The La Jolla Institute for Immunology and Scripps Research team developed the vaccine, now in human trials, to train immune cells to see past HIV’s defenses.
A new HIV vaccine developed by La Jolla Institute for Immunology and Scripps Research scientists and the International AIDS Vaccine Initiative is the first to generate a high number of “broadly neutralizing,” virus-fighting antibodies in primates.
The results, published June 30 in Nature, are the culmination of 14 years of collaboration between the La Jolla researchers, part of the Scripps Consortium for HIV/AIDS Vaccine Development, with co-leader and LJI chief scientific officer Shane Crotty calling the project a “huge success.”
“We constructed a successful vaccine from the ground up,” he said in a press release.
The vaccine, now in human trials, works by intervening in a process called B cell maturation. B cells make antibodies, after an early “naive” stage.
B cells start to mature once they get the signal that a pathogen, such as a virus, is trying to attack. B cells “see” pieces of that pathogen’s molecular structure and start producing antibodies to bind to that structure and halt infection.
HIV doesn’t give B cells a chance to develop effective antibodies, as HIV first disguises itself from the immune system and then mutates quickly, changing its shape upon infection and eluding B cell detection.
The La Jolla team, co-led by Scripps Research Professor William Schief, PhD, hunted for rare, “broadly neutralizing” antibodies that can actually bind to HIV and recognize key viral structures and then looked at the B cell maturation process to train B cells to recognize HIV response early.
With rare molecular engineering, the Schief Lab developed vaccine molecules that resembled the real HIV antigens; the scientists then worked with Emory National Primate Research Center to test this potential HIV vaccine in a non-human primate species called rhesus macaques.
The scientists found that around 44 percent of the animals went on to produce an abundance of broadly neutralizing antibodies against HIV in their blood.
“We succeeded in taking ultra-rare antibody responses and turning them into common responses by the end of the vaccination process,” Crotty said.
The team didn’t test whether these antibodies could prevent infection, but it’s significant that these antibodies could be found in the blood, where they could encounter and potentially block HIV.
“We believe this vaccine approach is even more likely to succeed in humans,” Crotty said.
