Using T-cell repertoire profiles as predictor in a primary mucosal melanoma

Dynamics of T-cell receptor repertoire in patients with ankylosing spondylitis after biologic therapy

INTRODUCTION

Ankylosing spondylitis (AS) is a chronic inflammatory autoimmune disease in which T-cell immune responses play important roles. AS has been characterized by altered T-cell receptor (TCR) repertoire profiles, which are thought to be caused by expansion of disease-related TCR clonotypes. However, how biological agents affect the TCR repertoire status and whether their therapeutic outcomes are associated with certain features or dynamic patterns of the TCR repertoire are still elusive.

MATERIAL AND METHODS

We collected clinical samples from AS patients pre- and post-treatment with biologics. TCR repertoire sequencing was conducted to investigate associations of TCRα and TCRβ repertoire characteristics with disease activity and inflammatory indicators/cytokines.

RESULTS

Our results showed that good responders were associated with an increase in the TCR repertoire diversity with higher proportions of contracted TCR clonotypes. Additionally, we further identified a positive correlation between TCR repertoire diversity and interleukin (IL)-23 levels in AS patients. A network analysis revealed that contracted AS-associated TCR clonotypes with the same complementary-determining region 3 (CDR3) motifs, which represented high probabilities of sharing TCR specificities to AS-related antigens, were dominant in good responders of AS after treatment with biologic therapies.

CONCLUSIONS

Our findings suggested an important connection between TCR repertoire changes and therapeutic outcomes in biologic-treated AS patients. The status and dynamics of TCR repertoire profiles are useful for assessing the prognosis of biologic treatments in AS patients.

Divergent Characteristics of T-Cell Receptor Repertoire Between Essential Hypertension and Aldosterone-Producing Adenoma

Aldosterone-producing adenoma (APA) is a benign adrenal tumor that results in persistent hyperaldosteronism. As one major subtype of primary aldosteronism, APA leads to secondary hypertension that is associated with immune dysregulation. However, how the adaptive immune system, particularly the T-cell population, is altered in APA patients remains largely unknown. Here, we performed TCR sequencing to characterize the TCR repertoire between two age-matched groups of patients: one with APA and the other one with essential hypertension (EH). Strikingly, we found a significant reduction of TCR repertoire diversity in the APA group. Analyses on TCR clustering and antigen annotation further showed that the APA group possessed lower diversity in TCR clonotypes with non-common antigen-specific features, compared with the EH group. In addition, our results indicated that the strength of correlation between generation probabilities and frequencies of TCR clonotypes was significantly higher in the APA group than that in the EH group. Finally, we observed that clinical features, including plasma aldosterone level, aldosterone–renin ratio, and blood sodium level, were positively associated with the strength of correlation between generation and abundance of TCR clonotypes in the APA group. Our findings unveiled the correlation between T-cell immune repertoire and APA, suggesting a critical role of such adrenal adenoma in the T-cell immunity of patients with hypertension.

Profiling of T Cell Repertoire in SARS-CoV-2-Infected COVID-19 Patients Between Mild Disease and Pneumonia

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a public health emergency. The most common symptoms of COVID-19 are fever, cough, and fatigue. While most patients with COVID-19 present with mild illness, some patients develop pneumonia, an important risk factor for mortality, at early stage of viral infection, putting these patients at increased risk of death. So far, little has been known about differences in the T cell repertoires between COVID-19 patients with and without pneumonia during SARS-CoV-2 infection. Herein, we aimed to investigate T cell receptor (TCR) repertoire profiles and patient-specific SARS-CoV-2-associated TCR clusters between COVID-19 patients with mild disease (no sign of pneumonia) and pneumonia. The TCR sequencing was conducted to characterize the peripheral TCR repertoire profile and diversity. The TCR clustering and CDR3 annotation were exploited to further discover groups of patient-specific TCR clonotypes with potential SARS-CoV-2 antigen specificities. Our study indicated a slight decrease in the TCR repertoire diversity and a skewed CDR3 length usage in patients with pneumonia compared to those with mild disease. The SARS-CoV-2-associated TCR clusters enriched in patients with mild disease exhibited significantly higher TCR generation probabilities and most of which were highly shared among patients, compared with those from pneumonia patients. Importantly, using similarity network-based clustering followed by the sequence conservation analysis, we found different patterns of CDR3 sequence motifs between mild disease- and pneumonia-specific SARS-CoV-2-associated public TCR clusters. Our results showed that characteristics of overall TCR repertoire and SARS-CoV-2-associated TCR clusters/clonotypes were divergent between COVID-19 patients with mild disease and patients with pneumonia. These findings provide important insights into the correlation between the TCR repertoire and disease severity in COVID-19 patients.