[Comparative cytogenetic analysis of cells of mouse-mink inter-species hybridoma lines]. / Sravnitel'nyi tsitogeneticheskii analiz kletok linii mezhvidovoi gibridomy mysh'-norka.

The comparative cytogenetic analysis of the interspecific mouse-mink hybridoma cells revealed a segregation of the great number of the mink chromosomes, inter- and intraline variability according to the number of cells with the mink DNA and its quantity in the cells. No characteristics of the mink chromosomal material distribution in the hybridoma cells which secreted the immunoglobulins of the American mink or lost its secretion were found. The great changes in the karyotype of the hybrid cells were revealed by in situ hybridization with 3H-labelled total mink DNA. Numerous insertions of the regions from the mink chromosomes to the mouse chromosomes and the appearance of the chromosomes not typical of the mink and mouse parent cells were observed. The number of cells with translocations of fragments from the chromosomes to the mouse one was observed to grow in the hybridoma cell lines cultivated for a long time. Synthesis of the lambda-L-chains of the mink immunoglobulin in the cells of line 7 was absent because they lost lambda-gene.

[Interspecies mouse-mink hybridomas as producers of mink immunoglobulin]. / Mezhvidovye gibridomy mysh'--norka--produtsenty noroch'evo immunoglobulina.

The work is aimed at establishing the interspecies mouse-mink hybridomas from the fusion of American mink B-lymphocytes with the murine cell line NSO. The hybridoma (lime 10-B5) continued to secrete mink immunoglobulin L-chains in the culture for 6 months with constant reclonings. The hybridoma clone was characterized by a decrease in the secretory activity of cells. The karyological study et this clone has not reliably revealed the mink chromosomes in the genome of hybrid cells.

Mink-mouse interspecific hybridomas.

Mink-mouse interspecific hybridomas were produced by fusion of the american mink spleen cells with the NSO cells. Seven cloned lines of the mink-mouse hybridoma were isolated, and their functional mink Ig secretion and karyological characteristics are given. During cytogenetic analysis of mink-mouse hybridoma cell lines, we observed the elimination of mink chromosomes, and inter- and intralineral variability of the numbers of the cells with particular quantities of mink DNA. We did not find that the characteristic peculiarities of mink DNA distribution in the hybridoma cell lines had any bearing upon the secretion or non-secretion of mink Ig. There was no synthesis of lambda-L-chains of mink Ig in line 7 cells because the line lost the lambda-gene. With the aid of in situ hybridization with 3H-labeled total mink DNA, a considerable transformation of hybridoma cell karyotype was observed. Multiple integration of the mink DNA into mouse chromosomes and the appearance of chromosomes not characteristic for either the mink or mouse parent cells were noted. Increasing numbers of cells with translocations of mink chromosomes fragments into mouse chromosomes were found in the hybridoma lines cultivated for lengthy periods.

Mink-mouse hybridomas that secrete mink immunoglobulin G.

Optimum conditions were established to obtain mink-mouse interspecific hybridomas secreting mink IgG in fusions of mouse myelomas with mink immune spleen cells. Minks were immunized with allogeneic IgG, and the spleen cells were fused with three mouse myeloma lines P3-X63-Ag8.653, NSO and Sp2/0-Ag14. Of these, P3-X63-Ag8.653 and NSO were found to be the best fusion partners giving the highest yield of hybrid clones and number of IgG secreting clones. Cloning of mink-mouse hybridomas was efficient when BALB/c nu/nu peritoneal and spleen cells were used as feeders. The ten clonal lines produced secreted intact mink IgG molecules as shown by SDS-PAGE and subsequent immunoblotting. The secretion level of IgG ranged from 5 to 200 ng/ml in the clonal lines.