A T cell epitope for experimental allergic neuritis is an amphipathic α-helical structure

The bovine P2 protein is known to produce experimental allergic neuritis (EAN) in Lewis rats. The longest region of amphiphatic α-helix within the bovine P2 protein was identified as residues 61–72. A synthetic peptide representing this sequence was synthesized and shown to have the ability to (1) produce EAN in Lewis rats by direct sensitization, (2) produce a lymphoproliferative response in a P2-specific T cell line, and (3) stimulate a P2 protein-specific T cell line sufficiently to transfer EAN to naive recipient Lewis rats. Residues 61–72 is the shortest sequence thus far identified that will produce EAN in the Lewis rat and supports the contention that T cell determinants tend to be amphipathic α-helices.