Alexander Sankin1, Damini Chand2, Mark Schoenberg3, Xingxing Zang2. 1. Department of Urology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY. Electronic address: asankin@montefiore.org. 2. Department of Urology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY; Department of Microbiology and Immunology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY. 3. Department of Urology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY.
Abstract
BACKGROUND: High T-cell receptor (TCR) repertoire clonality is associated with clinical response to immune checkpoint blockade in bladder cancer. OBJECTIVE: To determine if TCR repertoire is more clonal in tumors than in benign inflammation. METHODS: We prospectively identified 12 patients with bladder lesions undergoing transurethral resection. Specimens were collected at time of transurethral resection and stored at -80C. DNA was extracted and high throughput DNA sequencing of the CDR3 region of the TCR beta chain using the immunoSEQ assay (Adaptive Biotechnologies) was performed. T-cell fraction, clonal dominance, and maximum frequency of TCR clone were assessed. RESULTS: Of the 12 bladder lesions resected, 3 of 12 were cT0, 3 of 12 were cTa, 3 of 12 were cT1, and 3 of 12 were cT2 or greater. The median number of T cells in urothelial carcinoma specimens (UC+) and benign (UC-) specimens was 5,569 and 25,872, respectively. The number of unique TCRs sequenced in UC+ and UC- specimens was 3,069 and 9,680, respectively. The median tumor infiltrating lymphocyte percentage in UC+ and UC- specimens was 2% and 12%, respectively. The UC+ specimens demonstrated clonality as evidenced by identification of a specific T-cell clone being present in up to 17% of the total tumor infiltrating lymphocyte pool, in contrast to 2% among UC- specimens. CONCLUSIONS: Primary urothelial tumors contain clonally expanded T-cell populations. These data support the hypothesis that bladder tumors induce an antigen-driven immunogenic host response, in contrast to the benign inflammatory response, which does not appear to demonstrate any T-cell clonal dominance.
BACKGROUND: High T-cell receptor (TCR) repertoire clonality is associated with clinical response to immune checkpoint blockade in bladder cancer. OBJECTIVE: To determine if TCR repertoire is more clonal in tumors than in benign inflammation. METHODS: We prospectively identified 12 patients with bladder lesions undergoing transurethral resection. Specimens were collected at time of transurethral resection and stored at -80C. DNA was extracted and high throughput DNA sequencing of the CDR3 region of the TCR beta chain using the immunoSEQ assay (Adaptive Biotechnologies) was performed. T-cell fraction, clonal dominance, and maximum frequency of TCR clone were assessed. RESULTS: Of the 12 bladder lesions resected, 3 of 12 were cT0, 3 of 12 were cTa, 3 of 12 were cT1, and 3 of 12 were cT2 or greater. The median number of T cells in urothelial carcinoma specimens (UC+) and benign (UC-) specimens was 5,569 and 25,872, respectively. The number of unique TCRs sequenced in UC+ and UC- specimens was 3,069 and 9,680, respectively. The median tumor infiltrating lymphocyte percentage in UC+ and UC- specimens was 2% and 12%, respectively. The UC+ specimens demonstrated clonality as evidenced by identification of a specific T-cell clone being present in up to 17% of the total tumor infiltrating lymphocyte pool, in contrast to 2% among UC- specimens. CONCLUSIONS:Primary urothelial tumors contain clonally expanded T-cell populations. These data support the hypothesis that bladder tumors induce an antigen-driven immunogenic host response, in contrast to the benign inflammatory response, which does not appear to demonstrate any T-cell clonal dominance.