造型immuno-oncology in a humanized mouse

作者:

帕特里克·艾莉森,博士

DATE:

2020年2月

免疫缺陷小鼠设计缺乏适应性方面nity which makes them an ideal host for supporting the transplantation and growth of human tumor cells. Preclinical xenograft models utilizing immune deficient mice are limited for the investigation of immunotherapies due to this lack of functional immune cells. This spotlight will highlight a method in which human T-lymphocytes cells can propagate within an immune compromised mouse and support tumor xenograft growth.

NOD-SCIDIL2RγUL(NSG)与人外周血单核细胞(HPBMC)一起使用的小鼠已经在异种移植模型中使用,以评估免疫检查点抑制剂的疗效和药物动力学靶向人T淋巴细胞的表位1。该模型在传统的异种移植物中是独特的,因为功能性人体T细胞可以在小鼠中靶向肿瘤上的人表位,直接可翻译的临床意义。NSG小鼠缺乏树突和巨噬细胞群,并携带两种特定突变,使它们具有高度缺乏淋巴细胞;PKRDC突变禁用DNA修复的方面,使小鼠B-和T细胞缺乏,并且缺失IL2Rγ块NK细胞成熟2。这种缺陷的组合允许HPBMC的植入并允许在NSG小鼠中扩增人T淋巴细胞。

The hPBMC engrafted NSG mouse does have caveats that must be evaluated prior to human donor and tumor model selection. First, administration of human immune cells to a mouse results in T-cell mediated toxicity consistent with Graft Versus Host Disease (GvHD), in which human lymphocytes attack mouse tissues, limiting the therapeutic window3. Second, engraftment efficiency, cell types present, and activity have been observed to be variable between human donor sources4. Finally, we have observed instances of hPBMC rejection of the human tumor xenograft (data not shown). Evaluation of these parameters with the donor source and tumor model of choice, prior to initiating definitive efficacy studies, is critical for the success of translational early development programs.

本研究的目的是评估向携带皮下人肿瘤异种移植物的NSG小鼠的HPBMC的人T淋巴细胞的植入。以AAALAC认可的设施在护理和使用实验室动物的指导中符合动物护理和使用。NSG小鼠(Jackson Laboratories,Bar Harbor Maine,USA,rucation#000557)携带皮下miapaca-2人胰腺导管腺癌静脉内施用来自四个不同正常健康供体的HPBMC(Hemacare,Los Angeles Ca,USA)。进行肿瘤生长,体重和GVHD样特性的评价。收集全血以进行人淋巴细胞标记物的流式细胞术分析,以确认CD45 +细胞的供体植入,包括CD4 +和CD8 +细胞,在第14,28天和第42天施用时(图1)。

Figure 1 – Experimental design assessing hPBMC engraftment in MiaPaca-2 tumor bearing NSG mice.
Figure 1 – Experimental design assessing hPBMC engraftment in MiaPaca-2 tumor bearing NSG mice.

未治疗对照动物的MiaPaCa-2肿瘤倍增时间(Td)为9.1天,每个供者组给予hPBMCs的动物的Td为8.7-11.6天。在植入后30天之后,服用hPBMCs的个体的生长变化被观察到。1000mm前肿瘤生长没有受到HPBMC植入的影响(图2)。这些结果表明,所使用的任何捐赠者都适用于评估尺寸(TES)为1000mm的MiaPaCa2疗效研究.

图2–hPBMC给药后MiaPaCa2皮下肿瘤(n=10)的肿瘤生长。
图2–hPBMC给药后MiaPaCa2皮下肿瘤(n=10)的肿瘤生长。

通过体重和临床观察监测GvHD症状的发生;虽然在本研究中未经病理证实,但在该模型中观察到的症状与疾病密切相关5。症状包括体重减轻(图3)超过基线的10%,皮毛粗糙,驼背姿势,皮肤损伤和腹泻-出现所有症状或严重程度高的动物被从研究中移除。注射hPBMC后32天,观察各组半数以上动物的临床症状。因GvHD症状而未切除的动物因肿瘤负荷超过2000mm而切除,或在学习终止。

图3  - 氟氯烃股局后体重变革的评估
图3 - 氟氯烃股局后体重变革的评估

通过NSG小鼠的外周血中的人免疫细胞标志物的免疫表型分析,测量HPBMC给药后的14,28和42天测量植入:MCD45(鼠泛白细胞),HCD45(人泛白细胞),HCD3(PAN-T细胞),通过流式细胞术检测HCD4(T-辅助和T-REG)和HCD8(细胞毒性淋巴细胞)(图4)。

图4-在用HPBMC重组的NSG小鼠中检测人类免疫细胞的示例门控策略。
图4-在用HPBMC重组的NSG小鼠中检测人类免疫细胞的示例门控策略。

Percent hCD45+ is calculated as the percent hCD45+ cells of total live cells (based on absolute cell counts/µL whole blood) and is used as an indicator of the extent of hPBMC engraftment. We found that %hCD45+ cells in whole blood were detected over time across all donors (Figure 5). However, Donors 2 and 4 exhibited greater increase of hCD45 cells on an individual basis compared to Donors 1 and 3 whose engraftment was not as high by day 42 post hPBMC administration. Animals across all groups achieved %hCD45 engraftment levels 28 days post hPBMC administration that is consistent with published literature on the model6.

向NSG小鼠施用hPBMCs可导致人类T细胞在小鼠体内持续存在,而对MiaPaCa-2肿瘤生长的影响最小。该模型代表了一个强大的临床前平台,用于研究利用人类T淋巴细胞直接抗肿瘤活性的新型药物的作用,具有直接的临床意义。未来的工作将证明FDA批准的免疫疗法在用hPBMCs重组的NSG小鼠中对人类肿瘤异种移植物的疗效。yaboapp体育官网

图5–在NSG小鼠全血中检测到hCD45+细胞植入HPBMC的程度
图5–在NSG小鼠全血中检测到hCD45+细胞植入HPBMC的程度

拜托联系我们的临床前肿瘤科学yaboapp体育官网家看看hPBMC移植的NSG小鼠如何用于下一步的翻译研究immuno-oncology study.

1癌症res;2015(75)17:3466-3478

2冷泉港协议;2014 (7): 694–708.

免疫学前沿;2018 (9): 43.

4FASEB; 2019 (33):3137-3151.

5Frontiers in Immunology; 2018 (9): 10.

6Curr Protoc Immunol Chapter 15: Unit 15.21.