Different hemagglutinin cleavage site variants of H7N7 in an influenza outbreak in chickens in Leipzig, Germany.
Different hemagglutinin cleavage site variants of H7N7 in an influenza outbreak in chickens in Leipzig, Germany.
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德国莱比锡鸡群流感暴发中 H7N7 的不同血凝素裂解位点变异。
DOI：
10.1006/viro.1996.0187
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Webster,RG
中科院分区：
文献类型：
--
作者：
Rohm,C;Suss,J;Pohle,V;Webster,RG
从单次暴发的4株h7n9禽流感分离株中发现血凝素（HA）基因具有不同的裂解位点，含有不同数量的碱性氨基酸残基（KKKKR、KRKKR、KKRKKR、KKKKKKR）。所有四种变异在鸡中均具有高致病性，并与A/tern/Potsdam/342 /6 /79 （H7N7）和A/swan/Potsdam/63-6/81 （H7N7）具有直接共同的HA祖先。这些病毒是非致病性的，在其血凝素的切割位点不含有额外的碱性氨基酸。在进化过程中，一种共同的前体病毒在HA的裂解位点获得不同的序列，并在鸡中具有高致病性。体外检测结果显示，在A/chicken/Leipzig/79中含有KKKKR的HA仅部分裂解（41%），而其他HA的裂解率为93-100%。由于所有四种病毒在鸡中都具有高致病性，因此这些发现证实，在体内的致病性程度并不完全取决于HA的可切割程度。
The hemagglutinin (HA) genes from four avian H7N7 influenza A isolates, from a single outbreak, were shown to possess different cleavage sites that contain varying numbers of basic amino acid residues (KKKKR, KRKKR, KKRKKR, KKKKKKR). All four variants are highly pathogenic in chickens and share an immediate common ancestral HA with A/tern/Potsdam/342-6/79 (H7N7) and A/swan/Potsdam/63-6/81 (H7N7). These viruses are nonpathogenic and contain no extra basic amino acids at the cleavage site of their HA. During evolution a common precursor virus acquired different sequences at the cleavage site of the HA and became highly pathogenic in chickens.In vitroassays revealed that the HA from A/chicken/Leipzig/79 with KKKKR at the cleavage site was only partially cleaved (41%), compared to 93–100% cleavage of the other HAs. Since all four viruses were highly pathogenic in chickens, these findings confirm that the degree of pathogenicityin vivois not exclusively determined by the degree of HA cleavability.