scholarly journals Dectin-1 Controls TSLP-Induced Th2 Response by Regulating STAT3, STAT6, and p50-RelB Activities in Dendritic Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Chao Gu ◽  
Katherine Upchurch ◽  
Joshua Horton ◽  
Mathew Wiest ◽  
Sandra Zurawski ◽  
...  

The epithelium-associated cytokine thymic stromal lymphopoietin (TSLP) can induce OX40L and CCL17 expression by myeloid dendritic cells (mDCs), which contributes to aberrant Th2-type immune responses. Herein, we report that such TSLP-induced Th2-type immune response can be effectively controlled by Dectin-1, a C-type lectin receptor expressed by mDCs. Dectin-1 stimulation induced STAT3 activation and decreased the transcriptional activity of p50-RelB, both of which resulted in reduced OX40L expression on TSLP-activated mDCs. Dectin-1 stimulation also suppressed TSLP-induced STAT6 activation, resulting in decreased expression of the Th2 chemoattractant CCL17. We further demonstrated that Dectin-1 activation was capable of suppressing ragweed allergen (Amb a 1)-specific Th2-type T cell response in allergy patients ex vivo and house dust mite allergen (Der p 1)-specific IgE response in non-human primates in vivo. Collectively, this study provides a molecular explanation of Dectin-1-mediated suppression of Th2-type inflammatory responses and suggests Dectin-1 as a target for controlling Th2-type inflammation.

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 518-518
Author(s):  
Tadafumi Iino ◽  
Hiromi Iwasaki ◽  
Kentaro Kohno ◽  
Shin-ichi Mizuno ◽  
Yojiro Arinobu ◽  
...  

Abstract Abstract 518 PU.1, a hematopoietic transcription factor, is indispensable for development of conventional dendritic cells (cDCs) from hematopoietic stem cells. However, the function of PU.1 in mature cDC remains unclear. To test the possible role of PU.1 in mature cDCs, we developed mice lacking PU.1 selectively in mature cDCs (DC-PU.1D/D mice) by crossing a PU.1flox mouse line with a transgenic Itgax (CD11c)-Cre strain. In these mice, cDCs were dramatically reduced in spleen, thymus, lymph node, and skin, down to <40%, <25%, <10% and <5% of DCs in control mice respectively, whereas bone marrow cDCs and common dendritic cells progenitors (CDPs) were not affected. Surprisingly, T cell numbers were significantly decreased in DC-PU.1D/D mice, whereas thymic T cell development was normal, suggesting that maintenance of mature T cell pool might be impaired, presumably by dysfunction of PU.1D/D cDCs. In fact, PU.1D/D cDCs failed to efficiently induce ovalbumin-specific T cell response and to produce inflammatory cytokines in response to Toll like receptor (TLR) stimulation both in vitro and in vivo. The intravenous transfer of spleen PU.1D/D cDCs failed to repopulate the spleen of recipient mice, suggesting their poor survival in vivo. Furthermore, the expression of critical molecules for inflammatory responses was downregulated in PU.1D/D cDCs as compared to normal cDCs. These molecules included Myd88 and NFkB that are downstream molecules of TLR signaling, CD86 that is required for T cell stimulation, and CCR7 that is required for cDC migration. These results clearly show that PU.1 is required for development of the functional cDC pool, and the cDC pool plays a critical role in T cell homeostasis. Disclosures: No relevant conflicts of interest to declare.


2004 ◽  
Vol 5 (2) ◽  
pp. 191-195 ◽  
Author(s):  
C. J. Howard ◽  
B. Charleston ◽  
S. A. Stephens ◽  
P. Sopp ◽  
J. C. Hope

AbstractDendritic cells are central to the initiation of primary immune responses. They are the only antigen-presenting cell capable of stimulating naive T cells, and hence they are pivotal in the generation of adaptive immunity. Dendritic cells also interact with and influence the response of cells of the innate immune system. The manner in which dendritic cells influence the responses in cells of both the innate and adaptive immune systems has consequences for the bias of the adaptive response that mediates immunity to infection after vaccination or infection. It also provides an opportunity to intervene and to influence the response, allowing ways of developing appropriate vaccination strategies. Mouse and human studies have identified myeloid, lymphoid and plasmacytoid dendritic cells. Studies in domesticated animals with agents of specific infectious diseases have confirmed the applicability of certain of the generic models developed from mice or from in vitro studies on human cells. In vivo and ex vivo studies in cattle have demonstrated the existence of a number of subpopulations of myeloid dendritic cells. These cells differ in their ability to stimulate T cells and in the cytokines that they produce, observations clearly having important implications for the bias of the T-cell response. Dendritic cells also interact with the innate immune system, inducing responses that potentially bias the subsequent adaptive response.


