本文对麒麟菜多糖抑制小鼠体内H22肝癌细胞增殖的作用机理进行了研究。构建动物肿瘤模型，观察实验期内各组小鼠肿瘤体积及脏器指数的变化，并通过Elisa实验确定各组小鼠血清中肿瘤特异性抗体含量，流式细胞术检测小鼠胸腺、脾脏、外周血及实体肿瘤内T细胞亚群比例，HE染色和PI单染分析小鼠实体肿瘤内细胞状态。结果表明，灌喂600 mg/(kg?d)麒麟菜多糖可显著抑制荷瘤小鼠肿瘤的生长，有效保护其胸腺和脾脏，并可显著增强胸腺发育分化CD4+ T细胞的能力(p<0.05)，提高小鼠血液中肿瘤特异性抗体的含量(p<0.05)和T细胞亚群比例(p<0.05)；模型组和多糖组小鼠实体肿瘤浸润淋巴细胞中均主要是CD8+ T细胞，但多糖组小鼠实体瘤内细胞凋亡率显著升高(p<0.05)。因此初步断定麒麟菜多糖可显著提高荷瘤小鼠的抗肿瘤免疫水平，使CD8+ T细胞在CD4+T细胞和肿瘤特异性抗体的辅助下有效抑制H22细胞体内增殖。

The mechanism of the inhibitory effect of Eucheuma polysaccharides on the proliferation of H22 hepatocellular carcinoma cells (H22) in mice was investigated in vivo. An animal tumor model was established and changes in tumor size and organ indices of the mice in all groups were observed during the experiments. The content of tumor-specific antibodies in serum were measured via ELISA assay. Meanwhile, the proportions of T-cell subsets in thymus, spleen, peripheral blood, and solid tumors were detected by flow cytometry, and the cell cycle status of solid tumor cells was analyzed by hematoxylin-eosin staining and propidium iodide single staining. The results showed that administration of 600 mg/(kg?d) Eucheuma polysaccharides could significantly inhibit tumor growth, effectively protect the thymus and spleen, significantly enhance the development of CD4+ T cells in the thymus (p<0.05), and significantly increase the content of tumor-specific antibodies in serum (p<0.05) and the proportion of T cell subsets in blood (p<0.05). In addition, the tumor-infiltrating lymphocytes in both the polysaccharide and model groups were mainly CD8+ T cells. However, the apoptosis rate of solid tumor cells in the polysaccharide group was significantly increased (p<0.05) compared to that of the model group. It was preliminarily concluded that Eucheuma polysaccharides could improve the antitumor effect significantly in tumor-bearing mice and allow CD8+ T cells to effectively inhibit the proliferation of H22 cells with the help of CD4+ T cells and tumor-specific antibodies.

国家自然科学基金面上项目（31271975）