Toh James Wei Tatt, Ferguson Angela L, Spring Kevin J, Mahajan Hema, Palendira Umaimainthan
Division of Surgery and Anaesthesia, Department of Colorectal Surgery, Westmead Hospital, Westmead Clinical School, The University of Sydney, Ingham Institute for Applied Medical Research, Westmead 2145, NSW, Australia.
Department of Infectious Diseases and Immunology, School of Medical Sciences, Faculty of Medicine and Health, Human Viral & Cancer Immunology, Centenary Institute, Charles Perkin Centre, The University of Sydney, Sydney 2000, NSW, Australia.
World J Clin Oncol. 2021 Apr 24;12(4):238-248. doi: 10.5306/wjco.v12.i4.238.
Recent studies in non-colorectal malignancy have associated T resident memory (T) cells with improved patient survival. It is unknown if T plays a role in colorectal cancer (CRC).
To examine the potential role of T cells in providing immunogenicity in CRC stratified by microsatellite instability (MSI) and BRAF status.
Patients with known MSI and BRAF mutation status were eligible for inclusion in this study. CRC tumour sections stained with haematoxylin and eosin were microscopically reviewed and the images scanned prior to assessment for location of invading edge and core of tumour. Sequential sections were prepared for quantitative multiplex immunohistochemistry (IHC) staining. Opal Multiplex IHC staining was performed with appropriate positive and negative controls and imaged using a standard fluorescent microscope fitted with a spectral scanning camera (Mantra) in conjunction with Mantra snap software. Images were unmixed and annotated in inForm 2.2.0. Statistical analysis was performed using Graphpad Prism Version 7 and Stata Version 15.
Seventy-two patients with known MSI and BRAF status were included in the study. All patients were assessed for MSI by IHC and high resolution capillary electrophoresis testing and 44 of these patients successfully underwent quantitative multiplex IHC staining. Overall, there was a statistically significant increase in CD8+ T cells in the MSI (BRAF mutant and wild type) group over the microsatellite stable (MSS) group. There was a statistically significant difference in CD8+ T between high level MSI (MSI-H):BRAF mutant [22.57, 95% confidence interval (CI): 14.31-30.84] MSS [8.031 (95%CI: 4.698-11.36)], = 0.0076 andMSI-H:BRAF wild type [16.18 (95%CI: 10.44-21.93)] MSS [8.031 (95%CI: 4.698-11.36)], = 0.0279. There was no statistically significant difference in CD8 T cells (both CD8+CD103- and CD8+CD103+T) between MSI-H: BRAF mutant and wild type CRC.
This study has shown that CD8+ T are found in greater abundance in MSI-H CRC, both BRAF mutant and MSI-H:BRAF wild type, when compared with their MSS counterpart. CD8+ T may play a role in the immunogenicity in MSI-H CRC (BRAF mutant and BRAF wild type). Further studies should focus on the potential immunogenic qualities of T cells and investigate potential immunotherapeutic approaches to improve treatment and survival associated with CRC.
近期针对非结直肠癌恶性肿瘤的研究表明，组织驻留记忆T（Trm）细胞与患者生存率提高相关。Trm细胞在结直肠癌（CRC）中是否发挥作用尚不清楚。
探讨Trm细胞在根据微卫星不稳定性（MSI）和BRAF状态分层的CRC中提供免疫原性的潜在作用。
已知MSI和BRAF突变状态的患者符合本研究纳入标准。对苏木精和伊红染色的CRC肿瘤切片进行显微镜检查，并在评估肿瘤侵袭边缘和核心位置之前扫描图像。制备连续切片用于定量多重免疫组织化学（IHC）染色。使用适当的阳性和阴性对照进行Opal多重IHC染色，并使用配备光谱扫描相机（Mantra）的标准荧光显微镜结合Mantra snap软件成像。图像在inForm 2.2.0中进行解混和注释。使用Graphpad Prism 7版和Stata 15版进行统计分析。
本研究纳入了72例已知MSI和BRAF状态的患者。所有患者均通过IHC和高分辨率毛细管电泳检测评估MSI，其中44例患者成功进行了定量多重IHC染色。总体而言，MSI（BRAF突变型和野生型）组的CD8+ T细胞数量较微卫星稳定（MSS）组有统计学显著增加。高水平MSI（MSI-H）：BRAF突变型[22.57，95%置信区间（CI）：14.31-30.84]与MSS[8.031（95%CI：4.698-11.36）]相比，P = 0.0076；MSI-H：BRAF野生型[16.18（95%CI：10.44-21.93）]与MSS[8.031（95%CI：4.698-11.36）]相比，P = 0.0279，差异均有统计学意义。MSI-H：BRAF突变型和野生型CRC之间的CD8 T细胞（CD8+CD103-和CD8+CD103+T）无统计学显著差异。
本研究表明，与MSS CRC相比，MSI-H CRC（BRAF突变型和MSI-H：BRAF野生型）中CD8+ Trm细胞数量更多。CD8+ Trm细胞可能在MSI-H CRC（BRAF突变型和BRAF野生型）的免疫原性中发挥作用。进一步研究应聚焦于Trm细胞的潜在免疫原特性，并探索潜在的免疫治疗方法以改善CRC相关的治疗和生存情况。
