Infantes, SusanaLorente, ElenaBarnea, EilonBeer, IlanBarriga, AlejandroLasala, FátimaJimenez, MercedesAdmon, ArieLopez, Daniel2020-04-232020-04-232013-04-12J Biol Chem . 2013 Apr 12;288(15):10882-9.0021-9258http://hdl.handle.net/20.500.12105/9694The presentation of short viral peptide antigens by human leukocyte antigen (HLA) class I molecules on cell surfaces is a key step in the activation of cytotoxic T lymphocytes, which mediate the killing of pathogen-infected cells or initiate autoimmune tissue damage. HLA-B27 is a well known class I molecule that is used to study both facets of the cellular immune response. Using mass spectrometry analysis of complex HLA-bound peptide pools isolated from large amounts of HLA-B*2705(+) cells, we identified 200 naturally processed HLA-B*2705 ligands. Our analyses revealed that a change in the position (P) 2 anchor motif was detected in the 3% of HLA-B*2705 ligands identified. B*2705 class I molecules were able to bind these six GlnP2 peptides, which showed significant homology to pathogenic bacterial sequences, with a broad range of affinities. One of these ligands was able to bind with distinct conformations to HLA-B27 subtypes differentially associated with ankylosing spondylitis. These conformational differences could be sufficient to initiate autoimmune damage in patients with ankylosing spondylitis-associated subtypes. Therefore, these kinds of peptides (short, with GlnP2, and similar low affinity to all HLA-B27 subtypes tested but with unlike conformations in differentially ankylosing spondylitis-associated subtypes) must not be excluded from future researches involving potential arthritogenic peptides.engVoRhttp://creativecommons.org/licenses/by-nc-sa/4.0/Amino Acid MotifsCell LineHLA-B27 AntigenHumansPeptidesProtein BindingSpondylarthropathiesAtribución-NoComercial-CompartirIgual 4.0 Internacional234302492881510882-910.1074/jbc.M113.4553521083-351XThe Journal of biological chemistryopen access