BACKGROUND: Increasing evidence indicates that oxidative stress and interferon γ (IFNγ)-driven cellular immune responses are responsible for the pathogenesis of vitiligo. However, the connection between oxidative stress and the local production of IFNγ in early vitiligo remains unexplored. The aim of this study was to identify the mechanism underlying the production of IFNγ by mast cells and its impact on vitiligo pathogenesis. METHODS: Skin specimens from the central, marginal, and perilesional skin areas of active vitiligo lesions were collected to characterize changes of mast cells, CD8 + T cells, and IFNγ-producing cells. Cell supernatants from hydrogen peroxide (H 2 O 2 )-treated keratinocytes (KCs) were harvested to measure levels of soluble stem cell factor (sSCF) and matrix metalloproteinase (MMP)-9. A murine vitiligo model was established using Mas-related G protein-coupled receptor-B2 (MrgB2, mouse ortholog of human MrgX2) conditional knockout (MrgB2 -/- ) mice to investigate IFNγ production and inflammatory cell infiltrations in tail skin following the challenge with tyrosinase-related protein (Tyrp)-2 180 peptide. Potential interactions between the Tyrp-2 180 peptide and MrgX2 were predicted using molecular docking. The siRNAs targeting MrgX2 and the calcineurin inhibitor FK506 were also used to examine the signaling pathways involved in mast cell activation. RESULTS: IFNγ-producing mast cells were closely aligned with the recruitment of CD8 + T cells in the early phase of vitiligo skin. sSCF released by KCs through stress-enhanced MMP9-dependent proteolytic cleavage recruited mast cells into sites of inflamed skin (Perilesion vs . lesion, 13.00 ± 4.00/high-power fields [HPF] vs . 26.60 ± 5.72/HPF, P <0.05). Moreover, IFNγ-producing mast cells were also observed in mouse tail skin following challenge with Tyrp-2 180 (0 h vs . 48 h post-recall, 0/HPF vs . 3.80 ± 1.92/HPF, P <0.05). The IFNγ + mast cell and CD8 + T cell counts were lower in the skin of MrgB2 -/- mice than in those of wild-type mice (WT vs . KO 48 h post-recall, 4.20 ± 0.84/HPF vs . 0.80 ± 0.84/HPF, P <0.05). CONCLUSION Mast cells activated by MrgX2 serve as a local IFNγ producer that bridges between innate and adaptive immune responses against MCs in early vitiligo. Targeting MrgX2-mediated mast cell activation may represent a new strategy for treating vitiligo.
Vitiligo/metabolism* ; Mast Cells/immunology* ; Animals ; Interferon-gamma/metabolism* ; Mice ; Humans ; Melanocytes/metabolism* ; Receptors, G-Protein-Coupled/genetics* ; Mice, Knockout ; Mice, Inbred C57BL ; Male ; Female ; Matrix Metalloproteinase 9/metabolism* ; Stem Cell Factor/metabolism*

BACKGROUNDTh9 cells are a newly discovered CD4+ T helper cell subtype, characterized by high interleukin (IL)-9 secretion. Growing evidences suggest that Th9 cells are involved in the pathogenic mechanism of multiple sclerosis (MS). Mast cells are multifunctional innate immune cells, which are perhaps best known for their role as dominant effector cells in allergies and asthma. Several lines of evidence point to an important role for mast cells in MS and its animal models. Simultaneously, there is dynamic "cross-talk" between Th9 and mast cells. The aim of the present study was to examine the IL-9-mast cell axis in experimental autoimmune encephalomyelitis (EAE) and determine its interaction after neutralizing anti-IL-9 antibody treatment.

METHODSFemale C57BL/6 mice were randomly divided into three groups (n = 5 in each group): mice with myelin oligodendrocyte glycoprotein (MOG)-induced EAE (EAE group), EAE mice treated with anti-IL-9 antibody (anti-IL-9 Abs group), and EAE mice treated with IgG isotype control (IgG group). EAE clinical score was evaluated. Mast cells from central nervous system (CNS) were detected by flow cytometry. The production of chemokine recruiting mast cells in the CNS was explored by reverse transcription-polymerase chain reaction (RT-PCR). In mice with MOG-induced EAE, the expression of IL-9 receptor (IL-9R) complexes in CNS and spleen mast cells was also explored by RT-PCR, and then was repeating validated by immunocytochemistry. In vitro, spleen cells from EAE mice were cultured with anti-IL-9 antibody, and quantity of mast cells was counted by flow cytometry after co-culture.

