Meanings of defense line in English

As the first defense line, macrophages are able to induce inflammatory response.

I found him manning a makeshift defense line built from burned-out cars and sheet metal.

The third " defense line" involves stress testing lenders to check whether they hold enough capital to deal with losses.

They would join the road, and they would need to stay on it all the way to the defense line at the Bergues-Furnes canal.

By this arrangement I can keep my Defense Line going & still get a nice breeze in the room.

However, the defense lines may now be starting to kick in, he said, with consumer credit showing signs of slowing and new car registrations falling.