Role of the monocyte chemoattractant protein and eotaxin subfamily of chemokines in allergic inflammation

CCL13 and human diseases

CCL13/MCP-4 belongs to the CC chemokine family, which induces chemotaxis in many immune cells. Despite extensive research into its function in numerous disorders, a thorough analysis of CCL13 is not yet accessible. The role of CCL13 in human disorders and existing CCL13-focused therapies are outlined in this study. The function of CCL13 in rheumatic diseases, skin conditions, and cancer is comparatively well-established, and some studies also suggest that it may be involved in ocular disorders, orthopedic conditions, nasal polyps, and obesity. We also give an overview of research that found very little evidence of CCL13 in HIV, nephritis, and multiple sclerosis. Even though CCL13-mediated inflammation is frequently linked to disease pathogenesis, it's fascinating to note that in some conditions, like primary biliary cholangitis (PBC) and suicide, it might even act as a preventative measure.

Immune Activation in Functional Dyspepsia: Bystander Becoming the Suspect

Disorders of gut-brain interaction (DGBI), formerly termed functional gastrointestinal disorders (FGID), are highly prevalent although exact pathophysiological mechanisms remain unclear. Intestinal immune activation has been recognized, but increasing evidence supports a pivotal role for an active inflammatory state in these disorders. In functional dyspepsia (FD), marked eosinophil and mast cell infiltration has been repeatedly demonstrated and associations with symptoms emphasize the relevance of an eosinophil-mast cell axis in FD pathophysiology. In this Review, we highlight the importance of immune activation in DGBI with a focus on FD. We summarize eosinophil biology in both homeostasis and inflammatory processes. The evidence for immune activation in FD is outlined with attention to alterations on both cellular and molecular level, and how these may contribute to FD symptomatology. As DGBI are complex and multifactorial conditions, we shed light on factors associated to, and potentially influencing immune activation, including bidirectional gut-brain interaction, allergy and the microbiota. Crucial studies reveal a therapeutic benefit of treatments targeting immune activation, suggesting that specific anti-inflammatory therapies could offer renewed hope for at least a subset of DGBI patients. Lastly, we explore the future directions for DGBI research that could advance the field. Taken together, emerging evidence supports the recognition of FD as an immune-mediated organic-based disorder, challenging the paradigm of a strictly functional nature.

Functional Roles of Chemokine Receptor CCR2 and Its Ligands in Liver Disease

Chemokines are a family of cytokines that orchestrate the migration and positioning of immune cells within tissues and are critical for the function of the immune system. CCR2 participates in liver pathology, including acute liver injury, chronic hepatitis, fibrosis/cirrhosis, and tumor progression, by mediating the recruitment of immune cells to inflammation and tumor sites. Although a variety of chemokines have been well studied in various diseases, there is no comprehensive review presenting the roles of all known chemokine ligands of CCR2 (CCL2, CCL7, CCL8, CCL12, CCL13, CCL16, and PSMP) in liver disease, and this review aims to fill this gap. The introduction of each chemokine includes its discovery, its corresponding chemotactic receptors, physiological functions and roles in inflammation and tumors, and its impact on different immune cell subgroups.

Type 2 Inflammation in Eosinophilic Esophagitis: From Pathophysiology to Therapeutic Targets

Eosinophilic esophagitis (EoE) is a chronic immune-mediated disease of the esophagus characterized clinically by symptoms related to esophageal dysfunction and histologically by eosinophil-predominant inflammation, whose incidence is rising. It significantly affects patients’ quality of life and, if left untreated, results in fibrotic complications. Although broad consensus has been achieved on first-line therapy, a subset of patients remains non-responder to standard therapy. The pathogenesis of EoE is multifactorial and results from the complex, still mostly undefined, interaction between genetics and intrinsic factors, environment, and antigenic stimuli. A deep understanding of the pathophysiology of this disease is pivotal for the development of new therapies. This review provides a comprehensive description of the pathophysiology of EoE, starting from major pathogenic mechanisms (genetics, type 2 inflammation, epithelial barrier dysfunction, gastroesophageal reflux, allergens, infections and microbiota) and subsequently focusing on the single protagonists of type 2 inflammation (involved cells, cytokines, soluble effectors, surface proteins and transcription factors) that could represent present and future therapeutic targets, while summarizing previous therapeutic approaches in literature.

From Allergy to Cancer-Clinical Usefulness of Eotaxins

Simple Summary

Eotaxins are small proteins included in the group of chemokines. They act mainly on blood cells called eosinophils which are involved in the pathogenesis of inflammatory processes. This connection leads to involvement of eotaxins in the pathogenesis of all inflammatory related diseases, such as allergic diseases and cancer. This paper summarizes the current knowledge about eotaxins, showing their usefulness as markers that can be used not only in the detection of these diseases, but also to determine the effectiveness of treatment.

Abstract

Eotaxins are proteins which belong to the group of cytokines. These small molecules are secreted by cells that are mainly involved in immune-mediated reactions in the course of allergic diseases. Eotaxins were discovered in 1994 and their main role was considered to be the selective recruitment of eosinophils. As those blood cells are involved in the course of all inflammatory diseases, including cancer, we decided to perform an extensive search of the literature pertaining to our investigation via the MEDLINE/PubMed database. On the basis of available literature, we can assume that eotaxins can be used as markers for the detection and determination of origin or type of allergic disease. Many publications also confirm that eotaxins can be used in the determination of allergic disease treatment. Moreover, there are also studies indicating a connection between eotaxins and cancer. Some researchers revealed that CCL11 (C-C motif chemokine ligand 11, eotaxin-1) concentrations differed between the control and tested groups indicating their possible usefulness in cancer detection. Furthermore, some papers showed usefulness of eotaxins in determining the treatment efficacy as markers of decreasing inflammation. Therefore, in this paper we present the current knowledge on eotaxins in the course of allergic and cancerous diseases.

Eotaxins and Their Receptor in Colorectal Cancer-A Literature Review

Colorectal cancer (CRC) is one of the most common malignancies in the world, with a global incidence of almost 2 million new cases every year. Despite the availability of many diagnostic tests, including laboratory tests and molecular diagnostics, an increasing number of new cases is observed. Thus, it is very important to search new markers that would show high diagnostic sensitivity and specificity in the detection of colorectal cancer in early stages of the disease. Eotaxins are proteins that belong to the cytokine group-small molecules with a variety of applications. Their main role is the activation of basophils and eosinophils involved in inflammatory processes. Therefore, we performed an extensive search of the literature pertaining to our investigation via the MEDLINE/PubMed database. On the basis of available literature, we can assume that eotaxins accumulate in cancer cells in the course of CRC. This leads to a decrease in the chemotaxis of eosinophils, which are effector immune cells with anti-tumor activity. This may explain a decrease in their number as a defense mechanism of cancer cells against their destruction and may be useful when attempting anti-tumor therapy with the use of chemokines.

Antibody responses against the vaccine antigens Ov-103 and Ov-RAL-2 are associated with protective immunity to Onchocerca volvulus infection in both mice and humans

Background

The current strategy for the elimination of onchocerciasis is based on annual or bi-annual mass drug administration with ivermectin. However, due to several limiting factors there is a growing concern that elimination of onchocerciasis cannot be achieved solely through the current strategy. Additional tools are critically needed including a prophylactic vaccine. Presently Ov-103 and Ov-RAL-2 are the most promising vaccine candidates against an Onchocerca volvulus infection.

