Heparin potentiates in vivo neutrophil migration induced by IL-8

Chinese Society of Allergy Guidelines for Diagnosis and Treatment of Allergic Rhinitis

Allergic rhinitis (AR) is a global health problem that causes major illnesses and disabilities worldwide. Epidemiologic studies have demonstrated that the prevalence of AR has increased progressively over the last few decades in more developed countries and currently affects up to 40% of the population worldwide. Likewise, a rising trend of AR has also been observed over the last 2-3 decades in developing countries including China, with the prevalence of AR varying widely in these countries. A survey of self-reported AR over a 6-year period in the general Chinese adult population reported that the standardized prevalence of adult AR increased from 11.1% in 2005 to 17.6% in 2011. An increasing number of Journal Articles and imporclinical trials on the epidemiology, pathophysiologic mechanisms, diagnosis, management and comorbidities of AR in Chinese subjects have been published in international peer-reviewed journals over the past 2 decades, and substantially added to our understanding of this disease as a global problem. Although guidelines for the diagnosis and treatment of AR in Chinese subjects have also been published, they have not been translated into English and therefore not generally accessible for reference to non-Chinese speaking international medical communities. Moreover, methods for the diagnosis and treatment of AR in China have not been standardized entirely and some patients are still treated according to regional preferences. Thus, the present guidelines have been developed by the Chinese Society of Allergy to be accessible to both national and international medical communities involved in the management of AR patients. These guidelines have been prepared in line with existing international guidelines to provide evidence-based recommendations for the diagnosis and management of AR in China.

Increased migration of antigen presenting cells to newly-formed lymphatic vessels in transplanted kidneys by glycol-split heparin

Background

Chronic renal transplant dysfunction is characterized by loss of renal function and tissue remodeling, including chronic inflammation and lymph vessel formation. Proteoglycans are known for their chemokine presenting capacity. We hypothesize that interruption of the lymphatic chemokine–proteoglycan interaction interferes with the lymphatic outflow of leukocytes from the renal graft and might decrease the anti-graft allo-immune response.

Methods

In a rat renal chronic transplant dysfunction model (female Dark-Agouti to male Wistar Furth), chemokines were profiled by qRT-PCR in microdissected tubulo-interstitial tissue. Disruption of lymphatic chemokine–proteoglycan interaction was studied by (non-anticoagulant) heparin-derived polysaccharides in vitro and in renal allografts. The renal allograft function was assessed by rise in plasma creatinine and urea.

Results

Within newly-formed lymph vessels of transplanted kidneys, numerous CD45⁺ leukocytes were found, mainly MHCII⁺, ED-1^-, IDO^-, HIS14^-, CD103^- antigen presenting cells, most likely representing a subset of dendritic cells. Treatment of transplanted rats with regular heparin and two different (non-)anticoagulant heparin derivatives revealed worsening of kidney function only in the glycol-split heparin treated group despite a two-fold reduction of tubulo-interstitial leukocytes (p<0.02). Quantitative digital image analysis however revealed increased numbers of intra-lymphatic antigen-presenting cells only in the glycol-split heparin group (p<0.01). The number of intra-lymphatic leukocytes significantly correlates with plasma creatinine and urea, and inversely with creatinine clearance.

Conclusions

Treatment of transplanted rats with glycol-split heparin significantly increases the number of intra-lymphatic antigen presenting cells, by increased renal diffusion of lymphatic chemokines, thereby increasing the activation and recruitment of antigen presenting cells towards the lymph vessel. This effect is unwanted in the transplantation setting, but might be advantageous in e.g., dendritic cell vaccination.

