期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1992
卷号:89
期号:21
页码:10527-10531
DOI:10.1073/pnas.89.21.10527
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:A 41-kDa unprocessed human immunodeficiency virus 2 (HIV-2) gag precursor protein that has a deletion of a portion of the viral protease assembles as virus-like particles by budding through the cytoplasmic membrane of recombinant baculovirus-infected insect cells. We have constructed six different combinations of chimeric genes by coupling the truncated HIV-2 gag gene to the neutralizing domain (V3) or the neutralizing and the CD4 binding domains (V3+CD4BD) of gp120 env gene sequences from HIV-1 or HIV-2. The env gene sequences were inserted either into the middle of the gag gene or at the 3' terminus of the gag gene. Virus-like particles were formed by chimeric gene products only when the env gene sequences were linked to the 3' terminus of the gag gene. Insertion of env gene sequence in the middle of the gag gene resulted in high-level chimeric gene expression but without the formation of virus-like particles. Three different chimeric genes [gag gene with HIV-1 V3 (1V3), gag gene with HIV-2 V3 (2V3), and gag gene with HIV-2 V3+CD4BD (2V3+CD4BD)] formed virus-like particles that were secreted into the cell culture medium. In contrast, the HIV-1 V3+CD4BD/HIV-2 gag construct did not form virus-like particles. The chimeric gag-env particles had spherical morphology and the size was slightly larger than that of the gag particles, but the chimeric particles were similar to the mature HIV particles. Western blot analysis showed that the gag-env chimeric proteins were recognized by antibodies in HIV-positive human serum and rabbit anti-gp120 serum. Rabbit anti-gag 1V3 and anti-gag 2V3 sera reacted with authentic gp120 of HIV-1 and HIV-2, respectively, and neutralized homologous HIV infectivity. Our results show that precursor gag protein has potential as a carrier for the presentation of foreign epitopes in good immunological context. The gag protein is highly immunogenic and has the ability to carry large foreign inserts; as such, it offers an attractive approach for HIV vaccine development.