A team of scientists at Cold Spring Harbor Laboratory (CSHL) has discovered new details about how a simian strain of the AIDS virus replicates. The findings are significant because they suggest new strategies to prevent replication, and because they are applicable to human strains of the virus, which, despite the persistent efforts of scientists over two decades, can only be slowed by drug treatments but neither cured nor prevented.
Jacek Skowronski, Ph.D., CHSL associate professor, led a team that studied a virulent strain of simian immune-deficiency (SIV) virus called SIVsm/mac, named for two species of monkeys in which it occurs, sooty mangabeys and macaques. The team included members of Dr. Skowronskis CSHL lab and researchers at Stowers Institute for Medical Research in Kansas City, Missouri, and the Skirball Institute of Biomolecular Medicine in New York City.
Like versions of the virus that occur in humans, SIV viral particles, or virions, are composed of a few fundamental parts. At their heart are two identical but separate strands of RNA surrounded by a protective envelope of roughly 2,000 proteins called a capsid.
This tiny, conical capsule, in turn, is surrounded by multiple defensive rings, somewhat like the walls of a medieval city. Immediately surrounding it is a protective protein shell, or matrix, and beyond it a formidable double-walled viral envelope. Poking through the outer envelope are the viral equivalent of grappling hooks, protein molecules designed to lock onto receptors on the surface of the unfortunate cell that the virus will attach to and then invade.
Viruses Hijack Living Cells to Reproduce
Viruses, unlike cells, are not living things. They must penetrate a living cell and commandeer its internal machineries in order to reproduce. HIV and its simian cousin SIV are members of a viral subspecies called retroviruses that invert the usual reproductive procedure. Their gene
|Contact: Jim Bono|
Cold Spring Harbor Laboratory