51. T cell receptor sequencing of activated CD8 T cells in the blood identifies tumor-infiltrating clones that expand after PD-1 therapy and radiation in a melanoma patient
- Author
-
Sam Darko, Alice O. Kamphorst, Andreas Wieland, N. Volkan Adsay, Walter J. Curran, Yue Xue, Juan M. Sarmiento, Rafi Ahmed, Daniel C. Douek, David H. Lawson, Jonathan J. Masor, and Tahseen H. Nasti
- Subjects
0301 basic medicine ,Cancer Research ,medicine.medical_treatment ,Programmed Cell Death 1 Receptor ,Immunology ,Receptors, Antigen, T-Cell ,CD8-Positive T-Lymphocytes ,CD38 ,Lymphocyte Activation ,Article ,Metastasis ,03 medical and health sciences ,Lymphocytes, Tumor-Infiltrating ,0302 clinical medicine ,Humans ,Immunology and Allergy ,Medicine ,Cytotoxic T cell ,Melanoma ,Cell Proliferation ,Brain Neoplasms ,business.industry ,T-cell receptor ,CD28 ,Chemoradiotherapy ,Immunotherapy ,Prognosis ,medicine.disease ,Clone Cells ,Granzyme B ,030104 developmental biology ,Oncology ,030220 oncology & carcinogenesis ,Cancer research ,business - Abstract
PD-1 targeted therapy has dramatically changed advanced cancer treatment. However many questions remain, including specificity of T cells activated by PD-1 therapy and how peripheral blood analysis correlates to effects at tumor sites. In this study, we utilized TCR sequencing to dissect the composition of peripheral blood CD8 T cells activated upon therapy, comparing it with tumor-infiltrating lymphocytes. We report on a nonagenarian melanoma patient who showed a prominent increase in peripheral blood Ki-67+ CD8 T cells following brain stereotactic radiation and anti-PD-1 immunotherapy. Proliferating CD8 T cells exhibited an effector-like phenotype with expression of CD38, HLA-DR and Granzyme B, as well as expression of the positive costimulatory molecules CD28 and CD27. TCR sequencing of peripheral blood CD8 T cells revealed a highly oligoclonal repertoire at baseline with one clonotype accounting for 30%. However, the majority of dominant clones - including a previously identified cytomegalovirus-reactive clone - did not expand following treatment. In contrast, expanding clones were present at low frequencies in the peripheral blood but were enriched in a previously resected liver metastasis. The patient has so far remained recurrence-free for 36 months, and several CD8 T cell clones that expanded after treatment were maintained at elevated levels for at least 8 months. Our data show that even in a nonagenarian individual with oligoclonal expansion of CD8 T cells, we can identify activation of tumor-infiltrating CD8 T cell clones in peripheral blood following anti-PD-1-based immunotherapies.
- Published
- 2018