Intravenous immunoglobulins and recombinant granulocyte-colony stimulating factor modulate expression of NK cytotoxic receptors

Abstract

Natural killer cells (NK cells) are a population of innate immune lymphocytes capable of cytolysis of infected or transformed cells without prior sensitization. Natural killers are detected in various organs and tissues and may differ in phenotypic and functional characteristics depending on localization. For example, NK cells are the dominant population (up to 70%) of decidual lymphocytes in early pregnancy. NK cells are able to contact with trophoblast cells, exert cytotoxicity towards them, as well as regulate their invasion, contributing to spiral arteries remodeling and establishment of physiological blood flow between mother and fetus. The contribution of impaired NK cell functional activity to immune mechanisms of the reproductive disorders is widely discussed. Various drugs are used to treat infertility, including intravenous immunoglobulins (IVIG) and recombinant granulocyte colony stimulating factor (G-CSF). Increased rates of embryo implantation and higher frequency of successful gestation have been shown after treatment with these drugs. The effect of these drugs on NK cells phenotype and functional activity is assumed, thus requiring further studies on the effects of IVIG and G-CSF on the receptor profile of NK cells. The aim of this work was to evaluate expression of cytotoxic receptors on the NK-92 cells in presence of IVIG and recombinant G-CSF preparations. NK-92 cells were used as effectors, and trophoblast-derived JEG-3 line served as target population. The cells were co-cultured in presence of drugs, as well as without them. Expression of CD45, CD56, CD215, KIR2DL3, KIR2DS4, NKG2D, NKp44, NKp30 receptors by NK-92 cells was evaluated by flow cytometry. The number of NK-92 cells expressing NKG2D, NKp30, KIR2DL3 receptors and the expression intensity of NKG2D and NKp30 receptors were reduced in presence of IVIG preparations. The numbers of KIR2DL3+ and NKp44+ NK cells were reduced when supplied with G-CSF and trophoblast cells. The obtained results may be associated with both direct and indirect effects of the studied drugs on the NK cell phenotype.

Keywords

• nk cells
• nk-92
• trophoblast
• jeg-3
• intravenous immunoglobulins
• granulocyte colony stimulating factor
• cytotoxic receptors