Abstract
Immune cells carry out dynamic search processes for antigen and pathogens. T cells in vivo migrate primarily via undirected random walks, but it remains unresolved how these random walks generate a characteristic search behavior. Here we use light sheet microscopy to observe the native population of T cells in the larval zebrafish tail and fin fold over long times. We find that cell-to-cell variability is amplified by a correlation between speed and directional persistence, generating a characteristic cell behavioral manifold that is preserved under a perturbation to cell speeds. Our results suggest that speed-persistence coupling may be an intrinsic feature of T cell migration that provides an alternative to Levy flight for accessing a broad range of length scales in vivo.








