Characterization of TCRβ sequence diversity in colorectal carcinoma

T cells can play a critical role in mediating anti-tumour responses in cancer, but thus far have been characterized at low resolution. Each T cell receptor beta subunit (TCRβ) possesses a hypervariable sequence (CDR3) that is a principal site of contact with peptide-MHC complexes on heterologous cells and can be used to characterize TCRβ diversity. Here, I used a sequencing approach developed for interrogating peripheral blood immune repertoires to explore TCRβ sequence diversity associated with colorectal carcinoma (CRC). TCRβ sequences were amplified from RNA isolated from biopsies of tumour and matched control tissue of 43 CRC patients. Amplicons were indexed and survey sequenced on the Illumina platform. Sequence reads were assembled and filtered revealing a diverse sequence repertoire. Some abundant sequences shared between patients were significantly associated with improved overall survival. These results have great potential utility in the design of immunological approaches targeting tumours, and in the design of specific screening approaches for CRC.