Methodology/Principal findings

Protection induced by immunization of mice with the alum-adjuvanted Ov-103 or Ov-RAL-2 vaccines appeared to be antibody dependent since AID^-/- mice that could not mount antigen-specific IgG antibody responses were not protected from an Onchocerca volvulus challenge. To determine a possible association between antigen-specific antibody responses and anti-larvae protective immunity in humans, we analyzed the presence of anti-Ov-103 and anti-Ov-RAL-2 cytophilic antibody responses (IgG1 and IgG3) in individuals classified as putatively immune, and in infected individuals who developed concomitant immunity with age. It was determined that 86% of putatively immune individuals and 95% individuals with concomitant immunity had elevated IgG1 and IgG3 responses to Ov-103 and Ov-RAL-2. Based on the elevated chemokine levels associated with protection in the Ov-103 or Ov-RAL-2 immunized mice, the profile of these chemokines was also analyzed in putatively immune and infected individuals; both groups contained significantly higher levels of KC, IP-10, MCP-1 and MIP-1β in comparison to normal human sera. Moreover, human monospecific anti-Ov-103 antibodies but not anti-Ov-RAL-2 significantly inhibited the molting of third-stage larvae (L3) in vitro by 46% in the presence of naïve human neutrophils, while both anti-Ov-103 and anti-Ov-RAL-2 antibodies significantly inhibited the molting by 70–80% when cultured in the presence of naive human monocytes. Interestingly, inhibition of molting by Ov-103 antibodies and monocytes was only in part dependent on contact with the cells, while inhibition of molting with Ov-RAL-2 antibodies was completely dependent on contact with the monocytes. In comparison, significant levels of parasite killing in Ov-103 and Ov-RAL-2 vaccinated mice only occurred when cells enter the parasite microenvironment. Taken together, antibodies to Ov-103 and Ov-RAL-2 and cells are required for protection in mice as well as for the development of immunity in humans.

Conclusions/Significance

Alum-adjuvanted Ov-103 and Ov-RAL-2 vaccines have the potential of reducing infection and thus morbidity associated with onchocerciasis in humans. The development of cytophilic antibodies, that function in antibody-dependent cellular cytotoxicity, is essential for a successful prophylactic vaccine against this infection.

Onchocerca volvulus is the causative agent of river blindness that infects approximately 17 million people, mostly in Africa. The current strategy for elimination of O. volvulus focuses on controlling transmission through ivermectin-based mass drug administration programs. Due to potential ivermectin resistance, the lack of macrofilaricidal activity by ivermectin, and the prolonged time (>20 years) needed for successful interruption of transmission in endemic areas, additional tools are critically needed including a vaccine against onchocerciasis. Ov-103 and Ov-RAL-2 are presently the most promising vaccine candidates for a prophylactic vaccine. The mechanism of protective immunity induced in mice by the alum-adjuvanted Ov-103 or Ov-RAL-2 vaccines appear to be multifactorial with essential roles for antibodies, chemokines and the specific effector cells they recruit. In this study, we show for the first time that, anti-Ov-103 and anti-Ov-RAL-2 antibodies, chemokines and innate cells also appear to be associated with protective immunity against O. volvulus infection in humans, similar to the vaccine studies observed in the O. volvulus mouse model.

Elevated Plasma Chemokines for Eosinophils in Neuromyelitis Optica Spectrum Disorders during Remission

Background

A prominent pathological feature of neuromyelitis optica spectrum disorders (NMOSD) is markedly greater eosinophilic infiltration than that seen in other demyelinating diseases, like multiple sclerosis (MS). Eosinophils express the chemokine receptor CCR3, which is activated by eotaxins (CCL11/eotaxin-1, CCL24/eotaxin-2, CCL26/eotaxin-3) and CCL13 [monocyte chemoattractant protein (MCP)-4]. Moreover, CCL13 is part of the chemokine set that activates CCR2. The present study aimed to evaluate plasma levels of eotaxins (CCL11, CCL24, and CCL26) and MCPs (CCL13, CCL2, CCL8, and CCL7) in patients with NMOSD during remission.

Methods

Healthy controls (HC; n = 30) and patients with MS (n = 47) and NMOSD (n = 58) in remission were consecutively enrolled in this study between January 2016 and August 2017. Plasma CCL11, CCL24, CCL26, CCL2, CCL8, CCL7, CCL13, tumor necrosis factor (TNF)-α, and interleukin (IL)-1β levels were detected using the human cytokine multiplex assay.

Results

Plasma CCL13, CCL11, and CCL26 levels were all significantly higher in patients with NMOSD than in HC and patients with MS. No significant differences were found in the CCL13, CCL11, or CCL26 levels between patients with NMOSD receiving and not receiving immunosuppressive therapy. The plasma levels of TNF-α and IL-1β, which stimulate the above chemokines, were higher in patients with NMOSD than in HC. There was no difference in CCL24 levels among the three groups. In most cases, the CCL7 levels were below the threshold value of the human cytokine multiplex assay, which is in line with other studies. Adjusted multiple regression analyses showed a positive association of CCL13 levels with the number of relapses after controlling gender, age, body mass index, and disease duration in patients with NMOSD.

Conclusion

The study indicates that in NMOSD, the overproduction of cytokines such as IL-1β and TNF-α during remission stimulates eosinophilic chemoattractants such as CCL13, CCL11, and CCL26, which in turn bind to their receptor (CCR3); this could lead to eosinophil hypersensitivity. These findings suggest that the elevated secretion of CCL13, CCL11, and CCL26 may be a critical step in eosinophil recruitment during NMOSD remission.

Bindarit Attenuates Pain and Cancer-Related Inflammation by Influencing Myeloid Cells in a Model of Bone Cancer

C-C motif chemokine ligand 2 (CCL2) is a small cytokine that functions in inflammation and cancer development. Bindarit, a CCL2 inhibitor, is a small anti-inflammatory molecule proven safe by phase II trials in type 2 diabetic nephropathy patients. As cancer-related inflammation is a cause of pain, we investigated whether Bindarit suppresses cancer-related inflammation and pain. We established a bone-cancer mouse model by inoculating cancer cells. After applying Bindarit, we preformed pain sensitivity tests and checked cancer development by X-ray. Using flow cytometry and qRT-PCR assays, we assessed the effect of Bindarit on peripheral blood monocyte mobilization and M2 macrophage polarization. We also investigated the targets of Bindarit using western blotting and luciferase assay. Bindarit-treated mice performed better in pain sensitivity tests compare to control mice. X-ray imaging showed that Bindarit-treated mice had fewer cancer cell colonies and smaller overall tumor burden. Bindarit reduced the number of monocytes in peripheral blood and down-regulated the expression of M2 macrophage polarization makers. Bindarit also inhibited IKKβ phosphorylation. Bindarit efficiently relieves cancer-related pain and suppresses cancer development. Bindarit inhibits monocyte mobilization in peripheral blood as well as M2 macrophage polarization. IKKβ is identified as a target of Bindarit.

Kinetic and thermodynamic studies reveal chemokine homologues CC11 and CC24 with an almost identical tertiary structure have different folding pathways

BACKGROUND

Proteins with low sequence identity but almost identical tertiary structure and function have been valuable to uncover the relationship between sequence, tertiary structure, folding mechanism and functions. Two homologous chemokines, CCL11 and CCL24, with low sequence identity but similar tertiary structure and function, provide an excellent model system for respective studies.

RESULTS

The kinetics and thermodynamics of the two homologous chemokines were systematically characterized. Despite their similar tertiary structures, CCL11 and CCL24 show different thermodynamic stability in guanidine hydrochloride titration, with D_50% = 2.20 M and 4.96 M, respectively. The kinetics curves clearly show two phases in the folding/unfolding processes of both CCL11 and CCL24, which suggests the existence of an intermediate state in their folding/unfolding processes. The folding pathway of both CCL11 and CCL24 could be well described using a folding model with an on-pathway folding intermediate. However, the folding kinetics and stability of the intermediate state of CCL11 and CCL24 are obviously different.

CONCLUSION

Our results suggest homologous proteins with low sequence identity can display almost identical tertiary structure, but very different folding mechanisms, which applies to homologues in the chemokine protein family, extending the general applicability of the above observation.

