Morphofunctional changes of Jurkat T lymphoblasts upon short-term contact with a relief calcium phosphate surface

Human leukemic T lymphoblastoid cells (hereinafter, Jurkat T cells) have been used to model the morphofunctional reaction of T lymphocytes to 24-h in vitro contact with relief (roughness index Ra = 2.2–2.7 μm) pure titanium substrates (12 × 12 × 1 mm³) covered by a calcium phosphate (CP) bilateral coating prepared by the microarc method. Jurkat T cells placed in plastic multiwall plates (2D control of culture growth), as well as cells in contact for 24 h with oxide (TiO₂) microarc coating on pure titanium substrate (3D control), served as comparison tests. From 27 to 98% of immortalized cells in the 2D control culture had the 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, and CD95) were found in 0–2.5% of cells. IL-8 release elevated by the microtextured CP surface by 183 and 160% relative to 2D- and 3D-control cultures, respectively. The CD4/CD8 ratio dropped to 9: 1 (13: 1 and 82: 1 in 2D and 3D controls, respectively) due to CD4⁺ cell depletion and an increase in CD8⁺ cell number. The total cell number (TCN) in Jurkat T cell culture after 24-h contact with CP coating was decreased to 88% compared to 2D control (p < 0.04), which indicated cell division suppression. A drop in total cell number was accompanied with accelerated IL-8 secretion (r = −0.97, p < 0.00009). Low concentrations of IL-8 (pg/mL) induced apoptosis (r = 0.94, p < 0.0001). These results show that CP, rather than TiO₂, coating is a preferential surface material for endoprosthesis replacement and fracture osteosynthesis in patients suffering from hematological and bone malignancies.