人巨细胞病毒临床分离株糖蛋白B基因型分析

Genotyping of glycoprotein B of human cytomegalovirus clinical strains

目的 分析巨细胞病毒临床分离株糖蛋白B基因型。方法 以巢式聚合酶链反应(nested PCR)检测器官移植受者外周血细胞和输卵管妊娠患者生殖道组织中的巨细胞病毒gBn和gBcls基因并测序分型。结果 分离到 4 4例HCMVgBn、gBcls阳性基因 ,32例有HCMVgBn基因分型结果 ,其中 1型 8例 (2 5 % ) ,2型 2例 (6 % ) ,3型 2 2例 (6 9% ) ,未见 4型 ,分布以gBn3型为主。HCMVgBcls基因分型结果为 2 6例 ,其中 1型 14例 (5 4 % ) ,2型 5例 (2 0 % ) ,3型 7例 (2 6 % ) ,未见 4型 ,gBcls基因型则散在分布 ,以 1型为多见。 2 1例同时得到gBn、gBcls基因分型结果 ,其中 8例 (36 % )表现出基因型别不一致。表现为gBcls1 gBn3型。结论 HCMV临床分离株 ,其糖蛋白基因分别属于gB基因型 1～ 3型 ,并存在较多的gBcls与gBn基因型别的不对应现象 ,提示HCMV临床株有较高频率株内基因重组发生 ,是否由此导致病毒抗原性发生改变 ,值得进一步研究。

Objective To investigate genotypes of glycoprote in B of human cytomegalovirus clinical strains. Methods C ytomegalovirus gB N-terminus (gBn, 54-485nt) gene and gB endoprotease cleavage site (gBcls , 1?284-1?600nt) gene in blood samples of bone marrow and sol id organ transplant recipients and reproductive tissues of tubal pregnancy were amplified by nested-PCR. Positive samples were directly sequenced to identify g enotype. Results HCMV gB amplificates were detected in 19 strains of transplant recipients and 25 strains of tubal pregnancy. Sequence an alysis of 32 positive gBn fragments showed that 8 strains (25%) were gBn1 genoty pes, 2 strains (6%) of gBn2 genotypes, 22 strains (69%) of gBn3 genotypes, gBn4 genotype was not detected. The gBn3 genotype was dominant. In 26 positive gBcls fragments sequence analysis, results showed that 14 strains (54%) were gBcls1 ge notypes, 5 strains (20%) of gBcls2 genotypes, 7 strains(26%) of gBcls3 genotypes , gBcls4 genotype was not detected. gBcls1 genotype was dominant. In 21 stra ins, the gBn type appeared different from gBcls type. 8 strains (36%) appeared g Bcls1-gBn3. Conclusions This study demonstrated the gBn3 genotype of glycoprotein B of human cytomegalovirus clinical strains from trans plant recipients and tubal pregnancy. The intragenic variability within the gB g ene was explained, as a result of homologous recombination.