Role of Extracellular Calcium Ions at Early Stages of Human T-Lymphocyte Polyclonal Activation in vitro

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I. S. Litvinov^1*, M. A. Fomichev², and M. P. Kirpichnikov¹

¹Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia; fax: (495) 330-4011; E-mail: lis@mx.ibch.ru

²Moscow State Medical Stomatological University, ul. Delegatskaya 10, 111125 Moscow, Russia

^* To whom correspondence should be addressed.

Received February 4, 2008; Revision received October 8, 2008

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In this work we comparatively analyzed interleukin-2 (IL-2) and interferon γ production (IFN-γ) and also CD69 and CD25 expression by activated T-cells depending on extracellular calcium concentration ([Ca²⁺]_e), which was varied with EGTA. The expression of CD69 molecules on the surface of T-cells depended only on the presence of phorbol myristate acetate, occurred at [Ca²⁺]_e higher than 0.2 mM, and did not require the presence of ionomycin. The increase in [Ca²⁺]_e by itself cannot induce expression of CD25 and CD69 molecules by activated cells. The values of [Ca²⁺]_e, at which maximal fractions of CD3⁺CD69⁺(IL-2)⁺, CD3⁺CD69⁺(IFN-γ)⁺, and CD3⁺CD25⁺ activated T-cells were reached, never coincided with mean values of [Ca²⁺]_e for healthy donors and were different from each other. So, there is different [Ca²⁺]_e dependence for initial stages of activated T-cells differentiation. The relation between T-cells activation parameters and their differentiation is discussed.

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KEY WORDS: human peripheral blood, ionomycin, PMA, cell activation, EGTA, IL-2, IFN-γ

DOI: 10.1134/S0006297909030043

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