background and objectives:scrophularia variegata m. beib. (scrophulariaceae) is a medicinal plant, used for various inflammatory diseases in iranian traditional medicine. in the present study, we evaluated the immune modulation and antioxidant effects of the hydroalcoholic extract of s.  variegata. methods: the splenocytes were harvested from the spleen of balb/c mice and were cultured. the spl...

Natural killer (NK) cell cytotoxicity involves the formation of an activating immunological synapse (IS) between the effector and target cell through which granzymes and perforin contained in lytic granules are delivered to the target cell via exocytosis. Inhibition of nonmuscle myosin II in human NK cells with blebbistatin or ML-9 impaired neither effector-target cell conjugation nor formation...

The calmodulin antagonist W7 and 4 of its analogues were examined for their ability to inhibit human NK cell mediated cytotoxicity. With the exception of one of these compounds, which is extremely hydrophobic, there was a good correlation between the ability of drugs to inhibit human NK antitumour cytotoxicity and calmodulin-dependent phosphodiesterase activity in vitro. The most potent of the ...

Natural killer (NK) cells, which represent a small fraction of normal peripheral blood mononuclear cells, were purified by immunofluorescent cell sorting of NKH1+ cells. Cytotoxicity of NKH1+ cells could be enhanced through activation by monoclonal antibodies (anti-T112 and anti-Ti13) specific for epitopes of the sheep erythrocyte receptor or by recombinant interleukin-2 (rIL2). After 18 h, inc...

Our previous reports demonstrated that the magnitude of natural killer (NK) cell-mediated cytotoxicity correlate directly with the stage and level of differentiation of tumor cells. In addition, we have shown previously that activated NK cells inhibit growth of cancer cells through induction of differentiation, resulting in the resistance of tumor cells to NK cell-mediated cytotoxicity through ...

HIV-1 infected cells are eliminated in infected individuals by a variety of cellular mechanisms, the best characterized of which are cytotoxic T cell and NK cell-mediated killing. An additional antiviral mechanism is antibody-dependent cellular cytotoxicity. Here we use primary CD4(+) T cells infected with the BaL clone of HIV-1 as target cells and autologous NK cells, monocytes, and neutrophil...

Cell surface antigens, the expression of which is highly enhanced along with the transformation of cells, were analyzed. W14 and W31, EJ-ras oncogene-induced transformants of a WKA rat fetus-derived fibroblast WFB, strongly expressed several transformation-associated antigens as defined by monoclonal antibodies 109, 061, and 081. These monoclonal antibodies recognized Mr 86,000, 62,000, and 101...

BACKGROUND Natural killer (NK) cells are important in destroying tumor cells. However, they are damaged by radiation therapy. We studied the effects of single and fractionated irradiation on the viability and cytotoxicity of human non-selected NK cells and sub-groups with cluster of differentiation (CD) CD16(+) and CD56(+) in vitro. Only very few studies dealing with the standard radiobiologica...

To determine the role of NK cells in regulation of tissue growth, the phenotype and function of liver-resident NK cells were studied after 70% partial hepatectomy in rats. The process of liver regeneration was generally completed by day 14. In contrast, the number of liver-resident NK cells (NKR-P1bright) was restored as early as day 3 after partial hepatectomy. However, spontaneous functions o...