MHC class II-associated invariant chain peptide replacement by T cell epitopes: engineered invariant chain as a vehicle for directed and enhanced MHC class II antigen processing and presentation
✍ Scribed by Georg Malcherek; Christoph Wirblich; Nicholas Willcox; Hans-Georg Rammensee; John Trowsdale; Arthur Melms
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 198 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0014-2980
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✦ Synopsis
Proteolysis of the invariant chain (li) leads to the generation of abundant MHC class II-associated invariant chain peptides (CLIP), which bind in the MHC class II binding groove via supermotifs in a manner similar to that of antigenic peptides. We have engineered an li vector with the capacity to express any antigenic peptide of interest instead of CLIP, for T cell stimulation. When peripheral blood mononuclear cells (PBMC) were pulsed with li hybrids encoding T cell epitopes of tetanus toxin or acetylcholine receptor, stimulation of T cells was dramatically enhanced compared to stimulation after priming with either the native or recombinant proteins. Site-specific insertion of antigenic sequences into the CLIP region promoted enhanced antigenicity of li hybrids which were shown to be processed intracellularly in a chloroquine-sensitive compartment. Naturally processed T helper epitopes were visualized directly on the surface of PBMC and identified as analogs of CLIP associated with MHC class II molecules. This novel li vector provides a flexible and efficient system for the delivery of defined peptide epitopes to T cells which might be useful in the development of specific vaccines and in the study of intracellular processing.