A non-infectious and quantitative cell-based bioassay for screening HIV entry inhibitors targeting HIV envelope proteins / 南方医科大学学报

ABSTRACT

<p><b>OBJECTIVE</b>To develop an objective bioassay for quantitative detection of HIV-induced cell-cell fusion for screening HIV entry inhibitors.</p><p><b>METHODS</b>HL2/3 cells expressing HIV envelope proteins gp120/gp41, Tat, and other HIV proteins were co-cultured with HeLa-CD4-LTR-beta-gal cells expressing CD4 receptor and HIV LTR triggered reporter gene beta-galactosidase. The enzyme activities of beta-galactosidase were detected by a chromogenic substrate, chlorophenol red-beta-galactopyranoside (CPRG). Specific HIV entry inhibitors were used to validate the established detecting method.</p><p><b>RESULTS</b>No syncytium was formed by mixing HL2/3 and HeLa-CD4-LTR-beta-gal cells. However, the membrane could be fused and the Tat expressed by HL2/3 cells could bind to HIV LTR on HeLa-CD4-LTR-beta-gal cells and trigger the expression of beta-galactosidase. CPRG allowed quantitative and sensitive detection of the activity of beta-galactosidase. Further studies showed that HIV entry inhibitors could inhibit the activity of beta-galactosidase in a dose-dependent manner.</p><p><b>CONCLUSION</b>We have developed a simple, cheap, objective and quantitative non-infectious cell-cell fusion bioassay that can be used to screen for anti-HIV agents targeting the virus entry from natural and synthetic compound libraries.</p>