Motile immune cells like neutrophils (the most abundant type of white blood cell) track down invading microbes by chemotaxis, keep hold of them by adhesion, and neutralize them by phagocytosis.  We integrate concepts and tools from immunobiology and biophysics to examine the mechanistic underpinnings of this amazing, cross-disciplinary feat.  Single-live-cell experiments using micropipette manipulation, optical tweezers, and a new type of horizontal atomic force microscope allow us to assess the nano-to-microscale ingredients of one-on-one encounters between human neutrophils and their targets (such as opsonized particles or pathogenic fungi and bacteria).  We dissect such encounters by examining separately the immunophysical roles of opsonization, chemotaxis, immune-cell priming, adhesion, and phagocytosis, as well as their vital interplay.  Providing a fresh view of the initiation of host-pathogen interactions, this approach demonstrates how the integration of essential physical insight with immunobiology allows us to define tighter constraints on possible explanations of cell and molecular behavior. 

Reference:

Heinrich, V., and C.-Y. Lee.  (2011).  Blurred line between chemotactic chase and phagocytic consumption:  An immunophysical, single-cell perspective.  Journal of Cell Science  124(18):3041-3051.