RESULTSCompared with IgG group, IL-9 blockade delayed clinical disease onset and ameliorated EAE severity (t = -2.217, P = 0.031), accompany with mast cells infiltration decreases (day 5: t = -8.005, P < 0.001; day 15: t = -11.857, P < 0.001; day 20: t = -5.243, P = 0.001) in anti-IL-9 Abs group. The messenger RNA expressions of C-C motif chemokine ligand 5 (t = -5.932, P = 0.003) and vascular cell adhesion molecule-1 (t = -4.029, P = 0.004) were significantly decreased after IL-9 neutralization in anti-IL-9 Abs group, compared with IgG group. In MOG-induced EAE, the IL-9R complexes were expressed in CNS and spleen mast cells. In vitro, splenocytes cultured with anti-IL-9 antibody showed significantly lower levels of mast cells in a dose-dependent manner, compared with splenocytes cultured with anti-mouse IgG (5 μg/ml: t = -0.894, P = 0.397; 10 μg/ml: t = -3.348, P = 0.019; 20 μg/ml: t = -7.639, P < 0.001).

CONCLUSIONSThis study revealed that IL-9 neutralization reduced mast cell infiltration in CNS and ameliorated EAE, which might be relate to the interaction between IL-9 and mast cells.

Animals ; Antibodies ; therapeutic use ; Central Nervous System ; metabolism ; Encephalomyelitis, Autoimmune, Experimental ; drug therapy ; metabolism ; Female ; Immunohistochemistry ; Interleukin-9 ; antagonists & inhibitors ; immunology ; metabolism ; Mast Cells ; metabolism ; Mice ; Mice, Inbred C57BL ; RNA, Messenger ; genetics ; Reverse Transcriptase Polymerase Chain Reaction

To achieve immune homeostasis in such a harsh environment as the intestinal mucosa, both active and quiescent immunity operate simultaneously. Disruption of gut immune homeostasis leads to the development of intestinal immune diseases such as colitis and food allergies. Among various intestinal innate immune cells, mast cells (MCs) play critical roles in protective immunity against pathogenic microorganisms, especially at mucosal sites. This suggests the potential for a novel MC-targeting type of vaccine adjuvant. Dysregulated activation of MCs also results in inflammatory responses in mucosal compartments. The regulation of this yin and yang function of MCs remains to be elucidated. In this review, we focus on the roles of mucosal MCs in the regulation of intestinal allergic reaction, inflammation and their potential as a new target for the development of mucosal adjuvants.
Adjuvants, Immunologic/*therapeutic use ; Animals ; Humans ; Hypersensitivity/*immunology/prevention & control ; Inflammation/immunology/metabolism/prevention & control ; Intestinal Mucosa/cytology/*immunology ; Mast Cells/*immunology

This study is to investigate the anti-allergic effect of anthocyanidin and to explore its possible mechanism. The experiments of passive cutaneous anaphylaxis reaction (PCA) and colorimetry were used to determine the effect of anthocyanidin on degranulation of mast cells in vivo. For in vitro study, various concentrations of anthocyanidin (100, 50 and 25 micromol x L(-1)) were added to the culture medium of mast cells cultured with 100 microg x L(-1) of dinitrophenyl (DNP) specific IgE overnight. The azelastine (100 micromol x L(-1)) was selected as the positive control. The antigen (DNP-human serum albumin, DNP-HAS)-induced release of degranulation was measured by enzymatic assay, histamine was determined by EIA, and interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) were measured by Western blotting, separately. In addition, the effects of anthocyanidin on phosphorylation of NF-kappaB, p38MAPK and Akt were observed by Western blotting. The results showed that treatments with anthocyanidin (100 and 50 mg x kg(-1)) were followed by a decrease in PCA of rats. Anthocyanidin (100 and 50 micromol x L(-1)) obviously suppressed the degranulation from mast cells, whereas results from anthocyanidin (100 and 50 micromol x L(-1)) group indicated significant inhibitory effect on histamine, the calcium uptake, TNF-alpha, IL-6, phosphorylation of NF-kappaB, p38MAPK and Akt of mast cells induced by antigen. Anthocyanidin may suppress the anaphylactic reaction by inhibiting the action of mast cells. NF-kappaB, p38MAPK and Akt at least in part contribute to this event.
Animals ; Anthocyanins ; pharmacology ; Anti-Allergic Agents ; pharmacology ; Calcium ; metabolism ; Cell Degranulation ; drug effects ; Histamine Release ; drug effects ; Immunoglobulin E ; immunology ; Interleukin-6 ; metabolism ; Male ; Mast Cells ; immunology ; metabolism ; physiology ; Passive Cutaneous Anaphylaxis ; drug effects ; Proto-Oncogene Proteins c-akt ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Transcription Factor RelA ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism ; p38 Mitogen-Activated Protein Kinases ; metabolism

