[Experimental research on the cellular interactions during hemopoiesis]

We present a review of experimental studies performed at the Laboratory of Histogenesis of the Institute of Developmental Biology, Russian Academy of Sciences, on the problem of cell interactions during hemopoiesis. Special attention has been given to original experimental models, such as production of hemopoietic foci on underlayers of fibroblasts encapsulating a foreign body in the peritoneal cavity of rodents (after intraperitoneal transplantation of hemopoietic cells) and repopulation of ectopic hemopoietic territories under the kidney capsule of mice by syngeneic or xenogeneic hemopoietic cells. We describe the competitive interactions of genetically different hemopoietic cells after the transplantation of their mixtures to irradiated mice (multicomponent radiation chimeras). Xenogeneic and multicomponent chimeras have also been obtained in long-term bone marrow culture. We have examined characteristics of hemopoiesis on stromal cell underlayers produced by cells of various origins in vitro and then transplanted into the peritoneal cavity of irradiated mice. We discuss the results obtained and possible mechanisms of these phenomena.