Mast cells in health and disease

2011 ◽  
Vol 120 (11) ◽  
pp. 473-484 ◽  
Author(s):  
Charlotte L. Weller ◽  
Sarah J. Collington ◽  
Tim Williams ◽  
Jonathan R. Lamb

Although MCs (mast cells) were discovered over 100 years ago, for the majority of this time their function was linked almost exclusively to allergy and allergic disease with few other roles in health and disease. The engineering of MC-deficient mice and engraftment of these mice with MCs deficient in receptors or mediators has advanced our knowledge of the role of MCs in vivo. It is now known that MCs have very broad and varied roles in both physiology and disease which will be reviewed here with a focus on some of the most recent discoveries over the last year. MCs can aid in maintaining a healthy physiology by secreting mediators that promote wound healing and homoeostasis as well as interacting with neurons. Major developments have been made in understanding MC function in defence against pathogens, in recognition of pathogens as well as direct effector functions. Probably the most quickly developing area of understanding is the involvement and contribution MCs make in the progression of a variety of diseases from some of the most common diseases to the more obscure.

2000 ◽  
Vol 191 (9) ◽  
pp. 1611-1616 ◽  
Author(s):  
Sandra Kleinau ◽  
Pernilla Martinsson ◽  
Birgitta Heyman

Receptors for immunoglobulin (Ig)G (FcγRs) are important for the antibody-mediated effector functions of the immune system. FcγRI and FcγRIII trigger cell activation through a common γ chain, whereas FcγRII acts as a negative regulator of antibody production and immune complex–triggered activation. Here we describe the in vivo consequences of FcγR deficiency in a mouse model of human rheumatoid arthritis. FcRγ chain–deficient mice on arthritis-susceptible DBA/1 background were immunized with collagen for induction of collagen-induced arthritis. The DBA/1 mice lacking FcRγ chain were protected from collagen-induced arthritis in contrast to wild-type mice, although both groups produced similar levels of IgG anticollagen antibodies. In comparison, DBA/1 mice lacking FcγRII developed an augmented IgG anticollagen response and arthritis. These observations suggest a crucial role of FcγRI and FcγRIII in triggering autoimmune arthritis.


2006 ◽  
Vol 203 (7) ◽  
pp. 1795-1803 ◽  
Author(s):  
Himanshu Kumar ◽  
Taro Kawai ◽  
Hiroki Kato ◽  
Shintaro Sato ◽  
Ken Takahashi ◽  
...  

IFN-β promoter stimulator (IPS)-1 was recently identified as an adapter for retinoic acid–inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (Mda5), which recognize distinct RNA viruses. Here we show the critical role of IPS-1 in antiviral responses in vivo. IPS-1–deficient mice showed severe defects in both RIG-I– and Mda5-mediated induction of type I interferon and inflammatory cytokines and were susceptible to RNA virus infection. RNA virus–induced interferon regulatory factor-3 and nuclear factor κB activation was also impaired in IPS-1–deficient cells. IPS-1, however, was not essential for the responses to either DNA virus or double-stranded B-DNA. Thus, IPS-1 is the sole adapter in both RIG-I and Mda5 signaling that mediates effective responses against a variety of RNA viruses.


2021 ◽  
Vol 22 (7) ◽  
pp. 3687
Author(s):  
Joanna Homa ◽  
Alina Klosowska ◽  
Magdalena Chadzinska

Arginase is the manganese metalloenzyme catalyzing the conversion of l-arginine to l-ornithine and urea. In vertebrates, arginase is involved in the immune response, tissue regeneration, and wound healing and is an important marker of alternative anti-inflammatory polarization of macrophages. In invertebrates, data concerning the role of arginase in these processes are very limited. Therefore, in the present study, we focused on the changes in arginase activity in the coelomocytes of Eisenia andrei. We studied the effects of lipopolysaccharide (LPS), hydrogen peroxide (H2O2), heavy metals ions (e.g., Mn2+), parasite infection, wound healing, and short-term fasting (5 days) on arginase activity. For the first time in earthworms, we described arginase activity in the coelomocytes and found that it can be up-regulated upon in vitro stimulation with LPS and H2O2 and in the presence of Mn2+ ions. Moreover, arginase activity was also up-regulated in animals in vivo infected with nematodes or experiencing segment amputation, but not in fasting earthworms. Furthermore, we confirmed that the activity of coelomocyte arginase can be suppressed by l-norvaline. Our studies strongly suggest that similarly to the vertebrates, also in the earthworms, coelomocyte arginase is an important element of the immune response and wound healing processes.


mBio ◽  
2014 ◽  
Vol 5 (4) ◽  
Author(s):  
Adria Carbo ◽  
Danyvid Olivares-Villagómez ◽  
Raquel Hontecillas ◽  
Josep Bassaganya-Riera ◽  
Rupesh Chaturvedi ◽  
...  

