Identification of CD4+T Cells Expression Profiles Based on Transcriptome Analysis Between Primary Sclerosing Cholangitis and Ulcerative Colitis

Introduction: Primary sclerosing cholangitis (PSC) and Ulcerative colitis (UC) are gastrointestinal disorders induced by abnormal autoimmune mechanisms. In recent years, both UC and PSC have reported gene mutations and polymorphisms, including genome-wide association studies, and there are also reports of genes that are common to each other. However, their functional analysis has not been sufficiently performed. Therefore, the applicant thought that by adding mutation information to the gene expression analysis in the immune system of UC, PSC, and Healthy control. UC is an autoimmune disease often associated with PSC, and we think it would be possible to clarify a part of the autoimmunity mechanism common to them. Here, we comprehensively elucidated the pathophysiology of gene expression fluctuations and gene mutations in CD4+ T cells which are common to the 2 groups. Subsequently, we found the common mechanism and searched for measures to make clear the immune mutation mechanisms of UC and PSC in an integrated manner. Methods: A total of 3 patients with UC, 3 patients with PSC, and 3 healthy controls were prospectively and consecutively enrolled. PBMC were isolated by density gradient centrifugation with Ficoll-Paque®, and CD4+ cells were enrichened by negative selection through MACS® Separator (Miltenyi Biotec) with human CD4+ T cells Isolation Kit (Miltenyi Biotec). Genome-Wide Association Study (GWAS) was done by RNA sequencing using the QIAGEN RNeasy Mini Kit®. RNA quality from enriched cells was above a RIN of 8. 3 groups of RNA-Seq were performed. We used the DESeq2 tool through R to identify differentially expressed genes and the Gene Ontology (GO) enrichment analysis to find the common pathogenesis genes between PSC and UC. Results: 1486 differently expressed genes (DEGs) showed variability in expression compared between 3 groups (Wald test, P< 0.01). In the UC group, 220 DEGs were upregulated, and 62 DEGs were downregulated compared to healthy controls. In the PSC group, 238 DEGs were upregulated, and 44 DEGs were downregulated (Figure 1). Conclusion: It was clarified that the expression fluctuations of disease-specific immune-related molecules were observed in the CD4+ T cells of UC and PSC, and the PSC with UC showed both characteristics. The CD4+ T cells from patients with PSC showed a unique gene expression profile. From there, we would like to extract a group of genes that distinguish UC and PSC and proceed to select molecules that serve as markers for distinguishing between PSC and UC.Figure 1.: The role of CD4+ T cells in PSC and UC.