Ambushed. T cells killed by HIV hiding in the latent reservoir of a patient on antiviral treatment.
Potent cocktails of anti-HIV drugs can fight the AIDS virus to undetectable levels in the blood. But a pair of tomorrow's paper Science (pp. 1291 and 1295), report that the virus can survive the bombing in a small number of T cells, immune cells that are the main HIV target. Viruses in this hidden reservoir, moreover, can be awakened from their shock shell and allowed to reproduce, at least in the test tube. Or current treatment regimens can take many years to completely rid the body of HIV, experts say, or they are not powerful enough to do it
Although HIV had already been taken lurking in cells Immunity after medical treatment, some scientists had speculated that the virus might exist in a damaged form of impotence. To check this perspective, two research teams - one led by immunologist Robert Siliciano at Johns Hopkins University School of Medicine in Baltimore, and the other by virologist Douglas Richman of the University of California, San Diego, School of Medicine in La Jolla --looked for HIV in the so-called memory T cells, which help lead the attack when the immune system encounters microbial invaders it has seen before.
researchers took blood cells, including memory T cells, HIV-positive patients who were on a strict diet of multi-drug therapy and cultured with cells from people not infected. When the researchers triggered the memory T cells become activated, the virus began to replicate and infect HIV-negative cells - even if viral levels in HIV-infected cells were tiny. Although the results seem to confirm that HIV survives an attack of chemotherapy, the researchers did find some good news. There was no evidence that the virus had mutated survivor, suggesting that it had not become drug resistant
AIDS researchers are not surprised by the viral return. "We knew that the patients during this time period become positive virus if treatment is withdrawn," said retrovirologist John Coffin of Tufts University in Medford, Massachusetts. "The virus still has to be somewhere." Indeed, the results "should not have any impact on what we recommend to patients," said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases in Bethesda, Md. "We are reaping huge benefits for patients bearing the virus as low as possible for as long as possible. "
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