2000 ◽  
Vol 191 (10) ◽  
pp. 1661-1674 ◽  
Author(s):  
Cristiana Fè d'Ostiani ◽  
Giuseppe Del Sero ◽  
Angela Bacci ◽  
Claudia Montagnoli ◽  
Antonio Spreca ◽  
...  

The fungus Candida albicans behaves as a commensal as well as a true pathogen of areas highly enriched in dendritic cells, such as skin and mucosal surfaces. The ability of the fungus to reversibly switch between unicellular yeast to filamentous forms is thought to be important for virulence. However, whether it is the yeast or the hyphal form that is responsible for pathogenicity is still a matter of debate. Here we show the interaction, and consequences, of different forms of C. albicans with dendritic cells. Immature myeloid dendritic cells rapidly and efficiently phagocytosed both yeasts and hyphae of the fungus. Phagocytosis occurred through different phagocytic morphologies and receptors, resulting in phagosome formation. However, hyphae escaped the phagosome and were found lying free in the cytoplasm of the cells. In vitro, ingestion of yeasts activated dendritic cells for interleukin (IL)-12 production and priming of T helper type 1 (Th1) cells, whereas ingestion of hyphae inhibited IL-12 and Th1 priming, and induced IL-4 production. In vivo, generation of antifungal protective immunity was induced upon injection of dendritic cells ex vivo pulsed with Candida yeasts but not hyphae. The immunization capacity of yeast-pulsed dendritic cells was lost in the absence of IL-12, whereas that of hypha-pulsed dendritic cells was gained in the absence of IL-4. These results indicate that dendritic cells fulfill the requirement of a cell uniquely capable of sensing the two forms of C. albicans in terms of type of immune responses elicited. By the discriminative production of IL-12 and IL-4 in response to the nonvirulent and virulent forms of the fungus, dendritic cells appear to meet the challenge of Th priming and education in C. albicans saprophytism and infections.


2001 ◽  
Vol 86 (11) ◽  
pp. 1257-1263 ◽  
Author(s):  
Attilio Bondanza ◽  
Angelo Manfredi ◽  
Valérie Zimmermann ◽  
Matteo Iannacone ◽  
Angela Tincani ◽  
...  

SummaryScavenger phagocytes are mostly responsible for the in vivo clearance of activated or senescent platelets. In contrast to other particulate substrates, the phagocytosis of platelets does not incite pro-inflammatory responses in vivo. This study assessed the contribution of macrophages and dendritic cells (DCs) to the clearance of activated platelets. Furthermore, we verified whether antibodies against the β2 Glycoprotein I (β2GPI), which bind to activated platelets, influence the phenomenon. DCs did not per se internalise activated platelets. In contrast, macrophages efficiently phagocytosed platelets. In agreement with the uneventful nature of the clearance of platelets in vivo, phagocytosing macrophages did not release IL-1β, TNF-α or IL-10. β2GPI bound to activated platelets and was required for their recognition by anti-ββ2GPI antibodies. DCs internalised platelets opsonised by anti-ββ2GPI antibodies. The phagocytosis of opsonised platelets determined the release of TNF-α and IL-1β by DCs and macrophages. Phagocytosing macrophages, but not DCs, secreted the antiinflammatory cytokine IL-1β0. We conclude that anti-ββ2GPI antibodies cause inflammation during platelet clearance and shuttle platelet antigens to antigen presenting DCs.


Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 933
Author(s):  
Amin S. Asfor ◽  
Salik Nazki ◽  
Vishwanatha R.A.P. Reddy ◽  
Elle Campbell ◽  
Katherine L. Dulwich ◽  
...  

