In vivo deficiency of both C/EBPβ and C/EBPε results in highly defective myeloid differentiation and lack of cytokine response.
The CCAAT/enhancer binding proteins (C/EBPs) are transcription factors involved in hematopoietic cell development and induction of several inflammatory mediators. Here, we generated C/EBPβ and C/EBPε double-knockout (bbee) mice and compared their phenotypes to those of single deficient (bbEE and BBee) and wild-type (BBEE) mice. The bbee mice were highly susceptible to fatal infections and died within 2-3 months. Morphologically, their neutrophils were blocked at the myelocytes/metamyelocytes stage, and clonogenic assays of bone marrow cells indicated a significant decrease in the number of myeloid colonies of the bbee mice. In addition, the proportion of hematopoietic progenitor cells [Lin(-)Sca1(+)c-Kit(+)] in the bone marrow of the bbee mice was significantly increased, reflecting the defective differentiation of the myeloid compartment. Furthermore, microarray expression analysis of LPS- and IFNγ-activated bone marrow-derived macrophages from bbee compared to single knockout mice revealed decreased expression of essential immune response-related genes and networks, including some direct C/EBP-targets such as Marco and Clec4e. Overall, the phenotype of the bbee mice is distinct from either the bbEE or BBee mice, demonstrating that both transcription factors are crucial for the maturation of neutrophils and macrophages, as well as the innate immune system, and can at least in part compensate for each other in the single knockout mice.
Division of Hematology and Oncology, Cedars-Sinai Medical Center, University of California Los Angeles School of Medicine, Los Angeles, California, United States of America. tadayuki@staff.kanazawa-u.ac.jp
Tadayuki
T
Akagi
Nils H
NH
Thoennissen
Ann
A
George
Gay
G
Crooks
Jee Hoon
JH
Song
Ryoko
R
Okamoto
Daniel
D
Nowak
Adrian F
AF
Gombart
H Phillip
HP
Koeffler
D000818:Animals; D000831:Animals, Newborn; D001424:Bacterial Infections / Q000196:embryology / Q000235:genetics / Q000382:microbiology; D015153:Blotting, Western; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D022762:CCAAT-Enhancer-Binding Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D016000:Cluster Analysis; D016207:Cytokines / Q000378:metabolism*; D005260:Female; D020869:Gene Expression Profiling; D053263:Gene Regulatory Networks; D007371:Interferon-gamma / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D057507:Mice, 129 Strain; D018345:Mice, Knockout; D009504:Neutrophils / Q000166:cytology / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding / Q000187:drug effects; D011971:Receptors, Immunologic / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
D022782:CCAAT-Enhancer-Binding Protein-beta; D022762:CCAAT-Enhancer-Binding Proteins; C489468:Cebpe protein, mouse; D016207:Cytokines; D008070:Lipopolysaccharides; C092228:Marco protein, mouse; D011971:Receptors, Immunologic; D007371:Interferon-gamma