单倍体异基因淋巴细胞输注在小鼠移植物抗宿主病和移植物抗肿瘤效应中的意义

Significance of haploidentical allogeneic lymphocytes infusion in induction of graft versus host disease andgraft versus tumor in mice

目的建立小鼠免疫耐受模型，探讨单倍体异基因淋巴细胞输注在小鼠移植物抗宿主病（GVHD）和移植物抗肿瘤（GVT）效应中的意义。方法64只BALB／C雌性小鼠按随机数字表法分为4组，每组16只。对照组：实验第4天接种肿瘤细胞（小鼠大肠癌CT26细胞株配制成1×10^7／mL的瘤细胞悬液，接种到雌性小鼠右腋皮下）后不予任何特殊处理；化疗组：实验第4天接种肿瘤细胞，第7天开始化疗；供体淋巴细胞输注（DLI）组：实验开始时进行预处理，第4天接种肿瘤细胞，第13、15、17天输注单倍体异基因淋巴细胞（雄性BALB／C小鼠制备的脾淋巴细胞）；化疗＋DLI组：实验开始时进行预处理，第4天接种肿瘤细胞，第7天开始化疗，第13、15、17天输注单倍体异基因淋巴细胞。预处理方案为输注单倍体异基因淋巴细胞＋环磷酰胺＋输注单倍体异基因淋巴细胞。化疗方案为小鼠接种肿瘤细胞后第3天给予环磷酰胺腹腔化疗。每日观察各组小鼠临床GVHD的指标，并给予临床评分。观察荷瘤鼠肿瘤生长情况，计算接种成功后首日到小鼠死亡的时间和肿瘤质量，计算抑瘤率。应用流式细胞仪检测各组小鼠外周静脉血中T细胞数量，接种后15d各组处死3只小鼠取瘤体制作成观察切片，HE染色后光镜观察。多组比较采用方差分析，组间比较采用LSD—t检验。结果化疗＋DLI组的小鼠GVHD临床表现轻于其他组小鼠。对照组、化疗组、DLI组、化疗＋DLI组GVHD评分分别为（2．3±0．6）分、（1．5±1．1）分、（6．7±0．9）分、（3．4±0．5）分，4组比较，差异有统计学意义（F=148．68，P〈0．05）。4组小鼠全部接种CT26细胞成功。对照组、化疗组、DLI组、化疗＋DLI组小鼠肿瘤质量分别为（3．40±0．20）g、（0．80±0．10）g、（2．20±0．20）g、（0．50±0．30）g，4组比较，差异有统计学意义（F=149．17，P〈0．05）；4组小鼠抑瘤率分别为0、77％±9％、35％±3％、85％±44％；4组小鼠CD3’分别为52．3％±2．9％、44．8％±3．1％、62．9％±3．5％、65．9％±3．3％，4组比较，差异有统计学意义（F：28．04，P〈0．05）；4组小鼠CD3＋CD4＋分别为32．1％±2．6％、27．1％±1．1％、42．6％±1．8％、41．7％±2．4％，4组比较，差异有统计学意义（F=40．29，P〈0．05）；4组小鼠CD3＋CD8＋分别为22．7％±2．2％、20．7％±1．8％、26．7％±0．8％、26．1％±0．7％，4组比较，差异有统计学意义（F=10．74，P〈0．05）；4组小鼠CD3＋CD＋CD25＋分别为8．7％±0．6％、6．6％±0．6％、11．2％±0．4％、13．3％±0．7％，4组比较，差异有统计学意义（F=82．88，P〈0．05）。4组小鼠的肿瘤组织均有不同程度的坏死、出血，其中DLI组和化疗＋DLI组肿瘤组织大片坏死，瘤细胞变小，间质内有大量炎性细胞浸润，化疗＋DLI组还可见大量增生的淋巴滤泡。对照组、化疗组、DLI组、化疗＋DLI组小鼠生存时间分别为（16．8±2．5）d、（26．3±2．9）d、（23．4±2．5）d、（33．7±4．6）d，4组比较，差异有统计学意义（F=46．45，P〈0．05）。结论（1）预处理方案可以诱导小鼠的特异性免疫耐受。（2）单倍体异基因淋巴细胞输注与化疗具有协同作用，联合应用可以抑制小鼠皮下移植瘤瘤体的生长以及延长小鼠的生存时间。（3）化疗可降低供体淋巴细胞输注后诱发的GVHD效应并且提高了GVT效果。（4）CD3＋CIN＋CD25＋T淋巴细胞在降低GVHD反应中起着重要的作用。

