474 0007-4888/13/1554-0474 © 2013 Springer Science+Business Media New York Dexamethasone Effects on Activation and Proliferation of Immune Memory T Cells A. A. Gutsol, N. A. Sokhonevich*, V. I. Seledtsov*, and L. S. Litvinova Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 155, No. 4, pp. 468-470, April, 2013 Original article submitted March 26, 2012 Dose-dependent effects of dexamethasone on activation and proliferation of donor immune memory T cells (CD45RO + ) were studied. Activation of memory T cells associated with IL-2 production and membrane expression of CD25 molecule was resistant to dexamethasone. Proli- ferative activity of memory T cells associated with membrane expression of CD71 molecule was highly sensitive to dexamethasone. Hence, glucocorticoid hormones can maintain the clonal bal- ance in the lymphoid tissue without preventing realization of the immune memory mechanism. Key Words: dexamethasone; memory T-cells; cell activation; interleukin-2 Laboratory of Immunology and Cell Biotechnologies, *Center of Medical Biotechnologies, Innovation Park, E. Kant Baltic Federal University, Kaliningrad, Russia. Address for correspondence: gut- sol.alevtina@yandex.ru. A. A. Gutsol According to modern concepts, the efficiency of im- mune response to antigens of different nature (bacte- rial, viral, tumor, etc.) is determined by generation of antigen-specific immune memory cells [11]. CD4 + and CD8 + memory T cells are present in the organism without the antigen and their counts are replenished by homeostatic proliferation [9]. Failure of the mechanisms responsible for the for- mation of immunological memory underlies the de- velopment of some diseases [9]. This necessitates the search for effective methods for its regulation aimed in some cases at stimulation and in others at inhibition of immune processes. It is known that glucocorticoids are capable of modulating the immune system cells [8,10]. Dexamethasone (Dex), a synthetic glucocorticoid, is widely used in clinical practice for the treatment of immunopathological processes [7,10]. We studied the dose-dependent effects of Dex on activation and proliferation of immune memory T cells in vitro. MATERIALS AND METHODS The study was carried out on cells from 18 donors, 6 women and 12 men aged 20-39 years. Mononuclear cells (MNC) were isolated from heparin-treated ve- nous blood by centrifugation in ficoll-urograffin den- sity gradient (ρ=1.077 g/cm 3 ). The CD45RO + T cells were isolated from MNC by immunomagnetic separa- tion (MACS MultiStand; MidiMACS Separator, LS Columns, Miltenyl Biotec) using magnetic particles charged with antibodies to CD45RO molecule (Mi- croBeads, Miltenyl Biotec). The level of the target cell fraction was at least 95%. Isolated lymphocytes (10 6 /ml) were then cultured in Iskov medium (Sigma) containing 0.5% human serum albumin (Microgen), 5×10 –5 M mercaptoethanol (Acros Organics), and 30 μg/ml gentamicin with different concentrations of Dex (KRKA) or without it (control) for 48 h at 37 o C in a humid atmosphere with 5% CO 2 . Antibiotin particles with biotinilated antibodies to CD2, CD3, and CD28 molecules served as T cell activators (T Cell Activa- tion/Expansion Kit human, Multenyl Biotec). Culturing variants were as follows: intact sample (control), sample with T cell activator, samples with T-cell activator and Dex in concentrations of 10 –7 , 10 –6 , and 10 –5 M. The content of IL-2 in culture supernatants was measured by enzyme immunoassay using test systems according to the instruction (Vector-Best). The content of T cells expressing CD25 and CD71 molecules was measured by flow cytofluo- rometry on a GuavaEasyCyto TM Plus (Millipore) with antibodies labeled with fluorescent dyes (Sorbent, e-Bioscience). Viability of the studied cultures was Bulletin of Experimental Biology and Medicine, Vol. 155, No. 4, August, 2013 IMMUNOLOGY AND MICROBIOLOGY