Morphofunctional reaction of T lymphocytes on in vitro contact with calcium phosphate coating in the presence of T-cell activation kit

Morphofunctional activity of T lymphocytes invitrocontacted with calcium phosphate (CP) coating in the presence of particles with antibodies to CD2, CD3 and CD28 antigens has been studied. VT10 titanium plates (10 x 10 x 1 mm³) with a bilateral microarc rough (index R_a = 2—5 um) CP coating were used as a model samples to imitate the bone mineral matrix. MACSiBead™ magnetic particles of TCell Activation/Expansion Kit human with monoclonal antibodies to CD2, CD3 and CD28 antigens (Tcell activator, TCA) employed to simulate antigenpresenting cell (APC) signaling. Human blood mononuclear cells (hBMNCs; 98.8% of CD45CD3⁺ cells) were cultivated in the presence of the CPcoated samples and/or TCA (2 x 10⁶ particles per 1.5 ml of nutrient medium with a mixture of cells in a ratio of 2: 1) for 2 and 14 days. CP coating and TCA synergistically triggered in vitro adaptation of hBMNC culture via the mechanisms of hyperactivation and subsequent death of T lymphocytes. An immunoselection was conditioned by the accumulation of CD45RA⁺/R.C⁺ naive T lymphocytes and memory T cells and the simultaneous depletion of the pool of CD4⁺ and CD8⁺ T cells. Changing of T cell subsets was accompanied by enhanced cell secretion in 2 days versus its deprivation in 14 days of investigation. CP coating supported, as compared with cell culture on plastics the secretory capacity of lymphocytes Thl (IL12, TNFa, IFNy) and Th2 (IL4, IL6, IL10, IL13). At the same time, a prolonged TCA signal after 48 hours of activation led to depletion of morphofunctional activity of T cells. A hypothesis that the effects found invitrocould be important in switching of signaling between T lymphocytes, APC, and CP materials at the cell/foreign body interface is discussed. A change in the phases of inflammation/regeneration, the development of immune tolerance, successful osseointegration of implants or impaired bone tissue remodeUng may be an outcomes of such cellularmolecular crosstalk.