Glycopeptides bind MHC molecules and elicit specific T cell responses.

摘要: Carbohydrates are T cell independent antigens because they do not bind to MHC molecules. However, glycopeptides might potentially molecules via their peptide component for presentation cells. We have conjugated the disaccharide galabiose [Gal alpha (1-4)Gal beta] amino terminus of a determinant from hen egg-white lysozyme [HEL(52-61)]. The resulting glycopeptide (Gal2-52-61) and nonglycosylated analogue containing tyrosine glutamic acid at amino-terminus (YE-52-61) bound equally well purified I-Ak. hybridomas were produced after immunization with Gal2-52-61. Many glycopeptide-specific responded Gal2-52-61 but synthetic peptides or HEL presented by APC, indicating that carbohydrate moiety influenced recognition. Recognition was lost terminal attachment six acids longer than HEL(52-61). also only single galactosyl residue different I-Ak binding peptide. cells directed recognized having significant variation in structure, such as HEL(52-61) carrying lactose, cellobiose, hepta-o-acetylated galabiose. Peptide residues important features epitope; Ala substitutions two critical contact (Tyr53 Leu56) abrogated reactivity without affecting In conclusion, we propose these recognize conformation specific glycopeptide-I-Ak complexes this recognition does involve interaction between receptor.