Objective: By using phage display random peptide library, the B cell epitope of HIV protein was studied.
Methods: The library displaying random dodecamers was biopanned first with human total IgG antibodies against HIV-1, and then non-specific phages were subtracted by purified IgG from non-HIV sera. After three rounds of screening, the positive phages were tested by ELISA for their reactivity with HIV(+)-IgG and HIV(-)-IgG antibodies. Phage that showed positive reactivity with HIV(+)-IgG, but negative to HIV(-)-IgG, were selected and their displayed peptides were determined by DNA sequencing.
Results: All the 13 positive clones sequenced displayed five kinds of peptides (SPKCLGKLLCAF, THQCLGKLQCGV, SCSAKFTCTTQI, KSDCSARFMCSV, DCLKQWACEWSR) that have homology to the HIV-I gp4l (602GCSGKLICTIN613).
Conclusions: This method demonstrated there is a dominant epitope in the region of HIV-1 gp4l and can be used in the research of the B cell epitope of HIV protein.