(Click image for movie due to David Rogers, Vanderbilt University. A human neutrophil chases Staphylococcus aureus microorganisms among red blood cells.)

    An even more intriguing situation arises when a cluster of cells execute collective migration, which plays prominent roles in a variety of biological processes ranging from wound healing to neural crest cell migration during embryonic development. How do the cells interact among themselves and coordinate their movement? What signaling proteins and pathways are involved, and how do the chemical signaling interact with mechanotransduction? We have proposed a hypothesis of collective migration as an emergent behavior based on contact inhibition of locomotion and co-attraction, and used it to explain the spontaneous migration of a cell cluster in a confined geometry and the group advantage in chemotaxis. The movie below illustrates a simulation of spontaneous collective migration in a confined corridor:

    (Simulation of the spontaneous migration of a cluster of 49 neural crest cells in a channel. Blue/red lines pointing outward/inward indicate, respectively, the local Rac1/RhoA levels on the cell membrane.)

    (A neutrophil traversing a microfluidic channel with a contraction. The color indicates the magnitude of the membrane modulus as the cell fluidizes and later activates.)

    (A typical simulation of the stretching of a red blood cell by an optical tweezer. The color indicates the magnitude of instantaneous velocity.)

Department of ChBE / Department of Mathematics / Fluids Lab / James J. Feng / Research