Cytokine production by mouse myeloid dendritic cells in relation to differentiation and terminal maturation induced by lipopolysaccharide or CD40 ligation

Abstract

IntroductionMyeloid dendritic cells (DCs) are crucial antigen-presenting cells (APCs) for primary T-cell responses. They arise from bone marrow (BM) precursors that colonize peripheral tissues through the blood or lymph. 1,2 Tissue-resident immature DCs are excellent at internalizing and processing antigen, but they exhibit low ability to stimulate naive T cells. Exposure to allergens, bacterial (lipopolysaccharide [LPS], CpG DNA motifs) or viral (dsRNA) components, proinflammatory cytokines (interleukin-1␤ , tumor necrosis factor-␣ [TNF-␣], interferon ␣ [IFN-␣], granulocytemacrophage colony-stimulating factor (GM-CSF), and cognate T-cell interactions are some of the stimuli that trigger DC differentiation. 1,2 The capacity of mature DCs to prime naive T lymphocytes and to promote their differentiation into different T-cell subsets is attributed to the up-regulation of surface major histocompatibility complex (MHC), costimulatory and adhesion molecules, and the ability to secrete IL-1, Although the capacity of DCs to produce an ample repertoire of cytokines is documented in humans and rodents, there is little information on how cytokine genes are expressed during DC ontogeny. 4 In this study, we analyzed a range of cytokine transcripts and their respective proteins in highly purified mouse BM-derived myeloid DCs (BM DCs) at different stages of cell differentiation. Immature BM DCs expressed higher levels of IL-1␣, IL-1␤, TNF-␣, transforming growth factor ␤1 (TGF-␤1), and macrophage migration inhibitory factor (MIF) transcripts/ protein. After spontaneous differentiation in culture, the DCs up-regulated the levels of IL-6 and IL-15 mRNA and transcribed mRNA for IL-12p35, IL-12p40, and IL-18 de novo. Similar findings were found at the protein level by flow cytometry or enzyme-linked immunoabsorbent assay (ELISA).We also investigated the changes in the cytokine repertoire of BM DCs terminally differentiated with LPS or after CD40 cross-linking. Both stimuli increased the levels of IL-6, IL12p40, IL-15, and TNF-␣ transcripts/intracellular protein. However, only LPS markedly up-regulated the transcription of IL-1␣, IL-1␤, IL-12p35, and MIF genes. Although LPS or CD40 ligation augmented the T-cell allostimulatory capacity of DC, only LPS shifted the balance of naive T helper (Th) from a mixed Th1/Th2 population to Th1 cells, a result that agrees with the fact that only LPS was able to up-regulate the transcription of IL-12p35 in BM DCs. These results also demonstrate that, depending on the stimuli that induce the terminal differentiation of DCs, their T-cell stimulatory activity (signal 2) can be dissociated from their Th cell-driving ability (signal 3). 28 It appears that one of the key factors that regulates the Th cell-driving ability of myeloid DCs is the ability of the Materials and methods Experimental animalsTen-to 12-week-old C57BL/10 (B10; H2K b , IA b , IE Ϫ ) and C3H/He (C3H; H2K k , IA k , IE k ) mice were purchased from The Jackson Laboratory (Bar Harbor, ME) and maintained in the pathogen-free Central...

The Toll‐like receptor ligand MALP‐2 stimulates dendritic cell maturation and modulates proteasome composition and activity

“…Bacterial components (e.g. LPS, lipoteichoic acid) have been shown to induce IL-1 § , IL-6 or TNF- § secretion in human monocyte-derived DC [23][24][25][26], and LPS up-regulates IL-1 § and IL-6 expression in mice [27]. Our results clearly showed that MALP-2-treated DC secrete IL-12, suggesting that the resulting T cell response is directed versus a Th1 response.…”

Gene transduction efficiency and maturation status in mouse bone marrow-derived dendritic cells infected with conventional or RGD fiber-mutant adenovirus vectors

“…Maturation can be triggered by multiple stimuli, including contact components of bacteria and viruses, proinflammatory cytokines, and CD40-CD40L signaling. [47][48][49][50] Since Ad contains viral components, we sought to understand what effects Ad-infection would have on the maturation status of DCs.…”

Bacterial Lipopolysaccharide Signaling Through Toll-Like Receptor 4 Suppresses Asthma-Like Responses Via Nitric Oxide Synthase 2 Activity

“…For instance, LPS can induce the production of IL-12 by dendritic cells and provide an important signal for a Th1 shift (40). Alternatively, the lipid A portion of LPS can inhibit IL-4 production by CD4 ϩ T cells without inhibiting the production of IFN-␥ (41).…”