Abstract 3304: Immune repertoire sequencing enables accurate clonality determination

Abstract

The study of complex immunological diseases and tumor microenvironments has advanced through recent developments in sequencing of the immune repertoire. Using this approach, the interrogation of disease progression is facilitated through analysis of millions of V(D)J combinations from B cell receptors (BCRs) and T cell receptors (TCRs). One major challenge of immune repertoire sequencing is to accurately capture the structural and sequence complexities of antibodies and TCR genes during both library preparation and bioinformatic analysis. In addition, the lack of standard reference controls makes assessing sequencing accuracy and sensitivity challenging. Here, we present a method for accurate sequencing of full-length immune gene repertoires of B cells and T cells. RNA extracted from peripheral blood mononuclear cells (PBMCs) or tissues were used for reverse transcription, during which unique molecular identifiers (UMIs) were added to discretely barcode each mRNA molecule. BCR- and TCR-specific PCR primers were used to enrich full-length BCR and TCR sequences. We have implemented a data analysis pipeline to assemble the full length BCR/TCR transcripts and to collapse PCR copies of each mRNA fragment into a single consensus sequence using UMIs. UMI incorporation enables the absolute quantification of input RNA molecules and accurate ranking of antibody/TCR clone abundance. Furthermore, we developed an RNA control pool that contains a large dynamic range of BCR and TCR sequences with a variety of V(D)J combinations, which enables sensitivity and accuracy evaluation of BCR and TCR sequencing. Our immune repertoire sequencing approach allows accurate clonal determination for both BCR and TCR. This technique is applicable for various applications including design of antibody chains for in vitro synthesis, investigation of T cell infiltration of tumor microenvironments, and monitoring of minimal residual disease in cancer patients. Citation Format: Chen Song, Ariel Erijman, Sean Lund, Bradley W. Langhorst, Pingfang Liu. Immune repertoire sequencing enables accurate clonality determination [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3304.