Contribution of proteasome-mediated proteolysis to the hierarchy of epitopes presented by major histocompatibility complex class I molecules

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• 作者：Gabrlele Niedermann ; Stefan Butz ; Hans Georg Ihlenfeldt ; Rudolf Grimm ; Maria Lucchlarl ; Heinz Hoschotzky ; Gü ; nther Jung ; Bernhard Maier ; Klaus Elchmann
• 刊名：Immunity
• 出版年：1995
• 出版时间：March 1995
• 年：1995
• 卷：2
• 期：3
• 页码：289-299
• 全文大小：3628 K

文摘

Major histocompatibility complex (MHC) class I-restricted cytotoxic T lymphocytes (CTL) recognize peptide epitopes of protein antigens in a hierarchical fashion. We investigated whether proteolytic cleavage, in particular by proteasomes, Is important in determining epitope hierarchy. Using highly purified 20S proteasomes, we find preferred cleavage sites directly adjacent to the N- and C-terminal ends of the immunodominant epitope of chicken ovalbumin, Ova257–264, while most of the subdominant epitope, Ova55–62, is destroyed by a major cleavage site located within this epitope. Moreover, we show that variations in amino acid sequences flanking these epitopes influence proteasomal cleavage patterns In parallel with the efficacy of their presentation. The results suggest that proteasomal cleavage within and adjacent to class I-restricted epitopes contributes to their level of presentation.