A SOURCE OF GLYCOSYLATED HUMAN T-CELL LYMPHOTROPIC VIRUS TYPE-1 ENVELOPE PROTEIN - EXPRESSION OF GP46 BY THE VACCINIA VIRUS T7 POLYMERASE SYSTEM

Heterologous expression of the human T-cell lymphotropic virus type 1 (HTLV-1) envelope surface glycoprotein (gp46) in a vaccinia virus/T7 p olymerase system resulted in the production of authentic recombinant g p46. Five differentially glycosylated forms of the surface envelope pr otein were produced by this mammalian system, as demonstrated by tunic amycin inhibition of N-glycosylation and N-glycan removal with endogly cosidase H. and glycopeptidase F. These studies revealed that all four potential N-glycosylation sites in gp46 were used for oligosaccharide modification and that the oligosaccharides were mannose-rich and/or h ybrid in composition. Conformational integrity of the recombinant HTLV -1 envelope protein was determined by the ability to bind to various H TLV-1-infected human sera and a panel of conformational-dependent huma n monoclonal antibodies under nondenaturing conditions. Furthermore, t his recombinant gp46 was recognized by a series of HTLV-2-infected hum an sera and sera from a Pan paniscus chimpanzee infected with the dist antly related simian T-cell lymphotropic virus STLV(pan-p). Maintenanc e of highly conserved conformational epitopes in the recombinant HTLV- 1 envelope protein structure suggests that it may serve as a useful di agnostic reagent and an effective vaccine candidate.