Metastable HIV-1 Surface Protein Env Sensitizes Cell Membranes to Transformation and Poration by Dual-Acting Virucidal Entry Inhibitors

Dual-Acting Virucidal Entry Inhibitors (DAVEIs) have previously been shown to cause irreversible inactivation of HIV-1 Env-presenting pseudovirus by lytic membrane transformation. The current study examined whether this transformation could be generalized to include membranes of Env-presenting cells. Flow cytometry was used to analyze HEK293T cells transiently transfected with increasing amounts of DNA encoding JRFL Env, loaded with calcein dye, and treated with serial dilutions of microvirin (Q831K/M83R)-DAVEI. Comparing calcein retention against intact Env expression (via Ab 35O22) on individual cells revealed effects proportional to Env expression. "Low-Env" cells experienced transient poration and calcein leakage, while "High-Env" cells were killed. The cell-killing effect was confirmed with an independent mitochondrial activity-based cell viability assay, showing dose-dependent cytotoxicity in response to DAVEI treatment. Transfection with increasing quantities of Env DNA showed further shifts toward...