IL-7 up-regulates the expression of IL-8 from resting and stimulated human blood monocytes.
Blood monocytes are important cellular sources of a vast array of bioactive substances, including regulatory and chemotactic cytokines. The regulation of these cytokines is of critical importance to the expression of acute and chronic inflammatory responses. IL-7, a T and B cell-activating cytokine, has recently been shown to have stimulatory effects on the expression of several monocyte-derived proinflammatory cytokines. We now describe the induction of IL-8 mRNA and extracellular protein from human blood monocytes by IL-7. The up-regulation of IL-8 mRNA by IL-7 was not altered by concomitant treatment with cycloheximide, suggesting that the direct stimulatory effects of IL-7 were not dependent upon de novo protein synthesis. In addition, IL-7 significantly potentiated the production of IL-8 from LPS-, TNF-, and IL-1-treated peripheral blood monocytes. Our findings suggest that IL-7 may play a critical role in the modulation of macrophage-derived cytokine expression and may function in vivo as an important proinflammatory cytokine.
Standiford
T J
TJ
Department of Medicine, University of Michigan Medical School, Ann Arbor 48109-0602.
Strieter
R M
RM
Allen
R M
RM
Burdick
M D
MD
Kunkel
S L
SL
D001483:Base Sequence; D003513:Cycloheximide / Q000494:pharmacology; D004357:Drug Synergism; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007375:Interleukin-1 / Q000008:administration & dosage; D015851:Interleukin-7 / Q000008:administration & dosage*; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000008:administration & dosage; D008969:Molecular Sequence Data; D009000:Monocytes / Q000378:metabolism*; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D007375:Interleukin-1; D015851:Interleukin-7; D016209:Interleukin-8; D008070:Lipopolysaccharides; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D003513:Cycloheximide