Spring 2006 Table of Contents
     
Research in Focus
Dentistry Professor Examines the Role of "Parent" Viruses and Recombination in the Evolution of HIV
 


AIDS virus budding from t-cell surface
Credit: © Custom Medical Stock Photo


























As it courses through the body, the HIV virus mutates at a dizzying rate. In fact, the virus evolves so quickly that the diversity of genetic sequences within a single infected individual is roughly comparable to the diversity of influenza sequences worldwide in any given year. Although over 100 HIV vaccine preparations have been tested in humans and animals in the two-plus decades since HIV was identified, none have yet proven powerful enough to defend against this swiftly-changing virus.

Dr. David N. Levy, an Assistant Professor of Basic Science and Craniofacial Biology at the College of Dentistry, seeks to explain recombination, one factor in HIV’s rapid evolution that is not yet fully understood. Recombination occurs when two genetically-distinct HIV viruses, or “parents,” infect one cell and swap genetic material, causing “offspring” viruses to develop new characteristics. Until now, scientists haven’t been able to determine how often two or more HIV viruses infect a cell and recombine. Dr. Levy is addressing those questions in research that could enable scientists to predict how quickly HIV evolves by recombination. This information could be used to formulate vaccines and treatments that protect against mutations.

Funded by a two-year, $300,000 NIH grant, Dr. Levy analyzes recombination in individual cells, rather than in groups – a unique approach enabling him to observe subtle changes to the virus that might otherwise escape detection. For example, he investigates what occurs when a healthy virus recombines with a virus that cannot replicate because of a genetic defect. This recombination could transmit the defect to the offspring virus, or it could repair the defective gene and contribute to offspring that replicate even faster than its “parents.” A virus that replicates faster is likely to cause disease that spreads more quickly.

Infectious disease research is a priority for the College of Dentistry, which last year recruited Dr. Daniel Malamud, a biochemist and one of the leading researchers in anti-HIV agents and oral-based diagnostics. In addition to conducting his own research, Dr. Levy will collaborate with Dr. Malamud in investigating how a protein present in saliva can prevent HIV transmission – a study that could ultimately lead to the development of new vaccines or medications.