当前流行的乙型流感病毒血凝素蛋白的抗原性及其基因特性

通过抗原性分析弄清了近年来连续２次乙型流感病毒在我国人群中造成流感流行，是由于乙型流感病毒株发生抗原性变异所造成。通过毒粒基因分析发现，我国人群中流行的Ｂ／Ｐａｎａｍａ／４５／９０类毒株，其ＨＡＩ区氨基酸序列比国际代表性毒株Ｂ／Ｐａｎａｍａ／４５／９０病毒在１６５位点上多一个氨基酸（天冬酰胺），乙型流感病毒流行株可能具有地区性差异。     

当前流行的乙型流感病毒血凝素蛋白抗原性及其基因特性

通过抗原性分析弄清了近年来连续２次乙型流感病毒在我国人群中造成流感流行，是由于乙型流感病毒株发生抗原性变异所造成。通过毒粒基因分析发现，我国人群中流行的Ｂ／Ｐａｎａｍａ／４５／９０类毒株，其ＨＡ１区氨基酸序列比国际代表性毒株Ｂ／Ｐａｎａｍａ／４５／９０病毒在１６５位点上多一个氨基酸，乙型流感病毒流行株可能具有地区性差异。     

我国人群中一种新重配的H1N2亚型流感病毒株的发现

１９９６年１月太原铁路卫生防疫站从上感患者中分离到３株流感病毒。经血清学鉴定，它们不同于１９８９和１９９２年所发现的Ｈ１Ｎ２亚型毒株，其ＨＡ的抗原性类似于Ａ／ＰＲ／８／３４（Ｈ１Ｎ１）病毒，而明显不同于当前人群中流行的Ｈ１Ｎ１亚型毒株。病毒粒不同基因节段迁移率比较表明，它们的１～４基因节段迁移率接近于Ａ／ＰＲ／８／３４（Ｈ１Ｎ１）毒株，５～６基因节段迁移率类似于Ａ／武汉／３５９／９５（Ｈ３Ｎ２）病毒，而７～８两节段既不同于Ａ／ＰＲ／８／３４（Ｈ１Ｎ１），又不同于Ａ／武汉／３５９／９５（Ｈ３Ｎ２）病毒。故可认为它们是一种新重配的Ｈ１Ｎ２亚型毒株。     

1994～1997年深圳地区流感病毒活动及H3N2亚型毒株HA1基因演变特点

目的　了解近几年流感病毒在深圳地区活动的特点及甲３（Ｈ３Ｎ２） 亚型毒株ＨＡ１ 基因演变概况。方法　病毒分离采用常规的鸡胚双腔接种,毒株检定用常量半加敏ＨＩ测定。新鲜收获含病毒粒的鸡胚尿囊液用来提取ＲＮＡ,经逆转录合成ｃＤＮＡ,经聚合酶链反应（ＰＣＲ） 扩增,产物纯化,采用双脱氧链末端终止法进行核苷酸序列测定。结果　近几年来深圳地区流感活动概况与全国情况相一致：在人群中仍同时流行Ｈ３Ｎ２,Ｈ１Ｎ１ 亚型和乙型毒株,当甲型毒株活动减弱时,乙型毒株活动就增强,反之,甲型毒株增强时,乙型毒株就减弱。随着时间的推移,Ｈ３Ｎ２ 亚型毒株ＨＡ１ 基因不断地发生点突变,这种突变严重受人群免疫压力所影响,１９９６ 年的毒株与１９９５ 的毒株相比,不仅氨基酸替换点中多数是位于抗原决定簇区或受体结合部位上,并增加两个糖基化位点,故导致Ｈ３Ｎ２ 毒株於１９９６ 年活动明显增强。结论　近来在深圳地区人群中仍同时流行着Ｈ３Ｎ２,Ｈ１Ｎ１ 亚型和乙型流感病毒。然而,不同年其优势毒株是不一样的。１９９６ 年Ｈ３Ｎ２ 毒株活动增强是由于其ＨＡ１ 区氨基酸序列发生替换所造成。     

