Scientists looking for an HIV cure are finally one step closer. Researchers from the University of North Carolina at Chapel Hill studied the safety of a cell therapy involving expanding T cells and infusing them into HIV-infected individuals who had previously been treated with antiretroviral therapy (ART).

Preliminary results from a phase 1 clinical trial have now come through and show that the HIV immunotherapy drug is safe and tolerable for humans. "This study is focused on finding a way to re-educate the body's immune system to better fight HIV infection," said co-senior study author David Margolis of the University of North Carolina (UNC) at Chapel Hill."

Retooling ART

Since its use in HIV treatments, ART has managed to lengthen the lives of those suffering from HIV. However, ART isn't a cure. The virus will continue in a latent reservoir that's hidden from the body's immune system, researchers noted.

Previous research using pharmacological HIV-latency-reversal agents to induce the latent virus to express the viral protein managed to make it vulnerable to T cells. However, those existing HIV-specific responses in ART-treated patients aren't enough to clear up the existing HIV infection.

The researchers discovered harnessing T cell responses can be done using adoptive cellular therapy. This means T cells are taken from a patient, growing a lab to grow their numbers, and then given back to the patient to help their immune systems fight the disease.

"We found that this approach of re-educating the immune cells and reinfusing them was safe, which was the primary goal of the study," Margolis continued. "The data from this trial will continue to help us design improved immunotherapies against HIV."

Next steps in a cure for HIV

The researchers from UNC discovered that T cells generated by this new adoptive T-cell therapy strategy have been both well tolerated and highly effective.

"Before we can combine this approach with treatments meant to bring HIV out from hiding so the improved immune response can clear it from the body, we need to first establish that this immunotherapy approach is safe on its own," said co-senior study author Catherine Bollard of the Children's National Health System. "We have long-standing experience treating patients with virus-specific T cells targeting latent viruses such as Epstein-Barr virus and cytomegalovirus. Therefore, we were extremely excited to work with the UNC team to adapt this virus-specific T-cell-therapy approach to the HIV setting."

The UNC team noted that while the therapy didn't reverse the size of the latent reservoir, it didn't facilitate growth. In short, the new therapy also makes the body's immune system more prepared to respond.

"This is a promising advancement for the field," said first author Julia Sung of UNC. However, she cautioned people against over-interpreting the results.

"The study did not cure HIV and should not be interpreted as doing so, but we also are very encouraged by the safety data, so it should not be considered discouraging either," Sung explained. "This paves the way for the next step, which is to combine this immunotherapy approach with latency-reversal therapy in order to wake up the HIV out of its latent state, where it is invisible to the immune system, then clear it out with the immunotherapy."

The study was published in full in the September 21 edition of the journal Molecular Therapy.