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Induction of High Levels of Epitope‐Specific Antibodies by Epitope/Peptide Candidate Vaccines against Human Immunodeficiency Virus Type‐1 (HIV‐1)
Author(s) -
Yu Tianwei,
Bai Yun,
Dierich Manfred P.,
Chen YingHua
Publication year - 2000
Publication title -
microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 70
eISSN - 1348-0421
pISSN - 0385-5600
DOI - 10.1111/j.1348-0421.2000.tb01253.x
Subject(s) - epitope , immunogenicity , antibody , biology , titer , virology , antibody titer , immunoglobulin g , linear epitope , microbiology and biotechnology , immunology
To test the immunogenicity of GPGRAFY‐epitope‐based candidate vaccines, a peptide with four repetitive GPGRAFY epitopes, V3‐P1 [C‐(GPGRAFY) 4 ], and a peptide (PND) of the principal neutralizing domain (V3 loop: amino acid 301–328: C‐TRPNNNTRKSIRIQRGPGRAFYTIGKI) on gp120 were synthesized and covalently coupled to a carrier protein BSA. Immunization of BALB/c mice and New Zealand White Rabbits with these conjugate vaccines engendered strong antibody responses against the PND (mouse serum titer by 1:12,800–25,600; rabbit serum titer by 1:6,400–12,800). Interestingly, the V3‐P1‐BSA conjugates and the PND‐BSA conjugates could induce high levels of GPGRAFY‐epitope‐specific antibodies in the mice and rabbits (mouse serum titer by 1:25,600; rabbit serum titer by 1:12,800–25,600), while a recombinant gp160 subunit vaccine induced a low level of GPGRAFY‐epitope‐specific antibodies (serum titer by 1:400–1,600 in mice and rabbits). To confirm the above results, GPGRAFY‐epitope‐specific antibodies were isolated from rabbit sera induced by V3‐P1‐BSA, PND‐BSA conjugates and rgp160 vaccine. In fact, 23–38 and 13–22 μg epitope‐specific antibodies per milliliter serum were isolated from rabbit sera induced by V3‐P1‐BSA and PND‐BSA conjugate, respectively, while 1.34 μg epitope‐specific antibodies per milliliter serum were identified in rabbit serum induced by rgp160 vaccine. In the control group, only 0.069 μg proteins per milliliter serum were found in pooled pre‐immune serum (normal serum). These results from mouse and rabbit experiments indicate that epitope and peptide vaccines both induce high levels of GPGRAFY‐epitope‐specific antibodies in comparison with rgp160 subunit vaccine, suggesting that epitope/peptide vaccines may be a new strategy to induce protective activity.