@entity14341 is a triggering agent for reactive @entity625 in HLA-B27-susceptible individuals. Considering the intracellular multiplication of bacteria, it seems likely that bacterial peptides may be presented by the major histocompatibility complex (MHC) class I pathway. To examine this hypothesis, we infected @entity1530 *2705- and/or @entity1 @entity2262 -transfected @entity19 L-cell lines with @entity45041 , an invasive strain of @entity14341 . @entity2348 induced no detectable modifications in the biosynthesis and expression level of HLA-B27, as assessed by immunoprecipitation, Northern blot analysis, and flow cytometry. Using confocal microscopy, we observed that @entity2348 induced a clustering of HLA-B27 molecules during macropinocytosis and before bacterial dissemination from cell to cell. Peptides naturally bound to HLA-B27 molecules were acid eluted from infected cells and separated by high-performance liquid chromatography. Major differences were observed in high-performance liquid chromatography profiles and in the nature of peptides presented following @entity2348 . Although most of the antigens presented were not accessed by Edman degradation, we obtained two sequences partially homologous to bacterial proteins. These peptides lacked the major HLA-B27 peptide anchor ( @entity534 ) at position 2, and one had an unusual length of 14 @entity1522 . These data suggest that alterations in the peptide presentation by HLA-B27 occur during @entity281 , which could be relevant to the pathogenesis of HLA-B27-related @entity625 .

Alteration of HLA-B27 peptide presentation after @entity281 of transfected XXXX L cells by @entity14341 .

@entity1 :: ('9606', 'Species') :: ['human'] @entity1522 :: ('CHEBI:33709', 'Chemical') :: ['amino acids'] @entity1530 :: ('3106', 'Gene') :: ['HLA-B'] @entity625 :: ('MESH:D001168', 'Disease') :: ['arthritis'] @entity19 :: ('10090', 'Species') :: ['murine'] @entity2262 :: ('567', 'Gene') :: ['beta2-microglobulin'] @entity2348 :: ('MESH:D001424', 'Disease') :: ['bacterial infection', 'Bacterial infection'] @entity534 :: ('CHEBI:16467', 'Chemical') :: ['Arg'] @entity45041 :: ('p|SUB|M|90|T', 'ProteinMutation') :: ['M90T'] @entity281 :: ('MESH:D007239', 'Disease') :: ['infection'] @entity14341 :: ('623', 'Species') :: ['Shigella flexneri', 'S. flexneri']
@entity19 :: (10090,Species) :: ['murine']
