Screening and identification of RhD antigen mimic epitopes from a phage display random peptide library for the serodiagnosis of haemolytic disease of the foetus and newborn
Division of Transfusion Medicine, Department of Medicine
Diagnosis | Female Urogenital Diseases and Pregnancy Complications | Genetic Phenomena | Hematology | Hemic and Lymphatic Diseases | Maternal and Child Health | Medical Genetics | Pathology
BACKGROUND: Identification of RhD antigen epitopes is a key component in understanding the pathogenesis of haemolytic disease of the foetus and newborn. Research has indicated that phage display libraries are useful tools for identifying novel mimic epitopes (mimotopes) which may help to determine antigen specificity.
MATERIALS AND METHODS: We selected the mimotopes of blood group RhD antigen by affinity panning a phage display library using monoclonal anti-D. After three rounds of biopanning, positive phage clones were identified by enzyme-linked immunosorbent assay (ELISA) and then sent for sequencing and peptides synthesis. Next, competitive ELISA and erythrocyte haemagglutination inhibition tests were carried out to confirm the inhibitory activity of the synthetic peptide. To evaluate the diagnostic performance of the synthetic peptide, a diagnostic ELISA was examined.
RESULTS: Fourteen of 35 phage clones that were chosen randomly from the titering plate were considered to be positive. Following DNA sequencing and translation, 11 phage clones were found to represent the same peptide - RMKMLMMLMRRK (P4) - whereas each of the other three clones represented a unique peptide. Through the competitive ELISA and erythrocyte haemagglutination inhibition tests, the peptide (P4) was verified to have the ability to mimic the RhD antigen. The diagnostic ELISA for P4 proved to be sensitive (82.61%) and specific (88.57%).
DISCUSSION: This study reveals that the P4 peptide can mimic RhD antigen and paves the way for the development of promising targeted diagnostic and therapeutic platforms for haemolytic disease of the foetus and newborn.
mimotopes, phage display libraries, RhD antigen, HDFN
DOI of Published Version
Blood Transfus. 2019 Jan;17(1):53-59. doi: 10.2450/2018.0176-17. Epub 2018 Jan 16. Link to article on publisher's site
Blood transfusion = Trasfusione del sangue
Wang, Jiao; Song, Jingjing; Zhou, Shuimei; Fu, Yourong; Bailey, Jeffrey A.; and Shen, Changxin, "Screening and identification of RhD antigen mimic epitopes from a phage display random peptide library for the serodiagnosis of haemolytic disease of the foetus and newborn" (2019). Open Access Articles. 3740.