Despite this innate defense, the invading virus can often establish an infection in epithelial cells. Once the virus has been replicating there for about a week, our ADAPTIVE immune response "learns" to recognize it and mounts a defense. For this part of the question, focus on explaining the TC response. How is it activated, and how is it antiviral? An accompanying sketch should show all the important cell-cell interactions, and label all surface proteins that are required.