[Use of continuous human and animal cell lines for the production of viral vaccines].

History of development of safety criteria for continuous human and animal cell lines approved for manufacture of immunobiologic preparations. It was noted that current WHO documents recommend mandatory use of respective WHO's reference cell cultures (Vero-10-87 for continuous cell lines, and Wi-38 or MRC-5 for diploid cell lines) during attestation of new cell cultures proposed for the manufacturing of immunobiologic preparations. Examples of practical use of continuous cell lines (CCLs) for production of viral vaccines on industrial scale are described. On the basis of modern data most important principles were formulated which should be considered to provide safety and efficacy of vaccines produced on the CCLs.

[The morphology of cell lines suitable for vaccine production studied by scanning electron microscopy]. / Issledovanie morfologii kletochnykh linii, prigodnykh dlia proizvodstva vaktsin, s pomoshch'iu rastrovoi élektronnoi mikroskopii.

Five nontumorogenic cell lines suitable for vaccine production were studied by SEM. It was shown that diploid cell line 41 originated from sheep embryo kidney and also two heteroploid cell lines, line 4921 originated from embryo skin and muscles of the African green young monkey and line 4647 from kidney of the adult monkey, maintained normal cell morphology and normal growth pattern in early and in later passages in cultures. Some alterations in epithelial dense monolayer formation were revealed in the heteroploid cell lines: in line 455 originated from spleen of the adult African green monkey, and in line 4184 originated from line 41. The revealed alterations can be considered as the early morphological signs of the transformation of epithelial cells in culture. These cell lines also retained the stability of their morphological characteristics at the earlier and later passages. All the studied cell lines were free of contaminating agents.

[The protective activity of preparations made from the tick-borne encephalitis virus grown using different cell cultures]. / Izuchenie protektivnoi aktivnosti preparatov iz virusa kleshchevogo éntsefalita, vyrashchennogo s ispol'zovaniem razlichnykh kletochnykh kul'tur.

The preparations of tick-borne encephalitis (TBE) virus grown in swine embryo kidney cell culture have been shown to possess pronounced protective activity per unit of virion protein E in comparison with TBE virus preparations derived from cell culture 4647 and chick embryo cell culture. The antigenic activity of all virus preparations under study has proved to be practically the same. The role of post-translation modifications of TBE virus protein E in the manifestation of some of its biological properties is discussed.

[The purification of tick-borne encephalitis virus preparations of cellular DNA]. / Ochistka preparatov virusa kleshchevogo éntsefalita ot kletochnoi DNK.

According to the WHO requirements, the concentration of cellular DNA in vaccine preparations produced by pooling virus from continuous cell lines is limited to 100 ng/dose. In this study, different methods were used for purification of tick-borne encephalitis virus suspensions grown in continuous cultures of cell line 4647 from cellular DNA. Two approaches are proposed based on treatment with DNAse and promamin sulfate which allow one to reduce cellular DNA concentration in the virus preparation to the acceptable level. Prospects of their use in vaccine production are discussed.

[5-Iododeoxyuridine as well as 5-bromodeoxyuridine induce the formation of specific dicentric chromosomes in cells with micronuclei]. / 5-Ioddezoksiuridin, tak zhe kak i 5-bromdezoksiuridin, indutsiruet obrazovanie spetsificheskikh ditsentricheskikh khromosom v kletkakh s mikroiadrami.

5-iododeoxyuridine used instead of 5-bromodeoxyuridine for the induction of delayed disruption of telomeric links between chromosomes in polykaryocytes consisting of micronuclei was studied. It has been shown that treatment with 5-iododeoxyuridine (20 micrograms/ml) and colcemide (0.1 microgram/ml) for 42 hours induced the dicentric formation. Dicentrics were tested in 27% of all metaphases. This index was lower in comparison with 5-bromodeoxyuridine used for the same purpose.

[Activity of the nucleolus-organizing regions of the chromosomes of normal and transformed spleen cells in the African green monkey]. / Aktivnost' iadryshkoobrazuiushchikh raionov khromosom normal'nykh i transformirovannykh kletok selezenki afrikanskoi zelenoi martyshki.

The activity of nucleolus organizer regions (NOR's) of chromosomes in the African green monkey cells has been studied before and after the transformation. In cells before their transformation, one or two chromosomes entering into association and possessing NORs are involved in the formation of one nucleolus. In transformed cells no correlation between the numbers of nucleoli in interphase and those of chromosomes possessing NORs was revealed in metaphase plates. It is supposed that in chromosomes of the transformed cells with faintly stained NORs the gene activity is preserved only in part.

[Spontaneous sister chromatid exchanges in cultured African green monkey cells]. / Spontannye sestrinskie khromatidnye obmeny v kul'tiviruemykh kletkakh afrikanskoi zelenoi martyshki.

The frequencies of sister chromatid exchanges (SCE) were studied in primary kidney cell culture, diploid cell line 5018, pseudodiploid spontaneously transformed cell line 4647 and hypotetraploid cell line 455 of the African green monkey. Bromodeoxyuridine was used at a concentration of 10 micrograms/ml. The slides were stained with acridine orange and Giemsa for sister chromatid differentiation. In the first three cases, SCE were scored in 100 metaphases of each culture. The distribution of cells from the number of SCE differs from the normal law and was approximated fairly well by the lognormal distribution pattern. The geometrical means of SCE per cell were 6.90 for cells in primary culture, 9.26 for cells of diploid line 5018; 4.50 for cells of pseudodiploid transformed line 4647 and 9.76 for cells of hypotetraploid transformed line 455.