Bioscope ‘09

by  Dr. Barbara Price

Antivirals, the future of infectious medicine

          With the awareness of a pandemic disease, H1N1, comes a more acute awareness on how to fight or counter diseases. Infectious disease has been part of man's evolution. We learned about bacteria first because they were easier to see and understand. We could grow them in cultures and test drugs on them to see if we could keep them from growing or even kill them off. Tools to fight virus infections have been slower to develop because it requires electron microscopes to see them and we have not been able to grow them outside the body. There are some notable serendipitous finds in fighting viruses, including Pasteur's first vaccine against rabies and Jenner's vaccine against smallpox. In both of those, and many vaccines since, the body's immune system has been prodded to do a better job against a viral disease, often by taking components from a living system that can do a better job fighting the infection than we can.

          However, since we have learned to grow viruses in cell cultures, and tissue cultures, we have been able to use electron microscopes and elegant chemistry to study them. As we have learned how viruses invade cells, change things inside cells, reproduce in cells, leave cells and cause the cells to produce the chemicals that eventually kill the cells, we have learned more about ways to interfere with the viruses' usual life-cycle. This is the basis for many antivirals. Knowing the genomes for the viruses and humans, we can probe how our own proteins change how the viruses replicate; if we can't kill the virus, at least we can keep them from multiplying, which gives our immune system a better chance to cope with them. Another approach is to highlight the virus by attaching molecular tags on them so our bodies can recognize them faster and more effectively, thereby avoiding the sneaky aspects viruses use to get past our immune systems.

          Advances we have made since the early 1980s especially have been dramatic, but we expect them. All advances take time and we have learned from each encounter with viruses, some lessons are slow to mature and others present some "Aha!" moments. As we learn more, some of those uncharted or less-well described areas between the DNA we know, the so-called "junk DNA", take on greater importance. Much of the DNA does not encode proteins, but some of it does and we are beginning to learn which proteins and how to use them.

          The art of living is viewed by many of us as a battle with infectious agents fought on a molecular battleground. Most of our terminology reflects this. Viruses enter our cells and try to usurp our proteins, but if we can redirect some of those proteins for our own protection and refuse to cooperate with the virus, we can win one more fight.

For the Professional in Government and Industry with an interest in Nuclear, Biological and Chemical Defense, Disarmament and Verification; Emergency and Disaster Medical Planning; Industrial Health and Safety; and Environmental Protection