Q124640991
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HLA-B27 is a relative risk factor for ankylosing spondylitis (AS) and is present in about 10% in European populations but in 95% of AS patients. Various data suggest that the HLA-B27 molecule itself could be the strongest risk factor, but there is no explanation for this association. To define differential antigen presenting features of HLA-B27 in healthy individuals and AS patients, a question that cannot be addressed by biochemical studies on cell lines, the HLA-B27 protein was purified from peripheral blood lymphocytes of AS patients and healthy controls and pool sequencing of the bound peptides was performed. Results show that peptides are rich in proline (Pro) and the content of arginine (Arg) is much lower in comparison with sequences listed in the register of peptides eluted from cell cultures. Statistically significant differences were detected in frequencies of a subset of amino acids, predominantly at positions in the middle of the peptides. The frequency of Glu was increased and Gln was decreased in peptides from AS patients. Detailed analysis of purity of the immunoisolated HLA molecules excluded that the peptides might originate from any co-purified HLA molecules other than B27. We conclude that statistically significant increase in the Glu/Gln ratio of peptides from AS patients, consistent with increased deamidation in vivo, may account for differential antigenicity of HLA-B27 in patients. Source protein(s) of deamidated peptides remain unknown.
- MeSH
- ankylózující spondylitida genetika MeSH
- arginin genetika MeSH
- dospělí MeSH
- financování organizované MeSH
- glutamin genetika MeSH
- HLA-B27 antigen genetika chemie MeSH
- kyselina glutamová genetika MeSH
- lidé MeSH
- peptidové fragmenty genetika chemie genetika MeSH
- prolin genetika MeSH
- rizikové faktory MeSH
- sekvenční analýza proteinů MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- srovnávací studie MeSH
The sequences and profiles of peptides which bind to HLA-B*2705 splenocytes and peripheral blood cells were compared with those previously published from in vitro long-term cell cultures. B*2705 peptide profile analysed by solid-phase Edman degradation and 15 individual peptide sequences determined by LC-MS/MS were partially similar to those defined from in vitro long-term cell cultures. Arg at P2 was found in 11 of 15 sequenced peptides (73.3%). This value is lower in comparison with other published data. Two sequences were matching to unknown proteins, which displayed similarity with myosin. These are first data on peptide sequences isolated directly from HLA-B27 molecules without prior in vitro propagation of the cells.
Urolog ; č. 3
212 s. : obr., tab., grafy ; 19 cm
