But Oregon Health & Science University researchers who discovered the mechanism by which this destruction occurs say our innate protection system could have a leg up in the mle if drugs can be developed to target the HIV-encoded viral protein.
"We're thrilled about this," David Kabat, Ph.D., professor of biochemistry and molecular biology at OHSU, said of the discovery.
His OHSU collaborators were: Mariana Marin, research assistant professor, Susan Kozak, senior research associate, Department of Biochemistry and Molecular Biology; and Kristine Rose, graduate research assistant, Department of Cell and Developmental Biology.
The study, published Sunday in the November issue of the journal Nature Medicine, could have major implications for AIDS research. Not only does it give scientists insights into how the body's built-in defense system works, it's a shot in the arm for the search for more targeted, effective anti-HIV drugs.
"This is definitely relevant to drug development and pharmacology in the fight against AIDS," Kabat said.
Kabat's team found that the HIV-encoded protein viral infectivity factor, or Vif neutralizes a potent antiviral human protein called APOBEC3G that would, in the absence of Vif, inactivate HIV. Vif binds to APOBEC3G and induces its "extremely" rapid degradation, eliminating APOBEC3G from cells and keeping it from invading HIV particles where it could damage the virus' genetic material.
APOBEC3G is a nucleic acid-editing enzyme that exists in some cells, like white blood cells, but is absent in others, such as skin cells. Cells where APOBEC3G is present are "non-permissive," meaning they don't allow replication of an HIV mutant which lacks a Vif gene.