[The association of HLA-B27 binding peptide and spondylarthropathies].

OBJECTIVE

To explore the association of spondylarthropathies HAL-B27 binding peptide.

METHODS

B27 molecules expressed on the B27-T2 mutant cell line do not have peptides. Such empty B27 molecules were not recognized by peptide-dependent monoclonal antibody, B27.M2. Positive B27.M2 reactivity resulted when B27-T2 cells were incubated with peptide RRKAMFEDI derived from Chlamydia hsp60. THe importance of each residue in RRKAMFEDI was analysed by testing analogs in which each of the 9 residues in the peptide was consecutively substituted by 19 other amino acids.

RESULTS

B27.M2 reactivity was the highest with arginine in second residue. The reactivities of residues other than arginine were less than 30% of the value with the parent peptide.

CONCLUSION

The stringency for other residues was relatively low, indicating that immune recognition of B27-peptide complexes might have rather low stringency for peptide sequences. These peptide residues probably influenced antibody reactivity by inducing conformational changes.