Mycoplasma pneumoniae infection increases airway collagen deposition in a murine model of allergic airway inflammation

Mycoplasma pneumoniae (Mp) has been linked to chronic asthma. Airway remodeling (e.g., airway collagen deposition or fibrosis) is one of the pathological features of chronic asthma. However, the effects of respiratory Mp infection on airway fibrosis in asthma remain unclear. In the present study, we hypothesized that respiratory Mp infection may increase the airway collagen deposition in a murine model of allergic airway inflammation in part through upregulation of transforming growth factor (TGF)-beta1. Double (2 wk apart) inoculations of Mp or saline (control) were given to mice with or without previous allergen (ovalbumin) challenges. On days 14 and 42 after the last Mp or saline, lung tissue and bronchoalveolar lavage (BAL) fluid were collected for analyses of collagen and TGF-beta1 at protein and mRNA levels. In allergen-na?ve mice, Mp did not alter airway wall collagen. In allergen-challenged mice, Mp infections did not change airway wall collagen deposition on day 14 but increased the airway collagen on day 42; this increase was accompanied by increased TGF-beta1 protein in the airway wall and reduced TGF-beta1 protein release from the lung tissue into BAL fluid. Our results suggest that Mp infections could modulate airway collagen deposition in a murine model of allergic airway inflammation with TGF-beta1 involved in the collagen deposition process.     

Galectins in parasite infection and allergic inflammation

Galectins are increasingly recognised as important immunological mediators of homeostasis and disease regulation. This paper gives an overview of current knowledge of galectin involvement in parasite infection and allergic inflammation, two very different but immunologically linked phenomena. Galectins are produced by both the parasite and the host and appear to be intimately involved in parasite establishment, as well as directing the course of infection and the immune response. Host galectins have also been shown to be active participants in the recruitment of cells to sites of inflammation and modulating the effector function of mast cells, neutrophils and eosinophils. Moreover, the ability of galectins to induce differential expression of cytokine genes in leukocytes suggests that they are able to direct the nature of an adaptive immune response, in particular towards a T2-type allergic response. Published in 2004.     

Galectins in parasite infection and allergic inflammation

Galectins are increasingly recognised as important immunological mediators of homeostasis and disease regulation. This paper gives an overview of current knowledge of galectin involvement in parasite infection and allergic inflammation, two very different but immunologically linked phenomena. Galectins are produced by both the parasite and the host and appear to be intimately involved in parasite establishment, as well as directing the course of infection and the immune response. Host galectins have also been shown to be active participants in the recruitment of cells to sites of inflammation and modulating the effector function of mast cells, neutrophils and eosinophils. Moreover, the ability of galectins to induce differential expression of cytokine genes in leukocytes suggests that they are able to direct the nature of an adaptive immune response, in particular towards a T2-type allergic response.     

Effect of SPLUNC1 protein on the Pseudomonas aeruginosa and Epstein-Barr virus

Short palate, lung and nasal epithelium clone 1 (SPLUNC1) gene coded a secreted protein found at the surface of nasopharyngeal epithelium, which may be an innate immunity defensive molecular and a risk factor for nasopharyngeal carcinoma (NPC). Here, we observed the effects of SPLUNC1 on the Gram negative bacteria Pseudomonas aeruginosa, evaluated the ability of SPLUNC1 protein binding to lipopolysaccharide. To observe the effect of SPLUNC1 protein on Epstein-Barr virus (EBV), we raised three EBV-transformed B-lymphocyte lines and treated the cells by SPLUNC1 protein; cellular disruption, apoptosis, EBV DNA content, and viral oncogene expression were analyzed. We found that SPLUNC1 protein can bind to bacterial lipopolysaccharide, inhibit the growth of P. aeruginosa, enhance the disruption and apoptosis of EBV-infected B-lymphocytes, downregulate protein expression of EBV latent membrane protein 1, while upregulate protein expression of EBV envelope glycoprotein gp350/220. The total EBV DNA in the culture medium was decreased significantly after 7 days of treatment by SPLUNC1. This study shows that SPLUNC1 not only has the role of antibacteria and antivirus, but also inhibits the potential oncogenicity of EBV in respiratory epithelium. Hou-De Zhou and Xiao-Ling Li contributed equally to this work.     

