Murine eosinophil granulocyte proliferation kinetics in acute and chronic eosinophilia

Eosinophil proliferation kinetics have been determined by examining fraction-labeled mitoses (FLM) curves in femoral marrow of mice stimulated for eosinophil production. Mice with marrow eosinophilopoiesis increased as a result of infection with the parasite Schistosoma mansoni exhibited eosinophil cycle durations of 22 h. This time is not different from normal rates of murine eosinophil cell cycles. Acutely stimulated mice, however, with a rapid eosinophilia initiated by rechallenge with a soluble schistosome egg antigen preparation, had marrow eosinophil proliferative cycles of about 10 h. The long duration of eosinophil cell cycles in mice with an extensive commitment to the production of large numbers of eosinophil granulocytes suggests that several mechanisms regulate expansions of eosinophil granulocytopoiesis in vivo by hemopoietic marrow.