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*

OBJECTIVE: To observe the effects of acupuncture combined with bloodletting on the expression of inflammatory factors in serum, the morphology of sensitized skin tissue and the mast cell degranulation in urticaria rats, and to explore the potential mechanism of this therapy for urticaria. METHODS: Among 42 SD rats of SPF grade, 6 rats were randomly collected for the preparation of sensitized antiserum; and the rest 36 rats were randomized into a blank group, a model group, a positive drug group, an acupuncture group, a bloodletting group and a combined treatment group (acupuncture + bloodletting), 6 rats in each one. The rat model of urticaria was established by passive cutaneous anaphylaxis. In the positive drug group, loratadine (1 mg•kg^-1) by gavage was administered once a day. In the acupuncture group, 1 h after gavage with 0.9% NaCl (1 mL), acupuncture was delivered at "Baihui" (GV 20), "Zhongwan" (CV 12), and bilateral "Quchi" (LI 11) and "Xuehai" (SP 10) for 15 min, once daily . In the bloodletting group, 1 h after gavage with 0.9% NaCl (1 mL), bloodletting was operated at "Dazhui" (GV 14) and bilateral "Geshu" (BL 17), around 0.1 mL of bleeding volume at each point, once daily. In the combined treatment group, 1 h after gavage with 0.9% NaCl (1 mL), the interventions as the acupuncture group and the bloodletting group were adopted, once daily. All the interventions started on day 6 of modeling, lasting 2 weeks. After intervention completion, antigenic stimulation was performed in the rats of each group. Using ELISA, the levels of serum immunoglobulin E (IgE), tryptase (TPS), interleukin-4 (IL-4), interleukin-5 (IL-5), tumor necrosis factor-α (TNF-α) were detected. The diameter of the blue spots of the sensitized skin on the back was measured with ruler in each rat. The morphology of sensitized skin tissue was observed using HE staining, and the degranulation of mast cells was observed using Toluidine blue staining. RESULTS: Compared with the blank group, in the model group, the levels of serum IgE, TPS, IL-4, IL-5 and TNF-α increased (P<0.01), the diameter of blue spot on the sensitized part of the rat back was larger (P<0.01), the degranulation rate of mast cells was elevated (P<0.01), and there were obvious inflammatory cell infiltration and edema in the dermis of sensitized skin tissue on the rat back. Compared with the model group, the serum levels of IgE, TPS, IL-4, IL-5 and TNF-α were reduced in the positive drug group, the acupuncture group, the bloodletting group and the combined treatment group (P<0.01, P<0.05); skin blue spot diameter was smaller in the positive drug group and the combined treatment group (P<0.05); the degranulation rate of mast cells decreased in the positive drug group, the acupuncture group, the bloodletting group and the combined treatment group (P<0.01); and the dermal edema, inflammatory infiltration were attenuated in the positive drug group, the acupuncture group, the bloodletting group and the combined treatment group. Compared with the acupuncture group and the bloodletting group, the serum levels of IgE, TPS, IL-4, IL-5 and TNF-α, as well as the degranulation rate of mast cells in the sensitized tissue were lower in the positive drug group and the combined treatment group (P<0.05). CONCLUSION Acupuncture combined with bloodletting effectively suppress mast cell degranulation in the sensitized skin tissue on the back of urticaria rats, and ameliorate the histopathological morphology. Its effect mechanism may be related to inhibiting the differentiation and proliferation of helper T cells 2 and regulating the humoral immune response.
Animals ; Rats ; Mast Cells/immunology* ; Acupuncture Therapy ; Rats, Sprague-Dawley ; Male ; Cell Degranulation ; Humans ; Bloodletting ; Urticaria/immunology* ; Female ; Acupuncture Points ; Tumor Necrosis Factor-alpha/blood* ; Interleukin-4/blood* ; Interleukin-5/blood* ; Combined Modality Therapy ; Immunoglobulin E/blood* ; Disease Models, Animal