ABSTRACTThe development of gastritis duringHelicobacter pyloriinfection is dependent on an activated adaptive immune response orchestrated by T helper (Th) cells. However, the relative contributions of the Th1 and Th17 subsets to gastritis and control of infection are still under investigation. To investigate the role of interleukin-21 (IL-21) in the gastric mucosa duringH. pyloriinfection, we combined mathematical modeling of CD4+T cell differentiation within vivomechanistic studies. We infected IL-21-deficient and wild-type mice withH. pyloristrain SS1 and assessed colonization, gastric inflammation, cellular infiltration, and cytokine profiles. ChronicallyH. pylori-infected IL-21-deficient mice had higherH. pyloricolonization, significantly less gastritis, and reduced expression of proinflammatory cytokines and chemokines compared to these parameters in infected wild-type littermates. Thesein vivodata were used to calibrate anH. pyloriinfection-dependent, CD4+T cell-specific computational model, which then described the mechanism by which IL-21 activates the production of interferon gamma (IFN-γ) and IL-17 during chronicH. pyloriinfection. The model predicted activated expression of T-bet and RORγt and the phosphorylation of STAT3 and STAT1 and suggested a potential role of IL-21 in the modulation of IL-10. Driven by our modeling-derived predictions, we found reduced levels of CD4+splenocyte-specifictbx21androrcexpression, reduced phosphorylation of STAT1 and STAT3, and an increase in CD4+T cell-specific IL-10 expression inH. pylori-infected IL-21-deficient mice. Our results indicate that IL-21 regulates Th1 and Th17 effector responses during chronicH. pyloriinfection in a STAT1- and STAT3-dependent manner, therefore playing a major role controllingH. pyloriinfection and gastritis.IMPORTANCEHelicobacter pyloriis the dominant member of the gastric microbiota in more than 50% of the world’s population.H. pyloricolonization has been implicated in gastritis and gastric cancer, as infection withH. pyloriis the single most common risk factor for gastric cancer. Current data suggest that, in addition to bacterial virulence factors, the magnitude and types of immune responses influence the outcome of colonization and chronic infection. This study uses a combined computational and experimental approach to investigate how IL-21, a proinflammatory T cell-derived cytokine, maintains the chronic proinflammatory T cell immune response driving chronic gastritis duringH. pyloriinfection. This research will also provide insight into a myriad of other infectious and immune disorders in which IL-21 is increasingly recognized to play a central role. The use of IL-21-related therapies may provide treatment options for individuals chronically colonized withH. pylorias an alternative to aggressive antibiotics.


2021 ◽  
pp. 1-13
Author(s):  
Jonas Folke ◽  
Sertan Arkan ◽  
Isak Martinsson ◽  
Susana Aznar ◽  
Gunnar Gouras ◽  
...  

Background: α-synuclein (α-syn) aggregation contributes to the progression of multiple neurodegenerative diseases. We recently found that the isoform b of the co-chaperone DNAJB6 is a strong suppressor of a-syn aggregation in vivo and in vitro. However, nothing is known about the role of the endogenous isoform b of DNAJB6 (DNAJB6b) in health and disease, due to lack of specific antibodies. Objective: Here we generated a novel anti-DNAJB6b antibody to analyze the localization and expression this isoform in cells, in tissue and in clinical material. Methods: To address this we used immunocytochemistry, immunohistochemistry, as well as a novel quantitative DNAJB6 specific ELISA method. Results: The endogenous protein is mainly expressed in the cytoplasm and in neurites in vitro, where it is found more in dendrites than in axons. We further verified in vivo that DNAJB6b is expressed in the dopaminergic neurons of the substantia nigra pars compacta (SNpc), which is a neuronal subpopulation highly sensitive to α-syn aggregation, that degenerate to a large extend in patients with Parkinson’s disease (PD) and multiple system atrophy (MSA). When we analyzed the expression levels of DNAJB6b in brain material from PD and MSA patients, we found a downregulation of DNAJB6b by use of ELISA based quantification. Interestingly, this was also true when analyzing tissue from patients with progressive supranuclear palsy, a taupathic atypical parkinsonian disorder. However, the total level of DNAJB6 was upregulated in these three diseases, which may indicate an upregulation of the other major isoform of DNAJB6, DNAJB6a. Conclusion: This study shows that DNAJB6b is downregulated in several different neurodegenerative diseases, which makes it an interesting target to further investigate in relation to amyloid protein aggregation and disease progression.


Author(s):  
Jelena Damm ◽  
Joachim Roth ◽  
Rüdiger Gerstberger ◽  
Christoph Rummel

AbstractBackground:Studies with NF-IL6-deficient mice indicate that this transcription factor plays a dual role during systemic inflammation with pro- and anti-inflammatory capacities. Here, we aimed to characterize the role of NF-IL6 specifically within the brain.Methods:In this study, we tested the capacity of short interfering (si) RNA to silence the inflammatory transcription factor nuclear factor-interleukin 6 (NF-IL6) in brain cells underResults:In cells of a mixed neuronal and glial primary culture from the ratConclusions:This approach was, thus, not suitable to characterize the role NF-IL6 in the brain


2007 ◽  
Vol 179 (4) ◽  
pp. 747-760 ◽  
Author(s):  
Angelika Kümin ◽  
Matthias Schäfer ◽  
Nikolas Epp ◽  
Philippe Bugnon ◽  
Christiane Born-Berclaz ◽  
...  

