Scientists develop synthetic virus to aid new polio vaccine development

28 June 2008

A team of molecular biologists and computer scientists at State University of New York at Stony Brook has designed and synthesised a new class of weakened polio viruses. They used their synthesising method with computer software to systematically re-code the polio virus genome.

The team is the first to demonstrate that a synthetic weakened virus can immunise an animal. These results show promise in the creation of new attenuated ('live virus') anti-viral vaccines and are reported in the 27 June issue of Science.

Six years ago, Eckard Wimmer, Ph.D, distinguished professor, department of molecular genetics and microbiology at Stony Brook University, and his colleagues synthesised and generated poliovirus, the first artificial synthesis of any virus. Dr Wimmer and other scientists within the Department built on that finding in their recent work.

''Synthesising the wild-type poliovirus was an essential and important first step toward our current research,'' says Dr. Wimmer, noting that the new method involves impeding the synthesis of viral proteins, a new approach to developing attenuated vaccines. This type of vaccine is created by mutating the virus so it cannot cause disease. Generally, attenuated vaccines are easy to administer, inexpensive, and sometimes offer the best protection against disease.

''As all viruses depend on their host's cellular machinery to produce their proteins, targeting the synthesis of viral proteins by the host may be universally applicable to creating weakened strains of other viruses,'' says Steffen Mueller, Ph.D, senior author and research assistant professor of molecular genetics and microbiology, referring to the implications of the research results.

Because of the redundancy of the genetic code, there are an unimaginably large number of ways to encode any given protein. For poliovirus proteins, there are more possible encodings (10 to the 442 power) than atoms in the universe. Using a powerful computer algorithm, the team found particular re-codings of the genome predicted to weaken the virus.