Expansion of helper T-cell recognition in mice immunized with a synthetic peptide corresponding to the C-terminal thyrotropin receptor-specific insert

We previously reported that immunization with a synthetic peptide of human thyrotropin receptor (TSH-R) expanded humoral autoimmunity to TSH-R (Sugawa H, Ueda Y, Ueda hii, Kosugi S, Ichiyama S, Mori T. Immunization with the ' immunogenic Peptide' of TSH receptor induces oligoclonal antibodies with va rious biological activities. Peptide 1998;19:1303-7.). In the present study , we examined this phenomenon at the T-cell level. Balb/c mice were immuniz ed with a synthetic peptide corresponding to the C-terminal-specific insert of human TSH-R. Spleen cells were collected and subjected to antigen-speci fic ELISPOT assay. The number of interleukin 4-secreting cells specific to P354-367 increased within 3 weeks. Cells responding to the other peptides i ncreased 7 weeks after immunization. This phenomenon was not observed in mi ce immunized with bovine serum albumin alone. During immunization, numbers of interferon-gamma-secreting lymphocytes were not changed significantly. T hese results indicated that immunization with C-terminal TSH-R-specific ins ert peptide causes fluctuation in the type 2 helper T-cell population but n ot type 1 Th cells against the TSH-R, and the recognition repertoire of typ e 2 helper T cell was expanded by the peptide. (C) 1999 Elsevier Science In c. All rights reserved.