Chujo T, Machii T, Tagawa S, Kuratsune H, Ueda E, Kimura H, Kitani T
Department of Clinical Research, Osaka University, Japan.
Clin Exp Immunol. 1989 May;76(2):154-8.
An anti-Gc antiserum (anti-Gc) was prepared by immunizing rabbits with purified Gc, a major vitamin D-binding protein in human serum. Gc is expressed on the surfaces of a small proportion of resting T cells and almost all B cells are natural killer (NK) cells. We investigated the effects of anti-Gc on NK activity of normal peripheral blood lymphocytes. Both anti-Gc and purified IgG isolated from anti-Gc prominently inhibited human NK activity in vitro. Inhibition of anti-Gc was dependent on the concentration of the antiserum employed. Competition assay showed that purified Gc significantly blocked the inhibitory effect of anti-Gc. The inhibition of NK activity in the cells treated with anti-Gc was restored time-dependently by being cultured in anti-Gc free medium. Anti-Gc-treated NK cells retained their capacity to bind to target cells. These findings suggest that mGc is associated with the process of the NK cytolysis on the post-binding cytolytic phase.
通过用人血清中的主要维生素D结合蛋白纯化的Gc免疫兔子制备了抗Gc抗血清（抗Gc）。Gc在一小部分静止T细胞表面表达，几乎所有B细胞都是自然杀伤（NK）细胞。我们研究了抗Gc对正常外周血淋巴细胞NK活性的影响。抗Gc和从抗Gc中分离出的纯化IgG在体外均显著抑制人NK活性。抗Gc的抑制作用取决于所用抗血清的浓度。竞争试验表明，纯化的Gc显著阻断了抗Gc的抑制作用。用抗Gc处理的细胞中NK活性的抑制通过在无抗Gc培养基中培养而随时间依赖性恢复。抗Gc处理的NK细胞保留了其与靶细胞结合的能力。这些发现表明，mGc与结合后溶细胞阶段的NK细胞溶解过程有关。
