STAg联合ESA滴鼻免疫小鼠对弓形虫垂直传播的阻断作用

发布时间：2018-06-08 05:27

本文选题：刚地弓形虫 + 弓形虫病　；参考：《山西医科大学》2007年硕士论文

【摘要】： 目的本研究首先建立经口感染弓形虫RH株速殖子垂直传播小鼠模型,然后观察可溶性速殖子抗原(soluble tachyzoite antigen,STAg)滴鼻免疫小鼠对弓形虫垂直传播的阻断作用,探讨STAg联合排泄.分泌抗原(excreted/secreted antigens,ESA)滴鼻免疫小鼠对弓形虫垂直传播的阻断作用,为研制阻断弓形虫垂直传播疫苗提供实验依据。方法本研究分三部分:第一部分:54只妊娠0天的BALB/c孕鼠随机分为6组,于妊娠第8天,分别用0、1000、2000、4000、8000、16000个弓形虫速殖子灌胃感染,妊娠第18天处死,记录活胎率,测定母鼠肝、胎盘和胎仔脑组织弓形虫抗原。第二部分:130只5～6周龄BALB/c处女鼠随机分为2个大组:PBS组和STAg组。PBS组以PBS 20μl/只滴鼻,STAg组以STAg 20μg/只滴鼻,免疫2次,间隔2周。末次免疫后处女鼠与雄鼠以2∶1分批同笼交配,各组按免疫后攻虫时间不同再分为1,2,3组,每组10只。妊娠第8天(分别对应末次免疫后第11天、第17天、第23天)用8000个/只速殖子灌胃攻击小鼠。妊娠第18天颈椎脱臼处死,记录孕鼠感染率、活胎率,称重脾脏、胸腺重量,采集母鼠肠液进行IgA检测,测定母鼠肝、胎盘和胚胎脑组织弓形虫抗原。第三部分:BALB/c处女鼠40只随机分为4组:PBS组、STAg组、ESA组和联合抗原(STAg+ESA)组,每组10只。STAg组、ESA组和联合抗原(STAg+ESA)组分别用20μg/只STAg、20μg/只ESA和20μg/只联合抗原(10μg STAg+10μg ESA)滴鼻,PBS组用PBS以20μl/只滴鼻,免疫2次,间隔2周。末次免疫后第13天处女鼠与雄鼠以2∶1分批进行同笼交配。妊娠第8天用8000个速殖子/只灌胃攻击全部小鼠。妊娠第18天颈椎脱臼处死,记录孕鼠感染率、活胎率,计数脾组织内弓形虫速殖子,检测母鼠小肠冲洗液sIgA和血清IgG抗体水平,测定母鼠肝、胎盘和胎仔脑组织弓形虫抗原。结果不同剂量弓形虫经口感染孕鼠后,孕鼠死亡率与胎盘和胚胎感染率均随感染剂量的增加而升高,而活胎率下降。1000、2000组的胎盘、胚胎未发生感染,4000组的胚胎感染率5.13%,16000组的胚胎感染率20.00%,但孕鼠的健康状况差、死亡率高,均不适宜建立弓形虫垂直传播动物模型。而8000组孕鼠既有较高的存活率,又可保证胎盘和胚胎较高的感染率。用可溶性速殖子抗原(soluble tachyzoite antigen,STAg)鼻内免疫小鼠后,STAg第1、2、3组和PBS第1、2、3组孕鼠感染率和死亡率无统计学差异。STAg第3组活胎率要明显高于PBS第1组、2组和3组(P＜0.05)。各组脾脏重量未见明显变化;STAg第3组小鼠胸腺重量低于其它组(P＜0.05)。STAg第3组孕鼠肠液sIgA高于除STAg第2组外的其它组(P＜0.05);STAg第1组、2组、3组孕鼠感染率随免疫时间的增加而减少,而活胎率增高,胎盘、胚胎感染率随免疫时间的增加而减少。STAg第3组的胚胎感染率低于其它组。可溶性速殖子抗原(soluble tachyzoite antigen,STAg)联合排泄-分泌抗原(excreted/secreted antigens,ESA)鼻内免疫小鼠后,STAg组、ESA组和联合抗原组孕鼠感染率低于PBS组,但无统计学差异。PBS组活胎率显著低于ESA组和联合抗原组(P＜0.01)。STAg组、ESA组和联合抗原组脾组织内虫荷(速殖子数)显著低于PBS组(P＜0.01)。联合抗原组和ESA组小肠冲洗液特异性sIgA均显著高于PBS组(P＜0.01);PBS组、STAg组、ESA组、联合抗原组血清IgG含量依次增高,但无显著性差异。联合抗原组滴鼻免疫小鼠其胚胎感染率均低于其他组。结论孕鼠灌胃感染8000个速殖子为建立弓形虫垂直传播小鼠模型的适宜剂量。STAg20μg/只滴鼻免疫小鼠(免疫2次,间隔2周),末次免疫后第23天攻虫可有效降低母鼠感染率及胎盘和胚胎的感染率。STAg联合ESA鼻内免疫小鼠的效果优于单独STAg或ESA,STAg联合ESA(1∶1)20μg/只滴鼻免疫BALB/c小鼠(免疫2次,间隔2周),于末次免疫后第23天攻虫可降低母鼠感染率及胎盘和胚胎的感染率。
[Abstract]:Objective To establish a mouse model of vertical propagation of Toxoplasma gondii RH strain , and then observe the blocking effect of soluble tachyzoite antigen ( STAg ) on the vertical propagation of Toxoplasma gondii .

