Antibody-based immunotherapy could treat HIV
Two teams of researchers supported by the National Institute of Allergy and Infectious Diseases worked with monkeys infected with simian human immunodeficiency virus, which can cause AIDS in monkeys. The researchers chose monoclonal antibodies targeting two different sites on SHIV and gave the monkeys one or two infusions of one or a combination of two or three antibodies.
After measuring changes in the monkeys' viral load and their immune response to SHIV, one team found the antibody infusions reduced the viral load to an undetectable level in 16 of 18 monkeys within just seven days. The antibody infusions kept the viral load low for a median of 56 days, when the infused antibodies were no longer present. The infusions appeared to improve the monkeys' control of the virus and reduced the presence of SHIV DNA in blood and tissues without generating resistance to the antibodies.
The other research team found that an infusion of a single antibody to four monkeys quickly reduced SHIV viral load to undetectable levels for four to seven days. The virus reappeared thereafter and strains in two of the animals were antibody-resistant. The team found that an infusion of two antibodies caused viral load to fall to undetectable levels within seven to 10 days and remain at that level for 18 to 36 days. A second infusion dropped viral load to undetectable levels for four to 28 days.
The antibody infusions for the second team were most effective in SHIV-infected monkeys for more than three years with no symptoms.
The authors of the two studies proposed testing antibody-based immunotherapy in humans infected with HIV to explore the possible role of antibody infusions in curing humans.
The studies were recently published in Nature.