Effect of calcium-modulating cyclophilin ligand on human immunodeficiency virus type 1 particle release and cell surface expression of Tetherin

The HIV-1 accessory protein Vpu enhances virus particle release by counteracting a host factor that retains virions at the cell surface of infected cells. It was recently demonstrated that cellular protein BST2/CD317/Tetherin restricts HIV-1 release in a Vpu-dependent manner. CAML was also proposed to be involved in this process. We investigated whether CAML is involved in Tetherin cell-surface expression. Here, we show that CAML over-expression in permissive Cos-7 cells or CAML depletion in restrictive HeLa cells has no effect on HIV-1 release nor on Tetherin surface expression, indicating that CAML is not required for Tetherin-mediated restriction of HIV-1 release.

EAC is the Canada Research Chair in Human Retrovirology. The HeLa TZM cell line was obtained through the AIDS Research and Reference Reagent Program, Division of AIDS, NIH. MD is the recipient of a Banting and Best studentship from the Canadian Institute of Health Research (CIHR). This work was supported by grants from CIHR and the Fonds de recherche en santé du Québec (FRSQ) AIDS network to EAC.