[Cloning, expression and characterization of HIV-1 gp60 partially or completely deleted in the V3 loop].
In order to better understand the role of the immunodominant V3 loop in the type-specific immune response and also to determine if this sequence has a role in AIDS pathogenesis, notably in the induction of apoptosis in CD4+ cells, we have introduced 2 modifications in the env gene from pNL4-3: a partial deletion in the V3 loop, keeping only the conserved tip of the loop GPGRAF consensus sequence (env delta V3-GPGRAF) and, secondly, a complete deletion of V3 sequence plus 43 nucleotides in C3 (env delta V3+). These constructions as well as the non-modified env gene, were cloned and expressed in a baculovirus system. Western blot analysis has shown that both modified env gene products reacted with a reference anti-HIV-1 serum to the same extent as the non-modified gp 160. However, in contrast to the non-modified env-protein and to env delta V3-GPGRAF, the env delta V3+ protein failed to bind to CD4 molecule, although V3 is not directly involved in receptor binding. These modified and non-modified recombinant proteins will be very useful to determine the potential of the partially or totally V3-deleted gp 160 to induce broadly reactive neutralizing antibodies and also to determine if V3 has a role in certain aspects of HIV-induced pathogenesis, notably apoptosis.
Lavallée
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Laboratoire de recherche sur le sida, virologie, Institut Armand-Frappier, Laval, Canada.
Thibodeau
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D001483:Base Sequence; D003001:Cloning, Molecular; D017353:Gene Deletion; D015870:Gene Expression; D015752:Genes, env / Q000235:genetics; D019302:HIV Envelope Protein gp160 / Q000235:genetics* / Q000378:metabolism*; D015497:HIV-1 / Q000235:genetics*; D018257:Helix-Loop-Helix Motifs / Q000235:genetics*; D066298:In Vitro Techniques; D011995:Recombination, Genetic
D019302:HIV Envelope Protein gp160