Collecting the Viral Keys to Lassa Fever

December 22, 2016
Lassa virus illustration

Lassa hemorrhagic fever, which occurs regularly in Western Africa, can often lead to coma and death. This disease is caused by a member of the Arenavirus family, viruses that are passed from infected rodents to humans in the Southern tropics. There are no vaccines or effective drug treatments for most arenavirus infections. Dr. Yuying Liang studies a highly related Pichinde arenavirus that causes severe disease in guinea pigs, but not in people.  In a recent Journal of Virology article, Liang and her colleagues asked if certain amino acids linked together in a long chain within this arenavirus allows it to infect host cells and cause disease in guinea pigs. This chain, called the stable signal peptide or SSP, has eight specific amino acids that are conserved in all arenaviruses. Liang replaced each amino acid with the chemically “boring” amino acid alanine to make mutated versions of Pichinde virus.  Five amino acids affected the ability of the virus to bind and enter host cells. Two SSP amino acids were also important for viral replication. When guinea pigs were exposed to mutated virus containing changes in one of the two amino acids at a dose that would normally kill the animals, the animals had a mild fever, but fully recovered with no detectable virus particles in their blood. Key amino acids in the SSP may be important targets for antiviral drugs or vaccines against arenavirus infections, including Lassa fever.

David R. Brown, Ph.D., VBS Vice-chair