Discovery of a novel, advanced technique to identify the rare cells where human immunodeficiency virus (HIV) hides in patients taking antiretroviral therapy (ART). This is an important step forward in the search for a HIV/AIDS cure.
Why wake up the virus? To better kill it, of course. A team from the University of Montreal Hospital Research Centre (CRCHUM) has taken an important step forward in the search for a HIV/AIDS cure. The laboratory of Dr. Daniel Kaufmann has developed a highly accurate technique for detecting the rare cells that hide the virus and prevent current therapies from curing HIV infection.
T cells from a HIV-infected patient were stained for HIV RNA (red), HIV protein (green) and the nucleus (blue) and analyzed by microscopy. This approach allows researchers to analyze very rare HIV-infected cells from humans in unprecedented detail. Credit: Dr. Daniel Kaufmann laboratory, CRCHUM.
"We can wake up the virus and then find the rare cells that have been hiding it at very low numbers, a limit of one cell in a million. This is an unprecedented level of accuracy, which opens the door to individualized monitoring of HIV-positive patients and could facilitate the development of personalized treatments," said Dr. Kaufmann, senior author of a study on the subject published in a featured article in the current issue of Cell Host & Microbe.
HIV reservoirs are cells and tissues in which the virus persists despite ART. The virus predominantly lives and replicates in a particular type of white blood cell, CD4+ T lymphocytes. While antiretroviral drugs are generally successful in controlling the viral load in infected individuals, preventing the progression to acquired immunodeficiency syndrome (AIDS), some viruses remain hidden for years and can be reactivated if patients stop their treatment.
"CD4+ T lymphocyte populations are highly variable. To develop new, targeted treatments to eliminate these residual infected cells, we need to find exactly where in the CD4 T lymphocyte population the virus hides. Our research has uncovered these HIV hiding places. We were able to identify and quantify the cells containing hidden virus and then test drugs to wake up HIV,” said Kaufmann, who is a researcher and infectious disease specialist at the University of Montreal Hospital Centre (CHUM).
His team has developed an innovative technique for detecting these reservoirs – a way of taking a “photo” of each individual cell hiding the virus – a significant breakthrough, as this approach is 1,000 times more accurate than current technologies. Once the HIV hiding places are found, the researchers can use a “shock and kill” strategy to eliminate the virus in two stages. Firstly, the HIV must be woken up from its dormant state in the cells. The virus then becomes visible to the immune system or drugs that can eliminate it.
Professor Kaufmann’s team analyzed the blood of 30 patients infected with HIV, both before patients started treatment and after they received ART. “We were able to detect the virus in CD4+ T lymphocytes in almost all of the patients we analyzed,” said Amy Baxter, a postdoctoral fellow at the CRCHUM and first author of the study.
The researchers then tested two so-called latency reversal drugs: bryostatin and a derivative of ingenol. These drugs were developed to fight cancer, but might also be used against HIV. "While our studies were conducted in the laboratory, a clinical trial would involve using such drugs to wake up the virus while the patient continues taking ART to ensure that the reactivated virus can not infect other cells,” explained Dr. Kaufmann.
“In the laboratory we found that the two drugs wake up different populations of CD4+ T lymphocytes, thus waking up different reservoirs. The ingenol derivative activates a population called central memory cells. These cells can live for years in patients, all the while hiding the virus. Therefore, it is particularly important to target these reservoirs,” noted Baxter.
At first sight it appears as though the virus hides in similar places in different patients. However, Dr. Kaufmann’s team has revealed that there is also large variability from one patient to another. “We may have to adjust the treatment for individual patients, depending on the specific HIV hiding places in each case. To minimize the virus pools, we will have to assess patients and tailor the “shock and kill” therapies to their profiles,” said Dr. Kaufmann.
Before arriving at a potential treatment for humans, the researchers are planning to evaluate the effectiveness of new drugs to awaken similar virus reservoirs in monkeys and determine where the virus is hidden. If the drugs are well tolerated, clinical trials will begin in a few years. After 30 years of research to cure HIV infection and AIDS, this opens a whole new avenue in understanding how scientists could track and find infected cells, then wake up and kill the virus hiding deep inside.
Full bibliographic information
“Single-cell characterization of viral translation-competent reservoirs in HIV-infected individuals.", Amy E. Baxter, Julia Niessl, Rémi Fromentin, Jonathan Richard, Filippos Porichis, Roxanne Charlebois, Marta Massanella, Nathalie Brassard, Nirmin Alsahafi, Gloria-Gabrielle Delgado, Jean-Pierre Routy, Bruce D. Walker, Andrés Finzi, Nicolas Chomont, Daniel E. Kaufmann,
Cell Host & Microbe, September 14, 2016.
About the study
The study “Single-cell characterization of viral translation-competent reservoirs in HIV-infected individuals" was highlighted as a featured article of the September 14, 2016 edition of Cell Host & Microbe. Dr. Daniel Kaufmann (CRCHUM & University of Montreal) and Amy Baxter (CRCHUM & University of Montreal) are senior author and first author of the study, respectively. The study was funded primarily by the National Institutes of Health, the Canadian Institutes of Health Research (CIHR) (Grant #137694), the Canada Foundation for Innovation, and the Réseau sida et maladies infectieuses du Fonds de recherche du Québec – Santé (FRQS).
For more information, see the study: www.sciencedirect.com/science/article/pii/S1931312816303146
Cell Host & Microbre editorial:
Source: University of Montreal Hospital Research Centre (CRCHUM).
Julie Gazaille | AlphaGalileo
Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory
How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy