内源性危险信号低分子量硫酸乙酰肝素的免疫佐剂作用

Effect of Low Molecular Weight Heparan Sulfate,an Endogenous Danger Signal,as an Immunological Adjuvant

目的 研究内源性危险信号低分子量硫酸乙酰肝素(Heparan sulfate,HS)的免疫佐剂作用。方法按照HS的免疫剂量、免疫途径和免疫程序将ICR小鼠分组,同时设HBsAg对照组和铝佐剂对照组,分别于末次免疫后4、8、12、16、20和24周,采用ELISA法检测小鼠血清中的特异性IgG抗体水平;选择体液免疫效果最佳的剂量组免疫BALB/c小鼠,同时设空白对照组、抗原对照组和铝佐剂对照组,于末次免疫后8周,采用乳酸脱氢酶(LDH)法检测细胞杀伤活性。结果空白对照组小鼠在各检测时间点均未见IgG抗体产生。除第4组外,各实验组抗体滴度均在末次免疫后第8周达峰值,随着时间的推移,抗体水平呈下降趋势。第43组抗体水平升高快,峰值高,持续时间长;在实验剂量范围内,随着HS剂量的增加,针对HBsAg的特异性抗体水平也增加;HS的最佳剂量为100μg;皮下注射HS的免疫增强作用最佳,优于肌肉和鼻腔免疫;免疫程序对HS的佐剂作用影响不大。HS能诱导小鼠产生特异性的CTL细胞免疫效应,细胞杀伤活性显著高于空白对照组、抗原对照组及铝佐剂对照组(P﹤0.001)。结论 HS具有免疫佐剂作用,既能有效增强特异性体液免疫应答,又能显著诱导CTL细胞免疫效应,是一种优于铝佐剂的潜在人用疫苗佐剂。

Objective To investigate the effect of low molecular weight heparan sulfate（HS）,an endogenous danger signal,as an immunological adjuvant.Methods ICR mice were divided into various groups and immunized with HS at various dosages by various routes and schedules,setting blank,HBsAg and aluminium adjuvant control groups.The specific IgG levels in sera of mice were determined by ELISA 4,8,12,16,20 and 24 weeks after the last immunization respectively.BALB / c mice were immunized with HS according to the dosage,route and schedules in the group in which the humoral immune effect was satisfactory,setting blank,antigen and aluminium adjuvant control groups,and determined for CTL killing activity by lactic dehydrogenase（LDH） method.Results No IgG was detected in the ICR mice in blank control group in any time points.Except that in group 4,all the antibody titers in test groups reached peak values 8 weeks the last immunization and showed decreasing tendencies as time goes on.The antibody titer in group 43 increased rapidly,of which the peak value was high and last for a long time as compared with those in other groups.The specific antibody level against HBsAg increased with the increasing dosage of HS within the range studied.The optimal dosage of HS was 100 μg.The immunopotentiation of HS by s.c.injection was superior to those by i.m.and i.n.routes.However,immune schedule showed no significant influence on the effect of HS as an adjuvant.HS induced specific cellular immunity in mice.The CTL killing activity of mice in HS group was significantly higher than those in blank,antigen and aluminium adjuvant control groups（P 0.001）.Conclusion HS acted as an immune adjuvant,which enhanced specific humoral immune response effectively and induced CTL cellular immunity significantly and might be used as a potential adjuvant superior to aluminium adjuvant for vaccine for human use.