Bindarit reduces the incidence of acute aortic dissection complicated lung injury via modulating NF-κB pathway

The pathogenesis of acute aortic dissection (AAD) complicated acute lung injury (ALI) is not currently well defined. At present, no effective animal model has been established for AAD complicated ALI, which hinders research and development of an appropriate treatment regimen for the concurrent conditions. The aim of the present study was to evaluate the therapeutic effects of bindarit (Bnd), an indazolic derivative, on the production of monocyte chemoattractant protein (MCP)-1 in angiotensin II (AngII)-induced complicated ALI in rats. An AAD complicated ALI rat model was established using aminopropionitrile (BAPN) and AngII. The pathological features of AAD complicated ALI were assessed via biochemical and histopathological evaluations. AngII-stimulated human pulmonary microvascular endothelial cells (hPMVECs) were used to assess the effects of Bnd on MCP-1 expression. Western blot analysis was performed to analyze the expression of proteins that may be associated with the process. AAD complicated ALI was established following BAPN and AngII interference, and a massive accumulation of macrophages was observed in the lung tissues of the study rats. Bnd was able to significantly attenuate the incidence of AAD complicated ALI (P<0.05), and significantly inhibit the accumulation of macrophages (P<0.05). The overexpression of MCP-1 induced by AngII in hPMVECs was significantly inhibited by Bnd (P<0.05), which may be associated with downregulation of the classical nuclear factor-κB pathway. Bnd was able to attenuate the incidence of AAD complicated ALI, and inhibit the accumulation of macrophages in vivo. These findings provide a basis for future applications of Bnd as part of a therapeutic treatment schedule for aortic dissection complicated lung injury.

Regulation of Chemokine Activity - A Focus on the Role of Dipeptidyl Peptidase IV/CD26

Chemokines are small, chemotactic proteins that play a crucial role in leukocyte migration and are, therefore, essential for proper functioning of the immune system. Chemokines exert their chemotactic effect by activation of chemokine receptors, which are G protein-coupled receptors (GPCRs), and interaction with glycosaminoglycans (GAGs). Furthermore, the exact chemokine function is modulated at the level of posttranslational modifications. Among the different types of posttranslational modifications that were found to occur in vitro and in vivo, i.e., proteolysis, citrullination, glycosylation, and nitration, NH₂-terminal proteolysis of chemokines has been described most intensively. Since the NH₂-terminal chemokine domain mediates receptor interaction, NH₂-terminal modification by limited proteolysis or amino acid side chain modification can drastically affect their biological activity. An enzyme that has been shown to provoke NH₂-terminal proteolysis of various chemokines is dipeptidyl peptidase IV or CD26. This multifunctional protein is a serine protease that preferably cleaves dipeptides from the NH₂-terminal region of peptides and proteins with a proline or alanine residue in the penultimate position. Various chemokines possess such a proline or alanine residue, and CD26-truncated forms of these chemokines have been identified in cell culture supernatant as well as in body fluids. The effects of CD26-mediated proteolysis in the context of chemokines turned out to be highly complex. Depending on the chemokine ligand, loss of these two NH₂-terminal amino acids can result in either an increased or a decreased biological activity, enhanced receptor specificity, inactivation of the chemokine ligand, or generation of receptor antagonists. Since chemokines direct leukocyte migration in homeostatic as well as pathophysiologic conditions, CD26-mediated proteolytic processing of these chemotactic proteins may have significant consequences for appropriate functioning of the immune system. After introducing the chemokine family together with the GPCRs and GAGs, as main interaction partners of chemokines, and discussing the different forms of posttranslational modifications, this review will focus on the intriguing relationship of chemokines with the serine protease CD26.

Neurotensin-based hybrid peptide's anti-inflammatory activity in murine model of a contact sensitivity response

The objective of the study was to investigate the possibility of modulation of skin inflammation by topical treatment with a novel compound: an opioid-neurotensin hybrid peptide PK20 encompassing endomorphin-2 analog and modified fragment of neurotensin (8-13). Contact sensitivity response was induced in mice by skin sensitization with dinitrofluorobenzene (DNFB) followed by topical hapten application on ears. Mice were treated locally with PK20 or pure cream 2h after the challenge with DNFB. 2 and 24h after hapten exposure, ear thickness was determined. Ears were collected for histology and homogenization. Supernatants were used for measurement of contents of cytokines and lipid peroxidation products. Treatment with PK20 reduced significantly the late phase of contact sensitivity response, which was revealed by ear thickness diminution and reduction of inflammatory cell infiltration. The average concentrations of IL-1α, MCP-1, TNF-α and thiobarbituric acid-reactive substances were significantly decreased in the ears treated with the chimera in comparison to the control cream treated ears in DNFB sensitized/DNFB challenged group. We found that PK20 topical treatment alleviates hypersensitivity responses triggered by DNFB challenge and usage of the hybrid peptide may be a novel therapeutic strategy in the treatment of chronic inflammatory diseases. However, the mechanism remains unclear and needs further investigation.

The Immunomodulatory Role of Adjuvants in Vaccines Formulated with the Recombinant Antigens Ov-103 and Ov-RAL-2 against Onchocerca volvulus in Mice

BACKGROUND

In some regions in Africa, elimination of onchocerciasis may be possible with mass drug administration, although there is concern based on several factors that onchocerciasis cannot be eliminated solely through this approach. A vaccine against Onchocerca volvulus would provide a critical tool for the ultimate elimination of this infection. Previous studies have demonstrated that immunization of mice with Ov-103 and Ov-RAL-2, when formulated with alum, induced protective immunity. It was hypothesized that the levels of protective immunity induced with the two recombinant antigens formulated with alum would be improved by formulation with other adjuvants known to enhance different types of antigen-specific immune responses.

METHODOLOGY/ PRINCIPAL FINDINGS

Immunizing mice with Ov-103 and Ov-RAL-2 in conjunction with alum, Advax 2 and MF59 induced significant levels of larval killing and host protection. The immune response was biased towards Th2 with all three of the adjuvants, with IgG1 the dominant antibody. Improved larval killing and host protection was observed in mice immunized with co-administered Ov-103 and Ov-RAL-2 in conjunction with each of the three adjuvants as compared to single immunizations. Antigen-specific antibody titers were significantly increased in mice immunized concurrently with the two antigens. Based on chemokine levels, it appears that neutrophils and eosinophils participate in the protective immune response induced by Ov-103, and macrophages and neutrophils participate in immunity induced by Ov-RAL-2.

CONCLUSIONS/SIGNIFICANCE

The mechanism of protective immunity induced by Ov-103 and Ov-RAL-2, with the adjuvants alum, Advax 2 and MF59, appears to be multifactorial with roles for cytokines, chemokines, antibody and specific effector cells. The vaccines developed in this study have the potential of reducing the morbidity associated with onchocerciasis in humans.

Association between subchronic and chronic lead exposure and levels of antioxidants and chemokines

Purpose

This study aimed to compare the influence of lead on the non-enzymatic antioxidant defenses and the levels of chemokines in workers subchronically and chronically exposed to lead.

Methods

The study population was divided into three groups. The first group consisted of male workers subchronically exposed to lead for 40 ± 3.2 days, while the second group included male workers chronically exposed to lead. The third group was a control group.

Results

The levels of uric acid and bilirubin were significantly higher after a subchronic exposure to lead compared to the baseline by 22 and 35 %, respectively. Similarly, the values of total antioxidant capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) increased by 15, 50, and 33 %, respectively. At the same time, the levels of thiol groups and albumin decreased by 5 and 8 %, respectively. Additionally, the levels of interleukin-8 (IL-8) and macrophage inflammatory protein-1β (MIP-1β) were significantly higher after a subchronic exposure to lead compared to the baseline by 34 and 20 %, respectively. Moreover, IL-8 level was significantly higher by 40 % in the group of workers chronically exposed to lead than in the control group, while the level of interferon gamma-induced protein-10 (IP-10) was significantly lower by 28 %.

