Genomic specificity of anti-mouse TCR mAbs determined by single-cell RNAseq

Area of Science:

• Immunology
• Molecular Biology
• Genomics

Background:

• T cells are crucial for adaptive immunity, recognizing antigens via T cell receptors (TCRs).
• Monoclonal antibodies (mAbs) targeting TCR variable (V) regions are widely used but have complex, often unclear, nomenclature linking them to specific T cell receptor variable (TRV) genes.
• This ambiguity hinders precise analysis of T cell populations and their functions.

Purpose of the Study:

• To formally re-establish the link between established anti-TCR V region mAbs and their corresponding TRV genes.
• To investigate patterns of reactivity within T cell receptor variable (TRV) subfamilies.
• To provide a comprehensive resource for understanding anti-mouse TCR mAb specificity and T cell V-gene usage.

Main Methods:

• Sorting of T cells from C57BL/6 mice based on reactivity with 22 anti-V mAbs.
• Determination of TRV gene usage in sorted cells using single-cell TCR sequencing (TCRseq).
• Analysis of RNA sequencing (RNAseq) data to identify gene expression patterns, including retroviral elements.

Main Results:

• Established clear associations between specific anti-TCR V mAbs and their corresponding TRV genes.
• Identified a novel association between higher expression of ERV1-family LTR RLTR6Mm and T cells utilizing TRBV segments within a specific genomic region (TRBV23-TRBV30).
• Revealed insights into V-gene usage biases in T cells.

Conclusions:

• This study provides a definitive resource linking anti-mouse TCR mAbs to specific TRV genes, resolving nomenclature ambiguities.
• The findings offer valuable insights into T cell receptor variable (TRV) gene usage biases and T cell functional characteristics.
• The observed correlation with ERV1-family elements suggests potential roles in T cell biology or V-gene regulation.