University of Utah researchers have come closer toward a new treatment to prevent sexual transmission of the AIDS virus, after they discovered a new class of compounds that stick to the sugary coating of the virus and inhibit it from infecting cells.
Lectins are a group of molecules found throughout nature that interact and bind with specific sugars.
HIV is coated with sugars that help to hide it from the immune system. Previous research has shown that lectins derived from plants and bacteria inhibit the entry of HIV into cells by binding to sugars found on the envelope coating the virus.
However, the cost of producing and purifying natural lectins is prohibitively high.
So the study’s senior author, Patrick F. Kiser, and his colleagues developed and evaluated the anti-HIV activity of synthetic lectins based on a compound called benzoboroxole, or BzB, which sticks to sugars found on the HIV envelope.
They found that these BzB-based lectins were capable of binding to sugar residues on HIV, but the bond was too weak to be useful.
To improve binding, they developed polymers of the synthetic lectins. The polymers are larger molecules made up of repeating subunits, which contained multiple BzB binding sites.
The researchers discovered that increasing the number and density of BzB binding sites on the synthetic lectins made the substances better able to bind to the AIDS virus and thus have increased antiviral activity.
“The polymers we made are so active against HIV that dissolving about one sugar cube’s weight of the benzoboroxole polymer in a bath tub of water would be enough to inhibit HIV infection in cells,” stated Kiser, associate professor of bioengineering and adjunct associate professor of pharmaceutics and pharmaceutical chemistry at the University of Utah.
Kiser and his colleagues found that their synthetic lectins not only showed similar activity across a broad spectrum of HIV strains, but also were specific to HIV and didn’t affect other viruses with envelopes.
The study will be published in the journal Molecular Pharmaceutics.