Via Science Daily:
In a remarkable new advance against the virus that causes AIDS, scientists from the Jupiter, Florida campus of The Scripps Research Institute (TSRI) have announced the creation of a novel drug candidate that is so potent and universally effective, it might work as part of an unconventional vaccine. The research, which involved scientists from more than a dozen research institutions, was published February 18 online ahead of print by the journal Nature.
The study shows that the new drug candidate blocks every strain of HIV-1, HIV-2 and SIV (simian immunodeficiency virus) that has been isolated from humans or rhesus macaques, including the hardest-to-stop variants. It also protects against much-higher doses of virus than occur in most human transmission and does so for at least eight months after injection. “Our compound is the broadest and most potent entry inhibitor described so far,” said Michael Farzan, a TSRI professor who led the effort. “Unlike antibodies, which fail to neutralize a large fraction of HIV-1 strains, our protein has been effective against all strains tested, raising the possibility it could offer an effective HIV vaccine alternative.”
When HIV infects a cell, it targets the CD4 lymphocyte, an integral part of the body’s immune system. HIV fuses with the cell and inserts its own genetic material — in this case, single-stranded RNA — and transforms the host cell into a HIV manufacturing site. The new study builds on previous discoveries by the Farzan laboratory, which show that a co-receptor called CCR5 contains unusual modifications in its critical HIV-binding region, and that proteins based on this region can be used to prevent infection. With this knowledge, Farzan and his team developed the new drug candidate so that it binds to two sites on the surface of the virus simultaneously, preventing entry of HIV into the host cell.
The study was funded with grants from the NIH.