摘要
为了研究浙江省1999～2003年麻疹病毒分离株的抗原性变化以及基因特性,阐明其基因特性与麻疹流行的关系,以及抗原性变化对疫苗免疫效果的影响。我们从麻疹患者含漱液中分离麻疹病毒株,制备大鼠免疫血清,与疫苗株沪191和Edmonston株等进行交叉中和试验,测定各毒株之间抗原比;并采集儿童麻疹疫苗免疫前后血清,分别测定其对不同毒株的中和抗体滴度;采用RT-PCR法扩增麻疹毒株血凝素蛋白(H)及核蛋白(N)基因,进行核苷酸序列测定。结果浙江99-1和浙江02-2株与沪191株之间的抗原比分别为3.0和7.3;儿童免疫后血清对浙江02-2株的麻疹中和抗体平均几何滴度(GMT)为15.03,明显低于沪191疫苗株(GMT为68.12);浙江省1999～2003年麻疹分离株之间,H基因氨基酸同源性为99.8%,N基因氨基酸同源性为98.5%～100.0%;与沪191疫苗株的H基因和N基因相比较,分离株与其在氨基酸水平上同源性分别为95.5%～95.7%和95.9%～96.3%。从基因进化树显示,1999～2003年浙江省分离到的麻疹毒株属于H1基因型,但与疫苗株沪191在抗原性和基因特性上已存在明显的差异。
In order to elucidate the relationship between genetic characteristics and measles outbreak, and the influence of antigenic variation on measles vaccine effect, we investigated the genetic characteristics and antigenic variation of measles viruses isolated in Zhejiang province during 1999-2003. Rats were immunized with the measles virus isolated from patients and the titers of the antibody were measured by cross neutralization test using the antigen of the isolated measles virus, vaccine strains of Shanghai191 and Edmonston strain. Meanwhile, the antigenic ratios between the strains were calculated. The titers of neutralizing （NT） antibody to different measles strains in serum samples collected from children before and after immunized with the measles vaccine were tested. N and H genes of measles virus were amplified by RT-PCR and sequenced. The results showed that antigenic ratios of Zhejiang99-1 and Zhejiang02-2 to Shanghail91 strain were 3.0 and 7.3 respectively; The geometric mean titer （GMT） of the NT antibody to Zhejaing02-2 strain from the vaccinated children was 15.03, which was obviously lower than titer to the Shanghail91 vaccine strain （GMT was 68.12）; Besides, the homology of the amino acide sequence of HA protein and N protein was 99.8% and 98.5%-100% respectively between the measles virus circulating during 1999-2003 in Zhejiang Province. Comparing with China vaccine strain （Shanghail91）, the homology of H and N proteins was 95.5%-95.7%. and 95.9%-96.3% respectively. The measles virus isolated during 1999-2003 in Zhejiang Province were all H1 genotype analysed by the phylogenetic trees of H and N gene and they were obviously different from Shanghai 191 strain.
出处
《中国病毒学》
CSCD
2006年第1期1-5,共5页
Virologica Sinica
基金
浙江省自然科学基金资助(Y204458)
关键词
麻疹病毒
沪191疫苗株
抗原性
基因特性
Measles viruses
Shanghai-191 vaccine strain
Antigenicity
Genetic characteristics
