Changes in percentage and function of CD4+CD25+regulatory T cells in peripheral blood of patients with hay fever / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the changes in percentage and function of CD4+CD25+regu-latory T cells ( Tregs) in peripheral blood of patients with hay fever. Methods A total of 20 patients with hay fever, 20 patients with house dust mite-induced allergic asthma and 20 healthy subjects were enrolled in this study. Peripheral blood samples were collected from all subjects to isolate PBMCs. Percentages of Tregs in PBMCs were measured by flow cytometry. CD4+CD25+ Tregs and CD4+CD25-T cells ( Teffs) were isola-ted by immunomagnetic cell sorting. Effects of CD4+CD25+Tregs on the proliferation of Teffs were evaluated by MTT assay. Expression of Foxp3 and TGF-β1 at mRNA level was analyzed by RT-PCR. Results During the pollen season, the percentage of circulating Tregs in patients with hay fever [(1. 82+0. 82)％] was sig-nificantly lower than that in patients with house dust mite-induced allergic asthma [(2. 96±1. 34)％] and health subjects [(5. 78±2. 29)％] (both P<0. 05). Expression of Foxp3 at mRNA level was significantly reduced in patients with hay fever (0. 46±0. 25) as compared with that of the house dust mite-induced aller-gic asthma (0. 64±0. 31) and healthy control (1. 04±0. 21) groups (both P<0. 05). Expression of TGF-β1 at mRNA level in both hay fever (0. 34±0. 27) and house dust mite-induced allergic asthma (0. 43±0. 31) groups was lower than that of the healthy control group (0. 99±0. 34). Treg-mediated suppression of Teff proliferation was significantly decreased in patients with hay fever [(17. 1±8. 4)％] as compared with that in patients with house dust mite-induced allergic asthma [(21. 4±9. 1)％]) and healthy subjects [(36. 0± 13. 9)％] (P<0. 05). Conclusion Decreased percentage and defective function of Tregs might be one of the major causes for the occurrence and development of hay fever in children during the pollen season.