Vimentin provides target search efficiency and mechanical resilience for dendritic cell migration

Dendritic cells use amoeboid migration to pass through confined tissues to reach the lymph nodes, and this homing function is crucial for immune responses. The underlying mechanisms for this type of migration remain unknown. As vimentin intermediate filaments regulate adhesion-dependent migration, we analyzed whether they have a similar effect on amoeboid migration. We show that lack of vimentin impairs amoeboid migration in vitro in confined environments, and blocks lymph-node homing in mice in vivo . Importantly, we show that vimentin-deficient dendritic cells have a lower coupling factor between cell speed and persistence and reduced target search efficiency (e.g., finding a pathogen, or another cell). These data show that the characteristics of vimentin in its dynamic regulation of cell stiffness and load-bearing, and also elastic capacity, appear to explain the coupling between their migratory ability and search efficiency. Taken together, these data show that vimentin provides the specific mechano-dynamics required for dendritic cell migration and for efficient target searching. Summary statement Vimentin contributes to the mechanical stiffness of cells required for amoeboid cell migration through confined spaces, and improves cell-search efficiency. Vimentin-deficient cells migrate more slowly and their migration speed is less coupled to persistence compared to control cells. ### Competing Interest Statement The authors have declared no competing interest. * AFM : Atomic force microscopy BMDC : Bone marrow derived dendritic cell DC : Dendritic cell IF : Intermediate filament IMDM : Iscove’s modified Dulbecco’s medium KO : Knock-out LPS : Lipopolysaccharide MFPT : Mean first-passage time PDMS : Poly(dimethylsiloxane) PLL-PEG : Poly(L-lysine)-graft-poly(ethylene glycol) RT-DC : Real time deformability cytometry