Buravkova L B, Rykova M P, Grigorieva V, Antropova E N
Institute of Biomedical Problems RAS, Moscow, Russia.
J Gravit Physiol. 2004 Jul;11(2):P177-80.
To study cell-to-cell interactions in microgravity we examined the functional activity of natural killer cells on board of the ISS. NK cells are the effector cells with direct cytotoxic activity to oncogenic, virus-infected cells and cells with modified differentiation. Ground-based experiments have shown that the examination of target cell lysis after incubation with NK cells is a simple and informative model for studying the influence of microgravity. NK cytotoxicity was measured as the value of non-degradeted labeled myeloblasts (K-562) after 24 hrs exposure with human lymphocytes in suspension. A special device was developed for space flight experiments. Human cultured lymphocytes and labeled K-562 cells were loaded into special syringes and delivered to the Russian segment of the ISS. Cosmonauts prepared co-cultured suspensions during the first day of microgravity, exposed them at 37 degrees C for 24 hrs and then separated H3-labeled cells on special filters. The results of ISS-8 mission showed that human NK cells in vitro remain lysis activity toward target cells in microgravity. The basal level of NK cytotoxicity was low and we did not found significant differences between "control" and "flight" values. Interferon production during the interaction between immune and target cells (ratio 10:1) in microgravity did not differ compared with ground-based control experiments. Ground exposure of the same lymphocyte samples with K-562 cells to 24 hrs clinorotation also did not lead to significant differences. These experiments paved the way for understanding the cell interaction mechanisms in space flight and the obtained results suggest that microgravity does not disrupt the interaction of NK cells with tumor cells.
为了研究微重力环境下的细胞间相互作用，我们在国际空间站上检测了自然杀伤细胞的功能活性。自然杀伤细胞是对致癌、病毒感染细胞以及分化改变的细胞具有直接细胞毒性活性的效应细胞。地面实验表明，检测自然杀伤细胞与靶细胞孵育后的靶细胞裂解情况是研究微重力影响的一种简单且信息丰富的模型。自然杀伤细胞的细胞毒性通过悬浮状态下的人淋巴细胞与标记的成髓细胞（K - 562）孵育24小时后未降解的标记物的值来衡量。我们为太空飞行实验开发了一种特殊装置。将人类培养的淋巴细胞和标记的K - 562细胞装入特殊注射器，运送到国际空间站的俄罗斯舱段。宇航员在微重力环境的第一天制备共培养悬浮液，在37摄氏度下孵育24小时，然后在特殊滤器上分离出H3标记的细胞。国际空间站第8次任务的结果表明，体外培养的人类自然杀伤细胞在微重力环境下对靶细胞仍具有裂解活性。自然杀伤细胞细胞毒性的基础水平较低，我们未发现“对照”值与“飞行”值之间存在显著差异。在微重力环境下免疫细胞与靶细胞相互作用（比例为10:1）期间产生的干扰素与地面对照实验相比没有差异。将相同的淋巴细胞样本与K - 562细胞在地面进行24小时的clinorotation处理也未导致显著差异。这些实验为理解太空飞行中的细胞相互作用机制铺平了道路，所得结果表明微重力不会破坏自然杀伤细胞与肿瘤细胞之间的相互作用。
