Iloprost has potent anti-inflammatory properties on human monocyte-derived dendritic cells.
BACKGROUND
The stable prostaglandin I2 analogue (iloprost) iloprost has been shown to inhibit allergic airway inflammation in mice by modulating the function of myeloid dendritic cells (DCs).


OBJECTIVE
The aim of the current study was to investigate the biological activity of iloprost on human monocyte-derived DCs.


METHODS
I prostanoid (IP) receptor expression was analysed by RT-PCR. Cytokine secretion by DCs and CD4+ T cells was measured by ELISA. The expression of the transcription factor FoxP3 after co-culture of DCs with CD4+ CD45RA+ T cells was analysed by flow cytometry.


RESULTS
Human monocyte-derived DCs were found to express mRNA specific for the PGI2 receptor IP, and stimulation with iloprost resulted in increased cyclic AMP levels in both immature DCs (iDCs) and mature DCs (mDCs). Moreover, iloprost dose dependently inhibited the secretion of TNF-alpha, IL-6, IL-8 and IL-12p70 in mDCs, while it enhanced IL-10 production. Changes in cytokine secretion were paralleled by an altered T-cell priming capacity of DCs: in co-culture experiments of iloprost-treated mDC and naïve CD45RA+ T cells, an induction of regulatory T cells could be observed, as demonstrated by increased intracellular FoxP3 expression and IL-10 production. Additionally, iloprost inhibited the MIP-3beta-induced migration of mDCs.


CONCLUSIONS
In summary, our results provide evidence that iloprost profoundly affects the function of human myeloid DCs. Therefore, iloprost might also be a new therapeutical option for the treatment of asthma in humans.
Müller
T
T
Department of Pneumology, University of Freiburg, Freiburg, Germany.
Dürk
T
T
Blumenthal
B
B
Herouy
Y
Y
Sorichter
S
S
Grimm
M
M
Panther
E
E
Cicko
S
S
Norgauer
J
J
Idzko
M
M
D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D002469:Cell Separation; D016207:Cytokines / Q000096:biosynthesis; D003713:Dendritic Cells / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000096:biosynthesis; D006801:Humans; D016285:Iloprost / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D009000:Monocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism
D000893:Anti-Inflammatory Agents; D016207:Cytokines; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D016285:Iloprost