Mimotopes selected by biopanning with high-titer HIV-neutralizing antibodies in plasma from Chinese slow progressors
| Autor: | Xiaoli Zhang, Xiaoxu Han, Di Dai, Bao Mingjia, Zining Zhang, Min Zhang, Tristan Bice, Min Zhao, Yaming Cao, Hong Shang |
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| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: | |
| Zdroj: | Brazilian Journal of Infectious Diseases, Vol 16, Iss 6, Pp 510-516 (2012) |
| Druh dokumentu: | article |
| ISSN: | 1413-8670 1678-4391 |
| DOI: | 10.1590/S1413-86702012000600002 |
| Popis: | OBJECTIVE: One approach to identifying HIV-1 vaccine candidates is to dissect the natural antiviral immune response in treatment-naïve individuals infected for over ten years, considered slow progressor patients (SPs). It is suspected that SP plasma has strongly neutralizing antibodies (NAb) targeting specific HIV viral epitopes. METHODS: NAbs levels of 11 HIV-1-infected SPs were detected by PBMC-based neutralization assays. To investigate SP NAb epitope, this study used a biopanning approach to obtain mimotopes of HIV-1 that were recognized by SP plasma NAbs. IgG was purified from hightiter NAb SP plasma, and used as the ligand for three rounds of biopanning to select HIV-specific mimotopes from a phage-displayed random peptide library. Double-antibody sandwich ELISA, competitive inhibition assays, and peptide sequence analysis were used to evaluate the characteristics of phage-borne mimotopes. RESULTS: SPs had significantly more plasma neutralizing activity than typical progressors (TPs) (p = 0.04). P2 and P9 plasma, which have highest-titer HIV-NAb, were selected as ligands for biopanning. After three rounds of biopanning, 48 phage clones were obtained, of which 22 clones were consistent with requirement, binding with HIV-1 positive plasma and unbinding with HIV-1 negative plasma. Compared with linear HIV-1 protein sequence and HIV-1 protein structure files, only 12 clones were possible linear mimotopes of NAbs. In addition, the C40 clone located in gp41 CHR was found to be a neutralizing epitope, which could inhibit pooled HIV-1 positive plasma reaction. CONCLUSION: Biopanning of serum IgG can yield mimotopes of HIV-1-related antigen epitopes. This methodology provides a basis for exploration into HIV-1-related antigen-antibody interactions and furthers NAb immunotherapy and vaccine design. |
| Databáze: | Directory of Open Access Journals |
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