Construction of a gamma-retrovirus with a novel tropism dependent on human APJ as entry receptor

Background The gamma-retrovirus isolate SL3-2 belongs to the group of xenotropic-polytropicmurine leukemia viruses which uses the xenotropic-polytropic receptor Xpr1 for entry[1]. However, the SL3-2 isolate has a tropism restricted to murine cells, which makes SL3-2 interesting for receptor-retargeting experiments. To investigate SL3-2 as a new scaffold for retargeting experiments an alternativeentry receptor has been chosen, the human G-protein coupled receptor hAPJ. In addition, hAPJis known to be able to function as a coreceptor for some HIV-1 isolates.