Department of Immunology and Microbiology, School of Medicine, University of Colorado Denver Anschutz Medical Campus.
Division of Oncology, School of Medicine, University of Colorado Denver Anschutz Medical Campus.
J Vis Exp. 2022 Dec 16(190). doi: 10.3791/64606.
Reversing the immunosuppressive nature of the tumor microenvironment is critical for the successful treatment of cancers with immunotherapy drugs. Murine cancer models are extremely limited in their diversity and suffer from poor translation to the clinic. To serve as a more physiological preclinical model for immunotherapy studies, this protocol has been developed to evaluate the treatment of human tumors in a mouse reconstituted with a human immune system. This unique protocol demonstrates the development of human immune system (HIS, "humanized") mice, followed by implantation of a human tumor, either a cell-line derived xenograft (CDX) or a patient derived xenograft (PDX). HIS mice are generated by injecting CD34+ human hematopoietic stem cells isolated from umbilical cord blood into neonatal BRGS (BALB/c Rag2 IL2RγC NOD) highly immunodeficient mice that are also capable of accepting a xenogeneic tumor. The importance of the kinetics and characteristics of the human immune system development and tumor implantation is emphasized. Finally, an in-depth evaluation of the tumor microenvironment using flow cytometry is described. In numerous studies using this protocol, it was found that the tumor microenvironment of individual tumors is recapitulated in HIS-PDX mice; "hot" tumors exhibit large immune infiltration while "cold" tumors do not. This model serves as a testing ground for combination immunotherapies for a wide range of human tumors and represents an important tool in the quest for personalized medicine.
逆转肿瘤微环境的免疫抑制性质对于成功地用免疫疗法药物治疗癌症至关重要。鼠类癌症模型在多样性方面极其有限，并且在向临床转化方面存在很大困难。为了作为免疫治疗研究的更生理性的临床前模型，本方案旨在评估在用人免疫系统重建的小鼠中治疗人类肿瘤。该独特方案展示了人免疫系统（HIS，“人源化”）小鼠的开发，随后植入人类肿瘤，无论是源自细胞系的异种移植物（CDX）还是源自患者的异种移植物（PDX）。HIS 小鼠是通过将脐带血中分离的 CD34+人造血干细胞注入新生 BRGS（BALB/c Rag2 IL2RγC NOD）高度免疫缺陷小鼠中产生的，这些小鼠还能够接受异种肿瘤。强调了人免疫系统发育和肿瘤植入的动力学和特征的重要性。最后，描述了使用流式细胞术对肿瘤微环境进行的深入评估。在使用该方案的众多研究中，发现单个肿瘤的肿瘤微环境在 HIS-PDX 小鼠中得到了再现；“热”肿瘤表现出大量免疫浸润，而“冷”肿瘤则没有。该模型可作为广泛的人类肿瘤的联合免疫疗法的试验台，并代表了个性化医学探索中的重要工具。
