A ‘kick and kill’ strategy that forces the human immunodeficiency virus out of cells — leaving it vulnerable to injections of natural killer cells — offers hope of an HIV cure.
The University of California Los Angeles team reported that in laboratory testing on 10 mice, the treatment eliminated the virus from 40% of them.
The UN estimates that 38 million people are currently living with HIV in the world. In recent years, the virus has caused 36 million deaths.
If refined and proven safe and effective in human trials, the concept could remove the need for people with HIV to depend on ongoing courses of antiretroviral drugs.
A ‘kick and kill’ strategy that forces the human immunodeficiency virus (pictured) out of cells — thereby making it vulnerable to existing antivirals — offers hope of an HIV cure
Jocelyn Kim, an infectious disease specialist at UCLA, and her collaborators conducted the study.
“These findings demonstrate proof-of concept for a therapeutic approach to possibly eliminating HIV from your body, which was a daunting task for many years,” said Dr Kim.
“The study offers a paradigm shift in HIV treatment.”
At present, people with HIV take so-called antiretroviral medications which, rather than killing the virus, act to inhibit it at various stages in its ‘life cycle’ — such as, for example, when it enters a host cell or when it churns out new copies of itself.
This can reduce the viral load of the host to the point that it is undetectable or untransmissible. However, HIV may still be present in the system hiding in CD4+ cells which coordinate immune responses.
When people with HIV stop taking their antiretroviral treatment, the virus can escape from these boltholes and carry on replicating itself in the body — weakening the immune system and increasing the risk from potentially fatal cancers and infections.
The team’s strategy — which they have dubbed ‘kick and kill’, and was first proposed back in 2017 — works by tricking the dormant virus in the infected cells to reveal itself using a compound called ‘SUW133’, so that it can be targeted and eliminated.
The experts previously found that HIV-infected mice with altered immune systems were more likely to die from treatment than normal.
The researchers looked for an effective method to kill the infected cells and instead turned to natural killer cells. These cells are part of the immune system, so they can be used to destroy tumour or infected cells.
By injecting healthy natural killer cells along with the SUW133 that flushes HIV out of hiding, the team were able to completely clear HIV from 4 out of 10 infected mice.
The researchers were careful to analyse the mice’s spleens in particular, as this organ is known to harbour immune cells like the CD4+ T cells in which HIV can lie dormant.
After completing their initial research, researchers now work to improve their methods so they can eliminate HIV from all mouse cohorts.
Dr Kim stated that the research will be moved to preclinical studies with non-human primates, in order to eventually test the same method in humans.
Nature Communications published the full results of this study.