OBJECTIVETo establish a new, real time, dynamic and direct optical detection method for mast cell degranulation caused by anaphylactoid reaction.

METHODA CD63-GFP plasmid was constructed and introduced steadily into rat basophilic leukemia (RBL-2H3) cells. The movements of CD63-GFP, which was located on both the granule membranes and the plasma membranes of RBL cells stimulated by Compound 48/80, were studied by confocal laser scanning microscope (CLSM) and total internal reflection fluorescence microscope (TIRFM) both inside and on the surface of living RBL-2H3 cells.

RESULTBefore antigen stimulation, most granules with CD63-GFP hardly moved in RBL cells. However, after antigen stimulation, the granules moved dramatically. They reached the plasma membranes in a few minutes and fused with them instantaneously. The velocity of the granule movement toward the plasma membranes on antigen stimulation was calculated to be 0.05 micron x s(-1).

CONCLUSIONAnalysis of the movement of each granule provided a new insight into the elementary process of degranulation. The method is rapid, sensitive and reliable, which could be used as a new detection method for anaphylactoid reaction in vitro.

Anaphylaxis ; diagnosis ; immunology ; metabolism ; Animals ; Antigens, CD ; genetics ; Cell Degranulation ; Cell Line, Tumor ; Cell Movement ; Mast Cells ; cytology ; immunology ; Microscopy, Confocal ; Microscopy, Fluorescence ; Platelet Membrane Glycoproteins ; genetics ; Rats ; Tetraspanin 30 ; Time Factors

Mast cells are well recognized as key cells in allergic reactions, such as asthma and allergic airway diseases. However, the effects of mast cells and TNF-alpha on T-helper type 2 (Th2) cytokine-dependent asthma are not clearly understood. Therefore, an aim of this study was to investigate the role of mast cells on Th2 cytokine-dependent airway hyperresponsiveness and inflammation. We used genetically mast cell-deficient WBB6F1/J-KitW/KitW-v (W/Wv), congenic normal WBB6F1/J-Kit+/Kit+ (+/+), and mast cell-reconstituted W/Wv mouse models of allergic asthma to investigate the role of mast cells in Th2 cytokine-dependent asthma induced by ovalbumin (OVA). And we investigated whether the intratracheal injection of TNF-alpha directly induce the expression of ICAM-1 and VCAM-1 in W/Wv mice. This study, with OVA-sensitized and OVA-challenged mice, revealed the following typical histopathologic features of allergic diseases: increased inflammatory cells of the airway, airway hyperresponsiveness, and increased levels of TNF-alpha, intercellular adhesion molecule (ICAM)-1, and vascular cellular adhesion molecule (VCAM)-1. However, the histopathologic features and levels of ICAM-1 and VCAM-1 proteins in W/Wv mice after OVA challenges were significantly inhibited. Moreover, mast cell-reconstituted W/Wv mice showed restoration of histopathologic features and recovery of ICAM-1 and VCAM-1 protein levels that were similar to those found in +/+ mice. Intratracheal administration of TNF-alpha resulted in increased ICAM-1 and VCAM-1 protein levels in W/Wv mice. These results suggest that mast cells play a key role in a Th2 cytokine-dependent asthma model through production of adhesion molecules, including ICAM-1 and VCAM-1, by liberation of TNF-alpha.
Animals ; Asthma/*immunology/metabolism/pathology ; Blotting, Western ; Bronchoalveolar Lavage Fluid/immunology ; Cytokines/*immunology ; Intercellular Adhesion Molecule-1/biosynthesis ; Lung/immunology/pathology ; Mast Cells/*immunology/metabolism ; Mice ; Ovalbumin ; Th2 Cells/*immunology ; Tumor Necrosis Factor-alpha/*metabolism ; Vascular Cell Adhesion Molecule-1/biosynthesis