N-Arylacyl O-sulfonated aminoglycosides as novel inhibitors of human neutrophil elastase, cathepsin G and proteinase 3

The balance between neutrophil serine proteases (NSPs) and protease inhibitors (PIs) in the lung is a critical determinant for a number of chronic inflammatory lung diseases such as chronic obstructive pulmonary disease, cystic fibrosis and acute lung injury. During activation at inflammatory sites, excessive release of NSPs such as human neutrophil elastase (HNE), proteinase 3 (Pr3) and cathepsin G (CatG), leads to destruction of the lung matrix and continued propagation of acute inflammation. Under normal conditions, PIs counteract these effects by inactivating NSPs; however, in chronic inflammatory lung diseases, there are insufficient amounts of PIs to mitigate damage. Therapeutic strategies are needed to modulate excessive NSP activity for the clinical management of chronic inflammatory lung diseases. In the study reported here, a panel of N-arylacyl O-sulfonated aminoglycosides was screened to identify inhibitors of the NSPs. Dose-dependent inhibitors for each individual serine protease were identified. Select compounds were found to inhibit multiple NSPs, including one lead structure that is shown to inhibit all three NSPs. Two lead compounds identified during the screen for each individual NSP were further characterized as partial mixed inhibitors of CatG. Concentration-dependent inhibition of protease-mediated detachment of lung epithelial cells is demonstrated.

Mast cells and basophils are essential for allergies: mechanisms of allergic inflammation and a proposed procedure for diagnosis

The current definition of allergy is a group of IgE-mediated diseases. However, a large portion of patients with clinical manifestations of allergies do not exhibit elevated serum levels of IgE (sIgEs). In this article, three key factors, ie soluble allergens, sIgEs and mast cells or basophils, representing the causative factors, messengers and primary effector cells in allergic inflammation, respectively, were discussed. Based on current knowledge on allergic diseases, we propose that allergic diseases are a group of diseases mediated through activated mast cells and/or basophils in sensitive individuals, and allergic diseases include four subgroups: (1) IgE dependent; (2) other immunoglobulin dependent; (3) non-immunoglobulin mediated; (4) mixture of the first three subgroups. According to our proposed definition, pseudo-allergic-reactions, in which mast cell or basophil activation is not mediated via IgE, or to a lesser extent via IgG or IgM, should be non-IgE-mediated allergic diseases. Specific allergen challenge tests (SACTs) are gold standard tests for diagnosing allergies in vivo, but risky. The identification of surface membrane activation markers of mast cells and basophils (CD203c, CCR3, CD63, etc) has led to development of the basophil activation test (BAT), an in vitro specific allergen challenge test (SACT). Based on currently available laboratory allergy tests, we here propose a laboratory examination procedure for allergy.

Molecular functions of syndecan-1 in disease

Syndecan-1 is a cell surface heparan sulfate proteoglycan that binds to many mediators of disease pathogenesis. Through these molecular interactions, syndecan-1 can modulate leukocyte recruitment, cancer cell proliferation and invasion, angiogenesis, microbial attachment and entry, host defense mechanisms, and matrix remodeling. The significance of syndecan-1 interactions in disease is underscored by the striking pathological phenotypes seen in the syndecan-1 null mice when they are challenged with disease-instigating agents or conditions. This review discusses the key molecular functions of syndecan-1 in modulating the onset, progression, and resolution of inflammatory diseases, cancer, and infection.

Tumor-derived syndecan-1 mediates distal cross-talk with bone that enhances osteoclastogenesis

Tumor-stimulated bone resorption fuels tumor growth and marks a dramatic decline in the health and prognosis of breast cancer patients. Identifying mechanisms that mediate cross-talk between tumor and bone remains a key challenge. We previously demonstrated that breast cancer cells expressing high levels of heparanase exhibit enhanced shedding of the syndecan-1 proteoglycan. Moreover, when these heparanase-high cells are implanted in the mammary fat pad, they elevate bone resorption. In this study, conditioned medium from breast cancer cells expressing high levels of heparanase was shown to significantly stimulate human osteoclastogenesis in vitro (p < .05). The osteoclastogenic activity in the medium of heparanase-high cells was traced to the presence of syndecan-1, intact heparan sulfate chains, and heat-labile factor(s), including the chemokine interleukin 8 (IL-8). The enhanced osteoclastogenesis promoted by the heparanase-high cells results in a dramatic increase in bone resorption in vitro. In addition, the long bones of animals bearing heparanase-high tumors in the mammary fat pad had significantly higher numbers of osteoclasts compared with animals bearing tumors expressing low levels of heparanase (p < .05). Together these data suggest that syndecan-1 shed by tumor cells exerts biologic effects distal to the primary tumor and that it participates in driving osteoclastogenesis and the resulting bone destruction.

