[Cytokine profiles of CD4(+) T memory cells in asthma and their relationship with asthma severity]

Objective: To study the phenotype of memory CD4(+) T cells in peripheral blood of asthmatics and its relationship with asthma severity. Methods: From Dec 2014 to Aug 2015, thirty-three asthmatics, twenty-six chronic obstructive pulmonary disease (COPD) patients and twenty-two healthy volunteers were enrolled in Respiratory Clinics of Zhongshan Hospital, Fudan University. Peripheral blood mononuclear cells (PBMCs) were isolated from peripheral blood. Cell surface markers (CD45RO, CRTH2, CD62L, and CCR7) and intracellular protein[interleukin (IL)-5, IL-17, interferon (IFN)-γ]staining was performed using flow-cytometric techniques. CD4(+) T cells were cultured under neutralization and then Th2, Th2+ Lipopolysaccharide (LPS), Th2+ Home dust mite (HDM) conditions for 6 days and then intracellular proteins were analyzed using flow cytometry. Correlation analysis between memory CD4(+) T cells, asthma severity and drug consumption were performed. Results: The percentage of memory CD4(+) T (CD4(+) Tm) cells in circulating white blood cells was higher in asthmatics, than that in healthy subjects (48.0%±5.7% vs 32.0%±4.1%, P<0.05). The cytokine profiles of CD4(+) Tm cells in asthma patients were substantially different from those of COPD and healthy subjects, with increased IL-5 and IL-17 production. For COPD patients, the predominant cytokines were IFN-γ instead. IL-17-producing CD4(+) Tm cells were associated with the severity of disease and the level of medication consumption in asthma patients (R(2)=0.829 6, P<0.05). Conclusions: The cytokine profile is IL-5 and IL-17 predominant in memory CD4(+) T cells from asthmatics. The amount of IL-17(+) CD4(+) memory T cells is positively correlated with asthma severity.