从人群中分离到1株A／PR／8／34（H1N1）类病毒

１９９１年５月从１名上呼吸道感染的儿童患者中分离出１株流感病毒。经血清学鉴定和分析，分离物为Ａ／ＰＲ／８／３４（Ｈ１Ｎ１）类似毒株。病毒ＨＡ１区基因经核苷酸序列分析，分离物与Ａ／ＰＲ／８／３４毒株间有１２个位点不同，导致了ＨＡ１区蛋白分子上４个氨基酸的替换。在病毒基因组寡核苷酸指纹图分析中发现，分离物与Ａ／ＰＲ／８／３４毒株相比较丢失了２个点，而插入了９个点。因此，Ａ／广东／６／９１（Ｈ１Ｎ１）毒株不是由Ａ／ＰＲ／８／３４（Ｈ１Ｎ１）通过实验室污染而来。     

H1N2新亚型流感病毒神经氨酸酶基因来源的进一步研究

对流感病毒Ｈ１Ｎ２亚型重组株Ａ／哈防／１／８８、Ａ／哈防／１２／９２以及Ｈ３Ｎ２亚型病毒株Ａ／雅防／２／８７、Ａ／京防／５７／８９８和Ａ／粤防／１／９２神经氨酸酶（ＮＡ）基因核苷酸全序列的测定，进一步弄清了Ａ／哈防／１／８８病毒株的ＮＡ基因确来自当时人群中流行的Ｈ３Ｎ２亚型病毒株，很可能是来自Ａ／雅防／２／８７类病毒株；而Ａ／哈防／１２／９２病毒株的ＮＡ基因可能是与Ａ／哈防／１／８８病毒株的ＮＡ基     

甲型流感病毒（N1N2）亚型毒株血凝素和神经氨酸酶基 …

目的 研究新分离到的Ｈ１Ｎ２亚型毒株血凝素（ＨＡ）和神经氨酸酶（ＮＡ）基因的来源。方法 病毒通过鸡胚增殖后提取其ＲＮＡ,通过逆转录合成ｃＤＮＡ,经ＰＣＲ扩增和产物纯化,用双脱氧链终止法进行核苷酸序列测定,并用ＭｅｇＡｌｉｇｎ（１．０３版）和Ｅｄｉｔｓｅｑ（３．６９版）软件进行种系发生学分析。结果 新分离到Ｈ１Ｎ２毒株ＨＡ１区氨基酸序列与Ａ／ＰＲ／８／３４（Ｈ１Ｎ１）和Ａ／Ｇｕａｍｇｄｏｎｇ／６／９     

当前我国流行的乙型流感病毒血凝素蛋白抗原性及基…

通过病毒血凝素蛋白抗原性分析，弄清楚了近年来连续几年在我国人嫩中造成乙型流感病毒流行和局部暴发由于乙型流感病毒发生抗原性变异和在我国人群中至少有两第抗原性明显不同的乙型流感病毒同时并存所造成。同时还发现乙型流感病毒的流行具有地区性差异。通过对乙型流感病毒血凝素重键区核甘酸和氨基酸序列的分析发现，近年来在我国分离的两系乙型流病毒毒株之间有高达３０－４２个氨基酸的差异，Ｂ／Ｙａｍａｇａｔａ／１６／８８     

丙型肝炎病毒包膜糖蛋白高变区1多抗原肽设计及？…

目的 应用多抗原肽（ＭＡＰ）研究丙型肝炎病毒包膜糖蛋白高变区１（ＨＶＲ１）的抗原性。方法 根据已经获得的ＨＣＶ－ＢＪ株Ｅ２／ＮＳ１区氨基酸序列,参照国内外得所报道的ＨＶ ＨＶＲ１序列及抗原性参数,设计并合成含ＨＣＶ ＨＶＲ１３９０－４１１ａａ序列２２个氨基酸的线性表位多肽（以ＬＰ表示）及ＭＡＰ（对称８分枝）,分别以ＬＰ和ＭＡＰ免疫Ｂａｌｂ／Ｃ小鼠及家兔,比较其免疫原性。结果 ＭＡＰ免疫原性明显强于     

乙型肝炎病毒表面抗原S基因在人5型重组腺病毒中…

从美国Ｗｙｅｔｈ公司引进ｐＡｄ５△Ｅ３载体，将乙型肝炎病毒表面抗原基因（ＨＢＶＳ）ＰｒｅＳ２＋Ｓ，腺病毒晚期表达盒＋ＨＢＶＳ基因插入Ｅ３区，与ＥｃｏＲＩ消化的Ａｄ５ＤＮＡＡ片段共转染细胞获得重组腺病毒，相应命名为ｒＡｄ５Ｓ，ｒＡｄ５ＭＳ，ｒＡｄ５Ｓ２Ｓ。对所获得的重组病毒进行聚合酶链反应（ＰＣＲ）分析，证实重组病毒中含有目的基因，用ＥＬＩＳＡ分析ｒＡｄ５ＭＳ的表达量，其病变细胞和上清液滴度均为１：     