Expression of syndecan-2 in the amoeboid microglial cells and its involvement in inflammation in the hypoxic developing brain

The present study examined the expression of heparan sulphate proteoglycan, syndecan-2 (Sdc-2) in the corpus callosum and the amoeboid microglial cells (AMC) in the neonatal rat brain in response to hypoxia. In 1-day old Wistar rats subjected to hypoxia the mRNA and protein expression of Sdc-2 in the corpus callosum, heavily populated by AMC, was increased up to 3 days after the hypoxic exposure. Immunoexpression of Sdc-2 was localized in AMC as confirmed by double labeling using microglial marker. Primary cultures of microglial cells subjected to hypoxia showed a significant increase in Sdc-2 expression. Application of Sdc-2 to microglial cultures under hypoxia increased the release of tumor necrosis factor-alpha, interleukin-1beta, chemokine (C-C motif) ligand 2 (CCL2), and chemokine (C-X-C motif) ligand 12 (CXCL12) by the microglial cells. Additionally, Sdc-2 enhanced the production of reactive oxygen species (ROS) by microglia subjected to hypoxia. Edaravone [3-methyl-1phenyl-2-pyrazolin-5-one], an antioxidant drug, suppressed the hypoxia- and Sdc-2-induced increased production of cytokines, chemokines, and ROS. In the light of these findings, we suggest that Sdc-2 plays an important role in microglial production of inflammatory cytokines, chemokines, and ROS in hypoxic conditions. In this connection, edaravone suppressed the hypoxia- and Sdc-2-induced increased cytokine and ROS production suggesting its therapeutic potential in ameliorating neuroinflammation.

Staphylococcus aureus beta-toxin induces lung injury through syndecan-1

In pneumonia caused by the bacterium Staphylococcus aureus, the intense inflammatory response that is triggered by this infection can lead to the development of lung injury. Little is known, however, about the impact of specific virulence factors on this inflammatory disorder, which causes both significant mortality and morbidity. In this study, we examined the role of beta-toxin, a neutral sphingomyelinase, in S. aureus-induced lung injury. Our results showed that the central features of lung injury--specifically, increased neutrophilic inflammation, vascular leakage of serum proteins into the lung tissue, and exudation of proteins into the airway--are significantly attenuated in mice infected intranasally with S. aureus deficient in beta-toxin compared with mice infected with S. aureus expressing beta-toxin. In addition, intranasal administration of beta-toxin evoked the characteristic features of lung injury in wild-type mice whereas neutropenic mice were protected from such injury. However, mutant beta-toxin mice deficient in sphingomyelinase activity failed to trigger features of lung injury. Ablation of sphingomyelinase activity also interfered with the ability of beta-toxin to stimulate ectodomain shedding of syndecan-1, a major heparan sulfate proteoglycan found in epithelial cells. Moreover, syndecan-1-null mice were significantly protected from beta-toxin-induced lung injury relative to wild-type mice. These data indicate that S. aureus beta-toxin is a critical virulence factor that induces neutrophil-mediated lung injury through both its sphingomyelinase activity and syndecan-1.

The isolation of novel mesenchymal stromal cell chemotactic factors from the conditioned medium of tumor cells

Bone marrow-derived mesenchymal stromal cells (MSCs) localize to solid tumors. Defining the signaling mechanisms that regulate this process is important in understanding the role of MSCs in tumor growth. Using a combination of chromatography and electrospray tandem mass spectrometry we have identified novel soluble signaling molecules that induce MSC chemotaxis present in conditioned medium of the breast carcinoma cell line MDA-MB231. Previous work has employed survey strategies using ELISA assay to identify known chemokines that promote MSC chemotaxis. While these studies provide valuable insights into the intercellular signals that impact MSC behavior, many less well-described, but potentially important soluble signaling molecules could be overlooked using these methods. Through the less directed method of column chromatography we have identified novel candidate MSC chemotactic peptides. Two proteins, cyclophilin B and hepatoma-derived growth factor were then further characterized and shown to promote MSC chemotaxis.

