A luciferase-reporter gene-expressing T-cell line facilitates neutralization and drug-sensitivity assays that use either R5 or X4 strains of human immunodeficiency virus type 1

We describe the production and properties of a permanent cell line, CEM.NKR -CCR5-Luc. This line is a derivative of the CEM.NKR-CCR5 line, stably trans fected to express the luciferase reporter gene under the transcriptional co ntrol of the HIV-2 LTR. Thus the cells respond to Tat expression during HIV -1 infection by producing luciferase, a protein that can be readily and acc urately quantitated in a luminometer. The CEM.NKR-CCR5-Luc line expresses b oth the CCR5 and CXCR4 coreceptors and can therefore be infected with a ran ge of HIV-1 isolates, irrespective of their tropism properties. This is tru e of HIV-1 isolates from several genetic subtypes and also of a group O iso late. Furthermore, luciferase expression is also activated by infection of the cells with SIVmac239 or SIVmac251. We show that the CEM.NKR-CCR5-Luc ce lls can be used in assays of HIV-1 neutralization and also for identifying inhibitors of HIV-1 entry targeted at the CCR5 and CXCR4 coreceptors. The l uciferase end point simplifies the performance of neutralization and inhibi tor-screening assays compared to the use of more conventional end points su ch as the detection of extracellular p24 antigen. (C) 2001 Academic Press.