Analysis of Immune Landscape Reveals Prognostic Significance of Cytotoxic CD4+ T Cells in the Central Region of pMMR CRC

Jingwen Qi; Xiaoyan Liu; Peian Yan; Shangwen He; Yuhao Lin; Zhiwei Huang; Shenyan Zhang; Siyu Xie; Yanfeng Li; Xiaofei Lu; Yingjun Wu; Yangshu Zhou; Juanjuan Yuan; Ting Cai; Xiaojun Zheng; Yanqing Ding; Wei Yang

doi:10.3389/fonc.2021.724232

Analysis of Immune Landscape Reveals Prognostic Significance of Cytotoxic CD4⁺ T Cells in the Central Region of pMMR CRC

Front Oncol. 2021 Sep 22:11:724232. doi: 10.3389/fonc.2021.724232. eCollection 2021.

Authors

Jingwen Qi^{1

2

3}, Xiaoyan Liu^{1

2

3}, Peian Yan^{1

2

3}, Shangwen He⁴, Yuhao Lin⁴, Zhiwei Huang⁴, Shenyan Zhang^{1

2

3}, Siyu Xie^{1

2

3}, Yanfeng Li^{1

2

3}, Xiaofei Lu^{1

2

3}, Yingjun Wu^{1

2

3}, Yangshu Zhou^{1

2

3}, Juanjuan Yuan⁵, Ting Cai⁵, Xiaojun Zheng⁵, Yanqing Ding^{1

2

3}, Wei Yang^{1

2

3}

Affiliations

¹ Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.
² Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
³ Guangdong Provincial Key Laboratory of Molecular Oncologic Pathology, Southern Medical University, Guangzhou, China.
⁴ The First School of Clinical Medicine, Southern Medical University, Guangzhou, China.
⁵ Research Department of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.

Abstract

Background: Mismatch repair proficient colorectal cancer (pMMR CRC) lacks effective treatments and has a poor prognosis, which can be attributed to the complexity of tumor microenvironment. The coordinated function of immune cells is vital to anti-tumor immunity. However, the spatial characteristics of immune cells in the pMMR CRC immune microenvironment and their relationship with clinical prognosis are not fully understood. Meanwhile, the immune modulatory effect of neoadjuvant chemotherapy (NCT), which is the first-line treatment of pMMR CRC, needs further investigation. Therefore, this study aims to explore the spatial dynamics of immune cells and its prognostic value in pMMR CRC.

Methods: We analyzed the various immune cells in formalin-fixed, paraffin-embedded tumor tissues which were collected from 77 patients with stage II/III of pMMR CRC, including 39 non-NCT treated and 38 NCT treated patients. We used the optimized multiplex immunohistochemistry (mIHC) to identify and quantify the density, type and location of immune cells in pMMR CRC. Multivariate survival analysis was performed to assess the relationship of immune profiles and clinical prognosis of pMMR CRC patients.

Results: The densities of most T cell subsets, B cells and macrophages were higher in the central region of the pMMR CRC than in the invasion margin. Tumor infiltrating lymphocytes (TILs), especially the infiltration of CD4⁺ GzmB⁺ T cells in the central region of the tumor was identified to be positively correlated with the prognosis of the patients. Multivariate analysis confirmed that CD4⁺ GzmB⁺ T cells population was an independent predictor of disease-free survival (DFS) in non-NCT group. Meanwhile, NCT enhanced the infiltration of CD4⁺ GzmB⁺ T cells in the central region of the pMMR CRC, which was also identified as an independent protective factor of overall survival (OS) and DFS in NCT group.

Conclusion: We demonstrated that the level of CD4⁺ GzmB⁺ T cells located in the center of tumor could provide great prognostic value for pMMR CRC patients. And the application of neoadjuvant chemotherapy further improves the infiltration of CD4⁺ GzmB⁺ T cells in the central compartment. Further studies into the application of CD4⁺ GzmB⁺ T cells in tumor immunotherapy are needed.

Keywords: mismatch repair-proficient colorectal cancer; multiplex immunohistochemistry; neoadjuvant chemotherapy; tumor immune microenvironment; tumor infiltrating lymphocytes.