In vivo effects of interleukin-17 on haematopoietic cells and cytokine release in normal mice.
In order to gain more insight into mechanisms operating on the haematopoietic activity of the T-cell-derived cytokine, interleukin-17 (IL-17) and target cells that first respond to its action in vivo, the influence of a single intravenous injection of recombinant mouse IL-17 on bone marrow progenitors, further morphologically recognizable cells and peripheral blood cells was assessed in normal mice up to 72 h after treatment. Simultaneously, the release of IL-6, IL-10, IGF-I, IFN-gamma and NO by bone marrow cells was determined. Results showed that, in bone marrow, IL-17 did not affect granulocyte-macrophage (CFU-GM) progenitors, but induced a persistant increase in the number of morphologically recognizable proliferative granulocytes (PG) up to 48 h after treatment. The number of immature erythroid (BFU-E) progenitors was increased at 48 h, while the number of mature erythroid (CFU-E) progenitors was decreased up to 48 h. In peripheral blood, white blood cells were increased 6 h after treatment, mainly because of the increase in the number of lymphocytes. IL-17 also increased IL-6 release and NO production 6 h after administration. Additional in vitro assessment on bone marrow highly enriched Lin- progenitor cells, demonstrated a slightly enhancing effect of IL-17 on CFU-GM and no influence on BFU-E, suggesting the importance of bone marrow accessory cells and secondary induced cytokines for IL-17 mediated effects on progenitor cells. Taken together, these results demonstrate that in vivo IL-17 affects both granulocytic and erythroid lineages, with more mature haematopoietic progenitors responding first to its action. The opposite effects exerted on PG and CFU-E found at the same time indicate that IL-17, as a component of a regulatory network, is able to intervene in mechanisms that shift haematopoiesis from the erythroid to the granulocytic lineage.
Jovcić
G
G
Institute for Medical Research, Beograd, Serbia and Montenegro. gocaj@imi.bg.ac.yu
Bugarski
D
D
Petakov
M
M
Krstić
A
A
Vlaski
M
M
Stojanović
N
N
Milenković
P
P
D000818:Animals; D002455:Cell Division / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism*; D015672:Erythroid Precursor Cells / Q000187:drug effects / Q000276:immunology; D042381:Granulocyte Precursor Cells / Q000187:drug effects / Q000276:immunology; D006397:Hematinics / Q000494:pharmacology*; D006410:Hematopoiesis / Q000187:drug effects* / Q000276:immunology; D006412:Hematopoietic Stem Cells / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism*; D007275:Injections, Intravenous; D020381:Interleukin-17 / Q000494:pharmacology*; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D009569:Nitric Oxide / Q000378:metabolism; D011930:Reaction Time / Q000187:drug effects / Q000276:immunology; D015854:Up-Regulation / Q000187:drug effects / Q000276:immunology
D016207:Cytokines; D006397:Hematinics; D020381:Interleukin-17; D009569:Nitric Oxide