Shau H, Dawson J R
Immunology. 1984 Dec;53(4):745-51.
Recent evidence has indicated the importance of lysosomes in natural killing (NK). The lysosomotropic dye neutral red, at concentrations greater than 2 X 10(-5) M, inhibits NK activity of large granular lymphocytes (LGL). Inhibition is at the level of effector cell activity rather than target cell susceptibility. Neutral red inhibits NK activity without affecting the viability of the effector cell population or the response of lymphocytes to the mitogen, phytohaemagglutinin (PHA). While the mechanism of this inhibition is unknown, neutral red-treated peripheral blood lymphocytes (PBL) do not suppress untreated effector cell populations. Furthermore, neutral red does not influence the binding of effector cells to target cells. Since natural killing by neutral red-treated PBL recovers slowly upon incubation of the cells at 37 degrees, inhibition is not due to selective toxocity. Trypan blue, another frequently used lysosomotropic vital stain, has no effect when effector cells are pretreated with 10(-3) M dye for 30 min or less. However, effector cells first treated with neutral red lose red granular staining following treatment with trypan blue for as little as 10 min at room temperature. Natural killing by neutral red pretreated PBL also recovers more quickly following brief incubation with trypan blue. Treatment of effector cells with trypan blue and neutral red simultaneously prevents accumulation of neutral red in cytoplasmic granules and subsequent inhibition of NK.
最近的证据表明溶酶体在自然杀伤（NK）中具有重要作用。溶酶体亲和染料中性红，浓度大于2×10⁻⁵M时，会抑制大颗粒淋巴细胞（LGL）的NK活性。抑制作用发生在效应细胞活性水平，而非靶细胞敏感性水平。中性红抑制NK活性，却不影响效应细胞群体的活力或淋巴细胞对有丝分裂原植物血凝素（PHA）的反应。虽然这种抑制机制尚不清楚，但经中性红处理的外周血淋巴细胞（PBL）不会抑制未处理的效应细胞群体。此外，中性红不影响效应细胞与靶细胞的结合。由于经中性红处理的PBL在37℃孵育后自然杀伤活性恢复缓慢，所以抑制作用并非由于选择性毒性。另一种常用的溶酶体亲和活体染色剂台盼蓝，当效应细胞用10⁻³M染料预处理30分钟或更短时间时，没有效果。然而，先用中性红处理的效应细胞，在室温下用台盼蓝处理仅10分钟后，红色颗粒染色就会消失。经中性红预处理的PBL的自然杀伤活性在用台盼蓝短暂孵育后也恢复得更快。同时用台盼蓝和中性红处理效应细胞可防止中性红在细胞质颗粒中积累以及随后对NK的抑制。
