IFN-α and IFN-β exert antiviral effects by which mechanism?

• A. Inhibits RNase activity
• B. Induces RNase production and activates NK cells
• C. Directly lyses viral particles
• D. Inhibits NK cell activity

Answer: (B)

Type I interferons protect against viral infections by signaling neighboring cells to enter an antiviral state. This involves turning on antiviral enzymes, including RNase L through the OAS pathway, which degrades viral and cellular RNA to curb replication. They also boost natural killer (NK) cell activity, helping to kill infected cells. So the mechanism that combines inducing RNase activity and activating NK cells best explains their antiviral effects. They do not inhibit RNase; they promote it. They do not directly lyse viral particles. They do not suppress NK cells; they enhance NK cell function.