[Anticellular action of alpha-interferons of various origins].

The results of the study of the anticellular effect of alpha-interferons of various origins (human, porcine, and bovine) on the growth of human lymphoblastoid cells (Namalva and J-96). Both homologous (human) and heterologous (porcine and bovine) leukocyte interferons produced a similar anticellular effect on the cells under study. All 3 types of interferon inhibited proliferation of lymphoblastoid cells.

[Action of human leukocyte interferon on poliomyelitis virus reproduction in resistant MIO(r) cells].

The effect of human leukocyte interferon on reproduction of poliomyelitis virus in MIO cells resistant to this virus (MIOr) and sensitive MIO cells was studied. Interferon was shown to exert a short-time protective effect in the sensitive cells and to induce virus reproduction in the resistant cells. It is suggested that poliomyelitis virus reproduction in the resistant cells is due to activation of lysosomal enzyme, cathepsin D, in this system.

[Stability of C-band heterochromatin polymorphism in 2 transplantable human cell lines differing in sensitivity to Coxsackie virus B3].

Heterochromatin of chromosomes is studied by means of a C-banding technique for the J-96 line of human cells, which is susceptible to enteroviruses and for the J-41 cell line derived from this culture and possessing high specific resistance to Coxsackie B viruses. The data obtained demonstrate stability of variform C-heterochromatin of chromosome pairs 1, 9 16 and certain marker chromosomes in the course of long-term cultivation.

[Karyological characteristics of the transplantable human cell line J-96, susceptible to Coxsackie B3 virus, and of its derived subline J-41, specifically resistant to this virus].

The paper is concerned with comparative cytogenetic studies of human cell line J-96 and subline J-41 derived from it. Application of G-, R- and C-techniques for differential staining of chromosomes made it possible to determine both numeric and structural changes in chromosomes of the resistant subline as compared to the initial one. The mechanisms contributing to a decrease in the normal chromosome number and to appearance of new marker chromosomes in the resistant subline cells are discussed as well as the possible relation of the found chromosome changes to the loss of cell sensitivity to the Coxsackie B3 virus.

Comparative cytogenetic study of a continuous human cell line and its subline susceptible and resistant, respectively, to coxsackie B3 virus.

Cytogenetic characteristics of the J-96 human cell line and its J-41 subline, highly susceptible and resistant, respectively, to coxsackie B3 virus, were compared. The J-41 subline, as compared to the original J-96 line, had fewer chromosomes in the modal class cells (54-57 and 58-62, respectively) mostly at the expense of normal chromosomes. In most J-41 cells chromosome 21 was eliminated and the number of homologues of chromosomes 2, 9, 11, and 12 was reduced.

[Recovery of the sensitivity of J-41 cells to Coxsackie B3 virus by treatment with exogenous alkaline phosphatase].

It has been shown that injection of G-41 cell cultures, deficient as regards alkaline phosphatase and resistant to Coxsackie B3 virus, in conjunction with exposure to an alkaline phosphatase preparation from the calf intestine results in virus reproduction. Depending on the dose administered and multiplicity of infection there occur either complete destruction of the monolayer or death of some cells with the development of cytopathic changes specific for Coxackie virus.

Stimulation by calcium chloride of virus-induced interferon formation by blood, haemopoietic organ and continuous human cells.

Calcium chloride stimulated virus-induced production of leukocyte interferon by human and animal blood and haemopoietic organ cells. CaCl2 treatment of surviving cells (leukocytes, human and mouse bone marrow) and Namalva cells was the most effective when carried out simultaneously with adsorption of the virus-inducer or when CaCl2 pretreatment was combines with its subsequent addition together with the virus-inducer. Optimal CaCl2 concentrations were 5 mM for human bone marrow cells and 10 mM for human leukocytes and mouse bone marrow cells.

[Comparative karyologic study of transplantable MIO and MIO-r cells, sensitive and resistant to poliomyelitis virus].

The continuous MIO cell line, highly sensitive to poliovirus, and the derivative subline MIO-r specifically resistant to this virus have been studied karyologically. It has been shown that these cell lines are different in modal class of chromosomes, mean number of the copies of individual intact chromosomes per cell and in morphology of marker chromosomes.

[Karyotype change in human cell cultures in the process of the reversion of Coxsackie B virus sensitivity].

The study was done on a subline of cells reverting to sensitivity to Coxsackie B3 virus after treatment of J-41 cells resistant to this virus with a homogenate prepared from the sensitive J-96 cell culture. Cytogenetic examinations of this cell subline showed its karyological characteristics to approach those of the sensitive J-96 culture. The modal number of chromosomes and the number of chromosomes 2, 9, 11, 12, and 21 were completely restored and marker chromosomes typical of the sensitive culture appeared.

[Restoration of the sensitivity of cells resistant to Coxsackie B3 virus after treatment with sensitive cell filtrate].

The study was done with J-96 cell line sensitive to Coxsackie B3 virus and the subline J-41 derived from it and resistant to this virus. In order to determine the substrates responsible for the susceptibility or resistance of these cells to Coxsackie B3 virus, homogenates and filtrates of the susceptible cells were inoculated into resistant ones and vice versa. Inoculation of the resistant cell homogenates into the susceptible cells at various intervals after virus inoculation did not inhibit virus development.

[Heterochromatinic segments in chromosomes of cultured human cells, sensitive and resistant to Coxsackie B viruses].

Comparative karyological studies of C-heterochromatin have been made on line J-96 of human cells, which are susceptible to enteroviruses, and on cell line J-41 derived from this culture and possessing highly specific resistance to Coxsackie B viruses. It was shown that the development of specific resistance to Coxsackie B viruses was accompanied by the loss of one of the chromosomes of pairs 1 and 9, and by the dissapearance of two marker chromosomes. There appeared new marker chromosomes with additional C-heterochromatain regions.

[Relationship of the characteristics of the chromosome set in human cell cultures to the production and antiviral action of interferon].

The role of chromosomes 2, 5, 16, and 21 in production and effect of human interferon was checked in human diploid cells, human heteroploid cells J-96 and clone J-41 thereof. The J-41 cells were found to have a lower number of chromosomes 2 as compared to the other cells under study; J-41 cells produce less interferon than the other cells. Most J-41 cells lack chromosome 21.

[Relationship between group G chromosomes, especially chromosome 21, and the sensitivity of human cells to Coxsackie B viruses].

The R-method of differential chromosome staining by length was applied to comparative karyological studies on the culture of J 96 human cells susceptible to enteroviruses, and on the J 41 cell line derived from this culture and possessing high specific resistance to Coxsackie B viruses. Karyotype of the J 41 cell line was shown to be deprived of chromosome G21 (P less than 0.0001).

[Formation of heterosymplasts in human reticular cell cultures].

The cell fusion has been studied in human reticular cell cultures J-96 and J-41 treated with the Sendai virus or with polyethylene glycol 1000 and 6000. The J-96 cells have a high alkaline phosphatase activity, in J-41 cells the enzyme is not detectable. No heterogenous alkaline phosphatase activity was seen in the protoplasm of symplasts 18 hours after virus cell fusion.