In vivo administration of recombinant granulocyte-macrophage colony-stimulating factor results in a reversible inhibition of primary B lymphopoiesis.
To determine if in vivo administration of granulocyte-macrophage CSF (GM-CSF) affects production of B lymphocytes in the bone marrow, mice were treated with the cytokine and the kinetics of B cell production was analyzed. After 1 wk of GM-CSF treatment, the number of B cell progenitors that express the B220 Ag had fallen fivefold and surface IgM expressing B cells were barely detectable. Although cellularity in the spleen had increased two-fold, due in part to an increase in the number of granulocyte-macrophage progenitor cells, splenic B cell levels were not affected by the GM-CSF treatment. Although numbers of marrow B cells and their immediate progenitors declined due to cytokine treatment, cells capable of rapidly restoring B lymphopoiesis were present in that tissue. After cessation of GM-CSF treatment, B lymphopoiesis resumed in the marrow of the mice and rebounded to supernormal levels at 1 wk after the last GM-CSF injection. This effect may be due to actions of GM-CSF on the B lymphopoietic support capability of the marrow environment, because the overproduction of B cells was not observed when marrow from the GM-CSF donors was used to reconstitute sublethally irradiated severe combined immunodeficient mice.
Dorshkind
K
K
Division of Biomedical Sciences, University of California, Riverside 92521-0121.
D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects* / Q000502:physiology; D001853:Bone Marrow / Q000502:physiology; D016026:Bone Marrow Transplantation; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D006410:Hematopoiesis / Q000187:drug effects*; D007153:Immunologic Deficiency Syndromes / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D011994:Recombinant Proteins / Q000494:pharmacology
D011994:Recombinant Proteins; D016178:Granulocyte-Macrophage Colony-Stimulating Factor