Morphofunctional reaction of T-lymphoblasts of Jurkat line on the titanium oxides coating
Human leukemic T-lymphoblastoid cells (hereinafter Jurkat T-cells) which was applied actively for modeling of T-lymphocytes reaction have been used in vitro We have examined morphofunctional response of Jurkat T-cells to 24-h in vitro contact with titanium substrates (12x12x1 mm<sup>3</sup>) covered by titanium oxide (TiO, TiO<sub>2</sub>) bilateral coating that was prepared by microarc method from an aqueous solution of 20 mass % orthophosphoric acid. 27-98% of immortalized cells in control culture (without an addition of the specimens) had CD3+CD4+CD71+CD45RA+ immunophenotype and secreted IL-2, IL-4, IL-8, IL-10 and TNFα, but not IL-1b and IL-6. Other markers of cell activation, differentiation, maturation and death (CD8, CD16, CD56, CD25, CD95) were found at 0 - 2. 5% of the cell population. The addition of bulk specimens with oxide coating reduced statistically CD3, CD4, CD8 и CD95 membrane markers presentation on Jurkat T-cells and decreased IL-4 and TNFα secretion Structural (antigens expression) and functional (cytokines secretion) Jurkat T-cells inactivation was not connected with the generation of intracellular reactive oxygen species (ROS), and was not mediated by TiO<sub>2</sub> nanoparticles (diameter of 14±8 nm; doses of 1 mg/L or 10 mg/L) which can be released under samples biodegradation. Spearman's correlation analysis showed the inhibiting action of the oxide surface roughness in the range of Ra = 2,2-3,7 μm on the number of viable Jurkat T-cells (r<sub>s</sub> = -0. 95; n = 9; p<0. 0001) due to an elevating portion of necrotic forms in the cellular population, mainly In turn, magnitude of negative electrostatic potential of the oxide surface rose linearly (r = 0. 6; p<0. 000001, n = 60) with increase in the Ra roughness index The roughness of the oxide coating induces its surface voltage that seems to promote morphofunctional suppression of tumor immune cells by electrostatic/biological mechanisms are not connected with intracellular ROS generation