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目的探讨慢性乙型肝炎(chronic heptitis B,CHB)患者干扰素-α(IFN-α)治疗早期乙型肝炎病毒(hepatitis B virus,HBV)的适应性进化。方法对16例进入免疫清除期的慢性乙型肝炎患者进行IFN-α抗病毒治疗,治疗12周有6例取得完全病毒学应答,3例部分病毒学应答,7例无应答。分别采集治疗前和治疗12周的患者血清,提取HBV DNA后扩增HBV全基因组,进行分子克隆后测序,对病毒基因组4个开放读码框进行适应性进化分析,并研究适应性进化与IFN-α抗病毒效果的关系。结果用最大似然法分别检测治疗前后3组患者HBV基因组的正选择位点,一共检测到28个密码子位点。治疗前无应答组检测到的正选择位点(16个)多于完全应答组(9个)和部分应答组(8个),治疗12周部分应答组和无应答组的正选择位点数量减少。对检测到的正选择位点进行抗原表位定位,发现28个正选择位点中有18个位于已知的抗原表位区。治疗后新出现的正选择位点S-ORF188位密码子位点、P-ORF 213位密码子位点以及部分应答组和无应答组治疗12周都未消失的正选择位点X-ORF144位密码子位点突变可能与干扰素应答不良相关。结论慢性乙型肝炎免疫清除期各个基因都存在适应性进化,且检测到的正选择位点大部分位于免疫表位区。HBV基因组的正选择作用可能与氨基酸突变病毒逃逸宿主免疫应答有关,SORF188位密码子位点、P-ORF213位密码子位点以及X-ORF 144位密码子突变可能与干扰素-α治疗早期应答不佳相关。
Objective To investigate the adaptive evolution of hepatitis B virus (HBV) in patients with chronic heptitis B (CHB) treated with interferon-α (IFN-α). Methods Sixteen patients with chronic hepatitis B who entered the immune clearance period were treated with IFN-α antiviral therapy. Six of them achieved complete virological response after 12 weeks of treatment, three were partially virological and seven were non-responsive. Serum samples of patients before and after treatment for 12 weeks were collected, HBV genome was extracted and HBV genome was amplified, sequenced and sequenced. Four open reading frames (ORFs) of the viral genome were analyzed for adaptive evolution, and adaptive evolution and IFN -α antiviral effect of the relationship. Results The maximum likelihood method was used to detect the positive selection sites of HBV genomes in three groups before and after treatment, and a total of 28 codon positions were detected. The number of positive selection sites (16) in the non-responders before treatment was more than that in the complete response (n = 9) and partial response (n = 8), and the number of positive selection sites in the non-responders cut back. Epitope mapping was performed on the detected positive selection sites and found that 18 out of 28 positive selection sites were located in the known epitope region. After treatment, the newly emerged positive site of choice was S-ORF188 codon position, P-ORF codon 213 site and X-ORF144 site of positive selection site that did not disappear in partial response group and non-response group for 12 weeks Codon site mutations may be associated with poor response to interferon. Conclusion There is adaptive evolution in all the genes during the immune clearance of chronic hepatitis B, and most of the detected positive selection sites are located in the immunopotentiate region. The positive selection effect of HBV genome may be related to escape immune host response to amino acid mutation virus. The codon position of SORF188, codon position of P-ORF213 and codon 144 of X-ORF may be related to early response to interferon-α treatment Poor related.