Efficient Vpu-Mediated Tetherin Antagonism by an HIV-1 Group O Strain.

Simian immunodeficiency viruses (SIVs) use their Nef proteins to counteract the restriction factor tetherin. However, a deletion in human tetherin prevents antagonism by the Nef proteins of SIVcpz and SIVgor, which represent the ape precursors of human immunodeficiency virus type 1 (HIV-1). To promote virus release from infected cells, pandemic HIV-1 group M strains evolved Vpu as a tetherin antagonist, while the Nef protein of less widespread HIV-1 group O strains acquired the ability to target a region adjacent to this deletion.

Improved anticancer and antiparasitic activity of new lawsone Mannich bases.

Substituted lawsone Mannich bases 2a-e, 3a-e and 4a-e were prepared and tested for their biological activities. The new fatty alkyl substituted compounds 2a-c exhibited strong and selective growth inhibitory activities in the low one-digit micromolar and sub-micromolar range against a panel of human cancer cell lines associated with ROS formation. In addition, compounds 2a-c revealed sub-micromolar anti-trypanosomal activities against parasitic Trypanosoma brucei brucei cells via deformation of the microtubule cytoskeleton.