A study in monkeys, published online in Nature, demonstrates that T cells can be commandeered to provide protection against an HIV-like virus. Although this vaccine will never be used in humans, the findings show that in principle a vaccine could be effective in the fight against AIDS.
Dan Barouch and colleagues engineered the virus responsible for the common cold to carry a single protein from simian immunodeficiency virus (SIV), the monkey equivalent of HIV. Unlike other vaccine approaches, the monkeys were given booster shots with a vaccine made from a different strain of cold virus, to spark a robust immune reaction against the SIV protein. When challenged with a lethal dose of SIV, the vaccinated animals were able to fight off the development of AIDS and remain healthy for over a year after infection. The team find that this is due, at least in part, to the powerful immune response generated by the vaccine.
One of the cold virus strains used to prepare the vaccine - adenovirus serotype 5 - has already been shown in human clinical trials to increase susceptibility rather than protect against HIV. For this reason, the vaccine used in this study could never be used in humans. Yet the proof-of-concept suggests that T cells could be used to fight HIV.
Dan Barouch (Beth Israel Deaconess Medical Center, Boston, MA, USA)
Abstract available online.
(C) Nature press release.
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