Stimulate the phagocytes.
Macrophages are my latest obsession. If you look here (a film by Judith Behnsen, Priyanka Narang, Mike Hasenberg, Frank Gunzer, Ursula Bilitewski, Nina Klippel, Manfred Rohde, Matthias Brock, Axel A. Brakhage, Matthias Gunzer) you can see them in action. Usually they lurk in tissues quietly supping at whatever is around them, but then, when aroused by chemical signals of nearby microbe carnage, they become greedy - gulping voraciously at whatever comes their way... In the movie you can see them suddenly change as they are activated by being washed with a chemical, then start to swallow the orange bacteria. I find this as exciting as any Hollywood record-breaking block-buster.
Today I have been reading the Doctor's Dilemma by George Bernard Shaw. He seemed to understand a thing or two about macrophages (although he called them phagocytes) - which I think is impressive.