Dataset Information

TLR-mediated basophil production of IL-4 and IL-13 in human and mouse

ABSTRACT: It has been previously shown that airway exposure to Toll-like receptor ligands through lipopolysaccharide (LPS)-contaminated house dust or bacterial infections can exacerbate allergic inflammation; however, the underlying mechanism(s) controlling this response have not been fully elucidated. Here we report that basophils are the major source of Th2 cytokines that respond to TLR4 ligands, such as LPS and lipid A, in human PBMC and murine spleen cells. LPS activated human PBMCs to up-regulate mRNAs for not only pro-inflammatory cytokines such as IL-6 and chemokines such as CXCL8 (IL-8), CCL2 (MCP-1), but also Th2 cytokines such as IL-4 and IL13. Among PBMCs, we identified CD123+/BDCA4- basophils as the major source of IL-4 and IL-13 in response to LPS. Even in the absence of IgE, purified human basophils, as well as a basophilic cell line, were directly activated by LPS to produce IL-4 and IL-13. Moreover, LPS-stimulated IL-4 knockin mouse (4get mice) spleens identified the basophils as the major IL-4 producing cells in a TLR4-dependent manner. These results indicate that bacterial LPS may play a role in type-2 immunity through direct activation of basophils to produce IL-4 and IL-13. Keywords: Cell type comparison

ORGANISM(S): Homo sapiens

PROVIDER: GSE8589 | GEO | 2013/12/31

SECONDARY ACCESSION(S): PRJNA101745

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Interferon (IFN)γ and interleukin (IL)-4 are central regulators of T helper 1 (Th1) and T helper 2 (Th2) immune responses, respectively. Both cytokines have a major impact on macrophage phenotypes: IFNγ–priming and subsequent TLR4 activation induces so called classically activated macrophages that are characterized by pronounced pro-inflammatory responses, whereas IL-4–treated macrophages, commonly called alternatively activated, are known to develop enhanced capacity for endocytosis, antigen presentation, and tissue repair and are generally considered anti-inflammatory. Considering IL-4 as priming rather than activating stimulus, we now compared the TLR4–dependent global gene activation program in IFNγ– versus IL-4–pretreated mouse macrophages, which has rarely been studied so far. Although both cytokines frequently induced opposing effects on gene transcription, the subsequent activation of bone marrow-derived macrophages by lipopolysaccharide (LPS) produced a strong, priming dependent pro-inflammatory response in both macrophage types. For example, the production of key pro-inflammatory cytokines IL-6 and IL-12 was significantly higher in IL-4– versus IFNγ–primed macrophages and several cytokine genes, including Il19, Ccl17, Ccl22, Ccl24 and Cxcl5, were preferentially induced in alternatively primed and LPS activated mouse macrophages. In a subset of genes, including IL12a, IFNγ priming was actually found to suppress LPS–induced gene expression in a Stat1–dependent manner. Our data suggest that IL-4–priming is not per se anti-inflammatory but generates a macrophage that is “tissue protective” but still capable of mounting a strong inflammatory response after TLR4–dependent activation. Keywords: Gene expression profiling Gene expression was investigated in mouse bone marrow-derived macrophages (BMM). On day 7, BMM were stimulated with either IL-4 or IFNγ overnight (18h in total). LPS treatment was performed in primed and unprimed macrophages 4 h prior to harvesting. At least three independent experiments were performed for each condition.

Dataset Information

TLR-mediated basophil production of IL-4 and IL-13 in human and mouse

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure