HIV/HBV合并感染者HBV Pre-S/S区抗原表位变异分析

摘要

目的 分析HIV/HBV合并感染者外周血中HBV Pre-S/S区抗原表位变异特征,为研究合并感染致病机制提供实验依据.方法 收集广州市第八人民医院感染病中心2009年1月份至2011年12月份收治慢性HBV感染者的基本信息和实验室检查资料,按治疗前HIV抗体检测结果分为HIV/HBV合并感染组、HBV单一感染组,采集患者外周血,提取血清中HBV DNA,采用巢式PCR法扩增HBV DNA的Pre-S/S基因,将获得的PCR产物进行序列测定(直接测序法)后,采用ContigExpress软件进行序列拼接、BioEdit软件进行序列比对,参照相应基因型HBV的标准序列,分析比较HIV/HBV合并感染和HBV单一感染两组的HBV Pre-S/S区抗原表位变异.统计学处理采用X2检验,软件为SPSS19.0.结果 成功扩增HBV Pre-S/S基因的患者共150例,其中HIV/HBV合并感染者90例,HBV单一感染者60例,两组患者性别、年龄、基因型、HBeAg状态、谷丙转氨酶(ALT)、谷草转氨酶(AST)比较无统计学差异;HBV Pre-S/S各表位变异分析结果:HIV/HBV合并感染组所有的细胞毒性T细胞(CTL细胞)表位变异发生率均偏高,其中Pre-S2 aa1-15表位变异发生率比较有统计学意义(X2=6.964,P=0.008);PreS2 aa1-15表位变异中缺失发生率合并感染组(11.1％)高于HBV单一感染组(3.3％)(X2=2.959,P=0.085).B细胞表位中,Pre-S2 aa1-26 HIV/HBV合并感染组的变异发生率显著高于HBV单一感染组,差异有统计学意义(X2=6.924,P=0.010),其余B细胞表位在两组间比较无统计学意义(P值均＞0.05);两组间辅助性T细胞(Th细胞)表位变异发生率比较均无统计学意义(P值均＞0.05).结论 合并HIV感染可增加HBV Pre-S/S区CTL细胞表位变异,尤其是Pre-S2区5'端表位变异,提示HBV变异与宿主免疫状态相关,为进一步研究HIV/HBV合并感染的致病机制提供了可靠资料.%Objective To analyze the characteristic mutations of epitopes in HBV Pre-S/S region in HIV/HBV co-infected patients' peripheral blood to provide basic data for studying the pathogenesis of HIV/HBV co-infection.Methods The chronic hepatitis B infected patients admitted to the Infectious Disease Center of the Eighth People's Hospital of Guangzhou from January 2009 to December 2011 were enrolled into HIV/HBV co-infected group and HBV mono-infected group according to the result of HIV antibody detection respectively before treatment.HBV DNA in serum was extracted and Pre-S/S region of HBV DNA was amplified by nested-PCR.After sequencing of the obtained PCR products (direct sequencing),ContigExpress software was used for sequence splicing and BioEdit software was used for sequence alignment.With reference to the standard sequence of the matched genotype HBV,mutants of HBV Pre-S/S region in HIV/HBV co-infected group and HBV mono-infected group were analyzed respectively.Statistical analysis was performed by chi-square test with SPSS19.0 statistical analysis software.Results HBV Pre-S/S fragments were successfully amplified from 150 patients,including 90 cases of HIV/HBV co-infected group and 60 cases of HBV mono-infected group,with matched gender,age,genotype,HBeAgstatus,alanine aminotransferase (ALT),aspartate aminotransferase (AST).The result of analyzing mutants of HBV Pre-S/S region indicated that the incidence of mutation in all epitopes for cytotoxic T cells (CTL cells) was higher in the HIV/HBV co-infected group,and Pre-S2 aa1-15 epitope was significantly higher (X2=6.964,P =0.008).The incidence of deletions in PreS2 aa1-15 epitope in HIV/HBV co-infected group (11.1％) was higher than HBV mono-infected group (3.3％) (X2 =2.959,P =0.085).In the B cell epitopes,the incidence of mutations in Pre-S2 aa1-26 in the HIV/HBV co-infected group was significantly higher than HBV mono-infected group (X2 =6.924,P=0.010),and there was no statistical significance between two groups in other B cell epitopes.No differences in helper T cell (Th cell) epitopes were found between the two groups.Conclusions Co-infection with HIV increased the CTL cell epitopes' mutations in the HBV Pre-S/S region,especially the 5'end epitope mutations in Pre-S2 region,which indicated that HBV mutation is related to the host immune status,and showed guiding information for further study on the pathogenesis of HIV/HBV co-infection