Diversity of protein carbonylation in allergic airway inflammation

Oxidative stress is involved in asthma. This study assessed the carbonylation of sputum proteins in 23 uncontrolled adult asthmatic patients and 23 healthy controls. Carbonylated proteins (68 kDa and 53 kDa) were elevated in asthmatics when compared to controls and the 68-kDa carbonylated protein was significantly correlated with sputum eosinophilia. The kinetics of protein carbonylation in bronchoalveolar lavage fluid (BALF) were then examined in a mouse ovalbumin-induced allergic inflammation model. It was found that the carbonylation of various BALF proteins did not uniformly occur after challenge. The appearance of the 53-kDa carbonylated protein was limited within 24 h, while carbonylation of 68-kDa protein peaked at 48 h and was associated with BALF eosinophilia. Thus, it was demonstrated that the 68-kDa and 53-kDa proteins, corresponding to albumin and α1-antitrypsin, respectively, were specifically carbonylated in allergic inflammation in humans and in mice and that eosinophils may play a role in mediating carbonylation of albumin.     

Role of multidrug resistance-associated protein 1 in the pathogenesis of allergic airway inflammation

Multidrug resistance-associated protein 1 (MRP1) is a cysteinyl leukotriene (CysLT) export pump expressed on mast cells. CysLTs are crucial mediators in allergic airway disease. However, biological significance of MRP1 in allergic airway inflammation has not yet been elucidated. In this study, we sensitized wild-type control mice (mrp1(+/+)) and MRP1-deficient mice (mrp1(-/-)) to ovalbumin (OVA) and challenged them with OVA by aerosol. Airway inflammation and goblet cell hyperplasia after OVA exposure were reduced in mrp1(-/-) mice compared with mrp1(+/+) mice. Furthermore, CysLT levels in bronchoalveolar lavage fluid (BALF) from OVA-exposed mrp1(-/-) mice were significantly lower than those from OVA-exposed mrp1(+/+) mice. Levels of OVA-specific IgE, IL-4, and IL-13 in BALF were also decreased in OVA-exposed mrp1(-/-) mice. IgE-mediated release of CysLTs from murine bone marrow-derived mast cells was markedly impaired by MRP1 deficiency. Our results indicate that MRP1 plays an important role in the development of allergic airway inflammation through regulation of IgE-mediated CysLT export from mast cells.     

新的天然免疫保护分子SPLUNC1的结构与功能研究进展

腭、肺及鼻咽上皮克隆(palate,lung,and nasal epithelium clone,PLUNC) 家族为一新近发现的具有宿主防御功能的蛋白质家族,它们大多存在于呼吸道上皮与消化道上皮的表面,在上皮组织与外界各种信号之间起着信号传递中介与信号执行分子的作用．在迄今为止发现的人类10个PLUNC家族成员中,我们所克隆的NASG基因即为这一免疫保护分子家族的成员,对其结构与功能分析表明,它属于SPLUNC1 (short palate,lung,and nasal epithelium clone 1) 的全新转录本,具有杀菌/ 渗透增强蛋白质结构域,能对外来物理及化学刺激做出反应,并具有抗微生物、清除有害化学物质、抗肿瘤等多重功效．SPLUNC1 作为上呼吸道的一种新的天然免疫保护分子,在维持上呼吸道的正常生理活动以及抗炎杀菌抑瘤中起着重要作用．     

