Immune infiltration analysis reveals immune cell signatures in salivary gland tissue of primary Sjögren's syndrome

Hongxiao Gong; Xiaoting Qiu; Pingping Li; Runzhi Zhao; Beijia Wang; Ling Zhu; Xingxing Huo

doi:10.3389/fmed.2023.1033232

Immune infiltration analysis reveals immune cell signatures in salivary gland tissue of primary Sjögren's syndrome

Front Med (Lausanne). 2023 Jan 18:10:1033232. doi: 10.3389/fmed.2023.1033232. eCollection 2023.

Authors

Hongxiao Gong^{1

2}, Xiaoting Qiu^{1

2}, Pingping Li^{1

2}, Runzhi Zhao^{1

2}, Beijia Wang^{1

2}, Ling Zhu², Xingxing Huo¹

Affiliations

¹ Department of Scientific Research, Experimental Center of Clinical Research, The First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, Anhui, China.
² Department of Otolaryngology, The First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, Anhui, China.

Abstract

Introduction: Mouse models are the basis for primary Sjögren's syndrome (pSS) research. However, the depth of comparisons between mice and humans in salivary gland (SG) immune cells remains limited.

Methods: The gene expression profiles of SGs from normal subjects and pSS patients were downloaded from the Gene Expression Comprehensive Database. The proportion of infiltrating immune cell subsets was then assessed by cell type identification by estimating relative subsets of RNA transcripts (CIBERSORT). An experimental Sjögren's syndrome (ESS) mouse model was successfully constructed using SG protein. Based on mouse SG tissue RNA-Seq data, the seq-ImmuCC model was used to quantitatively analyze the compositional ratios of 10 immune cells in pSS patients and mouse model SG tissues.

Results: Computed and obtained 31 human data samples using the CIBERSORT deconvolution method. The immune cell infiltration results showed that, compared to normal human SG tissue, the content of gamma delta T cells was significantly different from naive CD4⁺ T cells and significantly increased, while the plasma cell content decreased. Principal component analysis indicated differences in immune cell infiltration between pSS patients and normal subjects. Meanwhile, for ESS model mouse data analysis, we found that the proportion of macrophages increased, while the proportion of CD4⁺ T cells, B cells, and monocytes decreased. Furthermore, we found that the proportion of monocytes was decreased, while the proportion of macrophages was increased in the SG tissues of pSS patients and model mice. The infiltration of CD4⁺ T, CD8⁺ T, and B cells also showed some differences.

Discussion: We comprehensively analyzed SG immune infiltration in pSS patients and model mice. We demonstrated conserved and nonconserved aspects of the immune system in mice and humans at the level of immune cells to help explain the primary regulation of immune mechanisms during the development of Sjögren's syndrome.

Keywords: RNA-seq sequencing; cross-species analysis; immune infiltration; primary Sjögren’s syndrome; salivary glands.

Grants and funding

This study was supported by the National Natural Science Foundation of China (No. 81803938) and Research Preparation Plan Project of Anhui Province (No. 2022AH050508).