In order to better understand differences in the outcome of infectious bursal disease virus (IBDV) infection, we inoculated a very virulent (vv) strain into White Leghorn chickens of inbred line W that was previously reported to experience over 24% flock mortality, and three inbred lines (15I, C.B4 and 0) that were previously reported to display no mortality. Within each experimental group, some individuals experienced more severe disease than others but line 15I birds experienced milder disease based on average clinical scores, percentage of birds with gross pathology, average bursal lesion scores and average peak bursal virus titre. RNA-Seq analysis revealed that more severe disease in line W was associated with significant up-regulation of pathways involved in inflammation, cytoskeletal regulation by Rho GTPases, nicotinic acetylcholine receptor signaling, and Wnt signaling in the bursa compared to line 15I. Primary bursal cell populations isolated from uninfected line W birds contained a significantly greater percentage of KUL01+ macrophages than cells isolated from line 15I birds (p < 0.01) and, when stimulated ex vivo with LPS, showed more rapid up-regulation of pro-inflammatory gene expression than those from line 15I birds. We hypothesize that a more rapid induction of pro-inflammatory cytokine responses in bursal cells following IBDV infection leads to more severe disease in line W birds than in line 15I.


2007 ◽  
Vol 82 (1) ◽  
pp. 196-206 ◽  
Author(s):  
Andreas Jung ◽  
Hiroki Kato ◽  
Yutaro Kumagai ◽  
Himanshu Kumar ◽  
Taro Kawai ◽  
...  

ABSTRACTToll-like receptors (TLRs) and retinoic acid-inducible gene I-like helicases (RLHs) are two major machineries recognizing RNA virus infection of innate immune cells. Intracellular signaling for TLRs and RLHs is mediated by their cytoplasmic adaptors, i.e., MyD88 or TRIF and IPS-1, respectively. In the present study, we investigated the contributions of TLRs and RLHs to the cytotoxic T-lymphocyte (CTL) response by using lymphocytoid choriomeningitis virus (LCMV) as a model virus. The generation of virus-specific cytotoxic T lymphocytes was critically dependent on MyD88 but not on IPS-1. Type I interferons (IFNs) are known to be important for the development of the CTL response to LCMV infection. Serum levels of type I IFNs and proinflammatory cytokines were mainly dependent on the presence of MyD88, although IPS-1−/−mice showed a decrease in IFN-α levels but not in IFN-β and proinflammatory cytokine levels. Analysis ofIfna6+/GFPreporter mice revealed that plasmacytoid dendritic cells (DCs) are the major source of IFN-α in LCMV infection. MyD88−/−mice were highly susceptible to LCMV infection in vivo. These results suggest that recognition of LCMV by plasmacytoid DCs via TLRs is responsible for the production of type I IFNs in vivo. Furthermore, the activation of a MyD88-dependent innate mechanism induces a CTL response, which eventually leads to virus elimination.


2006 ◽  
Vol 34 (04) ◽  
pp. 667-684 ◽  
Author(s):  
Chia-Yang Li ◽  
Jau-Ling Suen ◽  
Bor-Luen Chiang ◽  
Pei-Dawn Lee Chao ◽  
Shih-Hua Fang

Our previous studies had reported that morin decreased the interleukin-12 (IL-12) and tumor necrosis factor-alpha (TNF-α) production in lipopolysaccharide (LPS)-activated macrophages, suggesting that morin may promote helper T type 2 (Th2) response in vivo. Dendritic cells (DCs) are the most potent antigen presenting cells and known to play a major role in the differentiation of helper T type 1 (Th1) and Th2 responses. This study aimed to reveal whether morin is able to control the Th differentiation through modulating the maturation and functions of DCs. Bone marrow-derived dendritic cells (BM-DCs) were incubated with various concentrations of morin and their characteristics were studied. The results indicated that morin significantly affects the phenotype and cytokine expression of BM-DCs. Morin reduced the production of IL-12 and TNF-α in BM-DCs, in response to LPS stimulation. In addition, the proliferative response of stimulated alloreactive T cells was significantly decreased by morin in BM-DCs. Furthermore, allogeneic T cells secreted higher IL-4 and lower IFN-γ in response to morin in BM-DCs. In conclusion, these results suggested that morin favors Th2 cell differentiation through modulating the maturation and function of BM-DCs.


