Expression of the HTLV-III envelope gene by a recombinant vaccinia virus

Abstract

The discovery that the aetiological agent of acquired immune deficiency syndrome (AIDS) is a retro virus, referred to as human T-lymphotropic virus type III (HTLV-III) or lymphadenopathy-associated virus (LAV) (for review see ref. 1), has raised the possibility of developing a vaccine. In this regard, the envelope (env) proteins of murine retroviruses can induce protective immunity in mice2,3. The HTLV-III env gene specifies a primary polypeptide of ∼860 amino acids that is glycosylated to form a precursor of relative molecular mass (Mr) 160,000 (gp160), which gives rise to mature membrane-associated proteins4-9 of Mr 120,000 (gp120) and 41,000 (gp41). The HTLV-III env gene has been expressed in Escherichia coli 10 and by simian virus 40 (SV40) vectors5 but formation of the authentic proteins has not been demonstrated. Here, we describe the expression of the complete env gene by a vaccinia virus vector. Evidence is presented that synthesis, glycosylation, processing and membrane transport of the env polypeptide occurred without other HTLV-III gene functions; the env protein was recognized by sera from unrelated AIDs patients; and a single vaccination with the infectious recombinant vaccinia virus induced antibodies to gp120 in mice. © 1986 Nature Publishing Group.