卡介苗接种效果与树突状细胞表达的特异性表面分子重复序列区基因多态性的关系

Correlation of Immune Effect of Bacillus Calmette-Guerin with Dendritic Cell-Specific Intercellular Adhesion Molecule-Grabbing Nonintegin Gene Polymorphism in Infants

目的分析汉族婴儿接种卡介苗(BCG)后的免疫效果,探讨树突状细胞表达的特异性表面分子(DC-SIGN)编码第4外显子多拷贝重复序列区(简称DC-SIGN重复序列区基因)多态性与BCG接种效果的关系。方法收集200例符合以下入选条件的汉族婴儿作为研究对象:1.出生24 h内在出生医院接种BCG;2.BCG接种后12周在指定医疗机构进行结核菌素纯蛋白衍生物(PPD)试验;3.排除早产儿接种、伴随感染和漏接种后补接种等情况;4.获得婴儿监护人的知情同意。采集150例BCG接种后PPD试验阳性婴儿(PPD阳性组)和50例BCG接种后PPD阴性婴儿(PPD阴性组)的外周静脉血,通过全血基因组DNA抽提、基因片断的PCR扩增和琼脂糖电泳分析DC-SIGN重复序列区基因多态性,探讨BCG接种效果与DC-SIGN编码基因多态性的关系。结果在200例BCG接种后PPD阳性和PPD阴性汉族婴儿中,存在6型和7型2种DC-SIGN序列区基因型,分别组成7/7野生型纯合子(197例,占98.5%)或6/7变异型(3例,占1.5%)。150例PPD阳性婴儿的DC-SIGN重复序列区基因均为7/7(100.0%),50例PPD阴性组的DC-SIGN重复序列区基因中,47例为7/7纯合子(94.0%),3例为6/7杂合子(6.0%)。二组比较差异有统计学意义(2χ=9.137 1,P<0.05)。结论汉族婴儿DC-SIGN重复序列区基因以7/7野生型纯合子为主,BCG接种失败(PPD阴性)汉族婴儿存在6/7变异型杂合子。DC-SIGN重复序列区基因变异可能是导致BCG接种失败的原因之一。

Objective To analyze the changes of immune function and explore the relationship between immune effect and the gene polymorphism of dendritic cell-specific intercellular adhesion molecule-grabbing nonintegin（DC-SIGN） repeat region in Han infants vaccinated with bacillus calmette-guerin（BCG）.Methods A total of 200 Chinese Han infants were enrolled in the study with informed consentand from their parents and they all were satisfied the entrance requirement,as the infants were vaccinated with BCG within 24 hours after birth in the hospital,then purfied protein derivatives（PPD） test was performed after 12 weeks of vaccination.All infants excluded preterm infants inoculation,accompanied infection and supplementary inoculation.Peripheral blood specimen from 150 Han infants with positive PPD test（successfully vaccination,SV group） and 50 cases with negative PPD test（failure vaccination,FV group） were collected.DNA extraction from blood was performed.The gene polymorphisms of DC-SIGN repeat region was determined by polymerase chain reaction and agarose gel electrophoresis to analyze correlation of BCG immune effect with the gene polymorphism.Results There were two DC-SIGN alleles,i.e.6 and 7,consisted 2 idiotypes：i.e.homozygous 7/7 in 197 Han infants（98.5%） and heterozygous 6/7 in 3 Han infants（1.5%）.All 150 individuals（100.0%） in SV group had homozygous 7/7,of 50 individuals in FV group,47 cases had homozygous 7/7（94.0%）,but 3 cases had heterozygous 6/7（6.0%）.Compared with individuals vaccinated successfully,a higher prevalence of variations of DC-SIGN repeat region gene was observed among individuals vaccinated failure（χ2=9.137 1,P0.05）.Conclusions The major idiotype of DC-SIGN repeat region gene is homozygous 7/7 in Han individuals,but there is a heterozygous 6/7 among the Han individuals vaccinated failure.Variation of DC-SIGN repeat region gene may result in BCG vaccination failure.