Effects of Astragalus membranaceus in promoting T-helper cell type 1 polarization and interferon-gamma production by up-regulating T-bet expression in patients with asthma.
OBJECTIVE
To explore the effect of Astragalus membranaceus (AM) on T-helper cell type 1 (Thl) specific transcription factor T-box expressed in T cells (T-bet) expression and Thl/Th2 equilibrium.


METHODS
The levels of T-bet mRNA in peripheral blood mononuclear cells (PBMCs) from 15 patients with asthma and 15 healthy subjects were determined by reverse transcription-polymerase chain reaction (RT-PCR). PBMCs in asthma patients were incubated with AM and then the concentration of interferon gamma (IFN-gamma) and interleukin-4 (IL-4) in the supernate before and after AM intervention were determined by ELISA. The numbers of CD4 + CCR3 + and CD4 + CCR5 + cells were counted by flow cytometry.


RESULTS
The expression of T-bet mRNA and the level of IFN-gamma were lower, but level of serum IL-4 was higher in asthma patients when compared with those in healthy subjects respectively. After AM (60 microg/ml) intervention, the former two parameters raised and showed a positive correlation between them, while the level of IL-4 was decreased. The mean percentage of CD4 + CCR3 + cells in asthma patients was significantly higher but that of CD4 + CCR5 + cells was lower when compared with those in healthy subjects respectively. After AM intervention, the abnormal change in the two indexes was improved to certain extent, showing a reversing status of Th2 polarization.


CONCLUSIONS
AM could increase the expression of T-bet mRNA and Thl cytokines such as IFN-Y, and might reverse the Th2 predominant status in asthma patients.
Wang
Gang
G
Department of Integrated Traditional Chinese and Western Medicine, West China Hospital, Sichuan University, Chengdu (610041).
Liu
Chun-tao
CT
Wang
Zeng-li
ZL
Yan
Cun-liang
CL
Luo
Feng-ming
FM
Wang
Lei
L
Li
Ting-qian
TQ
D000328:Adult; D001249:Asthma / Q000188:drug therapy* / Q000276:immunology; D027885:Astragalus propinquus; D016764:Cell Polarity; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis* / Q000097:blood; D015847:Interleukin-4 / Q000097:blood; D008297:Male; D008875:Middle Aged; D008517:Phytotherapy; D012333:RNA, Messenger / Q000032:analysis; D054397:Receptors, CCR3; D019713:Receptors, CCR5 / Q000097:blood; D019707:Receptors, Chemokine / Q000097:blood; D020825:T-Box Domain Proteins / Q000235:genetics*; D018417:Th1 Cells / Q000187:drug effects* / Q000276:immunology; D015854:Up-Regulation; D000098815:T-bet Transcription Factor
C515350:CCR3 protein, human; D012333:RNA, Messenger; D054397:Receptors, CCR3; D019713:Receptors, CCR5; D019707:Receptors, Chemokine; D020825:T-Box Domain Proteins; D000098815:T-bet Transcription Factor; D015847:Interleukin-4; D007371:Interferon-gamma