title: Production of murine leukemia RLmale1 rejection antigen peptide pRL1a by proteolysis of natural precursor pRL1b.
abstract: In this study, we demonstrated that NH2-terminal Ser and Ile residues of pRL1b (SI-pRL1a) (SIIPGLPLSL) are not involved in the recognition by RLmale 1-specific cytotoxic T lymphocyte. The sensitization activity observed with pRL1b (SI-pRL1a) was not greater than that of peptides substituted with irrelevant amino acids at these positions. In serum-free medium, pRLla retained sensitization activity, but pRL1b (SI-pRL1a) did not. Furthermore, addition of bestatin to serum-containing medium blocked sensitization by pRL1b (SI-pRL1a). On the other hand, the addition of captopril enhanced it, probably by inhibiting the degradation of pRL1a by ACE. pRL1a-D peptide with D-Ile in place of the L-Ile residue of pRL1a (IPGLPLSL) showed sensitization, but SI-pRLla-2,3D peptide, which has D-Iles in place of the L-Ile residues of pRLlb (SI-pRL1a), and which was not cleaved between the two D-Iles, did not. The findings suggest that pRL1a is the antigenic peptide bound to L(d) molecules and pRL1b (SI-pRL1a) peptide is its natural precursor, which generates pRL1a via proteolysis.
authors.affiliation: Department of Parasitology and Immunology, Okayama University Medical School, Shikata-cho.
authors.forename: T
authors.initials: T
authors.lastname: Ono
authors.forename: A
authors.initials: A
authors.lastname: Uenaka
authors.forename: E
authors.initials: E
authors.lastname: Nakayama
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000096:biosynthesis* / Q000276:immunology / Q000378:metabolism; D000939:Epitopes / Q000378:metabolism; D005260:Female; D007942:Leukemia, Experimental / Q000201:enzymology / Q000276:immunology / Q000378:metabolism*; D007953:Leukemia, Radiation-Induced / Q000276:immunology / Q000378:metabolism; D008297:Male; D012515:Mast-Cell Sarcoma / Q000201:enzymology / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D010447:Peptide Hydrolases / Q000097:blood / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology; D012680:Sensitivity and Specificity; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
chemical_list: D000951:Antigens, Neoplasm; D000939:Epitopes; D011480:Protease Inhibitors; D010447:Peptide Hydrolases