. "Histocompatibility (H) Ags are responsible for chronic graft rejection and graft vs host disease in solid tissue and bone marrow transplantation among MHC-matched individuals. Here we defined the molecular basis of self-nonself discrimination for the murine chromosome 7 encoded H47 histocompatibility locus, known by its trait of graft-rejection for over 40 years. H47 encodes a novel, highly conserved cell surface protein containing the SCILLYIVI (SII9) nonapeptide in its transmembrane region. The p7 isoleucine-to-phenylalanine substitution in SII9 defined the antigenic polymorphism and T cell specificity. Despite absence of the canonical consensus motif and weak binding to D(b) MHC I, both H47 peptides were presented to CTLs. However, unlike all the other known H loci, the relative immunogenicity of both H47 alleles varied dramatically and was profoundly influenced by neighboring H loci. The results provide insights into the peptide universe that defines nonself and the basis of histoincompatibility." . . . "J. Immunol." . "Shastri N." . "Eden P." . "Mendoza L.M." . "Roopenian D." . "Villaflor G." . "2001"^^ . "4438-4445" . "Distinguishing self from nonself: immunogenicity of the murine H47 locus is determined by a single amino acid substitution in an unusual peptide." . "166" .