Molecular analysis of isolates from influenza B outbreaks in the U.S. and Nepal, 2005

Summary. Currently circulating influenza B viruses can be divided into two antigenically and genetically distinct lineages referred to by their respective prototype strains, B/Yamagata/16/88 and B/Victoria/2/87, based on amino acid differences in the hemagglutinin surface glycoprotein. During May and July 2005, clinical specimens from two early season influenza B outbreaks in Arizona and southeastern Nepal were subjected to antigenic (hemagglutinin inhibition) and nucleotide sequence analysis of hemagglutinin (HA1), neuraminidase (NA), and NB genes. All isolates exhibited little reactivity with the B/Shanghai/361/2002 (B/Yamagata-like) vaccine strain and significantly reduced reactivity with the previous 2003/04 B/Hong Kong/330/2001 (B/Victoria-like) vaccine strain. The majority of isolates were antigenically similar to B/Hawaii/33/2004, a B/Victoria-like reference strain. Sequence analysis indicated that 33 of 34 isolates contained B/Victoria-like HA and B/Yamagata-like NA and NB proteins. Thus, these outbreak isolates are both antigenically and genetically distinct from the current Northern Hemisphere vaccine virus strain as well as the previous 2003–04 B/Hong Kong/330/2001 (B/Victoria lineage) vaccine virus strain but are genetically similar to B/Malaysia/2506/2004, the vaccine strain proposed for the coming seasons in the Northern and Southern Hemispheres. Since these influenza B outbreaks occurred in two very distant geographical locations, these viruses may continue to circulate during the 2006 season, underscoring the importance of rapid molecular monitoring of HA, NA and NB for drift and reassortment.     

Cocirculation of two distinct evolutionary lineages of influenza type B virus since 1983

During 1988-1989 two highly distinct antigenic variants of influenza type B were recognized in hemagglutination-inhibition tests with postinfection ferret serum. These viruses were antigenically related to either B/Victoria/2/87, the most recent reference strain, or B/Yamagata/16/88, a variant that was isolated in Japan in May 1988. All influenza B viruses isolated in the United States during an epidemic in the winter of 1988-1989 were antigenically related to B/Victoria/2/87. However, in several countries in Asia, both B/Victoria/2/87-like viruses and B/Yamagata/16/88-like viruses were isolated. Sequence analysis of the hemagglutinin (HA) genes of several influenza B isolates from 1987 to 1988 indicated that the HA1 domains of the B/Yamagata/16/88-like viruses and B/VI/87-like viruses isolated in 1988 differed by 27 amino acids. Evolutionary relationships based on this sequence data indicated that the B/Yamagata/16/88-like viruses were more closely related to epidemic viruses from 1983 (B/USSR/100/83-like viruses) than to more recent reference strains such as B/Victoria/2/87. All other Asian strains, as well as selected isolates from the United States in 1988, were confirmed by sequence analysis as being genetically related to B/Victoria/2/87. These data provide clear evidence that two parallel evolutionary pathways of influenza type B have existed since at least 1983 and that viruses from each of the separate lineages were isolated from cases of influenza B in 1988. This finding is similar to earlier observations for type A H1N1 and H3N2 influenza viruses.     

Antigenic and genetic analyses of influenza B viruses\\ isolated in Lusaka, Zambia in 1999

Summary.  Previous studies of the hemagglutinin (HA) genes of various influenza B virus isolates demonstrated the existence of two antigenically distinct virus lineages represented by B/Victoria/2/87 and B/Yamagata/16/88, respectively. Here, we investigated the antigenic and genetic characteristics of influenza B viruses isolated from children living in Lusaka, Zambia between January and May 1999. Antigenic analysis with chicken antiviral sera showed that all the Zambian isolates had the HA protein belonging to B/Yamagata/16/88-related lineage. Furthermore, phylogenetic analyses of the eight RNA segments performed by using the total or partial nucleotide sequences of the two representative Zambian strains (B/Lusaka/270/99 and B/Lusaka/432/99) as well as the previously reported sequences suggested that the Zambian viruses are closely related to the recently circulating reassortants represented by B/Shiga/T30/98 and B/Yamanashi/166/98 which acquired the genes coding for three polymerase proteins (PB2, PB1, and PA), HA, nucleoprotein, and matrix protein from a B/Yamagata/16/88-like parent and the gene encoding nonstructural proteins (NS1 and NS2) from a B/Guandong/8/93-like parent. Accepted June 15, 2001 Received April 17, 2001     