Trichinella spiralis: infection reduces airway allergic inflammation in mice

In an effort to define the mechanism underlying the host immune downregulation inherent to Trichinella spiralis infection, we compared the levels of Th1, Th2, and regulatory cytokines and CD4⁺CD25⁺ forkhead box P3 (FoxP3)⁺ T (T_reg) cell recruitment, as well as cellular pathology in the airway between T. spiralis infected and uninfected asthma-induced mice. After the induction of allergic airway inflammation, we noted influxes of inflammatory cells into the peribronchial tree. However, in the T. spiralis infection groups, cellular infiltration was minimal around the bronchial tree, with only a smattering of inflammatory cells. In the OVA-challenged group after T. spiralis infection, the numbers of macrophages and eosinophils in the bronchial alveolar lavage fluid were reduced by 23% and 52%, respectively, as compared to those of the OVA-challenged group. Airway hyperresponsiveness of OVA-challenged mice after T. spiralis infection was significantly suppressed as compared to the OVA-only challenged mice. The T. spiralis-infected mice exhibited a significant reduction in IL-5 concentrations relative to that noted in the OVA-challenged group (p < 0.01). Nevertheless, the regulatory cytokines IL-10 and TGF-β levels were increased significantly as the result of T. spiralis infection, and we verified the recruitment of T_reg cells in lung draining lymph nodes via T. spiralis infection. Therefore, T_reg cells, which were recruited by T. spiralis infection, might ameliorate lung function and reduce allergic airway inflammation.     

Tissue distribution of the secretory protein, SPLUNC1, in the human fetus

We previously identified a tissue-specific gene, short palate, lung, and nasal epithelium clone 1 (SPLUNC1), in nasopharyngeal epithelial tissues. SPLUNC1 was differentially expressed in nasopharyngeal carcinoma. Bioinformatic analysis revealed that SPLUNC1 has the bactericidal permeability-increasing protein/lipid-binding protein (BPI/LBP) domain and a 19 amino acid signal peptide, which suggest that it is a secretory protein. Its precise cellular localization in the respiratory tract is mainly in mucous cells and ducts of submucosal glands. However, little is known about its expression pattern in various human tissues. We generated a highly specific antibody and analyzed its distribution in the human fetus by immunohistochemistry to more precisely determine SPLUNC1 protein localization in human tissues. The results were further validated by RT-PCR. Our results showed that SPLUNC1 protein is expressed at not only the serous glands and epithelium of the upper respiratory tract and digestive tract, but also in the oculi of human embryos. Interestingly, we also found positive staining in fetus adipose tissue, a result not previously reported in studies of adult human tissues. Western blot analysis detected a 24 kDa SPLUNC1 protein in the compounds of nasopharyngeal secretions. This secretory protein was also detected in saliva and tears. Our research suggests that SPLUNC1 protein may not only be an antimicrobial peptide that plays an important role in the maintenance of homeostasis in the upper respiratory tract, oculi, and alimentary tract, it may also be important in the development and lipid metabolism of the adipose tissue.     

Histone deacetylase 3 mediates allergic skin inflammation by regulating expression of MCP1 protein

We have shown the induction of histone deacetylase 3 (HDAC3) in antigen-stimulated rat basophilic leukemia cells via NF-κB. We investigated the role of HDAC3 in allergic skin inflammation. We used a BALB/c mouse model of triphasic cutaneous anaphylaxis (triphasic cutaneous reaction; TpCR) and passive cutaneous anaphylaxis (PCA) to examine the role of HDAC3 in allergic skin inflammation. Triphasic cutaneous reaction involved induction of HDAC3 and was mediated by HDAC3. HDAC3 showed an interaction with FcεRIβ. Trichostatin A (TSA), an inhibitor of HDAC(s), disrupted this interaction. Cytokine array analysis showed that the down-regulation of HDAC3 led to the decreased secretion of monocyte chemoattractant protein 1 (MCP1). FcεRI was necessary for induction of HDAC3 and MCP1. ChIP assays showed that HDAC3, in association with Sp1 and c-Jun, was responsible for induction of MCP1 expression. TSA exerted a negative effect on induction of MCP1. HDAC3 exerted a negative regulation on expression of HDAC2 via interaction with Rac1. The down-regulation of HDAC3 or inactivation of Rac1 induced binding of HDAC2 to MCP1 promoter sequences. TSA exerted a negative effect on HDAC3-mediated TpCR. The BALB/c mouse model of PCA involved induction of HDAC3 and MCP1. HDAC3 and MCP1 were necessary for PCA that involved ear swelling, enhanced vascular permeability, and angiogenesis. Recombinant MCP1 enhanced β-hexosaminidase activity and histamine release and also showed angiogenic potential. TSA exerted a negative effect on PCA. Our data show HDAC3 as a valuable target for the development of allergic skin inflammation therapeutics.     

