Morphological, Genetic and Functional Variability of a T-Cell Hybridoma Line

Dzhambazov, Balik M.; Teneva, I.; Koleva, L.; Asparuhova, D.; Popov, N.

doi:10.14712/fb2003049020087

Fol. Biol. 2003, 49, 87-94

https://doi.org/10.14712/fb2003049020087

Morphological, Genetic and Functional Variability of a T-Cell Hybridoma Line

Balik M. Dzhambazov¹, I. Teneva², L. Koleva³, D. Asparuhova³, N. Popov³

¹Section for Medical Inflammation Research, Department of Cell and Molecular Biology, Lund University, Lund, Sweden
²Junior Research Group, Molecular Animal Cell Toxicology, UFZ Centre for Environmental Research, Leipzig, Germany
³Cell Biology Laboratory, Department of Developmental Biology, University of Plovdiv, Plovdiv, Bulgaria

Received January 2003
Accepted February 2003

The variability in the morphology, modal number of chromosomes, TCR expression and functional reactivity of a CII-specific T-cell hybridoma at continuous subcultivation have been investigated. As the number of passages increased, besides the oval semiadherent cells (normal phenotype), fibroblast-like cells (transformed phenotype) were also observed. The two cell subpopulations differed in their karyotype characteristic, as well as in their functional reactivity. The cell population with a normal phenotype was characterized by a tetramodal number of chromosomes (30, 40, 48 and 70) and trisomies of chromosomes 6 and 14, while the cell population with a transformed phenotype was characterized by a trimodal number of chromosomes (11, 68 and 74) and trisomy of chromosome 12. A nullisomy of sex chromosomes was established in both types of cells. In the initial passages of subcultivation, 73.04% of the cells with a normal morphological phenotype expressed TCR-CD3 complexes on their surface and possessed high functional reactivity. After a two-week subcultivation, the values of these indices went down considerably: 46.11% of the cells expressed functional TCR-CD3 complexes, as a result of which their functional reactivity decreased. Only 2.71% of the cells with a transformed morphological phenotype expressed functional TCR-CD3 complexes on their surface. In these cells, a total loss of reactivity towards the specific antigens was established. The achieved results show that at continuous subcultivation the T-cell hybridomas are unstable, and with the increase in the number of passages there appear chromosome rearrangements, leading to loss of their functional reactivity.