Basaal I - P36 - Endogenous Interleukin-37 diminishes CXCL1 release by dendritic cells upon stimulation with TLR ligands

W.P.C. Pulskens, L.A. Joosten, C.A. Dinarello, L.B. Hilbrands, J. van der Vlag

Chair(s): dr. Michiel Betjes, Erasmus MC, Rotterdam

Thursday 10 march 2016

13:00 - 13:30h at Foyer

Categories: Postersessie

Parallel session: Postersessies XI - Opgesplitst in 3 tijdblokken en 3 categoriëen (klinisch, basaal, donatie)

Renal ischemia and subsequent reperfusion (IR) is an inevitable process upon transplantation procedures. Damage-associated molecular patterns (DAMPs) released upon IR induce innate immune responses by activating Toll-like receptors (TLRs) which subsequently exaggerate tubular damage and kidney dysfunction. Dendritic cells (DCs) are key players in innate immune responses and moreover drive the onset of adaptive immunity. 

The human cytokine Interleukin (IL)-37 is a potent inhibitor of innate immunity that can reduce the degree of DC activation and consequent adaptive immune responses, including lymphocyte proliferation. In this study we evaluated the effects of endogenous IL37 on the functional response of DCs by stimulation with different TLR ligands.  

Bone marrow cells were isolated from femurs obtained from wild type (WT) and transgenic mice expressing human IL37 (hIL37tg) and subsequently differentiated towards bone marrow-derived dendritic cells (BMDCs) by culturing in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) for 8 days. BMDCs were stimulated with proinflammatory TLR agonists (lipopolysaccharide (LPS), Pam3Cys, CpG oligonucleotides (ODNs)) for 24hrs. The subsequent inflammatory response was determined by measuring cytokine release in the supernatant (ELISA) and gene expression profiles (quantitative RT-PCR), whereas the degree of DC maturation was determined using flow cytometry by quantifying cell surface marker expression (CD40 and CD86) on CD11c+ cells. 

mRNA expression and protein secretion of the neutrophil attracting chemokine CXCL1 were strongly reduced upon stimulation of hIL37tg BMDCs as compared to WT BMDCs. In contrast, IL37 expression did not affect TNFα and IL6 mRNA and protein levels, nor the degree of IL10 mRNA levels. Of note, no differences were found in basal levels between unstimulated immature DCs of WT and hIL37tg origin. Various concentrations of LPS, and to a lesser extent Pam3Cys or CpG ODNs, clearly induced maturation of CD11c+ BMDCs, as reflected by elevated expression of co-stimulatory molecules CD40 and CD86. However, endogenous IL37 did not affect the degree of maturation. 

Our preliminary data indicate that endogenous IL37 selectively reduces CXCL1 production by DCs upon stimulation with TLR agonists. However, production of other proinflammatory cytokines and costimulatory molecules was not affected by endogenous IL37.