Mast cells are widely distributed in various parts of the body, especially in the mucosal surface between the body and the external environment. Mast cell is one of the important immune cells and plays important roles in innate immunity, adaptive immunity and immune regulation. Previous researches have shown that excessive activation of mast cells is closely related to the development of allergic and inflammatory diseases such as asthma, allergic rhinitis, food allergies, acute and chronic itching. Mast cells infiltrate into the inflammation site and release various allergic mediators during the occurrence and development of these diseases. Therefore, termination of mast cell activation can be one of the effective methods for the treatment of allergic and inflammatory diseases, and receptors related to mast cell activation are potential targets for the development of anti-allergic drugs. There are many receptors related to mast cell activation, and the effects mediated by different receptors varied from each other. In the recent years, new mast cell receptors are being discovered, but there are not many literatures discussing the possible functions of these newly discovered receptors. This review aims to summarize the receptors involved in mast cell activation and classify related receptors according to their effects.
Asthma ; immunology ; Humans ; Hypersensitivity ; immunology ; Immunity, Innate ; Inflammation ; immunology ; Mast Cells ; cytology ; immunology

The pathogenesis of allergic rhinitis(AR)is extremely complex.In recent years,a variety of allergens and other complexes have been developed to induce a series of signal transduction mechanisms by activating mast cells.Intracellular media release(mast cells,MCs)play an important role in the pathogenesis of AR.In this paper,we reviewed the progress of mast cells in the pathogenesis of allergic rhinitis in recent years in order to further understand its role in the pathogenesis of allergic rhinitis and provide new ideas on the therapeutic target for allergic rhinitis.
Allergens ; Cell Count ; Humans ; Mast Cells ; Rhinitis, Allergic ; immunology ; Signal Transduction

Mast cells, which are major effector cells in allergic reactions, are found in the perivascular spaces of most tissues and contain pro-inflammatory and vasoactive mediators. These mediators are released after IgE receptor cross-linking induced by allergens or other stimuli, including anaphylatoxins (C3a and C5a), aggregated IgG, certain drugs, venoms, and physical stimuli (pressure and temperature changes), as well as cytokines and neuropeptides. The excess release of these mediators can cause variable allergic symptoms and signs, such as bronchospasm, itching, flushing, nausea, vomiting, diarrhea, abdominal pain, vascular instability, and anaphylaxis. Furthermore, mast cell disorders may involve either excessive proliferation of mast cells or abnormal mast cell reactivity. Mast cell disorders can be broadly divided into 3 types: primary, secondary, and idiopathic. All of these disorders present with signs and symptoms of mast cell activation and differ in severity and involvement of various organ systems. The best characterized primary disorder is mastocytosis. Systemic and cutaneous forms of the disease are well described. Secondary disorders include typical allergic diseases and some types of urticarial diseases. In this article, the biochemical characteristics of mast cells and the role of mast cells in allergic inflammation, as well as the classification, diagnosis, and management of mast cell-related disorders, will be reviewed.
Abdominal Pain ; Allergens ; Allergy and Immunology ; Anaphylatoxins ; Anaphylaxis ; Bronchial Spasm ; Classification ; Cytokines ; Diagnosis ; Diarrhea ; Flushing ; Hypersensitivity ; Immunoglobulin E ; Immunoglobulin G ; Inflammation* ; Mast Cells* ; Mastocytosis ; Nausea ; Neuropeptides ; Pruritus ; Venoms ; Vomiting