Peroxiredoxin 6 (Prdx6) is a cytoprotective enzyme with largely unknown in vivo functions. Here, we use Prdx6 knockout mice to determine its role in UV protection and wound healing. UV-mediated keratinocyte apoptosis is enhanced in Prdx6-deficient mice. Upon skin injury, we observe a severe hemorrhage in the granulation tissue of knockout animals, which correlates with the extent of oxidative stress. At the ultrastructural level endothelial cells appear highly damaged, and their rate of apoptosis is enhanced. Knock-down of Prdx6 in cultured endothelial cells also increases their susceptibility to oxidative stress, thus confirming the sensitivity of this cell type to loss of Prdx6. Wound healing studies in bone marrow chimeric mice demonstrate that Prdx6-deficient inflammatory and endothelial cells contribute to the hemorrhage phenotype. These results provide insight into the cross-talk between hematopoietic and resident cells at the wound site and the role of reactive oxygen species in this interplay.


2021 ◽  
Author(s):  
Arnika K Wagner ◽  
Nadir Kadri ◽  
Chris Tibbitt ◽  
Koen van de Ven ◽  
Sunitha Bagawath-Singh ◽  
...  

ABSTRACTAlthough PD-1 was shown to be a hallmark of T cells exhaustion, controversial studies have been reported on the role of PD-1 on NK cells. Here, we found by flow cytometry and single cell RNA sequencing analysis that PD-1 can be expressed on MHC class I-deficient tumor-infiltrating NK cells in vivo. We also demonstrate distinct alterations in the phenotype of PD-1-deficient NK cells which in part could be attributed to a decrease in tumor-infiltrating NK cells in PD-1-deficient mice. NK cells from PD-1-deficient mice exhibited a more mature phenotype which might reduce their capacity to migrate and kill in vivo. Finally, our results demonstrate that PD-L1 molecules in membranes of PD-1-deficient NK cells migrate faster than in NK cells from wildtype mice, suggesting that PD-1 and PD-L1 form cis interactions with each other on NK cells.


Blood ◽  
1997 ◽  
Vol 90 (7) ◽  
pp. 2583-2590 ◽  
Author(s):  
Fulu Liu ◽  
Jennifer Poursine-Laurent ◽  
Huai Yang Wu ◽  
Daniel C. Link

Multiple hematopoietic cytokines can stimulate granulopoiesis; however, their relative importance in vivo and mechanisms of action remain unclear. We recently reported that granulocyte colony-stimulating factor receptor (G-CSFR)-deficient mice have a severe quantitative defect in granulopoiesis despite which phenotypically normal neutrophils were still detected. These results confirmed a role for the G-CSFR as a major regulator of granulopoiesis in vivo, but also indicated that G-CSFR independent mechanisms of granulopoiesis must exist. To explore the role of interleukin-6 (IL-6) in granulopoiesis, we generated IL-6 × G-CSFR doubly deficient mice. The additional loss of IL-6 significantly worsened the neutropenia present in young adult G-CSFR–deficient mice; moreover, exogenous IL-6 stimulated granulopoiesis in vivo in the absence of G-CSFR signals. Near normal numbers of myeloid progenitors were detected in the bone marrow of IL-6 × G-CSFR–deficient mice and their ability to terminally differentiate into mature neutrophils was observed. These results indicate that IL-6 is an independent regulator of granulopoiesis in vivo and show that neither G-CSFR or IL-6 signals are required for the commitment of multipotential progenitors to the myeloid lineage or for their terminal differentiation.


2020 ◽  
Vol 1 (1) ◽  
pp. 1-15
Author(s):  
Lamia M. El-Samad ◽  
◽  
Azza A. Attia ◽  
Basant A. Bakr ◽  
◽  
...  

Chitosan is recognized as a multipurpose biomaterial because of its low allergenicity, non-toxicity, biodegradability and biocompatibility. The present study was designed to estimate the role of chitosan derived from Lucilia cuprina on burn healing in diabetic mice; using histopathological and microbiological studies at different time intervals. Chitosan was prepared from L. cuprina with high molecular weight (MW) and high degree of deacetylation (DD) to evaluate its burn wound healing potential; skin burn closure assessment, histological and microbiological studies in vivo in male diabetic mice. Chitosan topical treatment was superior in wound closure acceleration; mainly in insulin injected group at all the time intervals. Additionally, earlier epidermal remodelling with mature and intense collagen deposition was encountered in all chitosan treated animals as well as non-diabetic burned animals. There was a significant delay in hair growth and poor epidermal remodelling with impairment of wound closure in diabetic groups. Moreover, chitosan treated groups assert the chitosan antibacterial effects with protecting the burn against contamination that hinders healing especially in this diabetic condition. Further researches needed to interpret effects of possible synergistic combination therapy.


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