卡介苗干预对哮喘小鼠干细胞因子表达的影响

摘要

目的：研究卡介苗（BCG）对哮喘小鼠干细胞因子（SCF）表达的影响。方法昆明小鼠随机分为哮喘组、BCG组和对照组，每组10只，以卵清蛋白（OVA）致敏激发建立哮喘模型。末次激发24 h后取肺组织及支气管肺泡灌洗液（BALF），计数嗜酸性粒细胞（EOS）；酶联免疫吸附法检测BALF中SCF水平；免疫组织化学图像分析技术测定肺组织中SCF蛋白表达。结果哮喘组、BCG组和对照组肺组织的EOS计数分别为（10.67±1.94）个/HP（、6.40±1.55）个/HP和（0.37±0.33）个/HP，BALF中EOS计数分别为（7.58±1.30）×107/L、（3.78±1.15）×107/L和0，三组间差异有统计学意义（P均<0.01）。哮喘组、BCG组和对照组的肺组织SCF蛋白免疫组化指数分别为（24787.97±7214.12）（、20509.50±4775.27）和（12261.66±3277.65），BALF中SCF水平分别为（280.25±14.20）pg/ml、（266.77±31.15）pg/ml和（223.59±15.61）pg/ml，其中哮喘组和BCG组均高于对照组，差异有统计学意义（P均<0.05），BCG组与哮喘组差异无统计学意义（P>0.05）。哮喘组肺部SCF表达与EOS计数呈正相关（P<0.05）。结论 BCG干预能显著减轻哮喘小鼠的气道炎症，但不能抑制SCF的表达。%Objective To study the effects of Bacillus Calmette-Guerin (BCG) intervention on the expression of stem cell factor (SCF) in asthma. Methods Kunming mice were randomly divided into asthmatic group, BCG group and control group of ten mice each group. Mice were sensitized and challenged with ovalbumin (OVA) to establish asthmatic model. After twenty-four hours of last challenge, eosinophils (EOS) were counted in the lung tissue and bronchoaveolar lavage fluid (BALF). The level of SCF in BALF was determined by enzyme-linked immunosorbent assay. The expression of SCF protein in lung tis-sue was measured by immunohistochemistry technique and computerized image analysis system. Results The number of EOS in lung tissue was (10.67±1.94)/HP, (6.40±1.55)/HP and (0.37±0.33)/HP in asthmatic, BCG and control group respectively. The number of EOS in BALF was (7.58 ± 1.30) × 107/L, (3.78 ± 1.15) × 107/L and 0 in asthmatic, BCG and control group respectively. The difference between each group was statistically significant (P<0.01). The immunohistochemical index of SCF protein in lung was (24787.97±7214.12), (20509.50±4775.27) and (12261.66±3277.65) in asthmatic, BCG and control group respectively. The SCF level of BALF was (280.25 ± 14.20) pg/ml, (266.77 ± 31.15) pg/ml and (223.59 ± 15.61) pg/ml in asthmatic, BCG and control group respectively. The SCF level in BALF in asthmatic and BCG group was significantly different from that in control group (P<0.05). There was no significant difference of SCF level in BALF between BCG and asthmatic group (P>0.05). In asth-matic group, the expression of SCF in lung was positively correlated with the number of EOS (P<0.05). Conclusions BCG treat-ment can markedly decrease the airway inflammation in asthmatic mice. BCG cannot inhibit the expression of SCF in asthma.