In vitro susceptibility to infection with SIVcpz and HIV-1 is lower in chimpanzee than in human peripheral blood mononuclear cells

This study was undertaken to evaluate and compare the susceptibility of chimpanzee versus human peripheral blood mononuclear cells (PBMCs) to infection with SIVcpz and HIV-1 non-syncitium inducing primary isolates. The results demonstrate clearly that chimpanzee PBMCs have a lower capacity to support viral replication as compared to human PBMCs. There was no experimental evidence that this difference was due to a lower availability of target cells for viral infection (PBMCs positive for CD4 and CCR5 molecules) or to a differential susceptibility to apoptosis (PBMCs positive for CD4 and CD95 molecules). A lower capacity of chimpanzee PBMCs to support SIVcpz and HIV-1 replication in vitro is related to a post-entry barrier to virus replication.