Shared and Distinct T-Cell Receptor Characteristics of CD4+ and CD8+ Drug-Specific T-Cells In Vitro Generated from Healthy Donors and Hypersensitive Patients

Abstract The initiation of T-cell-mediated drug hypersensitivity reaction requires the formation of a human leukocyte antigen (HLA)-peptide-drug-T-cell receptor (TCR) complex. While specific interactions between HLA molecules and drug antigens are well-defined, the characteristics of drug binding to the TCR are unclear. Herein, we sequenced the TCR mRNAs of T-cells that express drug-specific HLAs (including HLA-A*31:01, HLA-B*15:02, and HLA-B*13:01) and exhibit drug-specific immune responses against carbamazepine, sulfamethoxazole, and dapsone. This study included a total of 46 in vitro-generated monoclonal drug-specific (CD4+ and CD8+) T-cell clones. The T-cell clones were characterized for their drug-specific immune response, including HLA restriction properties, interferon-γ secretion, and cross-reactive responses. RNA isolated from these cells was used for TCR library preparation and subsequent long-read sequencing analyses. T-cell characterization studies showed different drug-responsiveness properties among the clones. TCR sequencing revealed wide heterogeneity among drug-specific T-cells. Only TCR Vβ (TRBV) and TCR Jβ (TRBJ) segments of CD4+ T-cell clones displayed noticeable shared characteristics. A YEQYF residue on CDR3β, which correlates with the preferential use of TRBJ2–7, was identified in 5 out of 16 CD4+ carbamazepine-specific clones. However, CD8+ drug-specific clones showed no preferential usage of TCR α/β. Sequence alignment analyses among clones with similar or different drug-responsiveness properties also showed no evidence of structure–function correlation. In summary, TCR specificity against drug antigens appears to be nonrestrictive, suggesting that the extent of possible binding and its key determinants are not rigid.