Flow cytometry imaging identifies rare T(H)2 cells expressing thymic stromal lymphopoietin receptor in a "proallergic" milieu.
J Allergy Clin Immunol 2010;
126:1049-58, 1058.e1-10. [PMID:
20888036 DOI:
10.1016/j.jaci.2010.07.023]
[Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Revised: 07/21/2010] [Accepted: 07/23/2010] [Indexed: 01/24/2023]
Abstract
BACKGROUND
Thymic stromal lymphopoietin (TSLP) is expressed at sites of allergic inflammation, including eczematous skin. This cytokine has been reported to exert its T(H)2-inducing properties through dendritic cells. Expression of TSLP receptor on the surface of activated T(H)2 cells could amplify T(H)2 responses at inflamed sites through the direct actions of TSLP.
OBJECTIVE
To test rigorously whether T(H)2 cells induced by "proallergic" factors express TSLP receptor and characterize these cells using an experimental platform that combines flow cytometry with microscopic capabilities.
METHODS
CD4(+) T cells isolated from patients with atopic dermatitis or normal healthy controls were cocultured with autologous dendritic cells in the presence of T(H)2-promoting stimuli (TSLP ± allergen and staphylococcal enterotoxin B ± TSLP). Surface expression of TSLP receptor was analyzed by image-based flow cytometry, and responsiveness of purified T cells to TSLP was assessed by phosphorylation of signal transducer and activator of transcription-5 and cytokine secretion.
RESULTS
T(H)2-promoting stimuli induced a robust population of activated T(H)2 cells (CD25(+)IL-4(+)). Regardless of the nature of the stimulus, flow cytometry imaging confirmed that T cells expressing TSLP receptor were rare, constituting a minor fraction of the IL-4(+) T cell pool; however, TSLP responsiveness was nonetheless detectable. Analysis of cell size and nuclear morphology revealed preferential expression of TSLP receptor on IL-4-expressing cells undergoing mitosis. Analysis of lesional skin in atopic dermatitis supported the view that rare IL-4(+) T cells expressing TSLP receptor are present at inflamed sites.
CONCLUSION
In a "proallergic" milieu, TSLP receptor is preferentially expressed on rare actively dividing T(H)2 cells. The direct action of TSLP on T cells could amplify T(H)2 responses at sites of allergic inflammation.
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