Lectin KM+-induced neutrophil haptotaxis involves binding to laminin

The lectin KM+ from Artocarpus integrifolia, also known as artocarpin, induces neutrophil migration by haptotaxis. The interactions of KM+ with both the extracellular matrix (ECM) and neutrophils depend on the lectin ability to recognize mannose-containing glycans. Here, we report the binding of KM+ to laminin and demonstrate that this interaction potentiates the KM+-induced neutrophil migration. Labeling of lung tissue by KM+ located its ligands on the endothelial cells, in the basement membrane, in the alveolus, and in the interstitial connective tissue. Such labeling was inhibited by 400 mM D-mannose, 10 mM Manalpha1-3[Manalpha1-6]Man or 10 microM peroxidase (a glycoprotein-containing mannosyl heptasaccharide). Laminin is a tissue ligand for KM+, since both KM+ and anti-laminin antibodies not only reacted with the same high molecular mass components of a lung extract, but also determined colocalized labeling in basement membranes of the lung tissue. The relevance of the KM+-laminin interaction to the KM+ property of inducing neutrophil migration was evaluated. The inability of low concentrations of soluble KM+ to induce human neutrophil migration was reversed by coating the microchamber filter with laminin. So, the interaction of KM+ with laminin promotes the formation of a substrate-bound KM+ gradient that is able to induce neutrophil haptotaxis.

Unique structural features that influence neutrophil emigration into the lung

Neutrophil emigration in the lung differs substantially from that in systemic vascular beds where extravasation occurs primarily through postcapillary venules. Migration into the alveolus occurs directly from alveolar capillaries and appears to progress through a sequence of steps uniquely influenced by the cellular anatomy and organization of the alveolar wall. The cascade of adhesive and stimulatory events so critical to the extravasation of neutrophils from postcapillary venules in many tissues is not evident in this setting. Compelling evidence exists for unique cascades of biophysical, adhesive, stimulatory, and guidance factors that arrest neutrophils in the alveolar capillary bed and direct their movement through the endothelium, interstitial space, and alveolar epithelium. A prominent path accessible to the neutrophil appears to be determined by the structural interactions of endothelial cells, interstitial fibroblasts, as well as type I and type II alveolar epithelial cells.

Viral chemokine receptors and chemokines in human cytomegalovirus trafficking and interaction with the immune system. CMV chemokine receptors

The ubiquitous, opportunistic pathogen human cytomegalovirus (CMV) encodes several proteins homologous to those of the host organism. Four different CMV genes encode chemokine receptor-like peptides. These genes, UL33, UL78, US27, and US28, are expressed at various stages of infection in vitro. Their functions remain largely unknown. To date, chemokine binding and signalling has only been demonstrated for the US28 gene product. Putative ligands for the other CMV-encoded chemokine receptors are discussed on basis of phylogenetic analysis. The potential roles of these receptors in virus trafficking, persistence, and immune evasion are summarized. Similarly, modulation of expression of the host chemokines IL-8, MCP-1a and RANTES in relation to viral dissemination and persistence is reviewed.

Sulfated polysaccharides increase plasma levels of SDF-1 in monkeys and mice: involvement in mobilization of stem/progenitor cells

