No difference in TCRβ repertoire of CD4+ naive T cell between patients with primary biliary cholangitis and healthy control subjects

TCR Repertoire Analysis During Therapeutic Interventions in Liver Diseases Using Next-Generation Sequencing

BACKGROUND AND AIM

The T cell receptor (TCR) can recognize a vast number of antigens and is closely associated with the pathogenesis of various diseases including autoimmune diseases and malignancies. However, the clinical significance of the TCR repertoire and its post-treatment changes remain unclear in liver diseases.

METHODS

We performed next-generation sequencing (NGS)-based TCR analysis using DNA obtained from peripheral blood mononuclear cells (PBMCs) of healthy donors (HD, n = 5), primary biliary cholangitis (PBC, n = 5), autoimmune hepatitis (AIH, n = 5), and hepatocellular carcinoma (HCC, n = 5) and evaluated the changes after treatment.

RESULTS

Baseline TCR repertoire analysis demonstrated that TCR clonotype usage is restricted and diversity is low in all three disease groups (PBC, AIH, and HCC), particularly in PBC and AIH compared to HD (p < 0.05). Following treatment, clonotype usage and diversity did not change significantly, except in AIH, where diversity decreased further (p < 0.05 for clone Shannon diversity and clone evenness). Disease-specific usage of TCR beta genes and specific changes after therapy were observed in all groups. Analysis of clonotypes shared with other individuals (public clonotypes) revealed that nine public clonotypes in PBC, eight in AIH, and eight in HCC disappeared after treatment. Motif analysis identified one characteristic motif (NQPQH) in PBC.

CONCLUSIONS

The diversity of the TCR repertoire, TCR beta chain usage, clonotypes, and motifs and their post-treatment changes are disease-specific in each liver disease, indicating that further TCR repertoire studies are needed to accelerate the understanding of liver disease pathogenesis from an immunological perspective.

Analysis of Gene Expression and TCR/B Cell Receptor Profiling of Immune Cells in Primary Sjögren's Syndrome by Single-Cell Sequencing

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease that is estimated to affect 35 million people worldwide and is characterized by lymphocytic infiltration, elevated circulating autoantibodies, and proinflammatory cytokines. The key immune cell subset changes and the TCR/BCR repertoire alterations in pSS patients remain unclear. In this study, we sought to comprehensively characterize the transcriptional changes in PBMCs of pSS patients by single-cell RNA sequencing and single-cell V(D)J sequencing. Naive CD8⁺ T cells and mucosal-associated invariant T cells were markedly decreased but regulatory T cells were increased in pSS patients. There were a large number of differentially expressed genes shared by multiple subpopulations of T cells and B cells. Abnormal signaling pathways, including Ag processing and presentation, the BCR signaling pathway, the TCR signaling pathway, and Epstein-Barr virus infection, were highly enriched in pSS patients. Moreover, there were obvious differences in the CD30, FLT3, IFN-II, IL-1, IL-2, IL-6, IL-10, RESISTIN, TGF-β, TNF, and VEGF signaling networks between pSS patients and healthy controls. Single-cell TCR and BCR repertoire analysis showed that there was a lower diversity of T cells in pSS patients than in healthy controls; however, there was no significant difference in the degree of clonal expansion, CDR3 length distribution, or degree of sequence sharing. Notably, our results further emphasize the functional importance of αβ pairing in determining Ag specificity. In conclusion, our analysis provides a comprehensive single-cell map of gene expression and TCR/BCR profiles in pSS patients for a better understanding of the pathogenesis, diagnosis, and treatment of pSS.

Comprehensive analysis of TCR repertoire of COVID-19 patients in different infected stage

BACKGROUND

The current pandemic of coronavirus disease 2019 (COVID-19), transmitted person-to-person by the severe acute respiratory syndrome of coronavirus 2 (SARS-CoV-2), poses a threat to global public health.

OBJECTIVE

In this study, we performed the comprehensive analysis of the T cell receptor (TCR) repertoire may contribute to a more in-depth understanding of the pathogenesis of COVID-19.

METHODS

A comprehensive immunological analysis was performed to explore the features of the TCR repertoire and identified TCR sequences correlated with SARS-CoV-2 viral antigens.

RESULTS

we analyzed the COVID-19 patients' TCR repertoires in peripheral blood mononuclear cells (PBMC) which obtained before (baseline), during (acute), and after rehabilitation (convalescent) by ImmunoSEQ-technology, and found that repertoire features of TCRβ-chain (TCRβ) complementary-determining region 3 (CDR3) in COVID-19 patients were remarkable difference, including decreased TCR diversity, abnormal CDR3 length, difference of TRBV/J gene usage and higher TCR sequence overlap. Besides, we identified some COVID-19 disease-associated TCRβ clones, and the abundance of them changed with the progression of the disease. Importantly, these disease-associated TCRβ clones could be used to distinguish COVID-19 patients from healthy controls with high accuracy.

CONCLUSIONS

We provide a clear understanding of the TCR repertoire of COVID-19 patients, which lays the foundation for better diagnosis and treatment of COVID-19 patients.

High-Throughput Sequencing-Based Analysis of T Cell Repertoire in Lupus Nephritis

T cell receptor (TCR)-mediated immune functions are closely related to autoimmune diseases, such as systemic lupus erythematosus (SLE). However, technical challenges used to limit the accurate profiling of TCR diversity in SLE and the characteristics of SLE patients remain largely unknown. In this study, we collected peripheral blood samples from 10 SLE patients with lupus nephritis (LN) who were confirmed by renal biopsy, as well as 10 healthy controls. The TCR repertoire of each sample was assessed by high-throughput sequencing to examine the distinction between SLE subjects and healthy controls. Our results showed statistically significant differences in TCR diversity and usage of TRBV/TRBJ genes between the two groups. A set of signature V–J combinations enabled efficient identification of SLE cases, yielding an area under the curve (AUC) of 0.89 (95% CI: 0.74–1.00). Taken together, our results revealed the potential correlation between the TCR repertoire and SLE status, which may facilitate the development of novel immune biomarkers.