TcR-α Recombinations in Renal Cell Carcinoma Exome Files Correlate with an Intermediate Level of T-cell Exhaustion Biomarkers

Renal cell carcinoma exome-derived, V(D)J recombination reads had an elevated presence and variability, for both TcR-α and -β, when compared to marginal tissue, reflecting an opportunity to assess tumor immunogenicity by comparison with marginal tissue T cells. PD-1, PD-L2, CTLA4 and FOXP3, all of which are implicated in the evasion of an anti-tumor immune response, had a significantly higher expression for samples representing co-detection of productive TcR-α and -β recombination reads. Samples representing tumors with productive TcR-α recombination reads but no detectable, productive TcR-β recombination reads, reflected a 20% survival advantage, and RNASeq data indicated an intermediate level of immune checkpoint gene expression for those samples. These results raise the question of whether relatively high levels of detection of productive TcR-α recombination reads, in comparison with detection of reads representing the TcR-β gene, identify a microenvironment that has not yet entered a T-cell exhaustion phase and may thereby represent conditions for immune enhancements that do not require anti-immune checkpoint therapies.