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

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

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

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

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

OBJECTIVETo investigate the role and significance of cardiac mast cells and Toll-like receptor 4 (TLR4) in the development and progression of viral myocarditis (VMC).

METHODSForty-eight Balb/c mice were randomly divided into a control group (n=24) and a model group (n=24). Coxsackievirus B3 was intraperitoneally injected into the model group mice to establish a VMC model. In each group, cardiac tissues were collected from 8 mice at 7, 14 and 28 days after the model was established. The cardiac tissues were stained with hematoxylin and eosin as well as Masson trichrome to observe pathological changes in cardiac tissues. The number and degranulation of cardiac mast cells at each time point were measured and evaluated by toluidine blue staining and transmission electron microscopy. The mRNA and protein expression of TLR4 in cardiac tissues was measured by RT-PCR and immunohistochemistry. In the model group, the correlation between number of cardiac mast cells and mRNA expression of TLR4 at all time points was analyzed.

RESULTSThe model group had significantly higher pathological scores of cardiac tissues than the control group at all time points (P<0.05). The myocardial collagen volume fraction in the model group at 28 days was significantly higher than in the control group at all time points and higher than in the model group at 7 and 14 days (P<0.05). At each time point, the model group had a significantly increased number of mast cells (P<0.05), and significantly increased mRNA and protein expression of TLR4 (P<0.05) compared with the control group. In the model group, the number of cardiac mast cells was positively correlated with the mRNA expression of TLR4 at all time points (R²=0.877, P<0.05).

CONCLUSIONSMice with VMC have significantly increased numbers of cardiac mast cells and expression of TLR4 compared with control mice at all time points, suggesting that mast cells and TLR4 may play important roles in the inflammatory response and fibrosis of VMC.

Animals ; Coxsackievirus Infections ; immunology ; Enterovirus B, Human ; Female ; Mast Cells ; physiology ; Mice ; Mice, Inbred BALB C ; Myocarditis ; immunology ; Myocytes, Cardiac ; pathology ; Toll-Like Receptor 4 ; analysis ; genetics ; physiology