Methods This study was divided into three parts : the first part : 54 pregnant BALB / c pregnant mice were randomly divided into 6 groups . On the 8th day of gestation , the BALB / c pregnant mice were infected with 0 , 1000 , 2000 , 4000 , 8000 , 16000 toxoplasmosis tachyzoites , and the live fetuses were sacrificed on the 18th day of gestation , and the toxoplasmosis antigens of the liver , placenta and fetal brain tissues were measured .

In the second part , 130 female BALB / c mice were randomly divided into 2 large groups : PBS group and STAg group . The groups were divided into 1 , 2 and 3 groups with STAg 20渭l / nose and STAg group at 2 : 1 . Each group was divided into 1 , 2 and 3 groups according to the time of immunization .

In the third part , 40 BALB / c virgins were randomly divided into four groups : PBS group , STAg group , ESA group and combined antigen ( STAg + ESA ) group . Each group consisted of 10 . STAg group , ESA group and combined antigen ( STAg + ESA ) group .

Results The mortality of pregnant mice and the infection rate of placenta and embryo increased with the increase of the infective dose , while the rate of live birth was decreased . The rate of embryo infection in 4000 groups was 5.13 % , and the rate of embryo infection in 4000 groups was 5.13 % .

In STAg group 3 , the percentage of fetal thymus weight was significantly higher than that in other groups ( P < 0.05 ) . The percentage of thymus weight of STAg group 3 was higher than that in other groups ( P < 0.05 ) . The infection rate of STAg group 3 was higher than that in other groups ( P < 0.05 ) . The infection rate of STAg group 3 was higher than that in other groups ( P < 0.05 ) .

In STAg group , both ESA group and combined antigen group were significantly lower than that in PBS group ( P < 0.01 ) . There was no significant difference in serum IgG content in STAg group , STAg group , ESA group and combined antigen group ( P < 0.01 ) .

Conclusion The effect of STAg combined ESA intranasal immunization is superior to that of single STAg or ESA , STAg combined ESA ( 1 : 1 ) 20 渭g / mouse immunized BALB / c mice ( 2 times , 2 weeks interval ) . The infection rate of maternal and mouse and the infection rate of placenta and embryo can be reduced at 23 days after the last immunization .
【学位授予单位】：山西医科大学
【学位级别】：硕士
【学位授予年份】：2007
【分类号】：R392

【参考文献】