It was previously reported that treatment with the sulfated polysaccharide fucoidan or the structurally similar dextran sulfate increased circulating mature white blood cells and hematopoietic progenitor/stem cells (HPCs) in mice and nonhuman primates; however, the mechanism mediating these effects was unclear. It is reported here that plasma concentrations of the highly potent chemoattractant stromal-derived factor 1 (SDF-1) increase rapidly and dramatically after treatment with fucoidan in monkeys and in mice, coinciding with decreased levels in bone marrow. In vitro and in vivo data suggest that the SDF-1 increase is due to its competitive displacement from heparan sulfate proteoglycans that sequester the chemokine on endothelial cell surfaces or extracellular matrix in bone marrow and other tissues. Although moderately increased levels of interleukin-8, MCP1, or MMP9 were also present after fucoidan treatment, studies in gene-ablated mice (GCSFR(-/-), MCP1(-/-), or MMP9(-/-)) and the use of metalloprotease inhibitors do not support their involvement in the concurrent mobilization. Instead, SDF-1 increases, uniquely associated with sulfated glycan-mobilizing treatments and not with several other mobilizing agents tested, are likely responsible. To the authors' knowledge, this is the first published report of disrupting the SDF-1 gradient between bone marrow and peripheral blood through a physiologically relevant mechanism, resulting in mobilization with kinetics similar to other mobilizing CXC chemokines. The study further underscores the importance of the biological roles of carbohydrates.

Increase in circulating SDF-1 after treatment with sulfated glycans. The role of SDF-1 in mobilization

SDF-1 is a potent chemoattractant for mature white blood cells and hemopoietic stem/progenitor cells (HPCs). An important role for this chemokine in mobilization has been postulated, but in vivo studies directly addressing its effects are lacking. After one injection of fucan sulfate (FucS) or dextran sulfate, plasma levels of SDF-1 are greatly increased in mice or primates. Increases are dose-dependent and correlate with mobilization of HPCs. Elevated levels of circulating SDF-1 appear to be uniquely associated with this treatment, as it was not seen with cytokine or anti-integrin antibody treatments that induce mobilization. In vitro, these sulfated glycans specifically bind to SDF-1 and inhibit SDF-1/heparin binding, suggesting a mechanism of release from sequestration on heparan sulfate proteoglycans in vivo. Although other chemokines including IL8 and cytokines like G-CSF also increase, evidence in GCSFR-deficient mice suggests that at least these two factors are unlikely participants in FucS-induced mobilization. Likewise, although the activity of the metallo-protease MMP9 increases after FucS treatment, experiments in MMP9-/- mice indicate its presence is dispensable for mobilization or SDF-1 release. However, effects of other proteases cannot be ruled out by these experiments. Finally, anti-SDF-1 antibodies partially inhibit FucS-induced mobilization, supporting a causative relationship. Our data offer a unique insight into the mechanism of sulfated glycan-induced mobilization and suggest a novel way of disturbing SDF-1 gradients between bone marrow and peripheral blood.

Macrophage Inflammatory Protein-3β Enhances IL-10 Production by Activated Human Peripheral Blood Monocytes and T Cells

We report that the addition of human macrophage inflammatory protein-3β (MIP-3β) to cultures of human PBMCs that have been activated with LPS or PHA results in a significant enhancement of IL-10 production. This effect was concentration-dependent, with optimal MIP-3β concentrations inducing more than a 5-fold induction of IL-10 from LPS-stimulated PBMCs and a 2- to 3-fold induction of IL-10 from PHA-stimulated PBMCs. In contrast, no significant effect on IL-10 production was observed when 6Ckine, the other reported ligand for human CCR7, or other CC chemokines such as monocyte chemoattractant protein-1, RANTES, MIP-1α, and MIP-1β were added to LPS- or PHA-stimulated PBMCs. Similar results were observed using activated purified human peripheral blood monocytes or T cells. Addition of MIP-3β to nonactivated PBMCs had no effect on cytokine production. Enhancement of IL-10 production by MIP-3β correlated with the inhibition of IL-12 p40 and TNF-α production by monocytes and with the impairment of IFN-γ production by T cells, which was reversed by addition of anti-IL-10 Abs to the cultures. The ability of MIP-3β to augment IL-10 production correlated with CCR7 mRNA expression and stimulation of intracellular calcium mobilization in both monocytes and T cells. These data indicate that MIP-3β acts directly on human monocytes and T cells and suggest that this chemokine is unique among ligands binding to CC receptors due to its ability to modulate inflammatory activity via the enhanced production of the anti-inflammatory cytokine IL-10.