Mast cells have been regarded for a long time as effector cells in IgE mediated type I reactions and in host defence against parasites. However, they are resident in all environmental exposed tissues and express a wide variety of receptors, suggesting that these cells can also function as sentinels in innate immune responses. Indeed, studies have demonstrated an important role of mast cells during the induction of life-saving antibacterial responses. Furthermore, recent findings have shown that mast cells promote and modulate the development of adaptive immune responses, making them an important hinge of innate and acquired immunity. In addition, mast cells and several mast cell-produced mediators have been shown to be important during the development of allergic airway diseases. In the present review, we will summarize findings on the role of mast cells during the development of adaptive immune responses and highlight their function, especially during the development of allergic asthma.
Animals ; Anti-Infective Agents/pharmacology ; Asthma/*immunology/metabolism ; Cytokines/metabolism ; Histamine/metabolism ; Humans ; Hypersensitivity/*immunology/metabolism ; Immune System ; Immunoglobulin E/immunology ; Leukotrienes/metabolism ; Mast Cells/*cytology ; Mice ; Models, Biological ; Prostaglandins/metabolism ; Tumor Necrosis Factor-alpha/metabolism

This study was performed in order to assess whether acute stress can increase mast cell and enterochromaffin (EC) cell numbers, and proteinase-activated receptor-2 (PAR2) expression in the rat colon. In addition, we aimed to investigate the involvement of corticotrophin-releasing factor in these stress-related alterations. Eighteen adult rats were divided into 3 experimental groups: 1) a saline-pretreated non-stressed group, 2) a saline-pretreated stressed group, and 3) an astressin-pretreated stressed group. The numbers of mast cells, EC cells, and PAR2-positive cells were counted in 6 high power fields. In proximal colonic segments, mast cell numbers of stressed rats tended to be higher than those of non-stressed rats, and their PAR2-positive cell numbers were significantly higher than those of non-stressed rats. In distal colonic segments, mast cell numbers and PAR2-positive cell numbers of stressed rats were significantly higher than those of non-stressed rats. Mast cell and PAR2-positive cell numbers of astressin-pretreated stressed rats were significantly lower than those of saline-pretreated stressed rats. EC cell numbers did not differ among the three experimental groups. Acute stress in rats increases mast cell numbers and mucosal PAR2 expression in the colon. These stress-related alterations seem to be mediated by release of corticotrophin-releasing factor.
Animals ; Colon/*metabolism ; Corticotropin-Releasing Hormone/antagonists & inhibitors/metabolism/pharmacology/*physiology ; Enterochromaffin Cells/cytology ; Male ; Mast Cells/*cytology/immunology/metabolism ; Peptide Fragments/pharmacology ; Rats ; Rats, Wistar ; Receptor, PAR-2/*metabolism ; Restraint, Physical ; *Stress, Physiological

BACKGROUNDMast cells are implicated in the development of irritable bowel syndrome (IBS), which is associated with the activation of the "neural-immune" system. The aim of this study was to investigate the role of mast cells in the remodeling of cholinergic and peptidergic neurotransmitters induced by acute cold restriction stress (ACRS) post infection (PI) using mast cell deficient rats (Ws/Ws) and their wild-type controls (+/+).

METHODSTransient intestinal infection was initiated by giving 1500 Trichinella spiralis (T.S.) larvae by gavage. ACRS was induced for 2 hours at day 100 PI. Samples of terminal ilea were prepared for H&E staining, mast cell counting and activation and assessment of IL-1beta and IL-10.

