External seminar - Theresa Jakuszeit (Institut Curie/IPFGG)

Abstract: Cell migration is a crucial component in a variety of vital processes, such as development, wound healing, and immune response, but also pathologies like cancer metastasis. For example, immune cells randomly explore tissues in search of pathogens and danger-associated molecular patterns. Once they encounter a target, they change their migratory behaviour and follow chemical gradients to ensure an effective immune response, in a process termed chemotaxis. The precise type of directed migration that they use has not been fully characterized and it is not known whether different immune cells might use distinct types of directed migration, adapted to their precise function. We quantify the chemotactic migration of two types of immune cells –dendritic cells and neutrophils – and show that both cell types employ distinct migratory strategies in response to a chemical gradient in complex environments. While the response of neutrophils is akin to the biased random walk of bacteria, an effective torque reorients dendritic cells, a phenomenon which had not been reported before for cells following a chemical gradient. We identify the cytoskeletal components required for the chemotaxis strategies and discuss the relationship between cell shape and gradient sensing.