摘要
目的观察卡介菌多糖核酸(BCGPSN)对结核分枝杆菌感染小鼠的免疫保护作用及其免疫学机制。方法将BALB/c小鼠48只随机分成BCGPSN免疫治疗组和结核菌感染对照组,每组24只。两组小鼠制成结核分枝杆菌感染模型。感染后1周,每天分别腹腔内注射BCGPSN(10mg/kg)或生理盐水(10mL/kg),连续7d。感染后3周和4周每组处死12只小鼠,检测小鼠体重以及肺、脾脏湿重,观察肺脏病理改变,取肺、脾组织进行结核菌培养和菌落计数,用real-timePCR法测定肺、脾组织IFNγmRNA、IL10mRNA和IL4mRNA的表达。结果感染后4周,治疗组小鼠体重和脾脏重量高于对照组,肺脏重量低于对照组,且肺部病变较轻。感染后3周和4周,治疗组小鼠肺、脾组织结核菌落均低于对照组,小鼠肺组织IFNγmRNA表达与对照组无差别,IL10mRNA和IL4mRNA的表达低于对照组。感染后3周,治疗组小鼠脾组织IFNγmRNA表达与对照组相似;感染后4周,脾组织治疗组脾组织IFNγmRNA的表达高于对照组。感染后3周和4周,IL10mRNA和IL4mRNA的表达低于对照组。结论BCGPSN可减轻结核病小鼠体重下降,减少结核病小鼠肺和脾脏结核菌数量,并增强Th1型免疫反应。
Purpose To study the immunotherapeutic effects and its mechanism of BCG-Polysaccharide Nucleic Acid （BCG-PSN） on murine infection with mycobacterium tuberculosis. Methods Forty-eight BALB/c mice were randomized into 2 groups,A group treated with BCG-PSN,B group treated with saline （n = 24）. 1 × 10^6 bacili in a volume of 300 μL saline were injected into the tail vein of mice in A and B groups. The mice from both group were treated with BCG-PSN （10 mg/kg once a day for 7 days）and saline （ 10 mL/kg once a day for 7 days） intraperitoneally respectively 1 week postinfection. The animals were sacrificed at 3 weeks and 4 weeks postinfection respectively. The weight of body,lung and spleen were measured. Then the lung and spleen of mice were fixed in 10% buffered formalin, paraffin embedded,and processed for histological examination. The numbers of viable bacteria in lung and spleen were counted. The expression of IFN-γ mRNA, IL-10 mRNA and IL-4 mRNA in lung and spleens were detected by real-time PCR method. Results At 4 weeks postinfection,the body weight of mice in A group was higher than that in B group, the lung weight of mice in A group was lower than that in B group,the spleen weight of mice in A group was higher than that in B group. At 3 weeks and 4 weeks postinfection, the numbers of viable bacteria in lungs and spleens of mice from A group were lower than that in B group respectively. At 3 weeks and 4 weeks postinfection,the expression of IFN-γ mRNA in lung tissue of mice from A group was similar to that in B group, the expression of IL-10 mRNA and IL-4 mRNA were less than those in B group respective- ly. At 3 weeks postinfection, the expression of IFN-γ mRNA in spleen tissue of mice from A group was similar to that in B group, while at 4 weeks postinfection, the expression of IFN-γ mRNA in spleen tissue of mice from A group was more than that in B group. At 3 weeks and 4 weeks postinfection,the expression of IL-10 mRNA and IL-4 mRNA were less than those in B group respectively. Conclusions BCG-PSN could improve host defence against mycobacterium tuberculosis and reduce mycobacterial outgrowth during tuberculosis and were associated with a decrease in inflammation in lung tissue by activating the Th1 response.
出处
《复旦学报（医学版）》
CAS
CSCD
北大核心
2005年第5期513-516,F0002,共5页
Fudan University Journal of Medical Sciences
关键词
卡介菌多糖核酸
分枝杆菌
结核
细胞因子
BCG-polysaccharide nucleic acid
mycobacterium
tuberculosis
cytokines
