Navigation Links
How sneaky HIV escapes cells

Like hobos on a train, HIV, the virus that causes AIDS, uses a pre-existing transport system to leave one infected cell and infect new ones, Hopkins scientists have discovered. Their findings, published in the June issue of Plos Biology, counter the prevailing belief that HIV and other retroviruses can only leave and enter cells by virus-specific mechanisms.

“It appears that cells make HIV and other retroviruses by a naturally occurring export mechanism,” says Stephen Gould, Ph.D., Professor of Biological Chemistry at Johns Hopkins. Cells normally export certain membrane-bound molecules to the outside world by means of small sacs known as exosomes. By studying human T-cells under a microscope, Gould, Yi Fang, Ning Wu, and other members of his team discovered what’s needed to qualify proteins for exosomal travel.

“Surprisingly, all that’s needed for a protein to get out of the cell in exosomes are the ability to clump together and attach to the cell’s membrane,” Gould says.

In one experiment, Gould and his team added chemicals to normal human cells that force nearby proteins together into a clump, and this was enough to get them sent out of the cell in exosomes. If they added a tether to force naturally-clumping proteins inside the cell to the membrane, the proteins met a similar exosomal deportation fate.

The major HIV protein ‘Gag’ has both of these properties that cells sense in selecting exosomal cargoes. When the researchers removed the tethers or clumping signals from Gag it could no longer get out of the cell. However, if they were replaced with synthetic membrane anchors and clumping domains Gag regained its ability to get out of cells in exosomes.

Gould speculates that cells may have initially developed exosomes as a quality control mechanism to get rid of clumped proteins, which are generally broken and useless. However, just as retroviruses exploit other cell processes for their own ends, it now appear s they rely on exosomes to get out of infected cells and infect fresh cells. As such, drugs that interfere with exosome formation might be one way to inhibit HIV infections.

“Viruses like HIV use pathways we barely recognize, much less understand,” Gould says. “Our paper highlights the importance of studying their basic biochemistry and cell biology, which can yield a better understanding of normal human biology as well as identify new avenues in the fight against human disease.”


'"/>

Source:Johns Hopkins Medical Institutions


Related biology news :

1. Movie spies on malaria parasites sneaky behavior
2. Wisconsin scientists grow critical nerve cells
3. Spleen may be source of versatile stem cells
4. Researchers discover way to make cells in the eye sensitive to light
5. Priming embryonic stem cells to fulfill their promise
6. Lack of enzyme turns fat cells into fat burners
7. Poor prenatal nutrition permanently damages function of insulin-producing cells in the pancreas
8. Elusive HIV shape change revealed; Key clue to how virus infects cells
9. Mouse brain cells rapidly recover after Alzheimers plaques are cleared
10. Enzyme allows B cells to resist death, leading to leukemia
11. Scientists rid stem cell culture of key animal cells

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:2/24/2017)... , Feb. 24, 2017  EyeLock LLC, a leader ... its elite iris biometric solution on the latest ... LTE at Mobile World Congress 2017 (February ... Booth in Hall 3, Stand 3E10. ... Qualcomm Haven™ security platform—a combination of hardware, ...
(Date:2/14/2017)... N.C. , Feb. 14, 2017  Wake Forest ... M.D., as its new chief executive officer (CEO). Freischlag ... CEO John D. McConnell , M.D., who last ... position at the Medical Center, after leading it since ... the full scope of Wake Forest Baptist,s academic health ...
(Date:2/8/2017)... YORK , Feb. 8, 2017 About ... individual,s voice to match it against a stored ... such as pitch, cadence, and tone are compared ... require minimal hardware installation, as most PCs already ... for different transactions. Voice recognition biometrics are most ...
Breaking Biology News(10 mins):
(Date:3/20/2017)... ... 2017 , ... SSCI and Whitehouse Laboratories, divisions of Albany Molecular Research, Inc, ... by the Parenteral Drug Association (PDA), the New York Interphex Show will open on ... and more than 625 exhibitors, the educational and networking opportunities are extremely valuable. INTERPHEX ...
(Date:3/20/2017)... ... March 20, 2017 , ... ... biotech companies, recently announced it will debut a brand new pressure vessel, the ... intelliVessel is controlled by a touch screen panel and features other revolutionary operations ...
(Date:3/20/2017)... Yorba Linda, CA (PRWEB) , ... March 20, ... ... interference and require expensive and laborious sample preparation methods in order to reduce ... is often underappreciated outside of the area of elemental analysis. , This ...
(Date:3/20/2017)... , ... March 20, 2017 , ... The fourth annual ... while innovating to make an extraordinary impact on peoples’ lives, launches today. Sponsored by ... challenge every 5 weeks and awards thousands in cash prizes to engineers, inventors and ...
Breaking Biology Technology: