Eosinophils from lineage-ablated Delta dblGATA bone marrow progenitors: the dblGATA enhancer in the promoter of GATA-1 is not essential for differentiation ex vivo.
A critical role for eosinophils in remodeling of allergic airways was observed in vivo upon disruption of the dblGATA enhancer that regulates expression of GATA-1, which resulted in an eosinophil-deficient phenotype in the DeltadblGATA mouse. We demonstrate here that bone marrow progenitors isolated from DeltadblGATA mice can differentiate into mature eosinophils when subjected to cytokine stimulation ex vivo. Cultured DeltadblGATA eosinophils contain cytoplasmic granules with immunoreactive major basic protein and they express surface Siglec F and transcripts encoding major basic protein, eosinophil peroxidase, and GATA-1, -2, and -3 to an extent indistinguishable from cultured wild-type eosinophils. Fibroblast coculture and bone marrow cross-transplant experiments indicate that the in vivo eosinophil deficit is an intrinsic progenitor defect, and remains unaffected by interactions with stromal cells. Interestingly, and in contrast to those from the wild type, a majority of the GATA-1 transcripts from cultured DeltadblGATA progenitors express a variant GATA-1 transcript that includes a first exon (1E(B)), located approximately 3700 bp downstream to the previously described first exon found in hemopoietic cells (1E(A)) and approximately 42 bp upstream to another variant first exon, 1E(C). These data suggest that cultured progenitors are able to circumvent the effects of the DeltadblGATA ablation by using a second, more proximal, promoter and use this mechanism to generate quantities of GATA-1 that will support eosinophil growth and differentiation.
Dyer
Kimberly D
KD
Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases/National Institutes of Health (NIAID/NIH), Bethesda, MD 20892, USA. kdyer@niaid.nih.gov
Czapiga
Meggan
M
Foster
Barbara
B
Foster
Paul S
PS
Kang
Elizabeth M
EM
Lappas
Courtney M
CM
Moser
Jennifer M
JM
Naumann
Nora
N
Percopo
Caroline M
CM
Siegel
Steven J
SJ
Swartz
Jonathan M
JM
Ting-De Ravin
Suksee
S
Rosenberg
Helene F
HF
D000818:Animals; D001665:Binding Sites / Q000235:genetics / Q000276:immunology; D001854:Bone Marrow Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics* / Q000276:immunology; D019070:Cell Lineage / Q000235:genetics* / Q000276:immunology; D049109:Cell Proliferation; D002478:Cells, Cultured; D018920:Coculture Techniques; D004742:Enhancer Elements, Genetic; D004804:Eosinophils / Q000166:cytology / Q000276:immunology / Q000378:metabolism* / Q000637:transplantation; D050982:GATA1 Transcription Factor / Q000235:genetics* / Q000502:physiology; D050989:GATA2 Transcription Factor / Q000235:genetics; D050990:GATA3 Transcription Factor / Q000235:genetics; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D015848:Interleukin-5 / Q000502:physiology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008817:Mice, Mutant Strains; D011401:Promoter Regions, Genetic / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology
D050982:GATA1 Transcription Factor; D050989:GATA2 Transcription Factor; D050990:GATA3 Transcription Factor; C494689:Gata1 protein, mouse; C494712:Gata2 protein, mouse; C494748:Gata3 protein, mouse; D015848:Interleukin-5