Multiple class I motifs revealed by sequencing naturally processed peptides eluted from rat T cell MHC molecules

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

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 153 KB
• Volume: 49
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/(sici)1097-4547(19970701)49:1<107::aid-jnr12>3.0.co;2-0

✦ Synopsis

Class I major histocompatibility complex (MHC) molecules interact with a diverse array of self and foreign peptides. Displayed on the cell surface, the class I/peptide complex provides an extracellular indication of the intracellular milieu. We have characterized the Lewis rat Vb8.21 T cell hybridoma C14/ BW12-12A1 by FACS analysis and have used immunoaffinity chromatography to purify class I molecules from these cells. Peptides eluted from the class I molecules have been fractionated by HPLC and sequenced. Self-peptide mixtures indicate two distinct peptide motifs, suggesting the possibility of multiple class I loci. The majority of the naturally processed peptide ligands were nonamers. Naturally processed peptide ligands fitting the first motif contained a hydrophobic leucine anchor residue at position three and a carboxyl-terminal serine anchor residue. A second motif was characterized by a tyrosine or phenylalanine residue at position three and a phenylalanine or isoleucine carboxyl-terminal residue. Four peptides derived from the Vb8.2 T cell receptor have sequences that fit these motifs, providing a mechanistic explanation for their immunoregulatory role. Identification of these class I peptide binding motifs will be useful for predicting potential CTL epitopes in studies on autoimmunity, immunoregulation and transplantation in the Lewis rat.