US researchers develop new approach to improve HIV vaccine effectiveness

Researchers from the University of Nebraska-Lincoln in the US have developed a new approach that could improve the safety and effectiveness of a potential vaccine for the HIV virus.

The researchers have engineered an on / off switch into a weakened form of HIV, which brings them a step closer to a HIV vaccine.

As part of a recent study, it was demonstrated that flipping the switch allows weakened HIV to replicate at a level that is expected to generate immunity in a host.

Later on, the researchers used their approach to switch off the replication at will.

The team started addressing the issue in 2014, when it genetically engineered a version of HIV that needs a synthetic amino acid to replicate.

During this process, they replaced a three-nucleotide sequence, or sense codon in HIV’s genetic code.

Each codon instructs the transfer-RNA to add its corresponding amino acid to a chain that becomes a protein and allows viral replication.

"The researchers have engineered an on / off switch into a weakened form of HIV, which brings them a step closer to a HIV vaccine."

University of Nebraska-Lincoln biological sciences professor Qingsheng Li said that the team’s combination of a 'nonsense' codon, genetic switch and synthetic amino acid represents a set of safeguards against unchecked replication.

That quality could expand its use against an array of viruses far removed from HIV, he added.

With the addition of more nonsense codons, the likelihood of a dangerous mutation would be reduced.

The project received support from the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, under grant 1R01AI111862.