Molecular basis for increased susceptibility of Indigenous North Americans to seropositive rheumatoid arthritis.Scally, S.W., Law, S.C., Ting, Y.T., Heemst, J.V., Sokolove, J., Deutsch, A.J., Bridie Clemens, E., Moustakas, A.K., Papadopoulos, G.K., Woude, D.V., Smolik, I., Hitchon, C.A., Robinson, D.B., Ferucci, E.D., Bernstein, C.N., Meng, X., Anaparti, V., Huizinga, T., Kedzierska, K., Reid, H.H., Raychaudhuri, S., Toes, R.E., Rossjohn, J., El-Gabalawy, H., Thomas, R.
(2017) Ann Rheum Dis 76: 1915-1923
- PubMed: 28801345
- DOI: https://doi.org/10.1136/annrheumdis-2017-211300
- Primary Citation of Related Structures:
6ATF, 6ATI, 6ATZ
- PubMed Abstract:
The pathogenetic mechanisms by which HLA-DRB1 alleles are associated with anticitrullinated peptide antibody (ACPA)-positive rheumatoid arthritis (RA) are incompletely understood. RA high-risk HLA-DRB1 alleles are known to share a common motif, the 'shared susceptibility epitope (SE)'. Here, the electropositive P4 pocket of HLA-DRB1 accommodates self-peptide residues containing citrulline but not arginine. HLA-DRB1 His/Phe13β stratifies with ACPA-positive RA, while His13βSer polymorphisms stratify with ACPA-negative RA and RA protection. Indigenous North American (INA) populations have high risk of early-onset ACPA-positive RA, whereby HLA-DRB1*04:04 and HLA-DRB1*14:02 are implicated as risk factors for RA in INA. However, HLA-DRB1*14:02 has a His13βSer polymorphism. Therefore, we aimed to verify this association and determine its molecular mechanism.
Department of Biochemistry and Molecular Biology, Infection and Immunity Program, Biomedicine Discovery Institute Monash University, Clayton, Australia.