Defective B cell development in Snell dwarf (dw/dw) mice can be corrected by thyroxine treatment.
Snell dwarf (dw/dw) mice are deficient in anterior pituitary hormones due to a mutation in the gene encoding the Pit-1 transcription factor. Bone marrow B cell development is also suppressed in the mice, providing circumstantial evidence that one or more anterior pituitary-derived products, or factors induced by them, are required for normal B lymphopoiesis. However, concluding that this is the case is dependent on showing that hormonal treatment of dwarf mice reverses their B cell defects. dw/dw mice were treated with growth hormone (GH), insulin-like growth factor-I (IGF-I), or thyroxine in an attempt to restore bone marrow B lymphopoiesis. GH and IGF-I increased the number of B lineage cells in the bone marrow and spleen but did not restore the frequency of bone marrow pre-B cells to normal. However, bone marrow cellularity in thyroxine-treated dw/dw mice was comparable to that in control animals, and both the frequency and absolute number of B lineage cells had increased to normal or even above normal. Taken together, these data indicate that endocrine factors, especially those regulated by the hypothalamic-pituitary-thyroid axis, are potent B lymphopoietic factors.
Montecino-Rodriguez
E
E
Division of Biomedical Sciences, University of California, Riverside 92521, USA.
Clark
R
R
Johnson
A
A
Collins
L
L
Dorshkind
K
K
D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology* / Q000473:pathology; D001853:Bone Marrow / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D016026:Bone Marrow Transplantation; D004392:Dwarfism / Q000188:drug therapy* / Q000235:genetics / Q000276:immunology*; D013006:Growth Hormone / Q000494:pharmacology; D006410:Hematopoiesis / Q000187:drug effects; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008817:Mice, Mutant Strains; D016513:Mice, SCID; D010908:Pituitary Hormones, Anterior / Q000172:deficiency / Q000276:immunology; D013974:Thyroxine / Q000494:pharmacology*
D010908:Pituitary Hormones, Anterior; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D013974:Thyroxine