New Canadian study reveals where HIV hides in different parts of the body
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A new study, co-led by Western University’s Stephen Barr, reveals that HIV cloaks itself in the DNA of infected cells using unique DNA patterns in the brain, blood and parts of the digestive tract.
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New Canadian study reveals where HIV hides in different parts of the body
Researchers at Western University and the University of Calgary have discovered how HIV hides in different parts of the body by embedding itself into the DNA of cells in a tissue-specific manner, offering new insights into why the virus is so difficult to eliminate and cure – even decades after infection and treatment.
The study, led by Western University’s Stephen Barr and UCalgary’s Guido van Marle, reveals that HIV cloaks itself in the DNA of infected cells using unique DNA patterns in the brain, blood and parts of the digestive tract. For example, in the brain, the virus avoids genes and hides in less active parts of the DNA.
The findings were published by the high impact journal Communications Medicine.
“We found that HIV doesn’t integrate randomly. Instead, it follows unique patterns in different tissues, possibly shaped by the local environment and immune responses,” said Barr, microbiology and immunology professor at Western’s Schulich School of Medicine & Dentistry. “This helps explain how HIV manages to persist in the body for decades, and why certain tissues may act as reservoirs of infection.”
For the study, Barr, van Marle and their collaborators at the Southern Alberta HIV Clinic and University of Alberta used rare tissue samples from people living with the virus during the early years of the HIV/AIDS pandemic (around 1993), before modern treatment existed. This gave the researchers a unique opportunity to look at how the virus behaved in its natural state across different organs – all within the same individuals.
“Our study is a powerful example of how we can learn from historic samples to better understand a virus that continues to affect tens of millions of people worldwide,” said Barr.
The research team acknowledges the individuals who volunteered to participate in studies during the early, uncertain days of the HIV/AIDS pandemic.
“Their willingness to contribute samples, at a time of stigma, fear and with limited treatment options, was an act of bravery, foresight and generosity that continues to advance scientific understanding of HIV and save lives today,” said van Marle, microbiology, immunology and infectious diseases professor at UCalgary’s Cumming School of Medicine.
New targeted attack
For this novel Canadian approach to understanding HIV, the researchers investigated historic samples taken from the esophagus, blood, stomach, small intestine and colon of individuals with unmatched brain tissue from other individuals. They evaluated how often the virus integrated into specific regions of the genome and compared these patterns across various tissues from different individuals.
“Knowing where the virus hides in our genomes will help us identify ways to target those cells and tissues with targeted therapeutic approaches – either by eliminating these cells or ‘silencing’ the virus,” said van Marle.
The research was supported by the Canadian Institutes of Health Research and the National Health Research and Development Program and builds on years of collaborative work between Western, UCalgary, the Southern Alberta HIV Clinic and UAlberta.
“Studies like this are highly collaborative and only possible when many of us work together,” said Barr.
Journal
Communications Medicine
Method of Research
Experimental study
Subject of Research
People
Article Title
Early pandemic HIV-1 integration site preferences differ across anatomical sites
Article Publication Date
6-Oct-2025
Antibody discovered that blocks almost all known HIV variants in neutralization assays
University of Cologne
An international research team led by the University of Cologne has discovered an antibody that could advance the fight against HIV. The newly identified antibody 04_A06 proved to be particularly effective in laboratory tests. It was able to neutralize 98.5 percent of more than 300 different HIV strains, making it one of the broadest antibodies against HIV identified. In experiments with humanized mice – animals whose immune system has been modified to resemble that of humans – 04_A06 permanently reduced the HIV viral load to undetectable levels. Most other HIV antibodies, in contrast, only achieve short-term effects in this animal model, as resistance develops quickly. The study ‘Profiling of HIV-1 elite neutralizer cohort reveals a CD4bs bNAb for HIV-1 prevention and therapy’ was published in Nature Immunology.
Antibodies are protein molecules of the immune system that specifically attack pathogens. Identifying an effective HIV antibody is a known challenge, given that the virus is constantly changing. As a result, many antibodies can only block certain variants of the virus. For the current study, the researchers examined blood samples from people referred to as ‘elite neutralizers’, whose immune system fights the virus with particular effectiveness. The researchers produced more than 800 antibodies from over 5,000 individual so-called B lymphocytes and tested their effectiveness. One stood out: antibody 04_A06 surpassed all others in terms of potency and breadth as determined by neutralization assays.
“With 04_A06, we have discovered an antibody that not only has an exceptionally broad activity, but also overcomes the virus’s typical resistance mechanisms. This could open up a promising approach for future clinical applications of antibodies against HIV,” says Dr Lutz Gieselmann, physician scientist at the Institute of Virology and first author of the study.
An important special feature of 04_A06 was revealed when analysing its structure. The antibody has an unusually long amino acid chain that reaches areas of the viral target that are often difficult to access. These areas are highly conserved and likely difficult for the virus to change without losing the ability to function. This may explain why 04_A06 maintains its antiviral properties against CD4bs viral escape variants, which otherwise lead to a loss of function of other antibodies.
In addition to the laboratory tests, the researchers used computer models to assess the prevention efficacy of 04_A06. The models predicted that a single administration of 04_A06 could offer over 93 percent protection in clinical applications.
Altogether, the antiviral properties of 04_A06 suggest its use as a promising approach for both treating people living with HIV and preventing infection in those at increased risk. The antibody 04_A06 has been exclusively licensed to Vir Biotechnology, Inc.
Professor Dr Florian Klein, director of the Institute of Virology at University Hospital Cologne and leader of the study, emphasizes the value of the international collaboration: “The success of this work relied on close collaboration with study centres in Africa, Nepal, and the USA. The next step is to further test the antibody’s safety and efficacy in clinical trials, thus paving its way to patient care.”
The study was supported by the Gates Foundation in furtherance of its charitable purposes, the German Research Foundation (DFG), the German Center for Infection Research (DZIF) and the European Research Council (ERC).
Journal
Nature Immunology
Method of Research
Experimental study
Subject of Research
Cells
Article Title
Profiling of HIV-1 elite neutralizer cohort reveals a CD4bs bNAb for HIV-1 prevention and therapy
Article Publication Date
6-Oct-2025
