Production of interleukin 4 and interferon gamma in CD8+ T cells from patients with intrinsic and extrinsic asthma

Park, Soo Young; Cho, Young Joo

Abstract

BACKGROUND: Asthma has been divided clinically into extrinsic and intrinsic variants. However, it is not clear whether these two types of clinically different asthma are mediated by immunolo- gically common pathogenesis or not. Recently, the role of CD8+ T cells in allergic inflammation was suggested.
OBJECTIVES
The aims of this study were to determine the role of CD8+ T cells in asthma through the production of interleukin 4 (IL-4) and interferon gamma (IFN-gamma), and to see if there were any differences in cytokine production in CD8+ T cell by the two clinically different asthma types, intrinsic and extrinsic asthma. METHOD: Peripheral blood mononuclear cells from intrinsic and extrinsic asthmatic patients and from healthy subjects were cultured and stimulated with phorbol ester and calcium ionophore. A three-color flow cytometric analysis was used for IL-4 and IFN-gamma detection in CD8+ T cells.
RESULTS
Intracytoplasmic IL-4 and IFN-gamma positive CD8+ T cells were significantly higher in asthmatic patients compared to normal subjects. However, there were no significant differences of IL-4 and IFN-gamma production between intrinsic and extrinsic asthmatic patients (IL-4:12.5+/-4.2% in intrinsic asthmatics, 16.3+/-7.2% in extrinsic asthmatics, 4.2+/-2.1% in normals; IFN-gamma: 33.4+/-3.2%, 35.4+/-5.5%, 25.3+/-9.8%, respectively)
CONCLUSION
These results suggest that intrinsic and extrinsic asthma have common immuno- pathogenesis and CD8+ T cells seem to participate in asthmatic inflammation by producing IL-4 and IFN-gamma.