Researchers at the University Hospital Cologne have identified a broadly effective antibody against HIV. It can neutralize a wide range of HIV variants in laboratory experiments, suggesting potential to prevent infection in HIV-negative individuals. The study results were published Monday in the journal Nature Immunology.The Cologne team, led by virology professor Florian Klein, studied blood sera from 32 so-called HIV elite neutralizers from Germany, Cameroon, Nepal, and Tanzania. These are people living with HIV who can develop a pa...
Researchers at the University Hospital Cologne have identified a broadly effective antibody against HIV. It can neutralize a wide range of HIV variants in laboratory experiments, suggesting potential to prevent infection in HIV-negative individuals. The study results were published Monday in the journal Nature Immunology.
The Cologne team, led by virology professor Florian Klein, studied blood sera from 32 so-called HIV elite neutralizers from Germany, Cameroon, Nepal, and Tanzania. These are people living with HIV who can develop a particularly strong and broadly acting antibody response. From their blood, they extracted 831 different monoclonal antibodies and tested them in lab experiments for their ability to neutralize a variety of artificially produced HIV variants. Monoclonal antibodies come from a single white blood cell and can be readily produced in the lab.
Antibody 04_A06 blocks HIV
The antibody named 04_A06 stood out in particular. It blocks the HIV virus’s CD4-binding site very efficiently — meaning the virus cannot enter the body. Moreover, the antibody was not susceptible to known mutations that HIV uses to circumvent the blockade. In experiments with mice infected with HIV, administration of 04_A06 completely suppressed the virus. According to the study, the antibody has a 93-percent chance of preventing HIV infection if given prophylactically three times within a 24-week window, i.e., before infection.
According to the authors, 04_A06 offers promising possibilities for effective treatment and prevention of HIV-1 infections. Despite decades of research, there is still no vaccine that protects against HIV infection. Antibodies could provide a form of passive immunization, as is already done with PrEP. Another example of passive immunization is Lenacapavir, which has recently been approved in Europe and does not need to be taken daily, but only twice a year.
In a Phase I clinical study, an American research team already tested a combination of three antibodies as a prevention strategy. Based on modeling data, the authors of the current study believe that a single dose of 04_A06 could achieve prevention efficacy comparable to that three-antibody combination. However, the results of future clinical trials will have to show whether this holds true. The University of Cologne has already filed a patent covering aspects of this research.
Results “promising”
The study’s results have been described as “promising” by other researchers. However, there is still a long way to go before potential clinical use, infectious disease specialist Christoph Spinner of the Technical University of Munich told the Science Media Center.
Alexandra Trkola, director of the Institute of Medical Virology at the University of Zurich, is even hopeful for a cure. She notes that neutralizing antibodies must be “simultaneously broadly active and highly potent.” Trkola says that 04_A06 meets these criteria better than any other candidate so far. To date, a cure has only been achieved in rare cases through stem cell transplantation (TheColu.mn reported).