Hiv Spikes a Thorn in Scientists' Side
2006 marks the 25th anniversary of the diagnosis of the first cases of HIV. Yet despite millions of dollars of global scientific toil, HIV has grown to become one of the worst pandemics ever known with at least 25 million deaths, 40 million people currently infected, over 4 million new cases occurring each year, and a predicated 100 million people affected by 2010. These figures make gloomy reading, but new research published in this week's edition of the journal Nature has given scientists their most intimate look at the AIDS virus yet, potentially opening up new avenues for vaccine research. Florida State University's Professor Ken Roux and his colleagues used the viral equivalent of a CAT scan, known as cryoelectron microscopy tomography, to produce detailed 3D images of the AIDS virus, which resembles a spiky meatball. The surface spikes behave like grappling hooks, enabling the virus to cling onto and hijack human cells. But our traditional understanding of what they look like - a lollypop - turns out to be wrong, which might partly explain why no successful vaccines have yet been produced. In fact, the spikes comprise a head supported by a tripod-shaped stalk. "Until now the design details of the spikes, and their distribution pattern on the surface of the virus, have been poorly understood limiting our understanding of how virus infection occurs and frustrating efforts to create a vaccine. So we're hoping, within a relatively short period of time, there'll be a new set of synthetic envelope spikes that could be used as vaccine candidates based on this new model", Roux said. To produce the images the research team suspended viral particles in a drop of water on a tiny copper grid. The floating particles were then flash frozen, encasing them in a flawless microscopic ice-cube, which the researchers were then able to examine under an electron microscope.