2013年云南省 H9N2亚型禽流感病毒两个进化分支毒株抗原性变异分析

摘要

In order to investigate the antigenic differences between Ⅲ-1 and Ⅲ-2 of the H9N2 subtype AIV in Yunnan province in 2013,and whether the antigenic difference is related to the amino acid mutation,7 vi-rus strains and vaccine strains were analyzed by phylogenetic analysis and serological cross test.The results showed that:the homologies of HA gene of the two subgroup strains were 86.6 % to 98.4%,the relation-ship was far with the vaccine strains before 2000,Ⅲ-1 strains were near with the vaccine strains (ACK-LGQ113 and ACKDL2010)after 2000.The HI cross test results by statistics analysis showed that the anti-genicity differences exist between Ⅲ-1 and Ⅲ-2 subgroups.Amino acid comparative analysis result showed that variations in different subgroup strains exist;compared with the antigenic epitope sites reported,the variation existed in parts of Ⅲ-1 strains and in Ⅲ-2 strains is no change,but there are unique variations in eight other amino acid sites of Ⅲ-2 strains,whether there is any unknown antigen epitope sites,or the other ancillary amino acid sites whether can affect antigen variation,have yet to be further studied.%为明确2013年云南省 H9N2亚型禽流感病毒Ⅲ-1和Ⅲ-2小分支间是否存在抗原性差异，以及这种抗原性差异是否与氨基酸位点变异有关，从2个小分支中选取7个毒株与疫苗株进行系统发育分析和血清学交叉比对试验。结果表明，2个小分支 HA 基因核苷酸序列同源性为86．6％～98．4％，与2000年前疫苗株亲缘关系较远，Ⅲ-1分支与2000年后疫苗株（ACKLGQ113和 ACKDL2010）亲缘关系较近。血清学交叉比对试验结果经统计学分析显示，Ⅲ-1和Ⅲ-2小分支间抗原性存在差别。氨基酸比对结果表明，不同进化亚分支毒株与疫苗株相比氨基酸存在变异；与已报道的抗原表位关键性位点相比，Ⅲ-1分支中部分毒株抗原表位关键性位点存在变异，Ⅲ-2分支毒株无变异，但在其他8个氨基酸位点存在特有变异，是否存在未知抗原表位关键性位点，以及其他氨基酸位点变异是否会辅助性影响抗原变异，还有待进一步研究。