Experimental Treatment Lengthens Lifespan of Monkeys With Simian Version of HIV

Macaque monkeys with simian immunodeficiency virus -- the simian equivalent of HIV -- that received a single dose of an experimental treatment survived nearly twice as long as monkeys who did not receive the drug, according to a study published Wednesday in the journal Nature, BBC News reports. Immunodeficiency viruses typically function by signaling the body to suppress immune responses; however, the new treatment blocks this signaling system and thus boosts immune cell function, according to BBC News.

For the study, researchers injected a blocking antibody into nine monkeys who had developed AIDS from SIV. The study found that monkeys who received the experimental treatment survived an average of two times longer than monkeys who did not receive the drug. In addition, the treated monkeys showed evidence of more active immune systems and reduced viral loads, both indicators that the experimental treatment helped control SIV more efficiently. Although the treatment did not fully suppress SIV for any of the monkeys, the researchers said the treatment might prove more successful when administered in multiple doses or in conjunction with antiretroviral treatment.

Rama Amara of the Emory University Vaccine Center, who led the study, said that it is "important to note" that the experimental treatment "was effective without antiretroviral drugs and in monkeys with severe AIDS." She added that stimulating protective immune responses is "critical" to the development of a "successful immune therapy to control" HIV/AIDS. Thomas Lehner, an immunologist from King's College London, called the study's findings "very interesting," adding that although the "safety of the drug is a concern," the treatment potentially could be modified for treating HIV-positive humans. Lehner added that multiple doses of the treatment could suppress the virus, "although the present experiment has not shown that." Ade Fakoya of the International HIV/AIDS Alliance said that although the study is "an important avenue" to pursue, there could be a "long process of many years" before SIV research could be applied to humans "on a large enough scale for it to be another useful tool in HIV treatments" (BBC News, 12/10).

Online An abstract of the study is available online.