HIV-killing cell discovery opens door for immunotherapy to be turned on the virus

A SECRET hidden in the immune cells of rare HIV-protected individuals has been unlocked by Melbourne scientists, opening the possibility of immunotherapies to overcome the virus.

A BREAKTHROUGH by Melbourne scientists has opened the possibility of using immunotherapy drugs to treat HIV in the same way the treatments are overcoming cancer.

After finding a set of receptors on immune cells capable of killing HIV, a Monash University team is now hoping to engineer a new class of drugs to supercharge people’s immune systems to fight the virus.

While antiretroviral treatments mean HIV is now largely non-fatal, no treatment has yet been discovered to eradicate the virus, which kills more than one million people around the world each year.

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An illustration of the deadly HIV virus surrounding and attacking a host cell.

But after studying samples from “super controllers” — a group of 15 HIV-positive people whose immune systems inexplicably protect them from progressing to AIDS — the Melbourne team and colleagues from Pasteur Institute in Paris may be one step closer.

Although immune cells drastically drop in number when a typical person becomes infected with HIV, the Monash team revealed super controllers retain their CD4 T cells so their bodies to detect and fight the virus.

Using the Australian Synchrotron, lead researcher Stephanie Gras and her team transferred immune receptors from the controllers to bind them with molecules common to other patients — a move that may allow the supercharged immune cells to be tolerated by more than a quarter of the world’s population.

Using the powerful Australian Synchrotron lead researcher Assoc Prof Stephanie Gras and her team were able to transfer immune receptors from the controllers and bind them with molecules common to other patients — a move that may allow the supercharged immune cells to be tolerated by more than a quarter of the world’s population.

“It is still really early on but, now that we have found them and understand how they work … the next step for us is to do the same thing in small animals to see if we can suppress the virus in vivo as well,” she said.

“In cancer therapy you can transfer T-cells back to individuals, and this is designing the same type of therapy.

“It is already successful in cancer and T-cells are really good at recognising viruses and infections for us it is a nice target for HIV therapy as well.”

Rather than targeting the disease itself, the latest groundbreaking cancer treatments know as immunotherapy are used to convince the immune system to attack the foreign cells.

Results published today (SAT) in the journal Science Immunology reveal the HIV-killer immune cells are able to detect even the smallest levels of the virus, which opens the possibility of them becoming an effective HIV immunotherapy even when a patient was on antiretroviral treatments, Assoc Prof Gras said.

“Because those receptors were responding in controllers, and because they can recognise low quantity of the virus, they would be able to detect even hiding infection and try to kill what is left,” she said.

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