The gp130-stimulating designer cytokine hyper-IL-6 promotes the expansion of human hematopoietic progenitor cells capable to differentiate into functional dendritic cells.
OBJECTIVE
Hyper-IL-6, a fusion protein of interleukin-6 and its specific receptor, together with stem cell factor leads to the proliferation of primitive hematopoietic progenitor cells. Based on these findings, the current study examined whether hyper-IL-6 promotes the growth of precursor cells that can be further differentiated into dendritic cells in the presence of additional cytokines.


METHODS
Dendritic cell cultures were generated from CD34(+) hematopoietic progenitor cells derived either from bone marrow or from peripheral blood. CD34(+) cells were cultured in the presence of cytokines for 2 weeks and then used for phenotyping and T-cell stimulation assays.


RESULTS
Hyper-IL-6 in the presence of stem cell factor induced a 60- to 80-fold expansion of CD34(+) progenitor cells following 2 weeks of culture in serum-free medium. The addition of granulocyte-macrophage colony-stimulating factor to hyper-IL-6 and stem cell factor was essential for the differentiation of expanded progenitor cells into antigen presenting cells capable of inducing a primary T-cell response to soluble protein, which is a typical feature of dendritic cells. Phenotypic analyses confirmed the expansion of immature dendritic cells, which could be further differentiated into mature CD83(+) dendritic cells under the influence of interleukin-4, interleukin-1beta, tumor necrosis factor-alpha, and prostaglandin E(2). The capacity of expanded dendritic cells to stimulate protein-specific CD4(+) T cells was used to stimulate a primary T-helper cell response to the recombinant protein of the hepatitis-B core antigen in healthy donors.


CONCLUSIONS
The expansion and differentiation of functional dendritic cells from CD34(+) progenitor cells under serum-free culture conditions allow for the possibility to develop more effective ways to immunize against viral infections and tumor diseases.
Bernhard
H
H
III Medizinische Klinik, Technische Universität München, München, Germany. helga.bernhard@lrz.tu-muenchen.de
Lohmann
M
M
Batten
W Y
WY
Metzger
J
J
Löhr
H F
HF
Peschel
C
C
zum Büschenfelde
K M
KM
Rose-John
S
S
D017951:Antigen Presentation / Q000276:immunology; D015703:Antigens, CD / Q000096:biosynthesis / Q000378:metabolism*; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D050822:Cytokine Receptor gp130; D003713:Dendritic Cells / Q000166:cytology* / Q000276:immunology; D015232:Dinoprostone / Q000494:pharmacology; D005434:Flow Cytometry; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects*; D006512:Hepatitis B Core Antigens / Q000276:immunology; D006801:Humans; D016130:Immunophenotyping; D007375:Interleukin-1 / Q000494:pharmacology; D015847:Interleukin-4 / Q000494:pharmacology; D015850:Interleukin-6 / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D010120:Oxytocics / Q000494:pharmacology; D018123:Receptors, Interleukin / Q000378:metabolism*; D019947:Receptors, Interleukin-6; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D011994:Recombinant Proteins; D019089:Stem Cell Factor / Q000378:metabolism / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D015703:Antigens, CD; D006512:Hepatitis B Core Antigens; C494199:IL6ST protein, human; D007375:Interleukin-1; D015850:Interleukin-6; D008562:Membrane Glycoproteins; D010120:Oxytocics; D018123:Receptors, Interleukin; D019947:Receptors, Interleukin-6; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D019089:Stem Cell Factor; D014409:Tumor Necrosis Factor-alpha; C104543:interleukin 6-interleukin 6 receptor fusion protein, recombinant; D050822:Cytokine Receptor gp130; D015847:Interleukin-4; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D015232:Dinoprostone