RESULTSWhen infected, both strains of rats experienced an acute infectious stage followed by a recovery. Histological scores were significantly higher in infected rats compared with those of the non-infected controls at day 10 PI (10 day-PI vs. control: +/+: 2.75+/-0.17 vs. 0.42+/-0.09; Ws/Ws: 2.67+/-0.67 vs. 0.50+/-0.34; P<0.01). In +/+ rats, post-infection ACRS induced the formation of low-grade inflammation, represented by the imbalance of IL-1beta and IL-10 (IL-1beta: PI+ACRS vs. control: (1812.24+/-561.61) vs. (1275.97+/-410.21) pg/g, P<0.05; IL-10: PI+ACRS vs. control: (251.9+/-39.8) vs. (255.3+/-24.7) pg/g, P>0.05), accompanied by hyperplasia and activation of mast cells (PI+ACRS vs. control: 58.8+/-19.2 vs. 28.0+/-7.6; P<0.01). The balance between acetylcholine (ACh) and substance P (SP) was also disturbed (ACh: PI+ACRS vs. control: (743.94+/-238.72) vs. (1065.68+/-256.46) pg/g, P<0.05; SP: PI+ACRS vs. control: (892.60+/-231.12) vs. (696.61+/-148.61) pg/g, P<0.05). Nevertheless, similar changes of IL-1beta/IL-10 and ACh/SP were not detected in Ws/Ws rats.

CONCLUSIONThe imbalance of ACh/SP, together with the activation of mucosal immunity induced by post-infection ACRS were lacking in mast cell deficient rats, which supports the premise that mast cells play an important role in cholinergic and peptidergic remodeling in the ileum of rats.

Acetylcholine ; metabolism ; Animals ; Enzyme-Linked Immunosorbent Assay ; Ileum ; metabolism ; Interleukin-10 ; metabolism ; Interleukin-1beta ; metabolism ; Intestines ; immunology ; metabolism ; parasitology ; Male ; Mast Cells ; cytology ; metabolism ; physiology ; ultrastructure ; Microscopy, Electron, Transmission ; Neurotransmitter Agents ; metabolism ; Radioimmunoassay ; Rats ; Substance P ; metabolism ; Trichinella spiralis ; physiology ; Trichinellosis ; immunology

OBJECTIVETo investigate the influence of Weichang Anwan on the treatment of IBS-D in model rats.

METHODAnimal model of compound diarrhea was induced by a lactose enriched diet in the Wistar rat, combining with restraint stress. At first, the best cycle of taking medicine was tested. In order to decide the best cycle of taking medicine, 24 female Wistar rats were randomly divided into normal control group, model group and 60 mg x kg(1) x d(-1) weichangan group. The rate of weight increase, the rate of diarrhea, the incubation period of diarrhea and the diarrhea index were observed. And then 45 female Wistar rats randomly divided into five groups: normal control group, model group and Weichang Anwan groups of high, medium and low doses( 80, 60, 40 mg x kg(-1) x d(-1)). The mast cells in mucous membrane were observed by light microscope. The level of NO in blood serum was checked by the method of nitrate reductase. 5-HT in blood serum was detected by fluorimetry. The level of SP in colon was measured by radioimmunoassay.

RESULTAfter taking Weichang Anwan for 4 days, the rate of weight increase in Weichangan group was higher than the model group's. And the rate of diarrhea was lower significantly. So the best cycle of taking medicine was 4 days. The levels of NO and 5-HT in blood serum decreased remarkably in the model group than those of the normal control group. At the same time, the amount of the mast cells and the level of SP in colon significantly increased. Compared with the model group, the levels of NO and 5-HT in blood serum increased remarkably in the groups of high doses and medium doses. Meanwhile, the amount of the mast cells and the level of SP in colon decreased significantly.

CONCLUSIONWeichang Anwan has the effect of antidiarrhea. It can adjust the levels of NO and 5-HT in blood serum and can inhibit the expression of SP in colon which can active the mast cell. Weichangan can also decrease the amount of the mast cells directly.

Animals ; Colon ; drug effects ; immunology ; metabolism ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; Female ; Humans ; Irritable Bowel Syndrome ; drug therapy ; immunology ; metabolism ; Mast Cells ; immunology ; Nitric Oxide ; blood ; Random Allocation ; Rats ; Rats, Wistar ; Serotonin ; blood ; Substance P ; metabolism