In Vitro Selection Of Aptamers To High-risk HPV L1Protein By SELEX

Objective: Human papillomavirus (HPV) infection is prerequisite for cervicalcancer. Screening HPV infection is the key to early detection, prevention, andtreatment for cervical cancer. A method of systematic evolution of ligands byexponential enrichment (SELEX) was used to obtain single strand DNA aptamersspecifically binding to high-risk HPV (HR-HPV) L1protein. Specific IgYcombining the high affinity aptamer was used to establish enzyme-linked aptamersorbent assay (ELASA) to rapidly detect HR-HPV.Methods: Bioinformatics were used to screen the B-cell epitopes derived fromL1antigen of HR-HPV (including16,18,58,52, and31type), and establish theHR-HPV antigen epitope peptide spectrum. Targeting with the synthetic antigenepitope peptides, a78-base ssDNA containing35bases of random sequence flankedby defined sites library was synthesized in vitro and used to screen ssDNA aptamersspecifically binding HPV L1protein by SELEX. Specific IgY was abtained fromegg yolk of immuned hens, and combined with the ssDNA aptamers to establishELASA to rapidly detect HR-HPV. Cervical secretions infected HR-HPV whichwere confirmed by HC-2test were used to verify the HR-HPV detection by thatmethod.Results: The purification of the synthetic peptide was more than99%. After10rounds of selection,18sequences were obtained, the sequence similarity was69.14%, and the secondary structures mainly consisted of stem-loop and hairpin.The3,7, and12aptamer with the combination of the peptide ability were higher thanothers, the Kd value of the12aptamer were low to53.93nmol/L. The most efficientprice of yolk antibody IgY was between1:12500-1:62500. The HR-HPV detectionby ELASA was shown specifically and sensitively.Conclusion: A suit of aptamers with high specificity and affinity against HR-HPV L1epitope was selected by SELEX technology. ELASA was established toearly and rapidly detect HR-HPV.