The BC3 cell line was isolated from a normal 56 year old Caucasian man. In vitro stimulation of peripheral blood mononuclear cells (PBMC) with a peptide of MBP was used to select for peptide reactive T cells. The peptide used (ENPVVHFFKNIVTPRTP) is believed to be the immunodominant epitope. The cell line is likely oligoclonal and recognizes the peptide presented by HLA-DRβ1*1501 and may also recognize peptide presented by HLA-DRβ1*14, though this has not yet been confirmed. The cells also recognize the peptide FFKNIVTPRTPPPSQGK, thus the minimal epitope for this line is FFKNIVTPRTP. The cells secrete interferon gamma, IL-13 and TNF alpha upon stimulation. They are CD4+ and, not surprisingly, FoxP3 negative.