two rounds of stimulation with OVA and APCs in vitro, and nuclear extracts were prepared. Expression of GATA-3 and FOXP3 was assessed in the nuclear extracts (7–10 ∝g of total protein) by Western blotting techniques. CREB-1 expression is shown as a marker for protein loading. (C) Shown is an average densitometric reading of FOXP3 and GATA-3 expression relative to that of CREB-1 from two independent experiments.