妊娠17～37周正常和感染胎儿的T细胞免疫

T lymphocyte-mediated immunity in normal and infected fetuses during 17-37 gestational weeks

目的探讨妊娠17-37周正常和宫内感染胎儿的T细胞免疫。方法超声引导下行脐带穿刺术收集129例胎儿外周血,其中97例为正常对照组胎儿血,32例为宫内感染组胎儿血(单纯疱疹病毒感染、弓形虫感染、风疹病毒感染),采用双色免疫荧光标记流式细胞仪技术测定胎儿外周血T细胞亚群百分率,3H-TdR掺入法检测T细胞增殖能力,分析生理状态下胎儿的T细胞亚群和T细胞增殖情况、宫内感染时胎儿T细胞亚群和增殖反应的变化。结果生理状态下胎儿CD3+、CD4+、CD8+T细胞百分率随孕龄增长而增加(P<0.01),相关系数为:r(CD3+)=0.63、r(CD4+)=0.45、r(CD8+)=0.27。CD4+/CD8+比值,CD8+HLA-DR+、CD3+CD45RO+、CD3+CD45RA+T细胞百分率,T细胞增殖能力与孕龄无相关。CD3+CD45RA+T细胞百分率为(96±2)%。宫内感染时,胎儿CD3+、CD4+、CD8+HLA-DR+T细胞百分率减少,CD8+T细胞百分率增多,CD4+/CD8+比值降低,T细胞增殖能力下降,与正常对照组相比差异显著。CD3+CD45RO+、CD3+CD45RA+T细胞百分率无明显变化。结论妊娠17-37周胎儿各T细胞亚群百分率随孕龄增长情况不同,但多数仍处于“初始状态”;宫内感染时,胎儿容易产生T细胞免疫抑制。

Objective To investigate T lymphocyte-mediated immunity in normal and infected fetuses during 17-37 gestational weeks.Methods One hundred and twenty nine fetal blood samples were recruited by cordocentesis and among them,97 were normal fetu-ses(control group),32 were involved in the infective group in which fetuses were infected by Herpes simplex virus,Toxoplasma gondii,or Rubella virus.T lymphocyte subpopulations were determined by two-color fluorescence flow cytometry.Lymphocyte transformation test was done by 3H-TdR intaking method.It was investigated that the percentages of T lymphocyte subpopulations and the capability of T lymphocyte transformation in normal and infected fetuses,and that the differences between control and infective group.Results During 17-37 gestational weeks,the percentages of CD3+,CD4+,CD8+ T cell increased steadily,while CD4+/CD8+ ratio,CD8+HLA-DR+,CD3+CD45RO+,CD3+CD45RA+ T cell,and the capability of T lymphocyte transformation remained constant.Most of the CD3+ T cell expressed CD45RA anti-gen(96±2)%.Compared with the control group,the infected fetuses were characterized by smaller percentages of CD3+,CD4+,and CD8+HLA-DR+ T cell,and by larger percentage of CD8+ T cell,and by lower level of CD4+/CD8+ ratio,and by decreased capability of T lymphocyte transformation.Conclusion During 17-37 gestational weeks,the increases of each T lymphocyte subpopulations are different as pregnancy advancing,but most T cells are primitive.When in face of infection,fetus is easily to be immunosupressive.