Dataset Information

Chlamydia abortus Pmp18.1 Induces IL-1? Secretion by TLR4 Activation through the MyD88, NF-?B, and Caspase-1 Signaling Pathways.

ABSTRACT: The polymorphic membrane protein D (Pmp18D) is a 160-kDa outer membrane protein that is conserved and plays an important role in Chlamydia abortus pathogenesis. We have identified an N-terminal fragment of Pmp18D (designated Pmp18.1) as a possible subunit vaccine antigen. In this study, we evaluated the vaccine potential of Pmp18.1 by investigating its ability to induce innate immune responses in dendritic cells and the signaling pathway(s) involved in rPmp18.1-induced IL-1? secretion. We next investigated the immunomodulatory impact of VCG, in comparison with the more established Th1-promoting adjuvants, CpG and FL, on rPmp18.1-mediated innate immune activation. Finally, the effect of siRNA targeting TLR4, MyD88, NF-?B p50, and Caspase-1 mRNA in DCs on IL-1? cytokine secretion was also investigated. Bone marrow-derived dendritic cells (BMDCs) were stimulated with rPmp18.1 in the presence or absence of VCG or CpG or FL and the magnitude of cytokines produced was assessed using a multiplex cytokine ELISA assay. Expression of costimulatory molecules and Toll-like receptors (TLRs) was analyzed by flow cytometry. Quantitation of intracellular levels of myeloid differentiation factor 88 (MyD88), nuclear factor kappa beta (NF-?B p50/p65), and Caspase-1 was evaluated by Western immunoblotting analysis while NF-?B p65 nuclear translocation was assessed by confocal microscopy. The results showed DC stimulation with rPmp18.1 provoked the secretion of proinflammatory cytokines and upregulated expression of TLRs and co-stimulatory molecules associated with DC maturation. These responses were significantly (p ? 0.001) enhanced by VCG but not CpG or FL. In addition, rPmp18.1 activated the expression of MyD88, NF-?B p50, and Caspase-1 as well as the nuclear expression of NF-?B p65 in treated DCs. Furthermore, targeting TLR4, MyD88, NF-?B p50, and Caspase-1 mRNA in BMDCs with siRNA significantly reduced their expression levels, resulting in decreased IL-1? cytokine secretion, strongly suggesting their involvement in the rPmp18.1-induced IL-1? cytokine secretion. Taken together, these results indicate that C. abortus Pmp18.1 induces IL-1? secretion by TLR4 activation through the MyD88, NF-?B as well as the Caspase-1 signaling pathways and may be a potential C. abortus vaccine candidate. The vaccine potential of Pmp18.1 will subsequently be evaluated in an appropriate animal model, using VCG as an immunomodulator, following immunization and challenge.

SUBMITTER: Pan Q

PROVIDER: S-EPMC5741698 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

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<i>Chlamydia abortus</i> Pmp18.1 Induces IL-1β Secretion by TLR4 Activation through the MyD88, NF-κB, and Caspase-1 Signaling Pathways.

Pan Qing Q Zhang Qiang Q Chu Jun J Pais Roshan R Liu Shanshan S He Cheng C Eko Francis O FO

Frontiers in cellular and infection microbiology 20171218

The polymorphic membrane protein D (Pmp18D) is a 160-kDa outer membrane protein that is conserved and plays an important role in <i>Chlamydia abortus</i> pathogenesis. We have identified an N-terminal fragment of Pmp18D (designated Pmp18.1) as a possible subunit vaccine antigen. In this study, we evaluated the vaccine potential of Pmp18.1 by investigating its ability to induce innate immune responses in dendritic cells and the signaling pathway(s) involved in rPmp18.1-induced IL-1β secretion. We ...[more]

PMID: 29326885

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Project description:BackgroundJianpi Yangxue Qufeng Compound (JPYXQFC) is a Chinese medicine widely used in the clinical treatment of atopic dermatitis (AD) and has a significantly therapeutic effect. However, the mechanism of JPYXQFC in AD has been not understood clearly.ObjectiveThis study aimed to explore the effect of JPYXQFC on AD model cells and rats by regulating TLR4/MyD88/NF-κB signaling pathway.MethodsThe rats (n > 5) were given JPYXQFC decoction orally twice a day for three days, and their abdominal aortic blood was collected. HaCaT cell proliferation rate was tested by cell counting kit-8 (CCK-8) assays. We induced AD rat model through 2, 4-dinitrofluorobenzene (DNFB). AD rats were given oral JPYXQFC decoction and cetirizine (positive control). HaCaT cells were pretreated with JPYXQFC drug serum or cetirizine for 0.5 h and then stimulated with TNF-α/IFN-γ for 1 h. The mRNA levels of TLR4, MyD88, NF-κB, IL-4, IL-13, MCP1, TNF-α and TSLP were detected by quantitative real-time PCR (Q-RT-PCR), and TLR4/MyD88/NF-κB pathway protein expression was tested by Western blot. The total serum levels of immunoglobulin E (IgE), thymus and activation regulated chemokine/chemokine (C-C motif) ligand 17 (TARC/CCL17) were detected by enzyme-linked immunosorbent assay (ELISA). The epidermal thickness was detected by hematoxylin and eosin (HE) staining. The dermatitis area and score were measured by a ruler and a four-point scoring method, respectively.ResultsJPYXQFC significantly inhibited mRNA and protein expression of the TLR4/MyD88/NF-κB pathway and Histone H3 in TNF-α/IFN-γ-induced HaCaT cells and DNFB-induced rats, decreased the mRNA of IL-4, IL-13, MCP1, CCL22, TSLP and the level of AD-related genes IgE and TAEC/CCL17 of TNF-α/IFN-γ-induced HaCaT cells. Meanwhile, JPYXQFC significantly reduced the dermatitis area and dermatitis score in DNFB-induced rats, inhibited the levels of pro-inflammatory cytokines IL-6 and TNF-α, and upregulated FLG, as well as inhibited the levels of IgE and TARC/CCL17 in the serum of AD rats.ConclusionJPYXQFC alleviates AD by inhibiting the activation of TLR4/MyD88/NF-κB pathway.

Dataset Information

Chlamydia abortus Pmp18.1 Induces IL-1? Secretion by TLR4 Activation through the MyD88, NF-?B, and Caspase-1 Signaling Pathways.

Publications

<i>Chlamydia abortus</i> Pmp18.1 Induces IL-1β Secretion by TLR4 Activation through the MyD88, NF-κB, and Caspase-1 Signaling Pathways.

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