Tachyplesin activates the classic complement pathway to kill tumor cells
Tachyplesin activates the classic complement pathway to kill tumor cells
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DOI：
10.1158/0008-5472.can-04-2253
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发表时间：
2005-06-01
期刊：
影响因子：
11.2
通讯作者：
Zhang, LR
中科院分区：
文献类型：
--
作者：
Chen, JG;Xu, XN;Zhang, LR
Tachyplesin是一种具有抗肿瘤特性的小阳离子肽。然而，其作用机制尚不清楚。我们利用噬菌体展示技术鉴定了一种与tachyplesin相互作用的蛋白，并分离出与补体途径中的关键组分C1q的胶原样结构域相对应的序列。它们的相互作用随后被ELISA和亲和沉淀证实。Tachyplesin似乎激活了经典的补体级联，因为它触发了几个下游事件，包括C4和C3的裂解和沉积以及C5b-9的形成。在血清存在的情况下，用tachyplesin处理TSU肿瘤细胞，通过流式细胞术、Western blotting和共聚焦显微镜可以检测到肿瘤细胞上活化的C4b和C3b。然而，当用透明质酸酶或大量过量的透明质酸处理肿瘤细胞时，这种作用被阻断，这表明透明质酸或相关的糖胺聚糖参与了这一过程。通过fitc -葡聚糖进入细胞质的能力可以看出，用速胞素和血清处理细胞增加了细胞膜通透性。最后，速胞素与人血清联合使用可显著抑制TSU细胞的增殖并导致其死亡，但在热灭活血清或添加透明质酸酶后，这种作用减弱。综上所述，这些观察结果表明速胞素与细胞表面的透明质酸和血清中的C1q结合，并激活典型的补体级联反应，从而破坏肿瘤细胞膜的完整性，导致其死亡。
Tachyplesin is a small, cationic peptide that possesses antitumor properties. However, little is known about its action mechanism. We used phage display to identify a protein that interacted with tachyplesin and isolated a sequence corresponding to the collagen-like domain of C1q, a key component in the complement pathway. Their interaction was subsequently confirmed by both ELISA and affinity precipitation. Tachyplesin seemed to activate the classic complement cascade because it triggered several downstream events, including the cleavage and deposition of C4 and C3 and the formation of C5b-9. When TSU tumor cells were treated with tachyplesin in the presence of serum, activated C4b and C3b could be detected on tumor cells by flow cytometry, Western blotting, and confocal microscopy. However, this effect was blocked when the tumor cells were treated with hyaluronidase or a large excess of hyaluronan, indicating that hyaluronan or related glycosaminoglycans were involved in this process. Treatment of cells with tachyplesin and serum increased in membrane permeability as indicated by the ability of FITC-dextran to enter the cytoplasm. Finally, the combination of tachyplesin and human serum markedly inhibited the proliferation and caused death of TSU cells, and these effects were attenuated if the serum was heat-inactivated or if hyaluronidase was added. Taken together, these observations suggest that tachyplesin binds to both hyaluronan on the cell surface and C1q in the serum and activates the classic complement cascade, which damages the integrity of the membranes of the tumor cells resulting in their death.