Single-cell mass cytometry on peripheral blood identifies immune cell subsets associated with primary biliary cholangitis

Abstract

The relationship between primary biliary cholangitis (PBC), a chronic cholestatic autoimmune liver disease, and the peripheral immune system remains to be fully understood. Herein, we performed the first mass cytometry (CyTOF)-based, immunophenotyping analysis of the peripheral immune system in PBC at single-cell resolution. CyTOF was performed on peripheral blood mononuclear cells (PBMCs) from PBC patients (n = 33) and age-/sex-matched healthy controls (n = 33) to obtain immune cell abundance and marker expression profiles. Hierarchical clustering methods were applied to identify immune cell types and subsets significantly associated with PBC. Subsets of gamma-delta T cells (CD3 + TCRgd + ), CD8 + T cells (CD3 + CD8 + CD161 + PD1 + ), and memory B cells (CD3 − CD19 + CD20 + CD24 + CD27 + ) were found to have lower abundance in PBC than in control. In contrast, higher abundance of subsets of monocytes and naïve B cells were observed in PBC compared to control. Furthermore, several naïve B cell (CD3 − CD19 + CD20 + CD24 − CD27 − ) subsets were significantly higher in PBC patients with cirrhosis (indicative of late-stage disease) than in those without cirrhosis. Alternatively, subsets of memory B cells were lower in abundance in cirrhotic relative to non-cirrhotic PBC patients. Future immunophenotyping investigations could lead to better understanding of PBC pathogenesis and progression, and also to the discovery of novel biomarkers and treatment strategies.

Alterations in Gamma-Delta T Cells in Patients With Primary Biliary Cholangitis

“…The change in the quantity of circulating γδ T cells in PBC patients remains controversial in previous studies [9][10][11][12]. Studies have found a signi cantly decreased frequency of circulating γδ T cells in PBC patients compared with HCs [11,12], whereas the other two studies showed a similar frequency of γδ T cells between the two groups [9,10].…”

“…Previous studies have demonstrated that γδ T cells are closely involved in the development of viral hepatitis and autoimmune liver diseases [5,8,9]. However, the frequency of γδ T cells in PBC remains controversial in previous studies with small sample sizes [9][10][11][12]. The function of γδ T cells in PBC also needs to be further explored.…”

The Role of B Cells and B Cell Therapies in Immune-Mediated Liver Diseases

“…Instead, proinflammatory cytokines such as IL-6 and IL-12 were produced and CD4 T cell differentiation towards a Th1 phenotype occurred (101). However, other studies have not detected differences in circulating B regulatory cells in PBC (73) and a recent analysis of immune cells at the single cell level found a different population of regulatory B cells with a B10 phenotype (high CD24 and IgD expression) were decreased rather than increased in PBC patients (98). Together these results suggest the role of different B cell subsets in PBC pathogenesis is likely to be nuanced, and dependent on the fine tuning of pro-and anti-inflammatory cytokines.…”

“…Studies of circulating lymphocytes in PBC have observed increases in CD19+ B cells and activated CD25+ B cells, correlating with disease stage (73,97). Within the B cell compartment, different B cells subsets seem to be altered including decreased circulating memory B cells and increased naïve B cells and PBs (73,98). In liver biopsy specimens from individuals with PBC, CD20+ B cells were found in lymphoid follicle like aggregations a distance from portal tracts, or more scantily as part of the lymphoplasmacytic infiltrate surrounding inflamed bile ducts.…”

Data processing workflow for large-scale immune monitoring studies by mass cytometry

“…On the other hand, the maximal acquisition capacity of CyTOF devices is limited to 1000 cells/s [5] , while a rate of 400 cells/s is recommended to avoid cell aggregation and doublet formation [6] , [7] . Because of this, it becomes problematic to acquire multiple samples per day, particularly if several tubes of complex tissues (like blood or liquid biopsies) are acquired to detect rare cell populations.…”