Endogenous attenuation of allergic lung inflammation by syndecan-1

The airway plays a vital role in allergic lung diseases by responding to inhaled allergens and initiating allergic inflammation. Various proinflammatory functions of the airway epithelium have been identified, but, equally important, anti-inflammatory mechanisms must also exist. We show in this study that syndecan-1, the major heparan sulfate proteoglycan of epithelial cells, attenuates allergic lung inflammation. Our results show that syndecan-1-null mice instilled with allergens exhibit exaggerated airway hyperresponsiveness, glycoprotein hypersecretion, eosinophilia, and lung IL-4 responses. However, administration of purified syndecan-1 ectodomains, but not ectodomain core proteins devoid of heparan sulfate, significantly inhibits these inflammatory responses. Furthermore, syndecan-1 ectodomains are shed into the airway when wild-type mice are intranasally instilled with several biochemically distinct inducers of allergic lung inflammation. Our results also show that syndecan-1 ectodomains bind to the CC chemokines (CCL7, CCL11, and CCL17) implicated in allergic diseases, inhibit CC chemokine-mediated T cell migration, and suppress allergen-induced accumulation of Th2 cells in the lung through their heparan sulfate chains. Together, these findings uncover an endogenous anti-inflammatory mechanism of the airway epithelium where syndecan-1 ectodomains attenuate allergic lung inflammation via suppression of CC chemokine-mediated Th2 cell recruitment to the lung.     

SPLUNC1多肽抗体的设计、制备与鉴定

通过设计SPLUNC1蛋白的一段多肽,快速制备抗SPLUNC1的多肽抗体,检测多肽抗体的性能,为SPLUNC1的功能研究提供可靠的平台. 用DS Gene1.1软件分析SPLUNC1蛋白的跨膜结构域、二级结构、疏水性、亲水性以及抗原性等,综合考虑抗体设计的其它因素,设计出两段15～20个氨基酸的多肽.将合成后的多肽与钥孔戚血蓝素（keyhole limpet hemocyanin,KLH）偶联,同时初筛出宿主血清与SPLUNC1无交叉反应的新西兰家兔,用与KLH相连的SPLUNC1多肽免疫家兔,2个月后获取血清,亲和纯化出抗SPLUNC1多肽抗体,通过ELISA法检测其效价,免疫印迹与免疫组化检测其特异性与适用范围.通过该方法得到了高效价与高特异性的SPLUNC1多克隆特异性抗体,ELISA法测定其效价可达到1∶10⁵,通过对包含有PLUNC家族不同成员的蛋白混合物进行Western印迹检测证明,该多肽抗体具有较高的特异性,不与同一家族中的其它蛋白发生交叉反应,而且该抗体可用于免疫组化,说明所制备的分泌性蛋白SPLUNC1抗体具有高特异、高效价等特点,将为SPLUNC1基因的功能研究提供有用的研究材料.     

