HLA Class-II‒Restricted CD8⁺ T Cells Contribute to the Promiscuous Immune Response in Dapsone-Hypersensitive Patients

• Main Authors: Qing Zhao, Mubarak Almutairi, Arun Tailor, Adam Lister, Nicolas Harper, James Line, Xiaoli Meng, Jirawat Pratoomwun, Kanoot Jaruthamsophon, Chonlaphat Sukasem, Yonghu Sun, Lele Sun, Monday O. Ogese, David J. MacEwan, Munir Pirmohamed, Jianjun Liu, David A. Ostrov, Hong Liu, Furen Zhang, Dean J. Naisbitt
• Other Authors: Ramathibodi Hospital
• Format: Article
• Published: 2022
• Subjects: Biochemistry, Genetics and Molecular Biology; Medicine
• Online Access: https://repository.li.mahidol.ac.th/handle/123456789/76019
• Institution: Mahidol University

HLA-B∗13:01 is associated with dapsone (DDS)-induced hypersensitivity, and it has been shown that CD4+ and CD8+ T cells are activated by DDS and its nitroso metabolite (nitroso dapsone [DDS-NO]). However, there is a need to define the importance of the HLA association in the disease pathogenesis. Thus, DDS- and DDS-NO‒specific CD8+ T-cell clones (TCCs) were generated from hypersensitive patients expressing HLA-B∗13:01 and were assessed for phenotype and function, HLA allele restriction, and killing of target cells. CD8+ TCCs were stimulated to proliferate and secrete effector molecules when exposed to DDS and/or DDS-NO. DDS-responsive and several DDS-NO‒responsive TCCs expressing a variety of TCR sequences displayed HLA class-I restriction, with the drug (metabolite) interacting with multiple HLA-B alleles. However, activation of certain DDS-NO‒responsive CD8+ TCCs was inhibited with HLA class-II block, with DDS-NO binding to HLA-DQB1∗05:01. These TCCs were of different origin but expressed TCRs displaying the same amino acid sequences. They were activated through a hapten pathway; displayed CD45RO, CD28, PD-1, and CTLA-4 surface molecules; secreted the same panel of effector molecules as HLA class-I‒restricted TCCs; but displayed a lower capacity to lyse target cells. To conclude, DDS and DDS-NO interact with a number of HLA molecules to activate CD8+ TCCs, with HLA class-II‒restricted CD8+ TCCs that display hybrid CD4‒CD8 features also contributing to the promiscuous immune response that develops in patients.