Performance of a clonal-based HIV-1 tropism phenotypic assay

- A clonal-based HIV-1 tropism phenotypic assay was developed.
- Env-pseudotyped viruses were produced by co-transfection of the env-pcDNA3.1/V5HisTOPO expression vector and a backbone pNL4-3.Luc.E-R- in 293T cell cultures.
- Coreceptor use was tested by infection of U87-CD4-CCR5+ and U87-CD4-CXCR4+ cells.
- This sensitive clonal based phenotypic assay was able to differentiate between the truly dual-tropic viruses and a mixture of R5- and X4-tropic viruses.
- Minor variants were always detectable when present at 0.4% or greater in the mixtures.