How flu virus disables immune system

Northwestern University scientists have discovered one of the ways the influenza virus disarms our natural defense system. The virus decreases the production of key immune system-regulating proteins in human cells that help fight the invader by turning on the microRNAs — little snippets of RNA — that regulate these proteins. The researchers, led by molecular biologist Curt M. Horvath, are among the first to show the influenza virus can change the expression of microRNA to control immune responses in human lung cells. The findings reveal a new aspect of the interaction between the influenza virus and its host. Knowing how viruses disable the immune system to wreak havoc in the body will help researchers design therapeutics to preserve the immune response and keep people healthy. The knowledge also may be valuable for future diagnostics. “It’s a battle of supremacy between virus and host,” said Horvath, the Soretta and Henry Shapiro Research Professor in Molecular...