Genetic Analysis and molecur Epidemiology of Parainfluenza virus type 4

克隆了人副流感病毒4B型(hPIV-4B)血凝素神经氨酸酶(HN)基因，并测定了其核苷酸序列。HPIV-4A和4B HN蛋白的核苷酸序列有81.4%的同源性，推导的氨基酸序列有87.3%的同源性。这种同源性被认为大于用单抗确定的hPIV-4A和-4B HN蛋白之间的免疫学相似性。为了阐明hPIV-4A和-4B HN蛋白抗原性差异的原因，我们构建了3个hPIV-4B HN的c DNA，它们的N-糖基化位点与hPIV-4A HN的c DNA部分或完全相同。我们比较了表达的野生型和突变型HN蛋白的抗原性，发现突变型hPIV-4B HN蛋白的抗原性更接近hPIV-4A HN蛋白，而不是突变的hPIN-4B HN蛋白。这项研究表明，抗原性DIV…人副流感病毒4A型(hPIV-4A)和人副流感病毒4B型(hPIV-4B)在猴肾LLC-MK2细胞(MK2细胞)和小鼠L929细胞(L929细胞)中的复制能力被检测。MK2细胞和L929细胞系(L929细胞)。MK2细胞和L929细胞都不允许复制hPIV-4。乙酰化胰酶对MK2细胞病毒复制有效，但对L929细胞病毒复制效果较差。内源性产生的干扰素对其在L929细胞中的复制没有影响。病毒特异性多肽的合成在L929细胞中受到抑制，未检测到HN-MTNA。这些结果表明，hPIV-4可以感染MK2细胞和L929细胞。在MK2细胞中，当细胞外培养上清液中有蛋白酶存在时，hPIV-4呈现多步生长。然而，在L929细胞中，不完全复制的原因可能是缺乏其他未知因素。较少

cDNAs encoding human parainfluenza virus type 4B (hPIV-4B) haemagglutinin-neuraminidase (HN) protein were cloned and the nucleotide sequences were determined. A high degree of identity (81.4%) was observed between the nucleotide sequences of hPIV -4A and 4B HN proteins, and 87.3% identity was found between the deduced amino acid sequences. This degree of identity is considered to be greater than the immunological similarity between hPIV -4A and -4B HN proteins determined using mAbs. To elucidate the causes of the antigenic difference between HN proteins of hPIV-4A and -4B, we constructed three cDNAs of hPIV -4B HN whose potential N-glycosylation sites were partially or completely the same as in hPIV -4A HN cDNA. We compared the antigenicity of the expressed wild type and mutant proteins, and found that the antigenicities of the mutant hPIV -4B HN proteins were more similar to the hPIV -4A HN protein than to the non-mutant hPIN -4B HN protein. This study indicated that the antigenic div … More ersity between hPIV -4A and -4B was partly caused by deletion or creation of glycosylation sites, showing that the point mutations resulting in deletion or creation of glycosylation sites in one of the initial steps leading to the division of virus into subtypes.Human parainfluemza virus type 4A (hPIV -4A) and type 4B (hPIV -4B) were tested for their ability to replicate in the monkey kidney LLC-MK2 cell line (MK2 cells) and the murine L929 cell line (L929 cells). Both MK2 cells and L929 cell line(L929 cells). Both MK2 cells and L929 cells were non-permissive for replication of hPIV -4. Acetylated trypsin was effective for the virus replication in MK2 cells, but less effective in L929 cells. Interferon (IFN) produced endogeneously played no role in their replication in L929 cells. Synthesis of virus specific polypeptides was suppressed in L929 cells HN -mTNA was not detected. These results indicate that hPIV -4 can infect both MK2 cells and L929 cells. In MK2 cells, when protease exists in the extracellular medium, hPIV -4 exhibits multistep growth. In L929 cells, however, the cause of incomplete replication might be lack of other unknown factors. Less