Conclusions

Similar to chronic lead exposure, subchronic exposure to lead is associated with elevated blood levels of uric acid and bilirubin in humans. This probably results in increased TAC value despite thiol depletion. However, the compensatory activation of non-enzymatic antioxidant defenses seems to be insufficient to protect against lead-induced oxidative stress, which may be additively enhanced by the pro-inflammatory action of chemokines, especially IL-8.

Elements Involved In Promoting Eosinophilic Gastrointestinal Disorders

Eosinophilic gastrointestinal disorders (EGID) are food allergen-induced allergic gastrointestinal disorders, characterized by accumulation of highly induced eosinophils in different segments of gastrointestinal tract along with eosinophil microabssess and extracellular eosinophilic granules in the epithelial layer. EGID are both IgE- and cell-mediated group of diseases that include eosinophilic esophagitis (EoE), eosinophilic gastritis (EG), eosinophilic gastroenteritis (EGE) and eosinophilic colitis (EC). Despite the increased incidences and considerable progress made in understanding EGID pathogenesis. The mechanism is still not well understood. It has been shown that IL-4, IL-5, IL-13, IL-15, IL-18, eotaxin-1, eotaxin-2 and eotaxin-3 play a critical role in EGID pathogenesis. Currently, the only criterion for diagnosing EoE, EGE and EC are repetitive endoscopic and histopathological evaluation of biopsies along with other clinical characteristics/manifestations. Antigen elimination and corticosteroid therapies are the most effective therapies currently in practice for the treatment of EGID. The cytokines (anti-IL-5 and anti-IL-13) therapy trials were not very successful in case of EoE. Most recently, a clinical trial using anti-IL-13 reported only 60% reduced esophageal eosinophilia without achieving primary endpoint. This clinical finding is not surprising and is in accordance with our earlier report indicating that IL-13 is not critical in the initiation of EoE. Notably, EGID still has no reliable noninvasive diagnostic biomarkers. Hence, there is a great necessity to identify novel noninvasive diagnostic biomarkers that can easily diagnose EGID and provide an effective therapy. Now, the attention is required to target cell types like iNKT cells that produce eosinophil active cytokines and is found induced in the pathogenesis of both experimental and human EoE. iNKT cell neutralization is shown to protect allergen-induced EoE in experimental model. In this review, we have discussed the key elements that are critical in the disease initiation, progression, pathogenesis and important for future diagnostic and therapeutic interventions for EGID.

Effect of metformin and adriamycin on transplantable tumor model

Adriamycin is a cytotoxic anthracycline antibiotic used in treatment of many types of cancer. Metformin is antidiabetic drug and is under investigation for treatment of cancer. The aim of this work was to study the effect of each of adriamycin and metformin alone and in combination on solid Ehrlich carcinoma (SEC) in mice. Eighty BALB/C mice were divided into four equal groups: SEC group, SEC+adriamycin, SEC+metformin, SEC+adriamycin+metformin. Tumor volume, survival rate, tissue catalase, tissue reduced glutathione, tissue malondialdehyde, tissue sphingosine kinase 1 activity, tissue caspase 3 activity and tissue tumor necrosis factor alpha were determined. A part of the tumor was examined for histopathological and immunohistochemical study. Adriamycin or metformin alone or in combination induced significant increase in the survival rate, tissue catalase, reduced glutathione and tissue caspase 3 activity with significant decrease in tumor volume, tissue malondialdehyde, tissue sphingosine kinase 1 activity and tumor necrosis factor alpha and alleviated the histopathological changes with significant increase in Trp53 expression and apoptotic index compared to SEC group. In conclusion, the combination of adriamycin and metformin had a better effect than each of these drugs alone against transplantable tumor model in mice.

Oral administration of nano-emulsion curcumin in mice suppresses inflammatory-induced NFκB signaling and macrophage migration

Despite the widespread use of curcumin for centuries in Eastern medicine as an anti-inflammatory agent, its molecular actions and therapeutic viability have only recently been explored. While curcumin does have potential therapeutic efficacy, both solubility and bioavailability must be improved before it can be more successfully translated to clinical care. We have previously reported a novel formulation of nano-emulsion curcumin (NEC) that achieves significantly greater plasma concentrations in mice after oral administration. Here, we confirm the immunosuppressive effects of NEC in vivo and further examine its molecular mechanisms to better understand therapeutic potential. Using transgenic mice harboring an NFκB-luciferase reporter gene, we demonstrate a novel application of this in vivo inflammatory model to test the efficacy of NEC administration by bioluminescent imaging and show that LPS-induced NFκB activity was suppressed with NEC compared to an equivalent amount of curcumin in aqueous suspension. Administration of NEC by oral gavage resulted in a reduction of blood monocytes, decreased levels of both TLR4 and RAGE expression, and inhibited secretion of MCP-1. Mechanistically, curcumin blocked LPS-induced phosphorylation of the p65 subunit of NFκB and IκBα in murine macrophages. In a mouse model of peritonitis, NEC significantly reduced macrophage recruitment, but not T-cell or B-cell levels. In addition, curcumin treatment of monocyte derived cell lines and primary human macrophages in vitro significantly inhibited cell migration. These data demonstrate that curcumin can suppress inflammation by inhibiting macrophage migration via NFκB and MCP-1 inhibition and establish that NEC is an effective therapeutic formulation to increase the bioavailability of curcumin in order to facilitate this response.

Eosinophilic esophagitis: interactions with gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) and eosinophilic esophagitis (EoE) are not mutually exclusive. The notion that GERD and EoE can be distinguished by the response to proton pump inhibitor (PPI) treatment is based on the mistaken assumption that gastric acid suppression is the only important therapeutic effect of PPIs, and therefore only GERD can respond to PPIs. We believe that a clinical or histologic response to PPIs does not rule in GERD or rule out EoE. We recommend a trial of PPI therapy for patients with symptomatic esophageal eosinophilia, even if the diagnosis of EoE seems clear-cut.

A CCL chemokine-derived peptide (CDIP-2) exerts anti-inflammatory activity via CCR1, CCR2 and CCR3 chemokine receptors: Implications as a potential therapeutic treatment of asthma

Allergic asthma is a chronic inflammatory disease characterized by the accumulation of eosinophils, Th2 cells and mononuclear cells in the airways, leading to changes in lung architecture and subsequently reduced respiratory function. We have previously demonstrated that CDIP-2, a chemokine derived peptide, reduced in vitro chemotaxis and decreased cellular infiltration in a murine model of allergic airway inflammation. However, the mechanisms involved in this process have not been identified yet. Now, we found that CDIP-2 reduces chemokine-mediated functions via interactions with CCR1, CCR2 and CCR3. Moreover, using bone marrow-derived eosinophils, we demonstrated that CDIP-2 modifies the calcium fluxes induced by CCL11 and down-modulated CCR3 expression. Finally, CDIP-2 treatment in a murine model of OVA-induced allergic airway inflammation reduced leukocyte recruitment and decreases production of cytokines. These data suggest that chemokine-derived peptides represent new therapeutic tools to generate more effective antiinflammatory drugs.

The multiple faces of CCL13 in immunity and inflammation

CCL13/MCP-4, is a CC family chemokine that is chemoattractant for eosinophils, basophils, monocytes, macrophages, immature dendritic cells, and T cells, and its capable of inducing crucial immuno-modulatory responses through its effects on epithelial, muscular and endothelial cells. Similar to other CC chemokines, CCL13 binds to several chemokine receptors (CCR1, CCR2 and CCR3), allowing it to elicit different effects on its target cells. A number of studies have shown that CCL13 is involved in many chronic inflammatory diseases, in which it functions as a pivotal molecule involved in the selective recruitment of cell lineages to the inflamed tissues and their subsequent activation. Based on these studies, we suggest that blocking the actions of CCL13 can serve as a novel strategy for the generation of agents with anti-inflammatory activity. The main goal of this review is to present the current information about CCL13, its gene and protein structure and the roles of this chemokine during innate/adaptive immune responses in inflammatory diseases.

