Variation in H-2Kk peptide motif revealed by sequencing naturally processed peptides from T-cell hybridoma class I molecules

✍ Scribed by G.G. Burrows; K. Ariail; B. Celnik; J.E. Gambee; B.F. Bebo Jr.; H. Offner; A.A. Vandenbark

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 800 KB
• Volume: 45
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/(sici)1097-4547(19960915)45:6<803::aid-jnr17>3.0.co;2-w

✦ Synopsis

Class I major histocompatibility complex (MHC) molecules interact with a diverse array of self and foreign peptides, displaying them on the cell surface and providing an extracellular indication of intracel-M a r invasion. The most clearly defined role for these class Upeptide complexes is to cause effector responses upon binding to antigen-specific receptors of cytotoxic T cells. We have characterized the mouse thymomdrat Vp8.2 + T-cell hybridoma C14/BW12-12A1 by fluorescence-activated cell sorting analysis and have used immunoaffinity chromatography to purify class I molecules from these cells. The peptides bound to the class I molecules were fractionated by high-performance liquid chromatography and sequenced. Self-peptide mixtures eluted from the mouse H-2Kk class I allele revealed a dominant primary sequence motif, with a carboxyl-terminal residue that appeared to be invariantly valine and a secondary or auxiliary anchor residue at position 2 that could be either glutamate or proline. The majority of naturally processed peptide ligands appeared to be octamers. Although peptides eluted off H-2Kk molecules from tissue derived from a number of different inbred mouse strains also appeared to be octamers, others have reported that isoleucine is the dominant carboxyl-terminal residue. Thus, different cell types displayed distinct differences in naturally processed peptides bound by the same class I alleles. The variation in naturally processed peptides loaded onto the same class I allele most likely reflects the nature of the pool of peptides within the cell available for loading Class 1 mo~ecu~es.