Emergency haematopoiesis initiates from an expanded pool of endothelium-derived haematopoietic stem cells within infected zebrafish

摘要

During steady-state conditions, myeloid leukocytes are produced from a small number of haematopoietic stem cells (HSCs). During the stressed state of infection, depleted myeloid leukocyte stocks are replenished via an emergency or demand-driven haematopoietic program within the bone marrow. How host/pathogen interactions at the infection site influence fate decisions made by haematopoietic progenitor cells in the bone marrow remains incompletely understood. To further understand the earliest events that contribute to the initiation of emergency haematopoiesis, and how these differ from normal haematopoiesis, we have exploited the genetic tractability and physical traits of the zebrafish model system to view this process, for the first time, within an intact whole animal system.