Assessing immune cell transcriptional diversity in the upper and lower esophagus of systemic sclerosis patients 4842

Abstract Description Esophageal dysfunction in SSc is a critical complication, often associated with reflux and fibrosis, leading to severe consequences. Prior studies linked tissue macrophage populations to disease severity and decreased survival in SSc patients. However, the distribution of immune cell populations within esophageal regions remains poorly understood. This study aims to examine the diversity of proximal and distal immune cells in the esophagus of SSc patients. A total of 15 samples from proximal and distal regions were collected. CD45+ immune cells were isolated using FACS from dissociated tissue, followed by single-cell RNA sequencing. Data analysis was performed using the 10x Genomics Cell Ranger 6.0.0 pipeline and the Seurat package, with CITE-Seq confirming the expression of specific cell-identifying markers. Analysis revealed from ∼30,000 cells, myeloid cells accounted for 18% of CD45+ cells, with eight distinct clusters, including dendritic cells (LAMP3+, ∼5%) and macrophages. Notably, dendritic cells were more abundant in the distal esophagus, while T and B cells were predominant in the proximal region. Cluster-specific analyses showed distinct gene expression profiles between regions. Markers such as FABP4, CCR2, and APOE were differentially expressed. HLA-antigen expression also varied, indicating regional differences in antigen presentation. This study provides the first comprehensive analysis of proximal and distal immune cells in the esophagus of SSc patients. Topic Categories Computational and Systems Immunology (COMP)