Antibody therapy can suppress HIV infections

Human immunodeficiency virus (HIV) is a retrovirus capable of infecting vital organs and CD4 cells, a type of lymphocyte, that comprise the human immune system. Once transmitted, the virus grows and progresses in the absence of antiretroviral therapy (ART), which is a drug therapy that either prevents HIV infection or slows down the spread of the virus. These antiretrovirals include several types of inhibitors. 

Among the more common subgroups of antiretrovirals are protease inhibitors, which inhibit the action of protease that aids in replicating HIV. Integrase inhibitors prevent the ability of the integrase enzyme to infect T cells with HIV. Nucleoside/nucleotide (NRTIs) and non-nucleoside (NNRTIs) reverse transcriptase inhibitors work to interfere with HIV as it replicates. Entry inhibitors block HIV from entering T cells.

Antiretroviral drugs are currently an indispensable part of treatment for HIV infections; however, they are usually administered in combinations due to the quick development of viral resistance against singular agents. Though these drugs are effective in their inhibition of viral replication, they typically require daily and life-long dosages.

Now a generation of broadly neutralizing antibodies provides a new and perhaps improved approach to treating HIV infection. 

The research behind this conclusion comes from a team of scientists led by Florian Klein, the director of the Institute of Virology at the University Hospital Cologne and a scientist at the German Center for Infection Research (DZIF). 

The study was a collaboration with scientists at the Rockefeller University in New York for the purpose of observing the impact of broadly neutralizing antibodies on HIV-infected patients.

This class of antibodies has longer half-lives than antiretroviral drugs and the ability to directly target the virus of interest. Previously conducted clinical trials by the University Hospital Cologne featured two variations of these antibodies — 3BNC117 and 10-1074 — which produced considerable reductions of the viral load. 

Nevertheless, the separate administration of these two antibodies ended with transient effects and had associations with viral resistance development. These two factors are comparable to the outcome of using the antiretroviral drugs.

In the study led by Klein, researchers administered the 3BNC117 and 10-1074 antibodies in combination to a group of 30 HIV-infected participants. They gave the mixture up to three times per person, and those who had not been taking antiretroviral drugs at the start of the trial experienced significant reductions in the levels of viral load. 

Within another group, participants who were undergoing antiretroviral drug treatment paused the treatment for this antibody trial. After administration of the final dosage of antibody combination, researchers detected no viruses for an extended period of time, even though such an interruption usually leads to a rapid reversal of HIV to the blood. 

Dr. Henning Grüll, co-first author of the publication and resident physician at the Institute of Virology at the University Hospital Cologne talked about the study results in a press release.

“The results of this clinical trial highlight the potential for antibody combinations to maintain long-term control of HIV,” Henning said.

In the same press release, Klein commented on the collaborative nature of the study.

“The success of these studies at the University Hospital Cologne is also a result of the close collaboration with the Infectious Diseases Research Group and the Infectious Diseases Outpatient Clinic. We are delighted that we were again able to safely and rapidly translate findings from basic research into clinical application.”

Although research on the topic is still ongoing at the DZIF site in Cologne, the results of the study up to this point indicate a positive conclusion. There might be additional promising results in the near future that provide a solution for those suffering from HIV, since current trials already hint at the possibility of long-term control of the HIV virus without the need for daily medication.