Medindia
Advertisement

Scientists Announce Anti-HIV Agent Which Can Work in a Vaccine

by Bidita Debnath on February 18, 2015 at 11:58 PM
Font : A-A+

 Scientists Announce Anti-HIV Agent Which Can Work in a Vaccine

Researchers have made 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.

Advertisement

The research, which involved scientists from more than a dozen research institutions, was published February 18 online ahead of print by the prestigious 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."
Advertisement

Blocking a Second Site

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.

"When antibodies try to mimic the receptor, they touch a lot of other parts of the viral envelope that HIV can change with ease," said TSRI Research Associate Matthew Gardner, the first author of the study with Lisa M. Kattenhorn of Harvard Medical School. "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."

The team also leveraged preexisting technology in designing a delivery vehicle-an engineered adeno-associated virus, a small, relatively innocuous virus that causes no disease. Once injected into muscle tissue, like HIV itself, the vehicle turns those cells into "factories" that could produce enough of the new protective protein to last for years, perhaps decades, Farzan said.

Data from the new study showed the drug candidate binds to the envelope of HIV-1 more potently than the best broadly neutralizing antibodies against the virus. Also, when macaque models were inoculated with the drug candidate, they were protected from multiple challenges by SIV.

"This is the culmination of more than a decade's worth of work on the biochemistry of how HIV enters cells," Farzan said. "When we did our original work on CCR5, people thought it was interesting, but no one saw the therapeutic potential. That potential is starting to be realized."

In addition to Farzan, Gardner and Kattenhorn, authors of the study, "AAV-expressed eCD4-Ig provides durable protection from multiple SHIV challenges," include Hema R. Kondur, Tatyana Dorfman, Charles C. Bailey, Christoph H. Fellinger, Vinita R. Josh, Brian D. Quinlan, Pascal Poignard and Dennis R. Burton of TSRI; Jessica J. Chiang, Michael D. Alpert, Annie Y. Yao and Ronald C. Desrosiers of Harvard Medical School; Kevin G. Haworth and Paula M. Cannon of the University of Southern California; Julie M. Decker and Beatrice H. Hahn of the University of Pennsylvania; Sebastian P. Fuchs and Jose M. Martinez-Navio of the University of Miami Miller School of Medicine; Hugo Mouquet and Michel C. Nussenzweig of The Rockefeller University; Jason Gorman, Baoshan Zhang and Peter D. Kwong of the National Institutes of Health; Michael Piatak Jr. and Jeffrey D. Lifson of the Frederick National Laboratory for Cancer Research; Guangping Gao of the University of Massachusetts Medical School; David T. Evans of the University of Wisconsin; and Michael S. Seaman of Beth Israel Deaconess Medical Center.

Source: Newswise
Advertisement

Advertisement
News A-Z
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
News Category
What's New on Medindia
World Alzheimer's Day 2021 - 'Know Dementia, Know Alzheimer's
'Hybrid Immunity' may Help Elude COVID-19 Pandemic
Stroop Effect
View all

Medindia Newsletters Subscribe to our Free Newsletters!
Terms & Conditions and Privacy Policy.

More News on:
Amyotrophic Lateral Sclerosis (ALS) Vaccination for Children 

Recommended Reading
AIDS/HIV
"AIDS is an epidemic disease, a potentially preventable, deadly infection for which there is no ......
AIDS/HIV - Epidemiology
AIDS or HIV is an epidemic disease, a potentially deadly infection that can be prevented with ......
AIDS/HIV - Common Opportunistic Infections
Kaposi sarcoma develops below the skin surfaces or in mucous membranes of mouth, nose or anus and .....
AIDS-HIV-Cancer
AIDS defining malignancies are cancers that occur in patients with AIDS due to their low immunity....
Amyotrophic Lateral Sclerosis (ALS)
Find out more about the degenerative disease- Amyotrophic lateral sclerosis....
Vaccination for Children
Vaccines are biological products that impart immunity to the recipient. Vaccines may be live attenua...

Disclaimer - All information and content on this site are for information and educational purposes only. The information should not be used for either diagnosis or treatment or both for any health related problem or disease. Always seek the advice of a qualified physician for medical diagnosis and treatment. Full Disclaimer

© All Rights Reserved 1997 - 2021

This site uses cookies to deliver our services. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use