Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.
Tumor Microenvironment Center, UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania.
Clin Cancer Res. 2022 Nov 14;28(22):4968-4982. doi: 10.1158/1078-0432.CCR-22-1471.
Ewing sarcoma and osteosarcoma are primary bone sarcomas occurring most commonly in adolescents. Metastatic and relapsed disease are associated with dismal prognosis. Although effective for some soft tissue sarcomas, current immunotherapeutic approaches for the treatment of bone sarcomas have been largely ineffective, necessitating a deeper understanding of bone sarcoma immunobiology.
Multiplex immunofluorescence analysis of immune infiltration in relapsed versus primary disease was conducted. To better understand immune states and drivers of immune infiltration, especially during disease progression, we performed single-cell RNA sequencing (scRNAseq) of immune populations from paired blood and bone sarcoma tumor samples.
Our multiplex immunofluorescence analysis revealed increased immune infiltration in relapsed versus primary disease in both Ewing sarcoma and osteosarcoma. scRNAseq analyses revealed terminally exhausted CD8+ T cells expressing co-inhibitory receptors in osteosarcoma and an effector T-cell subpopulation in Ewing sarcoma. In addition, distinct subsets of CD14+CD16+ macrophages were present in Ewing sarcoma and osteosarcoma. To determine pathways driving tumor immune infiltration, we conducted intercellular communication analyses and uncovered shared mechanisms of immune infiltration driven by CD14+CD16+ macrophages and unique pathways of immune infiltration driven by CXCL10 and CXCL12 in osteosarcoma.
Our study provides preclinical rationale for future investigation of specific immunotherapeutic targets upon relapse and provides an invaluable resource of immunologic data from bone sarcomas.
尤文肉瘤和骨肉瘤是最常见于青少年的原发性骨肉瘤。转移性和复发性疾病与预后不良相关。尽管某些软组织肉瘤的治疗有效，但目前针对骨肉瘤的免疫治疗方法在很大程度上无效，因此需要更深入地了解骨肉瘤的免疫生物学。
对复发性与原发性疾病的免疫浸润进行了多重免疫荧光分析。为了更好地了解免疫状态和免疫浸润的驱动因素，特别是在疾病进展过程中，我们对配对的血液和骨肉瘤肿瘤样本中的免疫群体进行了单细胞 RNA 测序（scRNAseq）。
我们的多重免疫荧光分析显示，尤文肉瘤和骨肉瘤的复发性疾病比原发性疾病的免疫浸润更多。scRNAseq 分析显示，骨肉瘤中表达共抑制受体的终末耗竭 CD8+T 细胞和尤文肉瘤中的效应 T 细胞亚群。此外，尤文肉瘤和骨肉瘤中存在不同的 CD14+CD16+巨噬细胞亚群。为了确定驱动肿瘤免疫浸润的途径，我们进行了细胞间通讯分析，并发现了 CD14+CD16+巨噬细胞驱动免疫浸润的共享机制，以及骨肉瘤中由 CXCL10 和 CXCL12 驱动免疫浸润的独特途径。
我们的研究为复发后针对特定免疫治疗靶点的进一步研究提供了临床前依据，并为骨肉瘤的免疫学数据提供了宝贵的资源。
