Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Scientists find HIV-blocking protein in monkeys


Organization of the HIV-1 Virion
Credit NIAID

Scientists at the Dana-Farber Cancer Institute have identified a protein that blocks HIV replication in monkey cells. Humans have a similar protein, although it is not as effective at stopping HIV, say the researchers whose work is published in this week’s issue of Nature. The team, headed by Joseph Sodroski, M.D., is supported by the NIH’s National Institute of Allergy and Infectious Diseases (NIAID).

"Identification of this HIV-blocking factor opens new avenues for intervening in the early stage of HIV infection, before the virus can gain a toehold," says NIAID Director Anthony S. Fauci, M.D. "The discovery also gives us critical insights about viral uncoating, a little understood step in the viral lifecycle. Basic discoveries like this provide the scientific springboard to future improvements in therapies for HIV disease."

"Over the years," notes Dr. Sodroski, "we’ve learned quite a bit about how HIV enters cells. More recently, we’ve developed a picture of the late stages of the viral lifecycle, as it leaves the cell. However, the steps between virus entry and conversion of the viral RNA into DNA have been a black box." A key preparatory step is the removal, or uncoating, of the protective shell surrounding HIV’s genetic material. This coat, called the capsid, must be removed before HIV can insert its genetic material into the host cell’s DNA and begin to make copies of itself. (See for a simplified diagram of HIV, including the capsid.)

The discovery of this host protein helps pry open the black box of uncoating. Called TRIM5-alpha, it is the first found to specifically target HIV’s capsid. With the identification of a specific protein that powerfully inhibits viral uncoating, says Dr. Sodroski, comes the possibility of manipulating and enhancing its activity. For example, he notes, humans have a version of TRIM5-alpha. While it is not as efficient as the simian version, it does have some HIV-blocking ability. "Perhaps this protein could be induced to greater activity, thereby increasing the level of resistance to HIV infection," says Dr. Sodroski.

The discovery could also shorten the path to an AIDS vaccine by making improved animal models of HIV disease possible. Because monkeys are not susceptible to the human version of AIDS, results of vaccine trials conducted on them are not directly applicable to humans. Now with a better understanding of why HIV cannot successfully infect monkey cells, scientists have a defined target to manipulate and could use that information to develop animal models that more closely mimic HIV disease.

Matthew Stremlau, Ph.D., a member of Dr. Sodroski’s team and lead author on the new paper, searched the rhesus monkey genome and isolated a stretch of DNA that encodes the TRIM5-alpha protein. In a series of experiments using lab-grown cells that either possessed or lacked TRIM5-alpha, the scientists determined that TRIM5-alpha is both necessary and sufficient to block HIV replication. Although the precise mechanism of TRIM5-alpha’s activity is not fully determined, says Dr. Sodroski, it may be that the protein chops up HIV’s capsid and thwarts the orderly uncoating the virus must undergo before proceeding to replicate.

"This is a very exciting finding," says NIAID’s Nabila Wassef, Ph.D., a program officer in NIAID’s Division of AIDS. "TRIM5-alpha strikes at the heart of HIV, preventing it from becoming an established infection. As we know, HIV disease can be treated, but not cured. In part this is due to the ability of HIV to take up permanent residence in the body. If we could find a way to disable the virus before it has a chance to replicate, this problem of latent infection would be eliminated."

NIAID is a component of the National Institutes of Health (NIH), an agency of the U.S. Department of Health and Human Services. NIAID supports basic and applied research to prevent, diagnose and treat infectious diseases such as HIV/AIDS and other sexually transmitted infections, influenza, tuberculosis, malaria and illness from potential agents of bioterrorism. NIAID also supports research on transplantation and immune-related illnesses, including autoimmune disorders, asthma and allergies.

Reference: M Stremlau et al. The cytoplasmic body component TRIM5-á restricts HIV-1 infection in Old World monkeys. Nature 427:848-53 (2004).

Press releases, fact sheets and other NIAID-related materials are available on the NIAID Web site at

Anne A. Oplinger | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht North and South Cooperation to Combat Tuberculosis
22.03.2018 | Universität Zürich

nachricht Researchers Discover New Anti-Cancer Protein
22.03.2018 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Modular safety concept increases flexibility in plant conversion

22.03.2018 | Trade Fair News

New interactive map shows climate change everywhere in world

22.03.2018 | Earth Sciences

New technologies and computing power to help strengthen population data

22.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>