Effect of atorvastatin and methotrexate on solid Ehrlich tumor

Hydroxymethyl glutaryl CoA reductase is the key enzyme in cholesterol synthesis. A relationship was found between cholesterol and the development of many types of cancer. Atorvastatin is a hypolipidemic drug that may have a role in treatment of cancer. Moreover, atorvastatin was reported to decrease the resistance of cancer cells to many chemotherapeutic agents. The aim of this work was to study the effect of each of methotrexate (MTX) and atorvastatin alone and in combination on solid Ehrlich carcinoma (SEC) in mice. Fifty BALB/c mice were divided into five equal groups: control untreated group, SEC, SEC+MTX, SEC+atorvastatin, SEC+MTX+atorvastatin. Tumor volume, tissue glutathione reductase (GR), catalase, malondialdehyde (MDA), cholesterol and tumor necrosis factor alpha (TNF-α) were determined. A part of the tumor was examined for histopathological and immunohistochemical study. MTX or atorvastatin alone or in combination induced significant increase in tissue catalase and GR with significant decrease in tumor volume, tissue MDA, cholesterol and TNF-α and alleviated the histopathological changes with significant increase in p53 expression and apoptotic index compared to SEC group. In conclusion, the combination of MTX and atorvastatin had a better effect than each of MTX or atorvastatin alone against solid Ehrlich tumor in mice.

IFNβ autocrine feedback is required to sustain TLR induced production of MCP-1 in macrophages

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MCP-1 mRNA levels and protein secretion in macrophages are induced by TLR activation.

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In response to LPS, the initial induction of MCP-1 mRNA is IFNβ independent.

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The sustained production of MCP-1 by LPS requires an IFNβ mediated feedback loop.

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The sustained production of MCP-1 by poly IC also requires IFNβ.

Chemokines, including MCP-1, are crucial to mounting an effective immune response due to their ability to recruit other immune cells. We show that sustained LPS or poly(I:C)-stimulated MCP-1 production requires an IFNβ-mediated feedback loop. Consistent with this, exogenous IFNβ was able to induce MCP-1 transcription in the absence of other stimuli. Blocking IFNβ signaling with Ruxolitinib, a JAK inhibitor, inhibited MCP-1 transcription. The MCP-1 promoter contains potential STAT binding sites and we demonstrate that STAT1 is recruited upon IFNβ stimulation. Furthermore we find that IL-10 knockout increases MCP-1 production in response to LPS, which may reflect an ability of IL-10 to repress IFNβ production. Overall, these results show the importance of the balance between IFNβ and IL-10 in the regulation of MCP-1.

New biomarker for neovascular age-related macular degeneration: eotaxin-2

Recently, eotaxin-CCR3 was reported to play an important role in choroidal neovascularization (CNV) development and was documented to be superior than vascular endothelial growth factor-A treatment when tested in CNV animals. As eotaxin studies are lacking in the human age-related macular degeneration (AMD) patients, we sought to determine whether eotaxin-2 (CCL24) has any association with inflammatory processes that occur in CNV. CCL24 levels were determined by enzyme linked immunosorbant assay (ELISA) after normalization to total serum protein and levels of ELISA were correlated to various risk factors in about 133 AMD patients and 80 healthy controls. The CCL24 levels were significantly higher in wet AMD patients as compared with dry AMD and normal controls. There was a significant difference when compared among wet AMD patients (i.e., minimally classic, predominantly classic, and occult). We also report significant difference in the CCL24 levels of Avastin-treated and untreated AMD patients. This study shows that CCL24 levels were found to be significantly increased in AMD patients despite Avastin treatment as compared with normal controls and those without Avastin, indicating that CCL24 may have an association with CNV and may be an important target to validate future therapeutic approaches in AMD in tandem with Avastin treatment.

Bindarit: an anti-inflammatory small molecule that modulates the NFκB pathway

The activation of nuclear factor (NF)κB pathway and its transducing signaling cascade has been associated with the pathogenesis of many inflammatory diseases. The central role that IκBα and p65 phosphorylation play in regulating NFκB signalling in response to inflammatory stimuli made these proteins attractive targets for therapeutic strategies. Although several chemical classes of NFκB inhibitors have been identified, it is only for a few of those that a safety assessment based on a comprehensive understanding of their pharmacologic mechanism of action has been reported. Here, we describe the specific anti-inflammatory effect of bindarit, an indazolic derivative that has been proven to have anti-inflammatory activity in a variety of models of inflammatory diseases (including lupus nephritis, arthritis and pancreatitis). The therapeutic effects of bindarit have been associated with its ability to selectively interfere with monocyte recruitment and the "early inflammatory response," although its specific molecular mechanisms have remained ill-defined. For this purpose, we investigated the effect of bindarit on the LPS-induced production of inflammatory cytokines (MCP-1 and MCPs, IL-12β/p40, IL-6 and IL-8/KC) in both a mouse leukaemic monocyte-macrophage cell line and bone marrow derived macrophages (BMDM). Bindarit inhibits the LPS-induced MCP-1 and IL-12β/p40 expression without affecting other analyzed cytokines. The effect of bindarit is mediated by the downregulation of the classical NFκB pathway, involving a reduction of IκBα and p65 phosphorylation, a reduced activation of NFκB dimers and a subsequently reduced nuclear translocation and DNA binding. Bindarit showed a specific inhibitory effect on the p65 and p65/p50 induced MCP-1 promoter activation, with no effect on other tested activated promoters. We conclude that bindarit acts on a specific subpopulation of NFκB isoforms and selects its targets wihtin the whole NFκB inflammatory pathway. These findings pave the way for future applications of bindarit as modulator of the inflammatory response.

Anti-inflammatory effects of tetradecylthioacetic acid (TTA) in macrophage-like cells from Atlantic salmon (Salmo salar L.)

Background

Commercial Atlantic salmon is fed diets with high fat levels to promote fast and cost-effective growth. To avoid negative impact of obesity, food additives that stimulate fat metabolism and immune function are of high interest. TTA, tetradecylthioacetic acid, is a synthetic fatty acid that stimulates mitochondrial β-oxidation most likely by activation of peroxysome proliferator-activated receptors (PPARs). PPARs are important transcription factors regulating multiple functions including fat metabolism and immune responses. Atlantic salmon experiments have shown that TTA supplemented diets significantly reduce mortality during natural outbreaks of viral diseases, suggesting a modulatory role of the immune system.

Results

To gain new insights into TTA effects on the Atlantic salmon immune system, a factorial, high-throughput microarray experiment was conducted using a 44K oligo nucleotide salmon microarray SIQ2.0 and the Atlantic salmon macrophage-like cell line ASK. The experiment was used to determine the transcriptional effects of TTA, the effects of TTA in poly(I:C) elicited cells and the effects of pretreating the cells with TTA. The expression patterns revealed that a large proportion of genes regulated by TTA were related to lipid metabolism and increased mitochondrial β-oxidation. In addition we found that for a subset of genes TTA antagonized the transcriptional effects of poly(I:C). This, together with the results from qRT-PCR showing an increased transcription of anti-inflammatory IL10 by TTA, indicates anti-inflammatory effects.

Conclusions

We demonstrate that TTA has significant effects on macrophage-like salmon cells that are challenged by the artificial dsRNA poly(I:C). The immune stimulatory effect of TTA in macrophages involves increased lipid metabolism and suppressed inflammatory status. Thus, suggesting that TTA directs the macrophage-like cells towards alternative, anti-inflammatory, activation. This has positive implications for TTA as a feed additive.

