Chai J G, Bando T, Kobashi S, Oka M, Nagasawa H, Nakai S, Maeda K, Himeno K, Sato M, Ohkubo S
Department of Parasitology and Immunology, School of Medicine, University of Tokushima, Japan.
Cancer Immunol Immunother. 1992;35(3):181-5. doi: 10.1007/BF01756185.
The antitumor activity of an extract of seeds from Aeginetia indica L., a parasitic plant, was investigated. BALB/c mice, inoculated i.p. 1 x 10(5) syngeneic Meth A tumor cells, were administered 2.5 mg/kg A. indica extract i.p. every 2 days from day 0. The untreated mice died of an ascitic form of tumor growth within 21 days, whereas all the treated mice completely recovered from tumor challenge without any side-effects. The extract did not exert direct cytotoxic activity against Meth A in vitro. Mice that survived after the first challenge as a result of A. indica treatment overcame the rechallenge with homologous Meth A without additional administration of the extract. On the other hand, those mice could not survive after rechallenge with Meth 1 tumor cells, which were also established in BALB/c mice but were different in antigenicity from Meth A, suggesting the development of antigen-specific concomitant immunity in the A. indica-cured mice. In the induction phase of antitumor resistance in this system, CD4+ T cells appeared to be the main contributors, since in vivo administration of anti-CD4 mAb completely abolished such resistance. In contrast, anti-CD8 mAb administration did not influence the effect of A. indica. The importance of CD4+ T cells in antitumor immunity was again clarified by Winn assay; that is, spleen and lymph node cells depleted of CD4+ T cells in vitro prior to assay abolished antitumor activity on co-grafted Meth A tumor cells in vivo.
对寄生植物印度野菰种子提取物的抗肿瘤活性进行了研究。给腹腔注射1×10⁵ 同基因Meth A肿瘤细胞的BALB/c小鼠，从第0天开始每2天腹腔注射2.5mg/kg印度野菰提取物。未处理的小鼠在21天内死于腹水型肿瘤生长，而所有处理过的小鼠在肿瘤攻击后完全恢复，且无任何副作用。该提取物在体外对Meth A没有直接的细胞毒性活性。由于印度野菰处理而在首次攻击后存活的小鼠，在未额外给予提取物的情况下，克服了同源Meth A的再次攻击。另一方面，在用Meth 1肿瘤细胞再次攻击后，这些小鼠无法存活，Meth 1肿瘤细胞也是在BALB/c小鼠中建立的，但抗原性与Meth A不同，这表明在印度野菰治愈的小鼠中产生了抗原特异性伴随免疫。在该系统抗肿瘤抗性的诱导阶段，CD4⁺ T细胞似乎是主要贡献者，因为体内给予抗CD4单克隆抗体完全消除了这种抗性。相比之下，给予抗CD8单克隆抗体并不影响印度野菰的作用。Winn试验再次阐明了CD4⁺ T细胞在抗肿瘤免疫中的重要性；也就是说，在体外检测前耗尽CD4⁺ T细胞的脾细胞和淋巴结细胞消除了体内共移植的Meth A肿瘤细胞的抗肿瘤活性。
