Acute myeloid leukaemia-derived Langerhans-like cells enhance Th1 polarization upon TLR2 engagement. (March 2016)

• Record Type: Journal Article
• Authors: Bock, Stephanie; Murgueitio, Manuela S.; Wolber, Gerhard; Weindl, Günther
• Is Part Of: Pharmacological research. Volume 105(2016:Mar.)
• Page Start: 44
• Page End: 53
• Publication Date: 2016-03
• Subjects: Acute myeloid leukaemia (AML) -- Langerhans cells -- Toll-like receptors (TLR) -- TLR2 -- Pro-inflammatory cytokines -- T helper type 1 (Th1) cells; Pharmacology -- Periodicals; Pharmacology -- Periodicals; Research -- Periodicals; Médicaments -- Recherche -- Périodiques; Pharmacologie -- Périodiques; 615.105
• DOI: 10.1016/j.phrs.2016.01.016
• Languages: English
• ISSNs: 1043-6618

Abstract

Graphical abstract: Abstract: Langerhans cells (LCs) represent a highly specialized subset of epidermal dendritic cells (DCs), yet not fully understood in their function of balancing skin immunity. Here, we investigated in vitro generated Langerhans-like cells obtained from the human acute myeloid leukaemia cell line MUTZ-3 (MUTZ-LCs) to study TLR- and cytokine-dependent activation of epidermal DCs. MUTZ-LCs revealed high TLR2 expression and responded robustly to TLR2 engagement, confirmed by increased CD83, CD86, PD-L1 and IDO expression, upregulated IL-6, IL-12p40 and IL-23p19 mRNA levels IL-8 release. TLR2 activation reduced CCR6 and elevated CCR7 mRNA expression and induced migration of MUTZ-LCs towards CCL21. Similar results were obtained by stimulation with pro-inflammatory cytokines TNF-α and IL-1β whereas ligands of TLR3 and TLR4 failed to induce a fully mature phenotype. Despite limited cytokine gene expression and production for TLR2-activated MUTZ-LCs, co-culture with naive CD4 + T cells led to significantly increased IFN-γ and IL-22 levels indicating Th1 differentiation independent of IL-12. TLR2-mediated effects were blocked by the putative TLR2/1 antagonist CU-CPT22, however, no selectivity for either TLR2/1 or TLR2/6 was observed. Computer-aided docking studies confirmed non-selective binding of the TLR2 antagonist. Taken together, our results indicate a critical role for TLR2 signalling in MUTZ-LCs considering the leukemic origin of the generated Langerhans-like cells.