http://www.sciencedaily.com/releases/2013/09/130919140621.htm

Disarming HIV With a Pop

Sep. 19, 2013 — Pinning down an effective way to combat the spread of the human immunodeficiency virus, the viral precursor to AIDS, has long been challenge task for scientists and physicians, because the virus is an elusive one that mutates frequently and, as a result, quickly becomes immune to medication. A team of Drexel University researchers is trying to get one step ahead of the virus with a microbicide they've created that can trick HIV into "popping" itself into oblivion.

Its name is DAVEI -- which stands for "Dual Action Virolytic Entry Inhibitor"- and it can pull a fast one on HIV. DAVEI was invented and tested by scientists from Drexel's College of Engineering; School of Biomedical Engineering, Science and Health Systems; and College of Medicine, and is the latest in a new generation of HIV treatments that function by specifically destroying the virus without harming healthy cells.

"While several molecules that destroy HIV have recently been announced, DAVEI is unique among them by virtue of its design, specificity and high potency," said Dr. Cameron Abrams, a professor in Drexel's College of Engineering and a primary investigator of the project.

A team co-led by Abrams and Dr. Irwin Chaiken in the Department of Biochemistry and Molecular Biology in Drexel's College of Medicine, and including Dr. Mark Contarino and doctoral students Arangassery Rosemary Bastian and R. V. Kalyana Sundaram, developed the chimeric recombinantly engineered protein -- that is, a molecule assembled from pieces of other molecules and engineered for a specific purpose, in this case to fight HIV. Their research will be published in the October edition of the American Society for Microbiology's Antimicrobial Agents and Chemotherapy.

The idea behind DAVEI was to design a molecule that hijacks the virus's fusion machinery, the tools it uses to attach to and attack a healthy cell, and trick the virus into destroying itself. HIV invades a healthy cell by first attaching via protein "spikes" that then collapse to pull viral and cell membranes together, fusing them and allowing the genetic contents of the virus to enter the healthy cell. The cell is rewired by the viral genetic material into producing more viruses instead of performing its normal function, which, in the case of cells infected by HIV, involves normal immunity. AIDS is the result.

"We hypothesized that an important role of the fusion machinery is to open the viral membrane when triggered, and it follows that a trigger didn't necessarily have to be a doomed cell," Abrams said. "So we envisioned particular ways the components of the viral fusion machinery work and designed a molecule that would trigger it prematurely," Abrams said.

They designed DAVEI from two main ingredients. One piece, called the Membrane Proximal External Region (MPER), is itself a small piece of the fusion machinery and interacts strongly with viral membranes. The other piece, called cyanovirin, binds to the sugar coating of the protein spike. Working together, the MPER and cyanovirin in DAVEI "tweak" the fusion machinery in a way that mimics the forces it feels when attached to a cell.

"For lack of a better term, DAVEI 'tricks' the virus into 'thinking' it is about to infect a healthy cell, when, in fact, there is nothing there for it to infect," Abrams said. "Instead, it releases its genetic payload harmlessly and dies." [...]

DAVEI is being developed as the active ingredient of a topical microbicide to block HIV transmission. Using it as a treatment will require substantial additional research.

According to UNAIDS, a member of the United Nations Development Group, 58 percent of people living with HIV/AIDS in sub-Saharan Africa are women. Although preventative drugs and condoms do block the transmission of HIV, neither are always practical, available or affordable in developing nations. Help could be on its way, however, in the form of an anti-HIV intravaginal ring that is worn continuously for up to 30 days.

http://www.gizmag.com/intravaginal-ring-could...nsmission-to-women/29263/

http://timesofindia.indiatimes.com/life-style.../articleshow/24695696.cms

Researchers have claimed that the amount of potentially active, dormant forms of HIV hiding in infected immune T cells may actually be 60-fold greater than previously thought. Just when some scientists were becoming more hopeful about finding a strategy to outwit HIV's ability to resist, evade and otherwise survive efforts to rid it from the body, another hurdle has emerged to foil their plans, new research from infectious disease experts at Johns Hopkins shows. [...]

Senior study investigator Robert Siliciano said his team's latest study findings pose a serious problem to prevailing hopes for the so-called "shock and kill" approach to curing HIV. That approach refers to forcing dormant pro-viruses to "turn back on," making them "visible" and vulnerable to the immune system's cytolytic "killer" T cells, and then eliminating every last infected cell from the body while anti-retroviral drugs prevent any new cells from becoming infected. Siliciano said this new discovery could boost support for alternative approaches to a cure, including renewed efforts to develop a therapeutic vaccine to stimulate immune system cells that attack and kill all HIV.

The study was published in journal Cell.

Merci beaucoup alged !
Cette foutue maladie a un sacré instinct de survie