Time-response relationship of nano and micro particle induced lung inflammation. Quartz as reference compound

An increasing number of engineered particles, including nanoparticles, are being manufactured, increasing the need for simple low-dose toxicological screening methods. This study aimed to investigate the kinetics of biomarkers related to acute and sub-chronic particle-induced lung inflammation of quartz. Mice were intratracheal instilled with 50 µg of microsized or nanosized quartz. Acute inflammation was assessed 1, 2, 4, 8, 16 or 48 hours post exposure, whereas sub-chronic inflammation was investigated 3 months after exposure. Markers of acute inflammation in the bronchoalveolar lavage fluid (BALF) were neutrophils (PMN), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, macrophage inflammatory protein-2 (MIP-2), keratinocyte derived chemokine (KC) and total protein, which were all close to maximum 16 hours post instillation. No major differences were seen in the time-response profiles of nano- and micro-sized particles. The potency of the two samples cannot be compared; during the milling process, a substantial part of the quartz was converted to amorphous silica and contaminated with corundum. For screening, BALF PMN, either TNF-α or IL-1β at 16 hours post instillation may be useful. At 3 months post instillation, KC, PMN and macrophages were elevated. Histology showed no interstitial inflammation three months post instillation. For screening of sub-chronic effects, KC, PMN, macrophages and histopathology is considered sufficient.

Role of eotaxin-1 signaling in ovarian cancer

PURPOSE

Tumor cell growth and migration can be directly regulated by chemokines. In the present study, the association of CCL11 with ovarian cancer has been investigated.

EXPERIMENTAL DESIGN AND RESULTS

Circulating levels of CCL11 in sera of patients with ovarian cancer were significantly lower than those in healthy women or women with breast, lung, liver, pancreatic, or colon cancer. Cultured ovarian carcinoma cells absorbed soluble CCL11, indicating that absorption by tumor cells could be responsible for the observed reduction of serum level of CCL11 in ovarian cancer. Postoperative CCL11 levels in women with ovarian cancer negatively correlated with relapse-free survival. Ovarian tumors overexpressed three known cognate receptors of CCL11, CC chemokine receptors (CCR) 2, 3, and 5. Strong positive correlation was observed between expression of individual receptors and tumor grade. CCL11 potently stimulated proliferation and migration/invasion of ovarian carcinoma cell lines, and these effects were inhibited by neutralizing antibodies against CCR2, CCR3, and CCR5. The growth-stimulatory effects of CCL11 were likely associated with activation of extracellular signal-regulated kinase 1/2, MEK1, and STAT3 phosphoproteins and with increased production of multiple cytokines, growth factors, and angiogenic factors. Inhibition of CCL11 signaling by the combination of neutralizing antibodies against the ligand and its receptors significantly increased sensitivity to cisplatin in ovarian carcinoma cells.

CONCLUSION

We conclude that CCL11 signaling plays an important role in proliferation and invasion of ovarian carcinoma cells and CCL11 pathway could be targeted for therapy in ovarian cancer. Furthermore, CCL11 could be used as a biomarker and a prognostic factor of relapse-free survival in ovarian cancer.

Signal-activated phospholipase regulation of leukocyte chemotaxis

Signal-activated phospholipases are a recent focus of the rapidly growing field of lipid signaling. The extent of their impact on the pathways regulating diverse cell functions is beginning to be appreciated. A critical step in inflammation is the attraction of leukocytes to injured or diseased tissue. Chemotaxis of leukocytes, a requisite process for monocyte and neutrophil extravasation from the blood into tissues, is a critical step for initiating and maintaining inflammation in both acute and chronic settings. Recent studies have identified new important and required roles for two signal-activated phospholipases A2 (PLA2) in regulating chemotaxis. The two intracellular phospholipases, cPLA2alpha (Group IVA) and iPLA2beta (Group VIA), act in parallel to provide distinct lipid mediators at different intracellular sites that are both required for leukocytes to migrate toward the chemokine monocyte chemoattractant protein-1. This review will summarize the separate roles of these phospholipases as well as what is currently known about the influence of two other classes of intracellular signal-activated phospholipases, phospholipase C and phospholipase D, in regulating chemotaxis in eukaryotic cells, but particularly in human monocytes. The contributions of these phospholipases to chemotaxis both in vitro and in vivo will be highlighted.

Herpes simplex virus type 2-induced mortality following genital infection is blocked by anti-tumor necrosis factor alpha antibody in CXCL10-deficient mice

The role of tumor necrosis factor alpha (TNF-alpha) was evaluated for CXCL10-deficient (CXCL10(-/-)) mice which succumbed to genital herpes simplex virus type 2 (HSV-2) infection and possessed elevated levels of virus and TNF-alpha but not other cytokines in the central nervous system (CNS) and vaginal tissue within the first 7 days following virus exposure. Anti-TNF-alpha but not control antibody treatment offsets the elevated mortality rate of CXCL10(-/-) mice, despite increased CNS viral titers. In addition, TNF-alpha neutralization suppressed recruitment of leukocyte subpopulations into the CNS, which is associated with reduced CCL2 and CXCL9 expression. Collectively, the results implicate TNF-alpha as the principal mediator of mortality in response to genital HSV-2 infection.

Reactive oxygen species and chemokines: Are they elevated in the esophageal mucosa of children with gastroesophageal reflux disease?

AIM: To determine the role of inflammatory cytokines and reactive oxygen species (ROS) in childhood reflux esophagitis.

METHODS: A total of 59 subjects who had complaints suggesting GERD underwent esophagogastroduodenoscopy. Endoscopic and histopathologic diagnosis of reflux esophagitis was established by Savary-Miller and Vandenplas grading systems, respectively. Esophageal biopsy specimens were taken from the esophagus 20% proximal above the esophagogastric junction for conventional histopathological examination and the measurements of ROS and cytokine levels. ROS were measured by chemiluminescence, whereas IL-8 and MCP-1 levels were determined with quantitative immunometric ELISA on esophageal tissue. Esophageal tissue ROS, IL-8 and MCP-1 levels were compared among groups with and without endoscopic/histo-pathologic esophagitis.

RESULTS: Of 59 patients 28 (47.5%) had normal esophagus whereas 31 (52.5%) had endoscopic esophagitis. In histopathological evaluation, almost 73% of the cases had mild and 6.8% had moderate degree of esophagitis. When ROS and chemokine levels were compared among groups with and without endoscopic esophagitis, statistical difference could not be found between patients with and without esophagitis. Although the levels of ROS, IL-8 and MCP-1 were found to be higher in the group with histopathological reflux esophagitis, this difference was not statistically significant.

CONCLUSION: These results suggest that the grade of esophagitis is usually mild or moderate during childhood and factors apart from ROS, IL-8 and MCP-1 may be involved in the pathogenesis of reflux esophagitis in children.

Nanotechnology: a focus on nanoparticles as a drug delivery system

This review will provide an in-depth discussion on the previous development of nanoparticle-based drug delivery systems (DDS) and discuss original research data that includes the therapeutic enhancement of antiretroviral therapy. The use of nanoparticle DDS will allow practitioners to use drugs to target specific areas of the body. In the treatment of malignancies, the use of nanoparticles as a DDS is making measurable treatment impact. Medical imaging will also utilize DDS to illuminate tumors, the brain, or other cellular functions in the body. The utility of nanoparticle DDS to improve human health is potentially enormous.

