TTFields treatment effects on newly diagnosed Glioblastoma patients in peripheral T lymphocytes

We report the application of RNA-based sequencing technology for high-throughput profiling of T cell enriched peripheral blood mononuclear cells. By sequencing in total of 12 pairs GBM patient samples, we extracted TCRαβ V(D)J sequences from the deep RNA-seq of T cells isolated from the 24 PBMCs to determine if TTFields treatment affected TCR diversity, using the Simpson’s diversity index (DI), which is the average proportional abundance of TCR clones based on the weighted arithmetic mean. Of the 12 patients, 9 exhibited negative log fold change (logFC) of TCR DI after TTFields, indicating clonal expansion. Notably, in all but 1 patient, the top 200 most abundant clones post TTFields, which accounted for 38.1% to 100% (median 67%) of detectable clones, showed substantial expansion compared to pre-TTFields T cells, and inversely correlated with the DI. Thus, TTFields treatment is associated with adaptive immune activation as evidenced by clonal expansion of peripheral T cells. Examination of TTFields treatment effects in T cell enriched peripheral blood mononuclear cells.