The Scripps Research Institute (TSRI) has announced researchers in their organization have developed a new drug candidate that could destroy all known forms of HIV.
The new agent is effective at destroying HIV-1, HIV-2, and simian immunodeficiency virus (SIV), including the most difficult-to-treat variants. The protein appears to be effective for a period of up to eight months after introduction to biological systems.
When HIV infects a human host, the virus attacks the CD4 lymphocyte, essential for the proper functioning of human immune systems. The virus inserts genetic code encoded on single-stranded RNA that hijacks the cell, turning it into a factory, manufacturing more HIV viruses.
"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," Michael Farzan from TSRI said.
A co-receptor known as Ccr5 contains codes in the region responsible for the binding of the structures to HIV. This structure is the first "anchor" to which HIV must bind before being able to enter cells. Researchers used this property to design proteins which may be used to battle HIV infection.
"When antibodies try to mimic the receptor, they touch a lot of other parts of the viral envelope that HIV can change with ease. We've developed a direct mimic of the receptors without providing many avenues that the virus can use to escape, so we catch every virus thus far," Matthew Gardner of TSRI said.
The new agent bonds onto two areas in the genetic structure, preventing HIV from binding onto cells, and hijacking their systems. This attachment is stronger than that seen in any other known agent designed to block HIV.
In order to propagate resistance in the immune system, the cell uses a method similar to that employed by the HIV virus. An adeno-associated virus, which does not cause disease, is utilized to turn cells into manufacturing centers, creating additional copies of the new protein. With further development, it may be possible for a vaccine to be developed from this new candidate drug that could provide protection to patients for years, or even decades.
After the virus attaches to the Ccr5 co-receptor, it next passes to another such structure, known as Cxcr4. When HIV reaches that point, the patient usually starts to exhibit symptoms typically associated with HIV infections.
Human trials of the new agent are still several years away, but this preliminary discovery could hold great promise in the battle against the HIV virus.
Development of the new drug candidate to combat HIV was published in the journal Nature.