2001年中国新分离维多利亚系乙型流感病毒的抗原性及基因特性分析

目的：研究2001年中国新分离维多利亚（Victoria)系乙型流感病毒的抗原性及基因特性。方法：鸡胚传代流感病毒，从尿囊液中提取流感病毒的RNA，进行逆转录－聚合酶链反应（RT－PCR），扩增产物用纯化试剂盒纯化后测序，然后用MegAlign软件进行基因种系发生树分析。结果：B／Sichuan/63/2001和B／Zhejiang/2/2001毒株的抗原性与B／Shandong/7/97毒株间存在有差异，编码血凝素重链区基因已发生了突变并导致了HA1蛋白抗原性表位两个位点（197和199）氨基酸不同于B／Shandong/7/97毒株，基因种系发生树分析同样也证明了它们的HA1基因不同于B／Shandong/7/97病毒。然而，B／Sichuan/63/2001与B／Zhejiang/2/2001毒株间无论抗原性还是HA1基因特性均很相似。结论：2001年我国人群中流行的乙型流感病毒维多利亚毒株系的抗原性已发生进一步的漂移。     

韶关市2006年B型流感病毒流行与HA1基因变异分析

目的了解2006年韶关市B型流感病毒的流行及基因变异情况。方法收集2006年韶关市流感监测及疫情资料,并随机选取流感疫情中分离的1株B型毒株,提取病毒RNA,RT-PCR扩增病毒HA1基因,纯化产物进行核苷酸序列测定,使用DNA Start MegAlign等生物软件包进行序列分析。结果 2006年流感监测与疫情中共分离到22株B型流感毒株,分离率为2.48%（22/887）,发生的35起流感疫情中有9起检出B型流感病毒,爆发时间多集中在3～4月;B/SG/y139/2006与B型代表株B/HongKong/330/2001相比,同源性为96.3%,其中有7个氨基酸替换发生在抗原决定蔟,在第197位增加了1个糖基化位点。2005和2006年分离的两毒株之间有2个氨基酸发生了替换。结论韶关市整体人群的B型Victoria系抗体水平比较低,2006年分离的B型流感毒株与B/HongKong/330/2001相比基因特性发生了变异,是2006年B型Victoria系流感病毒在韶关市成为优势毒株的原因。     

武汉市2003年流感监测及当前优势流行毒株的抗原性和基因特性分析

目的 探讨2003年武汉市流感流行概况，分析优势流行毒株抗原性和基因特性变异特征。方法 每周在流感监测哨点医院统计流行病学资料，采样分离流感病毒标本，对其中3株H3病毒做血凝抑制试验并对其编码HA1区基因进行序列测定和分析。结果 从418份咽拭标本中分离到流感病毒58株，其中5，7株为H3亚型，1株为乙型；全年月分离率和门诊流感样病例数的变化有冬、夏两个高峰，最高峰均出现在7月；新分离到的3株H3病毒的抗原性与本年度疫苗组分株A／Panama／2007／99有较大差异，编码HA1区的氨基酸序列有14个位点发生了变异，基因种系发生树分析也证实他们的HA1基因存在较大差异。结论 2003年武汉市流感活动呈双峰型增强，H3病毒活动显著加强，其抗原性和基因特性与疫苗株相比均发生了较大的变异。     

Rapid detection and identification of two lineages of influenza B strains with monoclonal antibodies.

Monoclonal antibodies (Mabs) against influenza B virus were obtained by immunizing mice with B/Nagasaki/1/87, one of the strains of the B/Victoria group. Immunoprecipitation analysis revealed that individual Mabs precipitated the nucleoprotein (NP), the matrix protein (M) or the hemagglutinin protein (HA). By using these Mabs by the peroxidase-antiperoxidase (PAP) staining method, a rapid detection and identification method for influenza B virus was established. Monolayers of Madin-Darby canine kidney cells in microplates were infected with each-strain and incubated for about 24 h, and then were subjected to the PAP staining method using the Mabs as the first antibody. Influenza B virus strains are classified into two major phylogenetic trees, the B/Victoria group and the B/Yamagata group. When anti-NP and anti-M antibodies were used in the PAP staining method, all 13 influenza B virus strains isolated from clinical specimens between 1940 and 1994 were detected regardless of the antigenic drift of the influenza virus. On the other hand, several anti-HA Mabs which reacted specifically with the strains of the B/Victoria group, did not react with any strain of the B/Yamagata group. In the 1996/97 influenza season in Osaka Prefecture in Japan, two antigenically distinct groups of influenza B virus strains were isolated. They belonged to different phylogenetic trees and were clearly distinguishable by the PAP staining method with anti-HA Mabs.     

