Increasing the potency of MHC class II-presented epitopes by linkage to Ii-Key peptide

Vaccine. 2000 Jun 1;18(24):2693-7. doi: 10.1016/s0264-410x(00)00067-0.


We previously found that peptide Ii77-92 from the immunoregulatory Ii protein significantly enhances the binding of antigenic peptides to MHC class II molecules. Now a series of hybrids have been constructed linking LRMK, the active core region of the Ii77-92 peptide, to an antigenic epitope of cytochrome C. In vitro T cell hybridoma stimulation by some of these hybrids is up to 250 times more potent than by the antigenic peptide. The biological activities of the hybrids were tested in terms of length and composition of the linker. Simple spacers containing a polymethylene bridge (-HN-CH(2)-CH(2)-CH(2)-CH(2)-CO(2)-) were fully active in these hybrids which can enhance vaccination with MHC class II-presented epitopes.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigens, CD / immunology*
  • Antigens, Differentiation, B-Lymphocyte / immunology*
  • Binding Sites
  • Cell Line
  • Cytochrome c Group / immunology
  • Histocompatibility Antigens Class II / immunology*
  • Molecular Sequence Data
  • Protein Structure, Secondary


  • Antigens, CD
  • Antigens, Differentiation, B-Lymphocyte
  • Cytochrome c Group
  • Histocompatibility Antigens Class II
  • invariant chain