Objective To establish the mice model of immunological tolerance, and investigate the sig- nificance of haploidentical allogeneic lymphocytes infusion in induction of graft versus host disease and graft versus tumor in mice. Methods Sixty-four BALB/C female mice were randomly divided into 4 groups with 16 mice in each group. Control group： no special treatment was given after inoculation of tumor cells at the 4th day （ CT26 eolorectal cancer cell lines with mixture of 1 x 107/mL tumor cells suspension was inoculated to the right subcuta- neous axillary of mice） ; Chemotherapy group： chemotherapy was applied at the 7th day after inoculation of tumor cells at the 4th day; DLI group： tumor cells were inoculated at the 4th day, and then haploid donor cells were infused at the 13th, 15th and 17th day; Chemotherapy ＋ DLI group： tumor cells were inoculated at the 4th day, chemotherapy was applied at the 7th day, and haploid donor cells were infused at the 13th, 15th and 17th day. The pretreatment scheme included haploidentical allogeneic lymphocyte ＋ ring ling amide ＋ haploidentical allogeneic lymphocyte, and the chemotherapy regimen included peritoneal infusion of cyclophosphamide at the 3rd day after inoculation of tumor cells in mice. The time from the first day after vaccination to the clay of death of mice and the mass of the tumors were detected to calculate the tumor inhibition rate. The clinical indexes of GVHD were observed, and clinical evaluation was made. The numbers of T lymphocytes in peripheral blood were detected by flow cytometry. Three mice were sacrificed in each group at the 15th day to make the tissue specimens, and they were observed under light microscope after HE staining. All data were analyzed using the analysis of variance or LSD-t test. Results The symptoms of GVHD of mice in the chemotherapy ＋ DLI group were milder than those in other groups. The GVHD scores of the control group, chemotherapy group and the chemotherapy ＋ DLI group were 2.3 ± 0.6, 1.5 ± 1.1,6.7 ± 0.9 and 3.4± 0.5, respectively, with significant difference between the 4 groups （ F = 148.68, P 〈 0.05 ）. The tumor masses of the control group, chemotherapy group, DLI group and the chemotherapy ＋ DLI group were （3.40 ± 0.20） g, （0.80 ± 0. 10） g, （ 2.20 ± 0.20） g and （0.50 ± 0.30） g, respectively, with significant difference between the 4 groups （F = 149. 17, P 〈 0.05 ）. The tumor inhibition rates of the control group, chemotherapy group, DLI group and the chemotherapy ＋ DLI group were 0, 77%± 9% , 35%± 3% , 85% ±44%. The levels of CD3＋ of the control group, chemotherapy group, DLI group and the chemotherapy ＋ DLI group were 52.3% ± 2.9% , 44.8% ± 3. 1%, 62.9% ± 3.5% , 65.9% ±3.3%, respectively, with significant difference between the 4 groups （F = 28.04, P 〈 0.05）. The levels of CD3 ~ CD4 ~ of the control group, chemo- therapy group, DLI group and the chemotherapy ＋ DLI group were 32. 1% ±2.6% , 27. 1% ± 1. 1% , 42.6% ± 1.8% and 41.7% ± 2.4% , respectively, with significant difference between the 4 groups （ F = 40. 29, P 〈 0.05 ）. The levels of CD3 ~ CD8 ＋ of the control group, chemotherapy group, DLI group and the chemotherapy ＋ DLI group were 22.7% ± 2.2%, 20.7% ± 1.8%, 26.7% ± 0.8 % and 26.1% ±0.7% , respectively, with significant differ- ence between the 4 groups （ F = 10. 74, P 〈 0.05）. The levels of CD3 ＋ CD4 ＋ CD25 ＋ of the control group, chemo- therapy group, DLI group and the chemotherapy ＋ DLI group were 8.7% ± 0.6%, 6.6%± 0.6%, 11.2% ± 0.4% and 13.3% ± 0.7% , respectively, with significant difference between the 4 groups （ F = 82. 88, P 〈 0.05 ）. Necrosis and bleeding of the tumor tissues were observed in all the 4 groups. Necrosis, shrinking of the tumor cells, inflammatory infiltration were observed in the DLI group and the chemotherapy ＋ DLI group. Proliferation of lymphoid follicles was observed in the chemotherapy ＋ DLI group. The survival time of mice in the control group, chemotherapy group, DLI group, chemotherapy ＋ DLI group were （ 16.8 ＋ 2.5） days, （26.3 _＋ 2.9） days, （23.4± 2.5 ） days and （ 33.7 ±4.6） days, respectively, with significant difference between the 4 groups （ F = 46.45, P 〈 0.05）. Conclusions （ 1 ） Pretreatment can induce specific immune tolerance in mice. （2） Haploidentical allo- geneic lymphocyte infusion and chemotherapy have synergistic effects, joint application of haploidentical allogeneic lymphocyte infusion and chemotherapy can inhibit the proliferation of tumor cells and prolong the survival time of mice. （3） Chemotherapy can reduce the GVHD of haploidentical allogeneic lymphocyte infusion and enhance the GVT. （4） CD3 ＋ CD4 ＋ CD25 ＋ T lymphocytes play important roles in decreasing GVHD.