Australian scientists have discovered a molecule that could prove the key to the development of a vaccine for West Nile virus and Dengue fever.
A research team at the University of Queensland found all flaviviruses produced a small molecule which, among other functions, controlled the host's response to viral infection. (West Nile and Dengue are both caused by flaviviruses.)
The molecule identified by the researchers, called a subgenomic noncoding ribonucleic acid (sfRNA), is a part of the virus genome.
Led by Associate Professor Alexander Khromykh at the university's School of Molecular and Microbial Sciences said, "As sfRNA is produced by all flaviviruses we tested so far, targeting it with an antiviral therapy may be effective for the whole range of flaviviruses.
"By using reverse genetic engineering we were able to generate viruses that do not produce this sfRNA and showed that these engineered viruses are no longer able to kill their hosts or elicit disease symptoms.
"These engineered viruses offer great potential as vaccine candidates as they are expected to elicit an antiviral immune response similar to the normal virus infection without causing a disease."
Dr Khromykh said by studying mice infected with these engineered West Nile viruses, the team learned more about how the body attempts to combat a flavivirus infection.
The part of the virus the infected cells in the body are unsuccessful in destroying forms the sfRNA, which helps the virus to kill cells and cause potentially deadly diseases, he said.
"We identified sfRNA as a potential antiviral target for the large group of medically important viruses," Dr Khromykh said.
"Moreover, the knowledge obtained from our studies with West Nile virus should be readily applicable for designing anti-viral drugs and engineering similar vaccine candidates for other medically important flaviviruses."