Cogoli A, Bechler B, Cogoli-Greuter M, Criswell S B, Joller H, Joller P, Hunzinger E, Müller O
Space Biology Group, ETH Technopark, Zürich, Switzerland.
J Leukoc Biol. 1993 May;53(5):569-75. doi: 10.1002/jlb.53.5.569.
The activation by concanavalin A Con A of human peripheral blood lymphocytes (PBLs) in the presence of monocytes as accessory cells was investigated in cultures exposed to microgravity conditions in Spacelab. Activation of T cells was measured as incorporation of [3H]thymidine into DNA, secretion of interleukin-2 (IL-2), and interferon-gamma, and expression of IL-2 receptors. Whereas, as discovered in earlier experiments, the activation of resuspended T cells is strongly inhibited, activation of cells attached to microcarrier beads is more than doubled in microgravity. The results suggest that the depression of the activation in resuspended cells may be attributed to a malfunction of monocytes acting as accessory cells. In fact, although the ultrastructure of resuspended monocytes is not altered in microgravity, the secretion of IL-1 is strongly inhibited. Our data suggest that (1) IL-2 is produced independently of IL-1, (2) IL-1 production is triggered only when monocytes (and lymphocytes?) adhere to microcarriers, (3) the expression of IL-2 receptors depends on IL-1, and (4) provided sufficient IL-1 is available, activation is enhanced in microgravity. Finally, cultures of resuspended PBLs and monocytes in microgravity constitute a complete and natural system in which monocytes are not operational. This may be useful for studies of the role of accessory cells and cell-cell interactions in T lymphocyte activation.
在太空实验室的微重力条件下，研究了在单核细胞作为辅助细胞存在的情况下，伴刀豆球蛋白A（Con A）对人外周血淋巴细胞（PBLs）的激活作用。通过测量[3H]胸腺嘧啶核苷掺入DNA、白细胞介素-2（IL-2）和干扰素-γ的分泌以及IL-2受体的表达来检测T细胞的激活情况。然而，正如早期实验所发现的，重悬T细胞的激活受到强烈抑制，而在微重力条件下，附着于微载体珠的细胞激活增加了一倍多。结果表明，重悬细胞激活的抑制可能归因于作为辅助细胞的单核细胞功能异常。事实上，尽管重悬单核细胞的超微结构在微重力条件下未发生改变，但IL-1的分泌受到强烈抑制。我们的数据表明：（1）IL-2的产生独立于IL-1；（2）只有当单核细胞（和淋巴细胞？）附着于微载体时才触发IL-1的产生；（3）IL-2受体的表达依赖于IL-1；（4）如果有足够的IL-1，在微重力条件下激活会增强。最后，微重力条件下重悬的PBLs和单核细胞培养物构成了一个完整的天然系统，其中单核细胞不起作用。这可能有助于研究辅助细胞的作用以及细胞间相互作用在T淋巴细胞激活中的作用。