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 reveal the innate immunity of mast cells against recombinant VP1-VP4 protein of foot-and-mouth disease virus (FMDV), mouse peritoneal mast cells (PMCs) were pulsed with recombinant VP1-VP4 protein. The supernatants harvested from PMCs cultures were applied to the high throughput ELISA array. Our results show that the expression levels of CCL19, L-selectin, CCL17, and TNF alpha released from PMCs pulsed with recombinant VP1-VP4 were significantly down-regulated compared with PMCs alone (P<0.001). Surprisingly, in comparison with PMCs alone, the expression levels of CCL19, IL-15, IL-9, G-CSF, and Galectin-1 in PMCs with the mannose receptor (MR) inhibitor were significantly up-regulated (Plt;0.01), and the expression level of IL-10 was also remarkably up-regulated (Plt;0.05). Importantly, the protein expression levels in PMCs treated with MR inhibitor were higher than PMCs pulsed with VP1-VP4, including IL-10, IL-17, CCL20, IL-15, IL-9, L-selectin, CCL17, TNF alpha, and CCL19 (Plt;0.01) as well as CCL21, and G-CSF (Plt;0.05). Differential expression analysis in bioinformatics shows that both L-selectin and CCL17 were recognized as differentially expressed protein molecules (Log2(ratio)≤-1) when compared with PMCs alone. Furthermore, the up-regulation of the expression levels of CCL20, CCL19, L-selectin, and IL-15 in PMCs treated with MR inhibitor was defined as differential expression (Log2(ratio)≥1). These data indicate that PMCs are capable of secreting CCL19, L-selectin, CCL17, and TNF alpha spontaneously and the recombinant VP1-VP4 has an inhibitive potential to PMCs during their performance of innate immune response. Given the protein expression levels from PMCs pre-treated with MR inhibitor were significantly increased, it can be deduced that immunosuppression of FMDV is presumably initiated by the VP1 recognition of MR on mast cells.
Animals ; Capsid Proteins ; immunology ; Cells, Cultured ; Cytokines ; immunology ; Enzyme-Linked Immunosorbent Assay ; Foot-and-Mouth Disease ; Foot-and-Mouth Disease Virus ; Interleukins ; immunology ; Mast Cells ; immunology ; Mice ; Proteome ; immunology ; Recombinant Proteins ; immunology ; Viral Structural Proteins ; immunology

To investigate me material basis of Mahuang Fuzi Xixin decoction (MFXD) for anti-inflammation and immune-suppression based on the combined method of serum chemical and serum pharmacological. The LC-MS/MS fingerprints of MFXD, drug-containing serum and blank serum were compared to define the components in plasma. Histamine, β-hexosaminidase released from RBL-2H3 cell infulenced by drug-containing serum at different time points were measured by ELISA. The effect of drug-containing serum on lipopolysaccharide-induced splenocyte proliferation at different time points were determined by MTT. A correlation analysis was made on components of MFXD and pharmacological indexes based the stepwise regression method. After the intragastrical administration with MFXD, 32 components were discovered in rat serum, including 27 prototype components (10 from Mahuang, 13 from Fuzi and four from Xixin) and five unknown components. Compared with blank serum, drug-containing serum could reduce the release of histamine from RBL-2H3 induced by antigen at different time points (P < 0.05); except the 4-hour drug-containing serum, all of the remaining drug-containing serums could inhibit the RBL-2H3 mastocyte degranulation induced by antigen at different time points (P < 0.05). Drug-containing serum could significantly lipopolysaccharide-induced mouse splenocyte proliferation at 15 and 30 min (P < 0.05). A regression analysis was made on the chemical data of components absorbed into blood and pharmacological indexes, i. e. release rate of histamine, release rate of β-hexosaminidase and inhibition rate of splenocyte. This suggested the close correlations among methyl pseudo-ephedrine, pseudoephedrine and histamine released from RBL-2H3 induced by antigen; pseudoephedrine, hypaconine, methyl pseudoephedrine and β-hexosaminidase released from RBL-2H3 induced by antigen; as well as benzoyl hypaconine, benzoylaconine, 14-benzoyl-10-OH-mesaconine, mesaconine and lipopolysaccharide-induced mouse splenocyte proliferation. Methylpseudoephedrine, pseudoephedrine, benzoyl hypaconine, benzoylaconine and mesaconine may be part of material basis of MFXD on anti-inflammation and immune suppression.
Animals ; Anti-Inflammatory Agents ; chemistry ; pharmacology ; Cell Degranulation ; drug effects ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; Female ; Histamine ; immunology ; Immunosuppressive Agents ; chemistry ; pharmacology ; Male ; Mass Spectrometry ; Mast Cells ; drug effects ; immunology ; Mice ; Rats ; Rats, Wistar ; Serum ; chemistry

