Shared amino acid sequences in the NDβN and Nα regions of the T cell receptors of tumor‐infiltrating lymphocytes within malignant glioma

Abstract

The purpose of this study was to assess the V-(D)-J junctional region of the T cell receptor (TCR), the CDR3 region, which is responsible for glioma-specific antigen contact in alpha beta TCR-mediated recognition. We sequenced the TCR alpha and beta chains of V alpha 7, and V beta 13.1 cDNA derived from tumor-infiltrating lymphocytes (TIL) of 12 glioma patients and also the corresponding clones from the patients' peripheral blood lymphocytes (PBL). A shared V beta 13.1 DJ sequence of the CDR3 region, ND beta N, was demonstrated in 49 of 66 V beta 13.1+ clones (74.2%) from the glioma TIL, whereas only 4 of 33 clones (12.1%) were observed in the V beta 13.1+ clones from the PBL (p < 0.001). A common VDJ sequence, FCASS (V beta 13.1)-YRLPWGTSDS (ND beta N)-GELFF (J beta 2.2), was observed not only in the gliomas from each patient, but also among all the patients with a preference for V beta 13.1. In contrast, the amino acid sequences of the V beta 13.1+ PBL clones were diverse and random. Next, we sequenced subclones from other V beta subfamilies randomly selected to compare their VDJ region rearrangements (V beta 3 and V beta 5.1). In contrast to V beta 13.1, the amino acid sequences of these junctional regions were completely different in these subclones. The V-J junctional region of the alpha chain is dominated by a few clones in some patients, and no shared amino acid sequences were detected in the TCR V alpha junctional region. However, in the N alpha region of the V alpha 7-bearing TIL clones, arginine was used in 27 of 44 clones (61.4%) compared to only 3 of 12 clones from the PBL (p < 0.05). These results are consistent with the hypothesis that a clonal expansion/accumulation of glioma lineage-specific T cells occurred in vivo at the tumor site and that these T cells may be recognizing glioma-specific antigens.