London, Aug 11 : In a major step towards the fight against AIDS, scientists have developed an "adapter plug" molecule that transforms spare antibodies into HIV killers.
In this novel way to treat AIDS and other viruses, the molecule targets the antibodies, called anti-gal, which are naturally present in humans and constitute 1 percent of all antibodies in the blood.
The anti-gals help to fight Salmonella and Escherichia coli by binding to a sugar on the bacteria's surfaces. However, they fail when it comes to fighting a serious infection.
"Most of the time these antibodies don't do much, so we thought it would be useful if we could teach them to recognise HIV," the New Scientist quoted Anders Vahlne at the Karolinska Institute in Stockholm, Sweden, as saying.
The researchers created a molecule with one end having the sugar group recognised by anti-gal. And on the other hand, they attached a string of atoms that imitates part of a receptor, found on human immune cells, that binds to HIV.
The resultant molecule binds to anti-gal and HIV, and behaves like a kind of adapter plug for the antibodies, enabling their inherent cell-destroying machinery to kill HIV-infected cells.
"The antibodies block the interaction between virus and host cell, recruit molecules that will destroy infected cells, and alert killer cells that will eat them," said Vahlne.
The researchers added HIV viruses to human cells that had been primed with the adapter molecules and anti-gal antibodies and found that nearly 90 percent of the viruses failed to infect the cells.
While there was a need to test the adapters in HIV-infected mice, Rowena Johnston of AIDS research foundation amfAR said that the work demonstrates how "we might be able to use the innate immune system in a surprising and intriguing way."