The Role of the Lymphocyte in Haemopoiesis

According to current dogma, circulating blood cells are all derived from the same progenitor, which therefore must be both pluripotent and capable of prolific self-replication. In the irradiated mouse, such haemopoietic stem cells (HSC) give rise to splenic colonies, and thus are designated as CFU-S (colony forming units-spleen). Definitive identification of a similar entity in man so far has proved elusive. However, primitive unipotent cells, …