A New Approach to Simultaneously Quantify Both TCR α- and β-Chain Diversity after Adoptive Immunotherapy

Purpose: T-cell receptor (TCR) variable V alpha and V beta gene diversity is a surrogate biomarker for the therapeutic potential of adoptive immunotherapy and cellular immunity. Therefore, creating a straightforward, rapid, sensitive, and reliable method to view the global changes of both TCRV alpha and V beta transcripts in heterogeneous populations of T cells is appealing. Experimental Design: We designed a direct TCR expression assay (DTEA) using a panel of customized bar-coded probes that simultaneously detects and quantifies 45 V alpha and 46 V beta transcripts in a nonenzymatic digital multiplexed assay from a small number of cells (10(4) cells) or as little as 100 ng of total RNA. Results: We evaluated DTEA on total RNA samples of tumor-infiltrating lymphocytes and peripheral blood obtained from patients with melanoma after adoptive T-cell therapy. DTEA detected a similar spectrum of the dominant patterns of TCRV beta gene usage as sequencing cloned TCRV beta CDR3 regions. However, DTEA was rapid, achieved a level of sensitivity to identify rare T-cell populations, and simultaneously tracked the full array of V alpha and V beta transcripts. Conclusions: DTEA can rapidly and sensitively track changes in TCRV alpha and V beta gene usages in T-cell pools following immune interventions, such as adoptive T-cell transfer, and may also be used to assess impact of vaccination or reconstitution of T-cell compartment after hematopoietic stem cell transplantation. Clin Cancer Res; 18(17); 4733-42. (C) 2012 AACR.