In a breakthrough, scientists have found that nanoparticles carrying a toxin found in bee venom can destroy HIV while leaving surrounding cells unharmed.
The finding is an important step towards developing a vaginal gel that may prevent the spread of human immunodeficiency virus (HIV), the virus that causes AIDS, researchers at Washington University School of Medicine in St Louis said.
"Our hope is that in places where HIV is running rampant, people could use this gel as a preventive measure to stop the initial infection," said researcher Joshua L Hood.
Bee venom contains a potent toxin called melittin that can poke holes in the protective envelope that surrounds HIV, and other viruses. Large amounts of free melittin can cause a lot of damage.
The new study shows that melittin loaded onto these nanoparticles does not harm normal cells because Hood added protective bumpers to the nanoparticle surface.
When the nanoparticles come into contact with normal cells, which are much larger in size, the particles simply bounce off.
HIV, on the other hand, is even smaller than the nanoparticle, so HIV fits between the bumpers and makes contact with the surface of the nanoparticle, where the bee toxin awaits.
"Melittin on the nanoparticles fuses with the viral envelope. The melittin forms little pore-like attack complexes and ruptures the envelope, stripping it off the virus," Hood said.
According to Hood, an advantage of this approach is that the nanoparticle attacks an essential part of the virus' structure.
In contrast, most anti-HIV drugs inhibit the virus's ability to replicate. But this anti-replication strategy does nothing to stop initial infection, and some strains of the virus have found ways around these drugs and reproduce anyway.
"We are attacking an inherent physical property of HIV. Theoretically, there isn't any way for the virus to adapt to that. The virus has to have a protective coat, a double-layered membrane that covers the virus," Hood said in a statement.
Beyond prevention in the form of a vaginal gel, Hood also sees potential for using nanoparticles with melittin as therapy for existing HIV infections, especially those that are drug-resistant.
The nanoparticles could be injected intravenously and, in theory, would be able to clear HIV from the blood stream.
While this work was done in cells in a laboratory environment, Hood and his colleagues said the nanoparticles are easy to manufacture in large enough quantities to supply them for future clinical trials.
The study was published in journal Antiviral Therapy
