Abstract: Peptides and pharmaceutical compositions comprising immunogenic peptides of a marker T cell receptor (TCR) characteristic of an immune-related disease, capable of preventing, suppressing, or treating the disease, are disclosed. In a preferred embodiment, the amino acid sequence of the peptide corresponds to at least part of the second complementarity determining region (CDR2) of the TCR. Antibodies and/or T cells immunologically reactive to the TCR peptide capable of preventing, suppressing, or treating an immune-related disease by passive transfer are also disclosed.