GLYCOSYLATION OF THE HEMAGGLUTININ-NEURAMINIDASE GLYCOPROTEIN OF HUMAN PARAINFLUENZA VIRUS TYPE-1 AFFECTS ITS FUNCTIONAL BUT NOT ITS ANTIGENIC PROPERTIES
GLYCOSYLATION OF THE HEMAGGLUTININ-NEURAMINIDASE GLYCOPROTEIN OF HUMAN PARAINFLUENZA VIRUS TYPE-1 AFFECTS ITS FUNCTIONAL BUT NOT ITS ANTIGENIC PROPERTIES
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DOI：
10.1016/0042-6822(91)90120-z
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发表时间：
1991-07-01
期刊：
影响因子：
3.7
通讯作者：
PORTNER, A
中科院分区：
文献类型：
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作者：
GORMAN, WL;PRIDGEN, C;PORTNER, A
人类副流感病毒1型（hPIV-1）的血凝素-神经氨酸酶（HN）糖蛋白在预测的蛋白序列和结构上与仙台病毒相似，但其糖基化程度更高。由于糖基化可以改变蛋白质的结构和功能，我们研究了糖基化对hPIV-1病毒HN抗原结构和生物学功能的影响。用内糖苷酶F处理纯化的hPIV-1病毒粒子进行抗原和功能分析，该酶去除碳水化合物运动，因为用糖基化抑制剂处理hPIV-1感染的llc - mk2细胞会导致病毒粒子缺乏HN和F表面糖蛋白。去除碳水化合物后，hPIV-1的HN抗原结构未发生变化；7组hPIV-1 HN单克隆抗体（mab）的表位识别与未处理的病毒粒子相比没有变化。另外，10株仙台病毒HN单克隆抗体中有8株的交叉反应性没有变化，其余2株的交叉反应性略有变化。碳水化合物去除似乎也没有影响血凝或神经氨酸酶活性；与鸡红细胞（cRBC）的血凝滴度不变，与小底物（n -乙酰神经氨基乳糖）的体外神经氨酸酶活性仅降低20%。然而，由于神经氨酸酶的活性，从凝集的cRBC中去糖基化的hPIV-1的洗脱减少了80%。这些结果表明，hPIV-1型HN的酶活性不受碳水化合物去除的直接影响，而洗脱量的降低是由于HN与宿主受体相互作用的改变。所有7种hPIV-1型hnmab抑制去糖化hPIV-1病毒血凝的能力降低了2- 16倍，进一步支持了这一点。发现hn -宿主受体相互作用的这种变化涉及受体特异性的变化，因为去糖基化病毒能够完全凝集原生糖基化病毒所需的剥离受体的cRBC。我们为我们的结果提出了以下模型：hPIV-1的HN去糖基化导致分子的血凝部分识别一个新的受体，该受体对神经氨酸酶的酶切不敏感。
The hemagglutinin-neuraminidase (HN) glycoprotein of human parainfluenza virus type 1 (hPIV-1) has been shown to be similar in predicted protein sequence and structure to those of Sendai virus, but it is more highly glycosylated. Because glycosylation can modify protein structure and function, we investigated the effect of glycosylation on the antigenic structure and biological function of the HN of hPIV-1. Antigenic and functional analyses were carried out with purified hPIV-1 virions treated with Endoglycosidase F, which removes carbohydrate moities, because treatment of hPIV-1-infected LLC-MK2cells with an inhibitor of glycosylation resulted in virions which were deficient in both HN and F surface glycoproteins. No change in the antigenic structure of the HN of hPIV-1 was detected after carbohydrate removal; epitope recognition by a panel of 7 hPIV-1 HN monoclonal antibodies (MAbs) was unchanged compared to untreated virions. Moreover, there was no change in the cross-reactivity of 8 of 10 Sendai virus HN MAbs, and only a slight change in the remaining 2. Nor did carbohydrate removal appear to affect hemagglutinating or neuraminidase activities; hemagglutination titers with chicken erythrocytes (cRBC) were unchanged, andin vitroneuraminidase activity with a small substrate (N-acetylneuraminlactose) showed only a 20% reduction. However, elution of deglycosylated hPIV-1 from agglutinated cRBC as a result of neuraminidase activity was reduced by 80%. These results suggest that the enzymatic activity of hPIV-1 HN was not directly affected by carbohydrate removal but that the reduction in elution was due to a change in the interaction of the HN with the host receptor. This was further supported by a 2-to 16-fold reduction in the ability of all 7 hPIV-1 HN MAbs to inhibit hemagglutination of deglycosylated hPIV-1 virus. Such a change in HN-host receptor interaction was found to involve a change in receptor specificity because deglycosylated virus was able to fully agglutinate cRBC stripped of receptors required by the native, glycosylated virus. We propose the following model for our results: deglycosylation of the HN of hPIV-1 causes the hemagglutinating portion of the molecule to recognize a new receptor which is not susceptible to enzymatic cleavage by the neuraminidase.