病毒疫苗制备用不同核型VERO细胞系在裸鼠体内致癌/致瘤性的系统实验研究

生产疫苗用细胞系可能具有致瘤性，一些常用的细胞系需要检查不同代次有无致癌性。在建立传代细胞种子库与工作库基础上，对研制生产病毒活疫苗所用8株VERO细胞系在219只裸鼠进行了致癌(瘤)实验。本研究结果表明，VERO细胞染色体核型可发生变异，亚四倍体JA株与超二倍体KA株具有强的致癌性，不能用于致弱活病毒疫苗制备，但可替代HeLa细胞系用作恶性肿瘤阳性对照细胞。筛出无致瘤性的YB、dC、M和JB株亚二倍体VERO细胞系，可替代BHK-21细胞用于狂犬病减毒活疫苗制备。VERO细胞系染色体遗传相对稳定。不同代次变化不大。研究发现细胞染色体遗传特征决定致瘤性质并具有种属特异性，不同核型细胞致瘤性不同，细胞染色体数目变异大小和致癌性成正相关，通过体内外交替选育可在裸鼠体内快速选育成功高变异率肿瘤细胞系。高变异率HeLa或VERO细胞系移植于裸鼠可能产生恶性横纹肌样瘤。因此，应当强调疫苗生产用细胞系致瘤性评价的重要性。

Systematically Experimental Investigation on Carcinogenesis or Tumorigenicity of VERO Cell Lines of Different Karyotypes in Nude Mice in vivo Used for Viral Vaccine Manufacture

Many cell lines used for vaccine production have a potentially strong tumorigenic character.Some of those routinely used need to be checked at different passage numbers for this characteristic.Using HeLa cell cultures as positive controls,and primary canine kidney cell (CKC) or feline kidney cell (FKC) cultures purified in vitro on passage three as negative controls,the tumorigenicity of VERO cell sublines was tested in 219 nude mice.The master cell stocks (MCS) and working cell banks (WCB) of eight strains of VERO African green monkey kidney cell (AGMKC) line used for canine,feline and mink vaccine preparation were established in China.The hypo-tetra-ploid JA or hyper-diploid KA strain of VERO line was highly tumorigenic.These data showed a variable chromosome karyotype of VERO line,and contraindicated the use of JA or KA strain of VERO line for the preparation of attenuated viral vaccines.JA or KA strain of VERO line could be a substitute for HeLa line as a positive-control malignant tumor (MT) cell model.The non-carcinogenic YB,JC,M and JB strains of VERO line were therefore selected for the preparation of modified live rabies viral vaccine in place of BHK-21.The cell sub-lines are comparatively stable in terms of their heritable characters,and show little significant changes between passages.In summary,we have found that:1)the tumorigenicity of cell line is different among different-karyotypic cells;2)it is the genetic characteristics of chromosomes of cell lines that determines their tumorigenicity,but with species-specific carcinogenicity;3)the chromosome number variation of cell lines has positive relationship with their carcinogenesis;4)highly variable strains of tumor cell line can be selected quickly and successfully in nude mice by alternate cultivation in vitro and in vivo.Malignant rhabdoid tumor (MRT) was evolved in nude mice inoculated with violently variable HeLa or VERO cells.The importance of assessing the tumorigenicity in cell sublines used for vaccine production is emphasised.