Exploration And Difference Study Of Local And Systemic Immunity In Takayasu Arteritis

Objectives Takayasu Arteritis(TA)is a highly specific vascular inflammation and poses threat to patients’ health.Although some patients have accepted medical treatment,their culprit lesions require surgical management.In recent years,although research on the mechanism of TA has made significant progress,there are still few studies on the immune cell atlas of TA patients in control period(TACP)who still require surgical treatment after receiving drug treatment.This study aimed at dissecting the transcriptomes of peripheral blood mononuclear cells(PBMCs)in these patients and to explore potential clinical markers for TA development and progression.Methods Peripheral blood were collected from four TACP patients requiring surgical management and four age-sex matched healthy donors.Single cell RNA sequencing(scRNA-seq)was adopted to explore the transcriptomic diversity and function of their PBMCs.ELISA,qPCR and FACS were conducted to validate the results of the analysis.Results A total of 29918 qualified cells were included for downstream analysis.Nine major cell types were confirmed,including CD14+ monocytes,CD8+T cells,NK cells,CD4+T cells,B cells,CD16+monocytes,megakaryocytes,dendritic cells and plasmacytoid dendritic cells.CD14+ monocytes(50.0%vs 39.3%,p<0.05)increased in TA patients,as validated by FACS results.CD 163 was highly expressed in the antigen presenting cells(APCs)membrane of TACP.The expression of TXNIP,AREG,and CD163 genes in peripheral blood of TACP patients was increased,and the protein levels of TXNIP and AREG in serum were higher after verification by qPCR and ELISA.Some ILs like IL-6,IL-6STP1,IL-6ST,IL-15,and IL-15RA increased in TACP group but the underlying mechanism remained to be further elucidated in the future.Conclusion Transcriptome heterogeneities of PBMCs in TACP patients requiring surgical management were revealed in the present study.In these TACP patients,CD14+ monocytes were increased and activated,indicating a new treatment and study direction in this field.The increased expression of reactive oxygen species(ROS)related genes and pathways such as TXNIP and RAGE also indicated that ROS may play an important role in TACP patients.Objectives To elucidate the distribution and functional differences of immune cells between local immunity and systemic immunity in Takayasu arteritis patients.Methods The carotid artery tissue and peripheral blood PBMC of 3 Takayasu arteritis patients were sequenced by single-cell RNA sequencing,and the differences in the composition of immune cells were analyzed and the different gene expression of the same types of cells in different environments were compared.The above findings were verified by immunohistochemical techniques.Results The inflammatory cells in the lesioned carotid tissue were mainly effector cells(especially cytotoxic CD4+ T cells),and the inflammatory cells in the peripheral blood PBMC were mainly CD14+ monocytes.In terms of gene expression,cytotoxic CD4+T cells in tissues mainly express LEF1,CCL4,IFITM1,and similar cells in peripheral blood mainly express DUSP2,ICAM1,and CD27.In terms of pathway analysis,cytotoxic CD4+ T cells mainly express TNF pathway in tissues and T cell differentiation pathway in peripheral blood;monocytes express antigen presentation and processing related pathways in tissues,and TNF and NFκB pathway in peripheral blood.Conclusion The immune cells in the lesioned tissue and peripheral blood of Takayasu arteritis patients are not only very different in composition,but also in function.Immune cells in diseased tissue tend to exert genes and pathways which can mediate surrounding tissue damage,while those in peripheral blood are more inclined to promote inflammatory cell maturation and proliferation.The large difference between the two also illustrates that immunosuppressive drugs may not sufficient to suppress inflammation in diseased tissue.Objective:To explore the cellular heterogeneity of renal artery tissue in Takayasu arteritis(TA)patients by single-cell RNA sequencing(scRNA-seq).Methods:This study included 2 TA patients with renal artery stenosis who underwent surgical bypass in Beijing Hospital.The obtained 2 renal artery samples were subjected to two different digestion protocol.scRNA-seq analysis were performed to explore the cellular heterogeneity and the impact of different enzymatic digestion protocols.Results:After quality control,a total of 2920 cells were included for downstream analysis.Nine cell subsets were obtained in this study,including two different endothelial cell,two types of vascular smooth muscle cells(VSMC)and two kinds of myeloid cells and one type of T cells and one without specific definition.Among them,the two types of VSMC showed obvious contractile and synthetic types,respectively.The proportion of each cell type was different with the two different digestion protocols.Conclusion:scRNA-seq can be used to explore the cellular heterogeneity of diseased vessels in TA patients.Different enzymatic digestion protocols may impact the proportion of different cell types.