T Lymphocyte Infiltration in Association with IDO1 Expression in Resected Lung Adenocarcinoma and Normal Adjacent Lung Tissues

Xiaoling Zhao,Yaran Li,Xu Yang,Hongzhen Liu,Xiaochong Zhang,Jing Xie,Shaoteng Li,Jun Guo,Lili He,Dengxiang Liu,Wei Chen,Syed Sameer Aga

doi:10.1155/2022/2381018

Xiaoling Zhao, Yaran Li + Show 10 more

Open Access

https://doi.org/10.1155/2022/2381018

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Abstract

Background Indoleamine 2,3-dioxygenase 1 (IDO1) catalyzes the first step of tryptophan catabolism in the kynurenine (Kyn) pathway. IDO1 downregulates natural killer cell receptors, and by mechanism, tumor cells escape immune surveillance. Methods IDO1 protein and mRNA were assessed by immunohistochemistry, immunoblotting, and PCR in the 68 resected lung adenocarcinomas at stages I–III as well as adjacent normal lung tissues. Infiltration of CD3, CD8, and CD4 lymphocytes in the tumor and adjacent normal lung tissues was assessed by immunohistochemical staining. Results IDO1 protein and mRNA were detected in various stages of lung adenocarcinoma with highest expression at stage III. In contrast, biomarkers of T cell subset, CD3, CD4, and CD8, were highly expressed in the normal lung tissues and stage I adenocarcinoma tissues but significantly reduced in the stage II and III tumor tissues. Conclusions The current study demonstrated that the higher level of IDO1 expression in the lung adenocarcinoma was, the less infiltration of T lymphocytes was found in the tumors. Findings of this study indicated that IDO1 may contribute to the reduction of T lymphocyte infiltration into the lung adenocarcinoma.

Highlights

Lung cancer is the predominant cancer in China and one of the most commonly seen malignant tumors in the world [1]
CD8 expression was detected in the normal tissues (Figure 5(d)), and it was slightly higher in stage I lung adenocarcinomas (Figure 5(a)), but it was significantly reduced in stage III tumor tissues (Figure 5(c))
It was found that IDO1 was significantly upregulated in stage I, II, and III lung adenocarcinomas compared to that of adjacent normal lung tissues

Summary

Introduction

Lung cancer is the predominant cancer in China and one of the most commonly seen malignant tumors in the world [1]. Infiltration of CD3, CD8, and CD4 lymphocytes in the tumor and adjacent normal lung tissues was assessed by immunohistochemical staining. IDO1 protein and mRNA were detected in various stages of lung adenocarcinoma with highest expression at stage III. Biomarkers of T cell subset, CD3, CD4, and CD8, were highly expressed in the normal lung tissues and stage I adenocarcinoma tissues but significantly reduced in the stage II and III tumor tissues. The current study demonstrated that the higher level of IDO1 expression in the lung adenocarcinoma was, the less infiltration of T lymphocytes was found in the tumors. Findings of this study indicated that IDO1 may contribute to the reduction of T lymphocyte infiltration into the lung adenocarcinoma

Methods

Results

Conclusion