Direct interaction between HLA-B and carbamazepine activates T cells in patients with Stevens-Johnson syndrome.

Published

Journal Article

BACKGROUND: Increasing studies have revealed that HLA alleles are the major genetic determinants of drug hypersensitivity; however, the underlying molecular mechanism remains unclear. OBJECTIVE: We adopted the HLA-B∗1502 genetic predisposition to carbamazepine (CBZ)-induced Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) as a model to study the pathologic role of HLA in delayed-type drug hypersensitivity. METHODS: We in vitro expanded CBZ-specific cytotoxic T lymphocytes (CTLs) from patients with CBZ-induced SJS/TEN and analyzed the interaction between HLA-B and CBZ analogs based on CTL response, surface plasmon resonance, peptide-binding assay, site-directed mutagenesis, and computer modeling. RESULTS: The endogenous peptide-loaded HLA-B∗1502 molecule presented CBZ to CTLs without the involvement of intracellular drug metabolism or antigen processing. The HLA-B∗1502/peptide/β(2)-microglobulin protein complex showed binding affinity toward chemicals sharing 5-carboxamide on the tricyclic ring, as with CBZ. However, modifications of the ring structure of CBZ altered HLA-B∗1502 binding and CTL response. In addition to HLA-B∗1502, other HLA-B75 family members could also present CBZ to activate CTLs, whereas members of the HLA-B62 and HLA-B72 families could not. Three residues (Asn63, Ile95, and Leu156) in the peptide-binding groove of HLA-B∗1502 were involved in CBZ presentation and CTL activation. In particular, Asn63 shared by members of the B75 family was the key residue. Computer simulations revealed a preferred molecular conformation of the 5-carboxamide group of CBZ and the side chain of Arg62 on the B pocket of HLA-B∗1502. CONCLUSIONS: This study demonstrates a direct interaction of HLA with drugs, provides a detailed molecular mechanism of HLA-associated drug hypersensitivity, and has clinical correlations for CBZ-related drug-induced SJS/TEN.

Full Text

Duke Authors

Cited Authors

  • Wei, C-Y; Chung, W-H; Huang, H-W; Chen, Y-T; Hung, S-I

Published Date

  • June 2012

Published In

Volume / Issue

  • 129 / 6

Start / End Page

  • 1562 - 9.e5

PubMed ID

  • 22322005

Pubmed Central ID

  • 22322005

Electronic International Standard Serial Number (EISSN)

  • 1097-6825

Digital Object Identifier (DOI)

  • 10.1016/j.jaci.2011.12.990

Language

  • eng

Conference Location

  • United States