Reassortment and evolution of current human influenza A and B viruses

During the 2001-2002 influenza season, human influenza A (H1N2) reassortant viruses were detected globally. The hemagglutinin (HA) of these H1N2 viruses was similar to that of the A/New Caledonia/20/99 (H1N1) vaccine strain both antigenically and genetically, while their neuraminidase (NA) was antigenically and genetically related to that of recent human influenza H3N2 reference viruses such as A/Moscow/10/99. All six internal genes of the H1N2 reassortants originated from an H3N2 virus. After being detected only in eastern Asia during the past 10 years, Influenza B/Victoria/2/87 lineage viruses reappeared in many countries outside of Asia in 2001. Additionally, reassortant influenza B viruses possessing an HA similar to that of B/Shandong/7/97, a recent B/Victoria/2/87 lineage reference strain, and an NA closely related to that of B/Sichuan/379/99, a recent B/Yamagata/16/88 lineage reference strain, were isolated globally and became the predominant influenza B epidemic strain. The current influenza vaccine is expected to provide good protection against H1N2 viruses because it contains A/New Caledonia/20/99 (H1N1) and A/Panama/2007/99 (H3N2) like viruses whose H1 HA or N2 NA are antigenically similar to those of recent circulating H1N2 viruses. On the other hand, widespread circulation of influenza B Victoria lineage viruses required inclusion of a strain from this lineage in influenza vaccines for the 2002-2003 season.     

Genetic characterization of the hemagglutinin of two strains of influenza B virus co-circulated in Taiwan.

Two isolates of influenza B virus were obtained in the spring of 1997. One strain, B/Taiwan/21706/97, was isolated from a patient who had acute tonsillitis. The other, B/Taiwan/3143/97, was isolated from a patient who was diagnosed with meningoencephalitis. This implies that the influenza B viruses not only cause respiratory symptoms but may also cause inflammation of the nervous system. Sequence analysis of the hemagglutinin (HA) gene, HA1 domain, indicated that there were remarkable amino acid changes in the strain B/Taiwan/3143/97 compared to B/Victoria/2/87, B/Yamagata/16/88, and B/Taiwan/7/88. The changes in the positions 116, 200, 238, 242, and 271 were correlated with receptor binding. Furthermore, a potential glycosylation site at position 233 was lost. In total, 30 amino acid changes were noted at positions ranging from 116 to 295. These changes may affect the antigenicity of the virus. Phylogenetic analyses also showed that the B/Taiwan/3143/97 was located in an independent lineage, when compared to the reference strains belonging to B/Victoria/2/87 and B/Yamagata/16/88 lineages. This supports the hypothesis that influenza B viruses with distinct genetic characteristic were co-circulated in Taiwan.     

Phylogenetic analysis of influenza B virus in Taiwan, 1997 to 2001.

Seventeen strains of influenza B virus were isolated and identified from 1997 to 2001. Throat swabs were collected in children who presented in medical centers in both central and northern parts of Taiwan. To clarify the molecular characteristics of these isolates, both partial hemagglutinin (HA) gene and nonstructural (NS) gene nucleotide sequences were cloned and subjected to nucleotide sequence analysis. The phylogenetic analysis of the HA gene revealed that 16 out of 17 strains were similar to B/Yamagata/16/88-like virus, but grouped together to form an independent cluster. Only one strain, B/Taiwan/21706/97, was similar to the B/Victoria/2/87-like lineage. In addition, all isolates, except for B/Taiwan/21706/97, were similar to B/Beijing/184/93 and B/Yamanashi/166/98, which were chosen as the recommended vaccine strains in 1999 and 2001. In contrast, the NS gene of these isolates was evolved from B/Guangdong/8/93. Based on the accumulation of antigenic drift in our isolates, we conclude that influenza B virus is still prevalent in Taiwan and the accumulation of nucleotide mutations indicated that our isolates form a new cluster that evolved from the YA88 lineage.