Acute inflammation plays a limited role in the regulation of adipose tissue COL1A1 protein abundance

Obesity is an inflammatory condition that is also associated with increased extracellular matrix (ECM) gene expression. However, a direct link between adipose tissue inflammation and ECM gene expression has not been established. Therefore, we determined the effect of chronic inflammation induced by obesity and acute inflammation by lipopolysaccharide (LPS) challenge on ECM genes including biglycan (BGN), collagen 1A1 (COL1A1) and COL6A1, major ECM genes in adipose tissue. Male C57BL/6J mice fed either a control diet (10% fat calories) or a high-fat diet (HFD) (60% fat calories) for 6 weeks were treated with LPS or saline 24 h before sacrifice. Expression of ECM genes in the epididymal (EWAT) and subcutaneous adipose tissue (SWAT) was determined by RT-PCR and protein abundance by Western blotting. Human SWAT from lean and obese subjects was also analyzed. Increased messenger RNA (mRNA) expression of ECM genes BGN and COL1A1 was observed in the mouse EWAT after HFD (P<.05). However, reduced amount of COL1A1 protein was observed in EWAT of mice on HFD and in SWAT from obese human subjects. Acute inflammation induced BGN mRNA in EWAT, enhanced the gene expression of matrix metalloproteases (MMPs) 3 and 9. Acute inflammation also resulted in higher MMP9 gelatinolytic activity; however, this showed no association with COL1A1 protein abundance. Higher MMP2 expression in mice on HFD suggests its involvement in the reduction of COL1A1 protein abundance with HFD. Elevated MMP9 gelatinolytic activity in SWAT from obese humans indicates a prominent role for MMP9 in SWAT COL1A1 protein turnover in humans.     

Nasal hyperreactivity and inflammation in allergic rhinitis

The history of allergic disease goes back to 1819, when Bostock described his own 'periodical affection of the eyes and chest', which he called 'summer catarrh'. Since they thought it was produced by the effluvium of new hay, this condition was also called hay fever. Later, in 1873, Blackley established that pollen played an important role in the causation of hay fever. Nowadays, the definition of allergy is 'An untoward physiologic event mediated by a variety of different immunologic reactions'. In this review, the term allergy will be restricted to the IgE-dependent reactions. The most important clinical manifestations of IgE-dependent reactions are allergic conjunctivitis, allergic rhinitis, allergic asthma and atopic dermatitis. However, this review will be restricted to allergic rhinitis. The histopathological features of allergic inflammation involve an increase in blood flow and vascular permeability, leading to plasma exudation and the formation of oedema. In addition, a cascade of events occurs which involves a variety of inflammatory cells. These inflammatory cells migrate under the influence of chemotactic agents to the site of injury and induce the process of repair. Several types of inflammatory cells have been implicated in the pathogenesis of allergic rhinitis. After specific or nonspecific stimuli, inflammatory mediators are generated from cells normally found in the nose, such as mast cells, antigen-presenting cells and epithelial cells (primary effector cells) and from cells recruited into the nose, such as basophils, eosinophils, lymphocytes, platelets and neutrophils (secondary effector cells). This review describes the identification of each of the inflammatory cells and their mediators which play a role in the perennial allergic processes in the nose of rhinitis patients.     

Y1 signalling has a critical role in allergic airway inflammation

Asthma affects 300 million people worldwide, yet the mechanism behind this pathology has only been partially elucidated. The documented connection between psychological stress and airway inflammation strongly suggests the involvement of the nervous system and its secreted mediators, including neuropeptides, on allergic respiratory disease. In this study, we show that neuropeptide Y (NPY), a prominent neurotransmitter, which release is strongly upregulated during stress, exacerbates allergic airway inflammation (AAI) in mice, via its Y1 receptor. Our data indicate that the development of AAI was associated with elevated NPY expression in the lung and that lack of NPY-mediated signalling in NPYKO mice or its Y1 receptor in Y1KO mice significantly improved AAI. In vivo, eosinophilia in the bronchoalveolar fluid as well as circulating immunoglobulin E in response to AAI, were significantly reduced in NPY- and Y1-deficient compared with wild-type mice. These changes correlated with a blunting of the Th2 immune profile that is characteristic for AAI, as shown by the decreased release of interleukin-5 during ex vivo re-stimulation of T cells isolated from the thoracic draining lymph nodes of NPY- or Y1-deficient mice subjected to AAI. Taken together this study demonstrates that signalling through Y1-receptors emerges as a critical pathway for the development of airway inflammation and as such potentially opens novel avenues for therapeutic intervention in asthma.