Ontogeny of the eotaxins in human lung

The ontogeny of the C-C chemokines eotaxin-1, eotaxin-2, and eotaxin-3 has not been fully elucidated in human lung. We explored a possible role for eotaxin in developing lung by determining the ontogeny of eotaxin-1 (CCL11), eotaxin-2 (CCL24), eotaxin-3 (CCL26), and the eotaxin receptor, CCR3. We tested discarded surgical samples of developing human lung tissue using quantitative RT-PCR (QRT-PCR) and immunostaining for expression of CCL11, CCL24, CCL26, and CCR3. We assessed possible functionality of the eotaxin-CCR3 system by treating lung explant cultures with exogenous CCL11 and analyzing the cultures for evidence of changes in proliferation and activation of ERK1/2, a signaling pathway associated with CCR3. QRT-PCR analyses of 22 developing lung tissue samples with gestational ages 10-23 wk demonstrated that eotaxin-1 mRNA is most abundant in developing lung, whereas mRNAs for eotaxin-2 and eotaxin-3 are minimally detectable. CCL11 mRNA levels correlated with gestational age (P < 0.05), and immunoreactivity was localized predominantly to airway epithelial cells. QRT-PCR analysis detected CCR3 expression in 16 of 19 developing lung samples. Supporting functional capacity in the immature lung, CCL11 treatment of lung explant cultures resulted in significantly increased (P < 0.05) cell proliferation and activation of the ERK signaling pathway, which is downstream from CCR3, suggesting that proliferation was due to activation of CCR3 receptors by CCL11. We conclude that developing lung expresses the eotaxins and functional CCR3 receptor. CCL11 may promote airway epithelial proliferation in the developing lung.

Interleukin (IL)-33 induces the release of pro-inflammatory mediators by mast cells

IL-33 (or IL-1F11) was recently identified as a ligand for the previously orphaned IL-1 family receptor T1/ST2. Previous studies have established that IL-33 and T1/ST2 exert key functions in Th2 responses. In this study, we demonstrate that IL-33 induces the production of pro-inflammatory mediators in mast cells. IL-33 dose and time-dependently stimulated IL-6 secretion by P815 mastocytoma cells and primary mouse bone marrow-derived mast cells (BMMC). This effect was dependent on T1/ST2 binding. In addition, IL-33 also induced IL-1beta, TNF-alpha, MCP-1, and PGD2 production in BMMC. By RNase protection assay, we demonstrated that IL-33 increased IL-6 and IL-1beta mRNA expression. These effects of IL-33 appeared to occur independently of mast cell degranulation, The results of this study show for the first time that IL-33, a novel member of the IL-1 family of cytokines, stimulates the production of pro-inflammatory mediators by mast cells in addition to its effect on T helper 2 responses. These findings open new perspectives for the treatment of inflammatory diseases by targeting IL-33.

Determination of the magneto-optical relaxation of magnetic nanoparticles as a homogeneous immunoassay

The interaction between human eotaxin (hEotaxin) and its polyclonal antibody anti-human eotaxin (anti-hEotaxin) was investigated by means of a novel liquid-phase immunoassay using the magneto-optical relaxation of ferrofluids. The binding quality as well as kinetic properties of the binding partners was determined using specifically binding magnetic probes. For this purpose, magnetic nanoparticles (MNP; DDM128N, Meito Sangyo, Japan) were initially functionalized with streptavidin. The biotin-nylated antibody was conjugated with streptavidin-MNP applying the streptavidin-biotin binding system. Binding reactions were detected by measuring the relaxation of the optical birefringence signal occurring when a pulsed magnetic field is applied to the ferrofluid. The addition of hEotaxin to anti-hEotaxin conjugated MNP in different amounts yielded an enlargement of the mean relaxation time due to the formation of MNP aggregates. In order to express the observed increase of the particles' effective diameter in terms of elementary kinetic processes between antigen and antibody, a kinetic model was introduced. Here, the binding reactions are described by a process of stepwise polymerization. The obtained results were compared with data received from surface plasmon resonance biosensor analysis, a standard tool for biomolecular interaction analysis.

Cbl-b is a negative regulator of inflammatory cytokines produced by IgE-activated mast cells

c-Cbl and Cbl-b E3 ubiquitin ligases are abundantly expressed in hemopoietic cells where they negatively regulate the activity and levels of many cell surface receptors and associated signaling molecules. By comparing bone marrow-derived mast cells from c-Cbl and Cbl-b-deficient mice it has recently been shown that Cbl-b is the dominant family member for negatively regulating signaling responses from high-affinity IgE receptors. In this study, we suggest that a possible reason for the greater enhancement of IgE receptor signaling in Cbl-b-deficient mice is the relatively higher levels of Cbl-b protein over c-Cbl in mast cells compared with other hemopoietic cells. We also directly compare mast cells from c-Cbl and Cbl-b-deficient mice and find that loss of Cbl-b, but not c-Cbl, increases cell growth, retards receptor internalization, and causes the sustained tyrosine phosphorylation of Syk and its substrates. However, loss of Cbl-b does not enhance the activation of ERK or Akt, nor does it promote a greater calcium response. Furthermore, loss of Cbl-b or c-Cbl does not increase levels of the Syk or Lyn protein tyrosine kinases. Most notable, however, is the extremely large increase in the production of proinflammatory cytokines TNF-alpha, IL-6, and MCP-1 by Cbl-b(-/-) mast cells compared with levels produced by c-Cbl(-/-) or wild-type cells. This marked induction, which appears to be restricted to these three cytokines, is dependent on IgE receptor activation and correlates with enhanced IkappaB kinase phosphorylation. Thus, Cbl-b functions as a potent negative regulator of cytokines that promote allergic and inflammatory reactions.

Effects of Diesel Exhaust on Lung Inflammation Related to Bacterial Endotoxin in Mice

We have previously shown that intratracheal instillation of diesel exhaust particles enhances lung inflammation and lung expression of proinflammatory cytokines and chemokines related to bacterial endotoxin (lipopolysaccharide) in mice. The present study was designed to elucidate the effects of inhalation of diesel exhaust on lung inflammation related to lipopolysaccharide. ICR mice were exposed for 12 hr to clean air or diesel exhaust at a soot concentration of 0.3, 1.0, or 3.0 mg/m(3) after intratracheal challenge with 125 microg/kg of lipopolysaccharide. Lung inflammation and lung expression of proinflammatory chemokines such as macrophage chemoattractant protein-1 and keratinocyte chemoattractant were evaluated 24 hr after intratracheal administration. Diesel exhaust inhalation decreased lipopolysaccharide-elicited inflammatory cell recruitment into the bronchoalveolar lavage fluid as compared with clean air inhalation. Histological study demonstrated that exposure to diesel exhaust did not affect lipopolysaccharide-enhanced neutrophil recruitment into the lung parenchyma. Lipopolysaccharide instillation elevated lung expression of macrophage chemoattractant protein-1 and keratinocyte chemoattractant under clean air or diesel exhaust inhalation. However, diesel exhaust exposure did not influence but rather did suppress these levels in the presence of lipopolysaccharide. These results suggest that short-term exposure to diesel exhaust did not exacerbate lung inflammation related to bacterial endotoxin.

Effects of Volatile Constituents of Rosemary Extract on Lung Inflammation Induced by Diesel Exhaust Particles

Epidemiological and experimental studies have implicated that diesel exhaust particles are involved in increases in morbidity and mortality from lung diseases. Recently, we have demonstrated that rosmarinic acid, a polyphenolic liquid component in perilla, inhibits lung inflammation induced by diesel exhaust particles in vivo, partly through its antioxidative property. We have also shown the antioxidative activities of volatile constituents of rosemary extract, the gaseous component in perilla, in vitro. The purpose of this study was to evaluate the effects of intratracheal administration of volatile rosemary extract on lung inflammation induced by diesel exhaust particles. ICR mice were treated with intratracheal administration of volatile rosemary extract before intratracheal exposure to diesel exhaust particles. Twenty-four hr later, diesel exhaust particles exposure elicited lung inflammation characterized by the infiltration of neutrophils and eosinophils, which was confirmed by cellular profile of bronchoalveolar lavage fluid and histological examination. Diesel exhaust particles enhanced the protein expressions of interleukin-1beta, macrophage inflammatory protein-1alpha, macrophage chemoattractant protein-1, and keratinocyte chemoattractant in the lung. Pretreatment with rosemary extract significantly inhibited the diesel exhaust particles-induced lung inflammation. Rosemary extract treatment also suppressed the diesel exhaust particles-enhanced lung expression of macrophage inflammatory protein-1alpha, macrophage chemoattractant protein-1, and keratinocyte chemoattractant. These results suggest that intratracheal administration of rosemary extract can prevent lung inflammation induced by diesel exhaust particles. The preventive effect is mediated, at least partly, through the inhibition of the enhanced lung expressions of macrophage inflammatory protein-1alpha, macrophage chemoattractant protein-1, and keratinocyte chemoattractants.

