Engineered stem cells may be key to fighting HIV, notes study

A recently published preliminary study involving primates has revealed that a form of engineered stem cell-derived chimeric antigen receptor (CAR) T-cells may be useful in the long-term suppression of HIV.

The study, performed by researchers based in the US, involved haematopoietic stem/progenitor cells (HSPCs) — which produce T cells as well as other blood cells. Once these had been genetically engineered all T-cells produced featured a protective CAR (CD4) that redirected the cells towards the HIV infection.

The primates in the study containing these modified T-cells were found to have less viral rebound post combination antiretroviral therapy (cART) and the cells lasted for more than two years without any measurable toxicity to the subject. This indicates that the CD4 protected T-cells have the potential for long-term binding allowing an immune memory-like response.

“The demonstration here that stem cells can be engineered to respond to AIDS virus-infected cells in an animal model is an impressive first step for harnessing the immune system to target HIV,” said Dr Bruce Walker, director of the Ragon Institute of MGH, MIT, and Harvard, when speaking about the study to STAT (he was not involved in the study group). “The effect at this point is modest, but clearly gives us something to build on.”

Furthermore, the team found the CAR-expressing cells in multiple lymphoid tissues, which are areas where viral replication occurs in non-treated disease.

The major advantage of engineering stem cells that creates T-cells (rather than the T-cells themselves) is that an unlimited number of T-cells that can attack the virus can be produced. This may be the vital factor to how this form of therapy can work effectively to treat and potentially eradicate HIV, although as the researchers noted more work is required.