The supportive effects of IL-7 on eosinophil progenitors from human bone marrow cells can be blocked by anti-IL-5.
Human rIL-7 was studied for its effects on myeloid and erythroid progenitors from human bone marrow cells. IL-7 did not support the granulocytic/monocytic or erythroid lineage but exclusively stimulated eosinophil colony formation (CFU-Eo) (4 +/- 3 vs 48 +/- 17 CFU-Eo/10(5) nonadherent fraction-non-T cell (NAF-NT) cells). This supportive effect was not mediated by T cells or monocytes because similar results were obtained with or without T cell or adherent depleted cell fractions. In addition, it was shown that CD34+ sorted cells could be stimulated by IL-7 (0 vs 15 +/- 9 CFU-Eo/3 x 10(3) CD34+ cells) Furthermore studies with IL-3 or granulocyte-macrophage CSF (GM-CSF) demonstrated an additive effect on the IL-7 supported colony formation. Finally, experiments were performed with anti-IL-3, anti-GM-CSF, anti-IL-1, and anti-IL-5 to exclude the possibility that IL-7 indirectly stimulated the eosinophil progenitor cell. Anti-GM-CSF, anti-IL-1, or anti-IL-3 did not influence the supportive effects of IL-7. However, anti-IL-5 did abolish the effects of IL-7 on the eosinophil colony formation (69 +/- 15 vs 3 +/- 2 CFU-Eo/10(5) NAF-NT, n = 3). Similar results were obtained with CD34+ sorted cells. Moreover, IL-5 mRNA expression could be demonstrated in IL-7-stimulated NAF-NT cells. These data suggest that the supportive effects of IL-7 on eosinophil precursors are mediated by the endogenous release of IL-5.
Vellenga
E
E
Division of Hematology, University Groningen, The Netherlands.
Esselink
M T
MT
Straaten
J
J
Stulp
B K
BK
De Wolf
J T
JT
Brons
R
R
Giannotti
J
J
Smit
J W
JW
Halie
M R
MR
D015703:Antigens, CD / Q000502:physiology; D018952:Antigens, CD34; D001483:Base Sequence; D001854:Bone Marrow Cells; D002454:Cell Differentiation / Q000276:immunology; D003114:Colony-Forming Units Assay; D004306:Dose-Response Relationship, Immunologic; D004804:Eosinophils / Q000166:cytology*; D005434:Flow Cytometry; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000502:physiology; D006412:Hematopoietic Stem Cells / Q000502:physiology; D006801:Humans; D007377:Interleukin-3 / Q000502:physiology; D015848:Interleukin-5 / Q000502:physiology*; D015851:Interleukin-7 / Q000502:physiology*; D008969:Molecular Sequence Data; D009000:Monocytes / Q000276:immunology; D016133:Polymerase Chain Reaction; D012313:RNA / Q000096:biosynthesis; D013601:T-Lymphocytes / Q000276:immunology; D014158:Transcription, Genetic
D015703:Antigens, CD; D018952:Antigens, CD34; D007377:Interleukin-3; D015848:Interleukin-5; D015851:Interleukin-7; D012313:RNA; D016178:Granulocyte-Macrophage Colony-Stimulating Factor