Interleukin (IL) 33, a member of the IL-1 superfamily, is an "alarmin" protein and is secreted in its active form from damaged cells undergoing necrotic cell death. Mast cells are one of the main effector cell types in allergic disorders. They secrete a variety of mediators, including T helper 2 cytokines. As mast cells have high-affinity IgE receptors (FcepsilonRI) on their surface, they can capture circulating IgE. IgE-bound mast cells degranulate large amounts of histamine, heparin, and proteases when they encounter antigens. As IL-33 is an important mediator of innate immunity and mast cells play an important role in adaptive immune responses, interactions between the two could link innate and adaptive immunity. IL-33 promotes the adhesion of mast cells to laminin, fibronectin, and vitronectin. IL-33 increases the expression of adhesion molecules, such as intracellular adhesion molecule-1 and vascular cell adhesion molecule-1, in endothelial cells, thus enhancing mast cell adhesion to blood vessel walls. IL-33 stimulates mast cell proliferation by activating the ST2/Myd88 pathway; increases mast cell survival by the activation of survival proteins such as Bcl-XL; and promotes the growth, development, and maturation of mast cell progenitors. IL-33 is also involved in the activation of mature mast cells and production of different proinflammatory cytokines. The interaction of IL-33 and mast cells could have important clinical implications in the field of clinical urology. Epithelial dysfunction and mast cells could play an important role in the pathogenesis of interstitial cystitis. Urinary levels of IL-33 significantly increase in patients with interstitial cystitis. In addition, the number of mast cells significantly increase in the urinary bladders of patients with interstitial cystitis. Therefore, inhibition of mast cell activation and degranulation in response to increase in IL-33 is a potential therapeutic target in the treatment of interstitial cystitis.
Adaptive Immunity* ; Allergy and Immunology ; Blood Vessels ; Cell Death ; Cystitis, Interstitial ; Cytokines ; Endothelial Cells ; Fibronectins ; Heparin ; Histamine ; Humans ; Immunity, Innate ; Immunoglobulin E ; Interleukin-1 ; Interleukins ; Laminin ; Mast Cells* ; Peptide Hydrolases ; Receptors, IgE ; Urinary Bladder ; Urology ; Vascular Cell Adhesion Molecule-1 ; Vitronectin

Mucosal immune responses against Pygidiopsis summa (Trematoda: Heterophyidae) infection were studied in ICR mice. Experimental groups consisted of group 1 (uninfected controls), group 2 (infection with 200 metacercariae), and group 3 (immunosuppression with Depo-Medrol and infection with 200 metacercariae). Worms were recovered in the small intestine at days 1, 3, 5, and 7 post-infection (PI). Intestinal intraepithelial lymphocytes (IEL), mast cells, and goblet cells were counted in intestinal tissue sections stained with Giemsa, astra-blue, and periodic acid-Schiff, respectively. Mucosal IgA levels were measured by ELISA. Expulsion of P. summa from the mouse intestine began to occur from days 3-5 PI which sustained until day 7 PI. The worm expulsion was positively correlated with proliferation of IEL, mast cells, goblet cells, and increase of IgA, although in the case of mast cells significant increase was seen only at day 7 PI. Immunosuppression suppressed all these immune effectors and inhibited worm reduction in the intestine until day 7 PI. The results suggested that various immune effectors which include IEL, goblet cells, mast cells, and IgA play roles in regulating the intestinal mucosal immunity of ICR mice against P. summa infection.
Animals ; Disease Models, Animal ; Enzyme-Linked Immunosorbent Assay ; Goblet Cells/immunology ; Heterophyidae/*immunology ; *Immunity, Mucosal ; Immunoglobulin A/analysis ; Intestine, Small/parasitology/pathology ; Leukocyte Count ; Lymphocytes/immunology ; Male ; Mast Cells/immunology ; Mice ; Mice, Inbred ICR ; Parasite Load ; Time Factors ; Trematode Infections/*immunology/parasitology