As health agencies around the world race to pinpoint the cause of severe acute respiratory syndrome (SARS), researchers are reporting success in developing a new theoretical model that shows how the pressure exerted by the immune response of an infected population can drive evolution of influenza virus.

The model does not aim to predict the emergence of new strains of influenza, but it does suggest that a short-lived general immunity to the virus might affect the virus's evolution. If immunologists can understand the basis of such a response by influenza virus, then vaccine designers might use that understanding to develop a vaccine that offers more general immunity to the virus, said the scientists.

The researchers -- led by Howard Hughes Medical Institute international research scholar Neil M. Ferguson at Imperial College London -- published an article outlining their model in the March 27, 2003, issue of the journal Nature. Co-authors are Alison Galvani from the University of California, Berkeley, and Robin Bush from the University of California, Irvine.

"The principal question we were trying to address with this model is what biological factors determine the particular patterns we see in influenza evolution," said Ferguson. "We wanted to understand the role of immunity in determining the competition between different flu strains."

Strains of flu virus differ from one another largely in the genes that code for surface molecules called glycoproteins, which are the primary targets of the body's immune system in defending against flu viruses, said Ferguson. Evolutionary changes in immune response against such "antigen" molecules are the reason that new vaccines must be developed against emerging strains of virus.

A central mystery, said Ferguson, was why only a few new flu strains emerge over time, replacing other strains that go extinct. Limitations
'"/>

Contact: Jim Keeley
keeleyj@hhmi.org
301-215-8858
Howard Hughes Medical Institute
26-Mar-2003

Page: 1 2 3 4
Related biology news :

1. Researchers determine genetic cause of Timothy syndrome
2. Researchers find color sensitive atomic switch in bacteria
3. Researchers identify protein promoting vascular tumor growth
4. Researchers devise potent new tools to curb ivory poaching
5. Researchers create nanotubes that change colors, form nanocarpet and kill bacteria
6. Researchers ID chlorophyll-regulating gene
7. Researchers develop fast track way to discover how cells are regulated
8. Researchers identify distinctive signature for metastatic prostate cancer
9. Researchers report new gene test for isolated cleft lip and palate
10. Researchers discover why mutant gene causes colon cancer
11. Researchers identify the genomes controlling elements