Lymphocytes play the music but the macrophage calls the tune.

Researchers interested in immunological aspects of bacterial, fungal, protozoan and helminthic infection are too often kept apart by artificial subject boundaries. These barriers were temporarily breached by a recent workshop* in which the complex interplay between microbes and their mammalian hosts were examined from a global viewpoint. The role of T-cell subsets and their products came under close scrutiny but the most forceful image was that of the macrophage. As host for infective agents, as modulator of specific immune activity and as ultimate mediator of the host response, the macrophage plays a virtuoso's role in the host-parasite drama.