Identification and screening the mimic epitopes of human Rh(D)blood type antigens / 中华检验医学杂志

ABSTRACT

Objective To screen the mimic epitopes of Rh(D)blood group antigens and identify their immunity from phage display peptide library.Methods A twelve mer phage peptide library was biopanned with anti-Rh(D)monoclonal antibody immobilized on plastic surface.After three round panning,thirty-five clones were randomly selected and positive clones were identified by ELISA and cross-reaction,followed by antibody competition inhibition assay and DNA sequencing to obtain the mimic epitopes of Rh (D)blood type antigens.The target phage clones were characterized and the antigenicity was analyzed by Western blot.Results After the third round screening,phages were enriched,and eleven positive clones were obtained.According to sequencing and competition inhibition analysis,the same"-WP-Q-"structure existed in seven of the eleven clones,and they had more than 40%inhibition ratio.The other clones had no same characteristics with low inhibition ratio possibly due to non-specific binding.Western blot analysis indicated that these phage clones could be specifically recognized by the anti-Rh(D)serum and they shared the same antigenicity of Rh(D)protein.Conclusions Rh(D)mimotope of"-WP-Q-"structure is successfully obtained by phage peptide library screening with anti-Rh(D)monoelonal antibody.The results lay the foundation for further exploration of pathogenesis and vaccine development of Rh(D)hemolytic diseases of newborn.