A beautiful problem to study

Bill Snyder
Published: April, 2004

The battle against HIV actually had its beginnings during the “war on cancer”—years before the first AIDS case was reported.

Three-dimensional image of a reovirus particle, a common pathogen used as a model for studying viral infections. This image, a computer reconstruction of cryo-electron micrographs of several reovirus particles, shows an outer or capsid protein (blue) used to infect cells, and a core protein (yellow) important in replication.
Image prepared by Emma Nason and B. V. Prasad (Baylor College of Medicine) and Denise Wetzel and Terence Dermody (Vanderbilt University School of Medicine).
In the 1960s, scientists were trying to figure out how certain viruses could cause tumors. One result of that research was the discovery of reverse transcriptase, the enzyme that allows RNA viruses to make DNA copies of themselves inside the cells they infect. Viruses that do this are called “retroviruses.”

By the time AIDS came along in the early 1980s, scientists were able to test tissues and blood for the presence of reverse transcriptase. The detection of the enzyme was an important clue that the disease was caused by a retrovirus. It led—in 1984—to the simultaneous discovery of HIV in the laboratories of Drs. Robert Gallo and Luc Montagnier.

Since then, AIDS research has accelerated, thanks in part to technologies such as the polymerase chain reaction, which allows rapid identification of genetic sequences.

Other clues are emerging from the study of relatively harmless viruses in laboratory animals. Among the most valuable are reoviruses, a family of RNA viruses that include rotaviruses. In humans, reovirus infection usually does not result in anything more serious than a mild cold or diarrhea, but infection during the first weeks of life—in rare instances—can cause bile duct scarring and resulting destruction of the liver.

Terence Dermody, M.D., who directs the Elizabeth B. Lamb Center for Pediatric Research at Vanderbilt, is an expert on reoviruses. Through their studies, he and his colleagues have gained an appreciation for the remarkable capacity of viruses to “home” to their target cells in the body, to dock in an intricately specific manner to the cell surface, slip into the cell, replicate and assemble themselves precisely into new packages of infectious material.

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