2022 ◽  
Author(s):  
Michael Valente ◽  
Nils Collinet ◽  
Thien-Phong Vu Manh ◽  
Karima Naciri ◽  
Gilles Bessou ◽  
...  

Plasmacytoid dendritic cells (pDC) were identified about 20 years ago, based on their unique ability to rapidly produce copious amounts of all subsets of type I and type III interferon (IFN-I/III) upon virus sensing, while being refractory to infection. Yet, the identity and physiological functions of pDC are still a matter of debate, in a large part due to their lack of specific expression of any single cell surface marker or gene that would allow to track them in tissues and to target them in vivo with high specificity and penetrance. Indeed, recent studies showed that previous methods that were used to identify or deplete pDC also targeted other cell types, including pDC-like cells and transitional DC (tDC) that were proposed to be responsible for all the antigen presentation ability previously attributed to steady state pDC. Hence, improving our understanding of the nature and in vivo choreography of pDC physiological functions requires the development of novel tools to unambiguously identify and track these cells, including in comparison to pDC-like cells and tDC. Here, we report successful generation of a pDC-reporter mouse model, by using an intersectional genetic strategy based on the unique co-expression of Siglech and Pacsin1 in pDC. This pDC-Tomato mouse strain allows specific ex vivo and in situ detection of pDC. Breeding them with Zbtb46GFP mice allowed side-by-side purification and transcriptional profiling by single cell RNA sequencing of bona fide pDC, pDC-like cells and tDC, in comparison to type 1 and 2 conventional DC (cDC1 and cDC2), both at steady state and during a viral infection, revealing diverging activation patterns of pDC-like cells and tDC. Finally, by breeding pDC-Tomato mice with Ifnb1EYFP mice, we determined the choreography of pDC recruitment to the micro-anatomical sites of viral replication in the spleen, with initially similar but later divergent behaviors of the pDC that engaged or not into IFN-I production. Our novel pDC-Tomato mouse model, and newly identified gene modules specific to combinations of DC types and activations states, will constitute valuable resources for a deeper understanding of the functional division of labor between DC types and its molecular regulation at homeostasis and during viral infections.


2005 ◽  
Vol 79 (3) ◽  
pp. 369-371 ◽  
Author(s):  
Lubin Fang ◽  
Boris Fehse ◽  
Melanie Engel ◽  
Axel Zander ◽  
Nicolaus Kr??ger

2006 ◽  
Vol 74 (7) ◽  
pp. 3817-3824 ◽  
Author(s):  
Karen L. Wozniak ◽  
Jatin M. Vyas ◽  
Stuart M. Levitz

ABSTRACT Dendritic cells (DC) have been shown to phagocytose and kill Cryptococcus neoformans in vitro and are believed to be important for inducing protective immunity against this organism. Exposure to C. neoformans occurs mainly by inhalation, and in this study we examined the in vivo interactions of C. neoformans with DC in the lung. Fluorescently labeled live C. neoformans and heat-killed C. neoformans were administered intranasally to C57BL/6 mice. At specific times postinoculation, mice were sacrificed, and lungs were removed. Single-cell suspensions of lung cells were prepared, stained, and analyzed by microscopy and flow cytometry. Within 2 h postinoculation, fluorescently labeled C. neoformans had been internalized by DC, macrophages, and neutrophils in the mouse lung. Additionally, lung DC from mice infected for 7 days showed increased expression of the maturation markers CD80, CD86, and major histocompatibility complex class II. Finally, ex vivo incubation of lung DC from infected mice with Cryptococcus-specific T cells resulted in increased interleukin-2 production compared to the production by DC from naïve mice, suggesting that there was antigen-specific T-cell activation. This study demonstrated that DC in the lung are capable of phagocytosing Cryptococcus in vivo and presenting antigen to C. neoformans-specific T cells ex vivo, suggesting that these cells have roles in innate and adaptive pulmonary defenses against cryptococcosis.


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