摘要
目的利用淋巴细胞减少期T细胞发生增殖活化的原理,以全身照射或环磷酰胺引起淋巴细胞减少,联合免疫重建及肿瘤疫苗免疫,以增强机体的肿瘤特异性免疫反应。方法分别以放疗或化疗(环磷酰胺)引起小鼠淋巴细胞减少,然后输入同系小鼠的未致敏脾细胞,建立免疫重建的淋巴细胞减少小鼠模型(RLM)。用黑色素瘤细胞F10对前者行免疫肿瘤攻击实验,并行T细胞亚群清除试验。而化疗RLM免疫模型的抗肿瘤免疫反应效果通过过继免疫治疗检测。免疫用瘤苗为GMCSF修饰的黑色素瘤细胞D6G6。免疫后9～10d,采集肿瘤疫苗接种部位的引流淋巴结,制备效应T细胞,然后过继回输给荷瘤3d(D5)的小鼠。2周后处死小鼠,计数肺转移灶数目。结果63.2%的放疗RLM免疫组小鼠可对肿瘤攻击产生抵抗,显著高于正常免疫组(16.7%,P<0.0001)。CD8+T细胞是介导抗肿瘤保护性免疫的主要效应细胞。延长免疫重建和瘤苗接种之间的间隔可削弱保护性抗肿瘤免疫。化疗RLM免疫组效应T细胞的在体抗肿瘤活性显著强于正常免疫组。结论在放、化疗引起的淋巴细胞减少期进行瘤苗免疫,有助于打破机体对肿瘤的免疫耐受,增强抗肿瘤免疫反应。
Objective To test whether vaccination performed during irradiation or chemotherapeuticsinduced lymphopenia-driven T cell proliferation could augmengt the antitumor immunity. Methods The study composed of two parts, investigating the anti-tumor efficacy of performing tumor vaccination during early immune reconstitution period following sublethal total body irradiation and cyclophosphamide（ Cy）-induced lymphopenia, respectively. Mice were subsequently reconstituted with naive splenocytes from syngeneic mice and were named RLM （ Reconstituted lymphopenic mice）. Immunization/vaccination （F10） and adoptive immunotherapy （D5-G6） were used to explore anti-tumor immune responses in vaccinated irradiation/RLM and vaccinated Cy/RLM, respectively. Both normal C57BL/6 mice and RLM were vaccinated with irradiated, weakly immunogenic F10 melanoma cells and subsequently challenged with F10 cells. In addition, to determine the role of CD4^＋ and CD8^＋ T cells in the protective anti-tumor immune response, irradiation/RLM were depleted of these subpopulations by administration of the appropriate mAb around challenge. In the second part, adoptive immunotherapy was used to evaluate the anti-tumor immune responses under chemotherapeutics-induced lymphopenic condition. Both normal mice and RLM （Cy-treated） were vaccinated with GM-CSF-modified D5 melanoma cells （D5-G6） and tumor vaccine draining lymph nodes （TVDLN） were harvested 9-10 days later. Effector T cells were generated in vitro from TVDLN cells and adoptively transferred to mice bearing 3-day pre-established pulmonary metastases （D5）. Recipient mice were sacrificed 2 weeks later after tumor inoculation and pulmonary metastases were enumerated. Results Significantly greater protection was induced in vaccinated irradiation/RLM, compared to vaccinated normal mice （63.2% vs 16.7%）. Protective immunity in RLM depended on CD8^＋ T cells. Increase in the interval between reconstitution and vaccination significantly decrease the protection. Effector T cells generated from vaccinated Cy-treated RLM demonstrated significantly higher in vivo anti-tumor efficacy over those of vaccinated normal mice. Conclusion This study suggests that vaccination of RLM could elicit augmented antitumor immunity compared to normal hosts, highlighting the potential clinical benefit of performing tumor vaccination during irradiation or chemotherapeutics-induced lymphopenia in cancer patients.
出处
《中华肿瘤杂志》
CAS
CSCD
北大核心
2005年第8期452-456,共5页
Chinese Journal of Oncology
