CD4 T‐cell epitopes of human α B‐crystallin

Of potential importance to multiple sclerosis (MS), oligodendroglial α B‐crystallin is expressed and associated with the myelin sheath at the earliest stage of MS lesion development. We selected T‐cell lines specific for human α B‐crystallin from peripheral blood mononuclear cells (PBMC) of HLA‐DR2 homozygous MS patients and found that the α B‐crystallin‐specific T‐cells were CD4+ and restricted by DRB1*1501, and expressed Th1 cytokines. The CD4 T‐cell epitopes of human α B‐crystallin were determined by proliferation of α B‐crystallin‐specific T‐cell lines to 17 20‐mer synthetic overlapping peptides spanning the entire molecule of human α B‐crystallin. It was found that the HLA‐DR2 donor‐derived α B‐crystallin‐specific T‐cell lines proliferated to α B‐crystallin peptides 21–40, 41–60, and to a lesser extent, 131–150. These T‐cell proliferation responses were associated with intracellular expression of interleukin‐2 (IL‐2) and secretion of interferon‐γ (IFN‐γ), and tumor necrosis factor‐α (TNF‐α). The amino acid sequences of these peptides were compatible with predicted HLA‐DR2‐restricted binding motifs. PBMC of an early active MS patient proliferated to the epitope‐containing peptides significantly better than did those of later stage MS patients or healthy controls. Taken together, these findings suggest that autoreactive α B‐crystallin‐specific Th1 cells may have the potential to contribute to MS pathogenesis. © 2004 Wiley‐Liss, Inc.