Search results for "Myeloid Differentiation Factor 88"

Langerinneg conventional dendritic cells produce IL-23 to drive psoriatic plaque formation in mice.

2013

Psoriasis is an autoinflammatory skin disease of unknown etiology. Topical application of Aldara cream containing the Toll-like receptor (TLR)7 agonist Imiquimod (IMQ) onto patients induces flares of psoriasis. Likewise, in mice IMQ triggers pathological changes closely resembling psoriatic plaque formation. Key cytokines like IL-23 and type-I IFN (IFN-I), both being produced mainly by dendritic cells (DCs), have been implicated in psoriasis. Although plasmacytoid DCs (pDCs) are the main source of IFNα and thought to initiate disease, conventional DCs (cDCs) appear to maintain the psoriatic lesions. Any role of cDCs during lesion formation remains elusive. Here, we report that selective ac…

Exclusive Expression of MyD88 on Dendritic Cells Is Sufficient to Induce Protection against Experimental Leishmaniasis

2022

Release of IL-12 by dendritic cells activated by TLR ligation is dependent on MyD88 signaling, whereas TRIF signaling is indispensable for TLR synerg…

2010

Abstract Synergistic activation of dendritic cells by combinations of TLR ligands requires both MyD88- and TRIF-dependent signaling. Recently, it has been shown that certain combinations of TLR ligands act in synergy to induce the release of IL-12 by DCs. In this study, we sought to define the critical parameters underlying TLR synergy. Our data show that TLR ligands act synergistically if MyD88- and TRIF-dependent ligands are combined. TLR4 uses both of these adaptor molecules, thus activation via TLR4 proved to be a synergistic event on its own. TLR synergy did not affect all aspects of DC activation but enhanced primarily the release of certain cytokines, particularly IL-12, whereas the …

CpG islands in MyD88 and ASC/PYCARD/TMS1 promoter regions are differentially methylated in head and neck squamous cell carcinoma and primary lung squ…

2021

Abstract Background Patients with head and neck squamous cell carcinoma (HNSCC) can develop lung squamous cell carcinoma (LuSCC), which could be the second primary tumor or HNSCC metastasis. Morphologically it is difficult to distinguish metastatic HNSCC from a second primary tumor which presents a significant diagnostic challenge. Differentiation of those two malignancies is important because the recommended treatments for metastatic HNSCC and primary LuSCC differ significantly. We investigated if the quantification of the promotor methylation status in HNSCC and LuSCC differs. Methods Primary HNSCC (N = 36) and LuSCC (N = 17) were included in this study. Methylation status in the ASC/TMS1…

CANDIDA ALBICANS INDUCES SELECTIVE DEVELOPMENT OF MACROPHAGES AND MONOCYTE DERIVED DENDRITIC CELLS BY A TLR2 DEPENDENT SIGNALLING

2011

As TLRs are expressed by haematopoietic stem and progenitor cells (HSPCs), these receptors may play a role in haematopoiesis in response to pathogens during infection. We have previously demonstrated that in in vitro defined conditions inactivated yeasts and hyphae of Candida albicans induce HSPCs proliferation and differentiation towards the myeloid lineage by a TLR2/MyD88 dependent pathway. In this work, we showed that C. albicans invasive infection with a low virulence strain results in a rapid expansion of HSPCs (identified as LKS cells: Lin(-) c-Kit(+) Sca-1(+) IL-7R alpha(-)), that reach the maximum at day 3 post-infection. This in vivo expansion of LKS cells in TLR2(-/-) mice was del…

Autoimmune skin inflammation is dependent on plasmacytoid dendritic cell activation by nucleic acids via TLR7 and TLR9

2010

Lupus-prone mice develop a chronic inflammatory response to cutaneous injury that depends on the production of type I interferon, TLR7, and TLR9.

MyD88 is dispensable for resistance toParacoccidioides brasiliensisin a murine model of blood-borne disseminated infection

2008

We have studied the role of MyD88, an adaptor protein of Toll-like receptors (TLRs), in murine defenses against Paracoccidioides brasiliensis in a model of blood-borne disseminated infection. Wild-type (WT) and MyD88-deficient mice infected intravenously with P. brasiliensis yeast cells showed an equivalent fungal burden, as well as similar levels of proinflammatory IL-1beta, IL-6, IL-12p70, tumor necrosis factor (TNF)-alpha and MIP-2, T-helper type 1 (Th1) (IFN-gamma) and Th2 cytokines (IL-4) in tissue homogenates. In vitro production of TNF-alpha, IFN-gamma and IL-12p70, by antigen-stimulated splenocytes from infected animals, was also similar in both types of mice; this production of Th1…

Dectin-1 Stimulation of Hematopoietic Stem and Progenitor Cells Occurs In Vivo and Promotes Differentiation Toward Trained Macrophages via an Indirec…

2020

Invasive candidiasis is an increasingly frequent cause of serious and often fatal infections. Understanding host defense is essential to design novel therapeutic strategies to boost immune protection against Candida albicans. In this article, we delve into two new concepts that have arisen over the last years: (i) the delivery of myelopoiesis-inducing signals by microbial components directly sensed by hematopoietic stem and progenitor cells (HSPCs) and (ii) the concept of “trained innate immunity” that may also apply to HSPCs. We demonstrate that dectin-1 ligation in vivo activates HSPCs and induces their differentiation to trained macrophages by a cell-autonomous indirect mechanism. This p…

Interruption of Macrophage-Derived IL-27(p28) Production by IL-10 during Sepsis Requires STAT3 but Not SOCS3

2014

Abstract Severe sepsis and septic shock are leading causes of morbidity and mortality worldwide. Infection-associated inflammation promotes the development and progression of adverse outcomes in sepsis. The effects of heterodimeric IL-27 (p28/EBI3) have been implicated in the natural course of sepsis, whereas the molecular mechanisms underlying the regulation of gene expression and release of IL-27 in sepsis are poorly understood. We studied the events regulating the p28 subunit of IL-27 in endotoxic shock and polymicrobial sepsis following cecal ligation and puncture. Neutralizing Abs to IL-27(p28) improved survival rates, restricted cytokine release, and reduced bacterial burden in C57BL/…

Signalling through TLR2/MyD88 induces differentiation of murine bone marrow stem and progenitor cells to functional phagocytes in response to Candida…

2009

Summary We have previously demonstrated that inactivated yeasts and hyphae of Candida albicans induce in vitro the proliferation of murine haematopoietic stem and progenitor cells (HSPCs, sorted as LKS cells: Lin - c-Kit + Sca-1 + ) as well as their differentia- tion to lineage-positive cells, through a MyD88- dependent pathway. In this work, we have found that this process is mainly mediated by TLR2, and that expanding cells express myeloid and not lym- phoid markers. Incubation of long-term repopulat- ing HSCs (Lin - CD105 + and Sca-1 + ) with C. albicans yeasts resulted in their proliferation and up regu- lation of the common myeloid progenitors (CMPs) markers, CD34 and FcgRII/III, by a …