SBIR-STTR Award

The recombinant HIV SOSIP Envelope Env trimer is the leading HIV vaccine candidate but current production levels are low in mammalian cell lines likely due to current trimer designs which include numerous disulfide bonds proteolytic cleavage and extensive glycosylation known to induce endoplasmic reticulum stress and cellular toxicity. This proposal will utilize the Nicotiana benthamiana pN bp plant expression system to produce the CH FR SOSIP Env CHSOSIP and address whether manipulation of ER chaperones will increase the host cell capacity for correct folding disulfide bond formation and post translational modification. Thus the unfolded protein response UPR will be induced by co expressing the master regulators bZIPs and bZIP active forms of transcription factors and selected ER chaperones BiPPDIPPICRT and CNX individually and in combination. The N bp plant platform offers an advantage for rapidly assessing cellular toxicity by phenotypic screening of leaf browning after days. In addition the proposed studies will examine whether fusions between the anti CLEC A antibody and CHSOSIP Env molecules will enhance stability and expression levels as well as provide for a generic protein A based downstream processing strategy. Finally the suitability of a stress resistant plant host. Nicotiana tabacum for producing VHSOSIP Env at a commercial scale will be evaluated