Video Captures Virus Infecting Cell

[Lionel]

For the first time, scientists have captured on video an influenza virus infecting a living, previously healthy, cell. The mini "flu show," as researchers are dubbing it, in the future could lead to better means of preventing influenza infection. The show's debut last Friday at the American Society for Cell Biology's annual meeting, held in San Francisco, comes at a critical juncture because of the early start, and apparent severity, of this year's flu season.The season's primary virus, labeled the H3N2 Fujian strain by the Centers for Disease Control and Prevention, already has led to a number of deaths. At least 11 children nationwide have succumbed to the illness, according to CDC reports issued in the past few weeks. Youths, seniors, and immunocompromised individuals are at particular risk.Adding to concerns are shortages of vaccines for flu shots, which this year guard against similar strains, but provide no direct protection against H3N2 Fujian.

The flu show captures a similar virus in action. In the video, the virus appears as a blue-red spot, while the dark background indicates the living cell. In three stages, the video shows an individual flu virus breaking through a cell's surface and then moving into the previously healthy cell.

"The first stage is indicated by the slow motion on the cell periphery, the second stage is indicated by the rapid, linear motion towards the nucleus, and the third stage is indicated by the relatively slow motion again," explained Xiaowei Zhuang, who filmed the video and is assistant professor of chemistry and physics in the Department of Chemistry and Chemical Biology at Harvard.

Zhuang used high-tech optical imaging to record the virus' movements. Previously such activity remained invisible because viruses are extremely small. Most measure around .01 micron. A single micron is equal to one-thousandth of a millimeter.

Viruses pack a lot of destructive power, despite their small size.

A protein called dynein works like a motor in each virus. As dynein burns fuel molecules, called ATP, it moves along microtubules within the virus. Zhuang likens these microtubules to highways that carry loads of dynein, which allow the virus to reside in a victim's cell, replicate, and then spread throughout the body.

View: Full Article | Source: Discovery Channel