A vector system for introducing foreign HIV-1 env genes and pseudotyping of MuLV particles with the recombinant HIV-1 envelope proteins for anti-HIV-1 assay

Abstract

We attempted to incorporate the HIV-1 envelope proteins derived from various HIV-1 strains into MuLV particles for developing a rapid and safe anti-HIV-1 screening system. In a previous study, only HIV-1 envelope protein lacking cytoplasmic 144 amino acids has been reported to be able to incorporate into MuLV particles. We designed and constructed a vector, pcKCX, expressing the envelope glycoprotein with cytoplasmic truncation by introducing the partial foreign HIV-1 env gene corresponding to the ectodomain of its envelope protein. Three HIV-1 env genes of AD8, BaL or 89.6 strains were cloned, and the HIV-1/MuLV pseudotypes were generated in the transfected TELCeB6 cells with all the cloned plasmids. The pseudotypes displayed host specificity depending on their original HIV-1 strains and their infection to the tar-et cells was inhibited by treatment of a potent anti-HIV-1 peptide C34. A stable cell clone against the HIV-1(BaL) strain was found to express the R5 tropic envelope glycoprotein on the cell surface and to produce continuously HIV-1(BaL)/MuLV pseudotypes. These results suggested that the vector system is useful for cloning of various foreign HIV-1 env genes and the recombinant envelope glycoproteins effectively incorporate into MuLV particles. The HIV-1/MuLV pseudotypes may be useful for anti-HIV-1 assay.