Study: Mass produced antibodies quickly kill HIV in monkeys

PORTLAND, Ore. » Human antibodies that were mass produced in a lab have eliminated HIV from newborn monkeys, a new study showed.

Researchers at Oregon Health & Science University were stunned by the results, published in Nature Medicine. Not only did the antibodies work in each instance to eliminate the virus that causes AIDS, the therapy was also quick, clearing the virus from the body within two weeks.

“We’re very excited about this study because we think it opens some doors for alternative therapies that could be used to prevent infection in babies and children,” said Nancy Haigwood, the lead investigator and head of the OHSU primate center.

This is the first time human antibodies have been used in this way, Haigwood said. Researchers have also tried administering antiretroviral drugs to attack a new infection, but those experiments have failed, she said. Antiretroviral drugs are given to pregnant women who are HIV positive to prevent them from transmitting the virus to their babies, but the drugs are expensive and not widely available in parts of the world where HIV is rampant.

Haigwood said the trial of antibody therapy, which was tested in rhesus macaques, was so successful that the approach could be tried in humans in South Africa or elsewhere where the mother-to-child transmission rate of HIV is high.

More than 200,000 children were born with HIV worldwide in 2013, according to the United Nations children’s organization, UNICEF. Without therapy, one-third of infected newborns die by their first birthday. Half don’t make it to their second, the agency said.

This therapy could change that. It could also be effective in newly infected adults, Haigwood said.

To do the study, investigators had to create a virus that was part human immunodeficiency virus and part simian immunodeficiency virus, the HIV equivalent that infects monkeys. Monkeys are not susceptible to HIV so researchers needed a hybrid that resembled the human virus enough to allow the antibodies to attack but would also take hold in monkeys, replicating like HIV does in humans.

The monkeys were infected orally when they were born, just as human babies become infected during the birth process by swallowing infected secretions from the mother. A day later, they were given the antibodies. Those originally came from humans. People who become infected with HIV produce them, but they’re not effective in eliminating an infection that’s taken hold because HIV multiplies so rapidly and escapes attacks by the immune system.

The antibodies can be cloned en masse in a lab.

After the first dose, the antibodies were administered on the fourth, seventh and 10th days. By the two-week mark, the virus was gone and never returned.

“It was 100 percent effective,” Haigwood said.

Past research has indicated that HIV takes three to seven days for the virus to spread. But Haigwood and her team discovered that the virus was in multiple tissues within 24 hours.

“It was must faster than we expected,” she said. “It’s very thorough in its ability to infect all parts of the tissue and the blood.”

The antibodies remain stable so they could be shipped around the world and stored, and they’re better than antiretroviral drugs because they’re not toxic. Drugs inevitably come with side effects, but the antibodies are produced by the human body. Haigwood said they might be used to not only wipe out an infection but allow a newborn to breastfeed, another mode of transmission.

Trials in humans testing the safety of antibody therapy to fight HIV are now underway in Africa and the United States. That’s a first step toward an efficacy trial.

At OHSU, Haigwood’s team will be carrying the experiment forward, looking at the use of different antibodies, administering them later, combining them with drug treatment and lowering the dose.

That’s enough to occupy the researchers for a few years, Haigwood said.