目的 建立一种定量分析副粘病毒包膜糖蛋白融合细胞功能的方法。方法 将vTF-7重组痘苗病毒感染BHK21细胞后，分别转染侍测基因DNA和pCIN17β-gal DNA，16h后将两个细胞群混合，37℃ 15h后用NP-40裂解细胞。取上清进行显色反应，在SOFTMAX软件支持下用ELISA自动测定性在570mm测吸光度A值。结果 指示基因法与细胞计数法有密系，r=0.9890（P<0.01）；与面积断法的符合率达100。最佳主要应成条件包括：16mmol/L底物浓度；显色反应20～25min；1μgDNA转染量；每种细胞量接种1×105个。结论 指示基因法是一种非常敏感、特异、可重复性好的细胞融合定量分析方法。可用于副粘病毒细胞融台作用功能的研究。并可作为其他病毒细胞融合作用研究的参考，具有较大的推广应价值。

The promolion of membrzme fusion by the fusion (F) protein of human parathfluenza vires 3 (fiPIV3) is dependenl on a vies specific eontnbution from the fiemagglulinin-neuraminidase (HN) protein By evaluarion of chimeric hPIV3-Newcasfle disease vires (NDV) HN proteins, we have previously show n that hPl V3 F-speci ficity is determined by a domain that extends lYnm the middle of the membrane anchor to the 82rid residue in the ectodomain [Virology 209. (1995) 457; Arch Virol 13 (1997) 115]. If the corresponding NDV-derived residues replace the two C-terminat residues in this domain, no fusion is dcteeled. However. these substitutions restore a glycosyladon sile present in NDV HN, but not in hPIV3 HN. Deletion of this site from a nested set of chbneras with fiPIV3-derived N terminal porlions of decreasing length partially restores fusion, suggesting that an ofigosacchande near the top of hPIV3 HN stalk modulates fusion In addition, further mutational analyses show that a chimera with only 125 N temdnal hPIV3-dedved residues (72 in the stalk) actually promotes fusion more efficiently than Ihe wt protein These findings Iocalize the C ternrinus of the F-specific domain in hPlV3 HN n full 10 residues closer to the membrane than previously shown

The ectodomain of the paramyxovirus haemagglutinin neuraminidase (HN) glycoprotein spike can be divided into two regions: a membrane-proximalp stalk-like structure and a terminal globular domain. The latter contains all the antibody recognition sites of the protein, as well as its receptor recognition and neuraminidase (NA) active sites. These two activities of the protein can be separated by monoclonal antibody functional inhibition studies and mutations in the 91obular domain. Herein, we show that mutation of several conserved residues in the stalk of the Newcastle disease virus HN protein markedly decrease its NA activity without a significant effect on receptor recognition. Thus, mutations in the stalk, distant from the NA active site in the globular domain, can also separate attachment and NA. These results add to an increasin9 body of evidence that the NA activity of this protein is dependent on an intact stalk structure.

Objective: To investigate the correlagon between rubella Jrus (RuV) antigen in peripheral Jymphocytes, the im mLine status and RuV infection in the central nervous system (CNS). Metbods: BALB/c mice were used as a model and treated with immunoaffecting medicines. Then, the mice were infected with RuV via the abdominal cavity, and the antigen lever in peripheral lymphocytes was examined 1.3, 7 and 14 days postinfection. RuV in the CNS was detected by immunohistocbemical meth ods. BALB/c mice were given dexamethasone and cytoxan before infection with the RuV JR23 strain. Immune functions and RuV invasion of the CNS were assayed on day 21 postinfection via the abdominal cavity, and their relationship was analyzed. Results: The mean antigen

目的 找到副牯病毒融合蛋白（F）分子上与血凝素-神经氪酸酶（HN）相互作用的特异性区域，弄清F融合细胞的分子机理。方法 采用基因定点突变法，创造一个酶切位点，得副突变株，然后用基因重组的方法得到各种重组株。并于真棱细胞内进行表达。Gimsa染色和指示基因法检测细胞融合功能，荧光强度分析（FACS）检测表达效率情况。结果 在将各有关F基因片段进行交换之前，创造一个酶切位点时所得突变株的细胞融合功能与野毒株相同；将新城疰病毒（NDV）F和副流感病毒（PIV）F在膜穿人部分和躯干部分交接处交换时。不影响细胞融合功能；进一步将F2进行交换时，也不影响细胞融台功能；而将F的头部进行交换时。则检测不到细胞融合作用，FACS分析表明，F没有达到细胞表面，结论 F分子上与HN相互作用的特异性区域位于膜穿大部分和躯干部分交接处与F1和F2交接处之间，即F1除去膜穿人部分和足部的剩余部分。