The failure of newborn mice infected with Escherichia coli to accelerate neutrophil production correlates with their failure to increase transcripts for granulocyte colony-stimulating factor and interleukin-6.
We quantified circulating and storage neutrophils, their precursors and progenitors, and mRNA for some of the cytokines involved in granulocytopoiesis, in newborn and adult mice following intrapulmonary inoculation of Escherichia coli. Four hours following inoculation of adult and newborn mice with a quantity of organisms 2 logs below the LD100, all animals were neutropenic. After 24 h, adults had recovered from the neutropenia but neonates had not (p < 0.001). Accelerated neutrophil production was evident in the infected adults, and correlated with the appearance of granulocyte colony-stimulating factor (G-CSF) transcripts in the liver, spleen, and lung, and interleukin-6 (IL-6) transcripts in the spleen and lung. An increase in neutrophil production was not observed in the neonates, and none of their organs tested had transcripts for either G-CSF or IL-6, but they did have transcripts for cytokines not involved in granulocytopoiesis; macrophage colony-stimulating factor and its receptor (c-fms). We speculate that the failure to increase neutrophil production in infected neonatal mice is the result of failure to increase production of relevant cytokines.
Liechty
K W
KW
Division of Human Development and Aging, University of Utah School of Medicine, Salt Lake City.
Schibler
K R
KR
Ohls
R K
RK
Perkins
S L
SL
Christensen
R D
RD
D000818:Animals; D000831:Animals, Newborn; D001773:Blood Cells / Q000473:pathology; D001853:Bone Marrow / Q000187:drug effects / Q000473:pathology; D002455:Cell Division; D002470:Cell Survival / Q000187:drug effects; D003114:Colony-Forming Units Assay; D004927:Escherichia coli Infections / Q000235:genetics / Q000473:pathology / Q000503:physiopathology*; D016179:Granulocyte Colony-Stimulating Factor / Q000235:genetics*; D015850:Interleukin-6 / Q000235:genetics*; D007962:Leukocytes / Q000473:pathology; D016173:Macrophage Colony-Stimulating Factor / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D009504:Neutrophils / Q000473:pathology*; D012333:RNA, Messenger / Q000378:metabolism*; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000235:genetics; D013936:Thymidine / Q000494:pharmacology; D013997:Time Factors
D015850:Interleukin-6; D012333:RNA, Messenger; D016179:Granulocyte Colony-Stimulating Factor; D016173:Macrophage Colony-Stimulating Factor; D016186:Receptor, Macrophage Colony-Stimulating Factor; D013936:Thymidine