The OPN-T cell interaction can be antagonized by serum from active vaccination with OPN peptides.

(A) 3 peptides derived from the OPN sequence plus a scrambled peptide were injected into mice. The MMP and thrombin cleavage sites are delineated by the vertical lines. The RGD binding site for αvβ3 integrins is marked with a red box and the SVVYGLR binding site for α4β1 and α4β9 integrins is marked with a mauve box. (B) Interference of postimmune serum with binding of Jurkat T cells to FL-OPN. (C) Interference of postimmune serum with binding of Jurkat T cells to Thr-cOPN. (D) Interference of postimmune serum with Jurkat T cells binding to MMP-cOPN; The different sera for the experiments were pooled from 5 mice with the OPN-T cell interaction determined once with each point detected in duplicate; mean ± SD depicted.