A viral peptide can mimic an endogenous peptide for allorecognition of a major histocompatibility complex class I product

摘要

AbstractAlloreactive class I‐restricted T cells may recognize the class I structure alone, in association with a specific peptide, or with any stabilizing peptide. We havetested the role of endogenous peptides in the recognition of H2Kbmolecules by two alloreactive cytolytic T lymphocyte (CTL) clones using the mutanttumor lineRMA‐S, which expresses its surface H‐2bmolecules devoid of peptides and is not lysed by these two CTL clones. Empty H‐2bmolecules on RMA‐S cells can be stabilized by binding exogenously added peptides. H‐2Kb−specific recognition of the RMA‐S cells by one of the CTL clones was restored by endogenous peptide extracts which only minimally stabilized H2Kbon the surface of RMA‐S cells, indicating the requirement for a specific peptide on a limited number of H2Kbmolecules. In addition, one out of three peptides which greatly enhance the expression of H2Kb, the nucleoprotein peptide 52–59 from vesicular stomatitis virus (VSV), was also able to restore the lysis of RMA‐S cells by the clone. The recognition of a common motif by an alloreactive clone (H‐2kanti‐H‐2Kb) and virus‐specific Kb−restricted clones suggests that both H‐2kand H‐2bthymic environments allow selection of T cells capable of recognizing H2Kb+VSV and that tolerance to self, as would be the case in the (H‐2kx H‐2b)F1mice, would par