In chronic idiopathic urticaria autoantibodies against Fc epsilonRII/CD23 induce histamine release via eosinophil activation

BACKGROUND

Chronic idiopathic urticaria is a common skin disorder characterized by recurrent, transitory, itchy weals for more than 6 weeks. An autoimmune origin has been suggested based on the findings of auto-antibodies (Abs) directed against either the alpha subunit of the high-affinity IgE receptor or the IgE molecule in nearly half of the patients.

OBJECTIVE

To identify other autoantigen targets in patients with chronic idiopathic urticaria.

METHODS

We used pooled IgG derived from 133 patients with chronic idiopathic urticaria to screen a random peptide library to identify disease-relevant autoantigen peptides. Among the identified peptides, one was recognized by the vast majority of patients' sera. Abs against this peptide were affinity purified from the patients' sera and assayed for their ability to induce histamine release from basophils.

RESULTS

We identified a peptide that showed similarity with the low-affinity IgE receptor (Fc epsilonRII/CD23) expressed on lymphomonocytes and eosinophils. Anti-peptide IgG Abs purified from the patients' sera bound cell surface CD23 and were able to induce histamine release from basophils. This effect appeared to be mediated by the release of major basic protein from eosinophils upon engagement of CD23. The same effects were obtained with the sera from mice immunized with the CD23 peptide.

CONCLUSION

Our results indicate that patients with chronic idiopathic urticaria have Abs against CD23 and that eosinophils, which infiltrate the skin of these patients, play a crucial role in maintaining the disease through the release of major basic protein upon engagement of the low-affinity IgE receptor by such auto-Abs.

Bovine eotaxin (CCL11)--an unusual member of the eotaxin group--attracts eosinophils in vitro but is not responsible for eosinophilia in the ovary

Under physiological conditions normally characterised by low tissue infiltration of eosinophils, a conspicuous number of these cells are attracted into the human and ruminant ovary. Eosinophils suddenly increase in the thecal layer of the preovulatory follicle and corpus luteum at very early development. Currently, we only have a limited understanding of the mechanism for the recruitment of the ovarian eosinophils. Eotaxin (CCL11) may be one of the chemoattractants involved in stimulating eosinophils to migrate selectively into ovary. As a prerequisite for the analysis of eotaxin expression in the bovine ovary, we determined the complete bovine eotaxin mRNA sequence since it was not available from databases. The bovine eotaxin is the first member of the monocyte chemoattractant protein (MCP)/eotaxin subfamily with two mRNA isoforms varying in length in the untranslated 3'-untranslated region. The unusual amino-acid sequence of bovine eotaxin contains structural features that are so far known to be characteristic for MCP, but not eotaxin. In our microchemotaxis assays, recombinant bovine eotaxin showed a functional pattern orthologous to known eotaxins. Thus, the chimeric structure of bovine eotaxin did not affect the favoured chemotactic activity on eosinophils. Semiquantitative RT-PCR was used to investigate the expression of eotaxin in different regions of the bovine ovary. We only detected faint eotaxin mRNA signals that did not indicate physiological significance even in stimulated granulosa cell cultures, follicle-derived macrophages or fibroblasts. Taken together, bovine eotaxin attracts eosinophils in vitro but is not responsible for eosinophilia in the ovary. Its unusual chimeric structure confirms the unity of the MCP/eotaxin subfamily of CC chemokines and distinguishes it from other CC chemokine subfamilies.

Anti-allergic properties of the bromeliaceae Nidularium procerum: inhibition of eosinophil activation and influx

New therapeutic approaches for the treatment of allergic diseases can be aided by the development of agents capable of regulating eosinophilic leukocytes. Here, we evaluated the anti-allergic properties of a crude extract of the Brazilian bromeliaceae Nidularium procerum, focusing on its effects on allergic eosinophilia. By studying allergic pleurisy in actively sensitized C57Bl/6 mice, we observed that pretreatment with N. procerum (2 mg/kg; i.p.) reduced pleural eosinophil influx triggered by allergen challenge. N. procerum was also able to reduce lipid body numbers found within infiltrating eosinophils, indicating that N. procerum in vivo is able to affect both migration and activation of eosinophils. Consistently, pretreatment with N. procerum blocked pleural eosinophil influx triggered by PAF or eotaxin, key mediators of the development of allergic pleural eosinophilia. The effect of N. procerum was not restricted to eosinophils, since N. procerum also inhibited pleural neutrophil and mononuclear cell influx. Of note, N. procerum failed to alter the acute allergic reaction, characterized by mast cell degranulation, oedema, and cysteinyl leukotriene release. N. procerum also had direct effects on murine eosinophils, since it inhibited both PAF- and eotaxin-induced eosinophil chemotaxis on an in vitro chemotactic assay. Therefore, N. procerum may be a promising anti-allergic therapy, inasmuch as it presents potent anti-eosinophil activity.

IL-9-mediated induction of eotaxin1/CCL11 in human airway smooth muscle cells

Recent work has shown the potential importance of IL-9 in allergic diseases. The development of transgenic mice overexpressing IL-9 has suggested a key role for this cytokine in the development of the asthmatic phenotype including airway eosinophilia. In this study, we evaluated the expression of the IL-9R and the effects of IL-9 on human ASM cells by examining the release of Th2-associated chemokines (eotaxin1/CCL11 and thymus- and activation-regulated chemokine (TARC)/CCL17). IL-9R alpha-chain mRNA and surface expression were detected in cultured human airway smooth muscle (ASM) cells. In addition, primary cultured ASM cells, as well as bronchial smooth muscle cells within biopsies of asthmatics and not control subjects, revealed IL-9R protein expression. IL-9 stimulation of human ASM cells resulted in release of eotaxin1/CCL11, but had no effect on the release of TARC/CCL17, in time- and dose-dependent manner. Moreover, in vitro chemotaxis assay demonstrated that conditioned medium from IL-9-stimulated ASM cells attracted human eosinophils. Neutralizing Abs to IL-9, but not to IL-4 or IL-13, reduced significantly IL-9-induced production of eotaxin1/CCL11 from ASM cells. Interestingly, real-time RT-PCR showed that IL-9 up-regulated eotaxin1/CCL11 mRNA expression, but had no effect on TARC/CCL17. Treatment with Act D abrogates IL-9-induced eotaxin1/CCL11 mRNA and protein release by ASM cells. Finally, transfection study using eotaxin1/CCL11 promoter luciferase construct confirmed that IL-9 induced eotaxin1/CCL11 at the transcriptional level. Taken together, these data provide new evidence demonstrating that IL-9-dependent activation of ASM cells contributes to eosinophilic inflammation observed in asthma.

A critical temporal window for selectin-dependent CD4+ lymphocyte homing and initiation of late-phase inflammation in contact sensitivity

Contact sensitivity (CS) is an inflammatory disorder characterized by early and late phases of leukocyte recruitment. We used a noninvasive intravital microscopy technique allowing for the direct visualization of leukocyte rolling and adhesion on blood vessel endothelium. By blocking specific adhesion molecules, we elucidated the molecular mechanisms mediating early leukocyte recruitment to be E- and P-selectin and demonstrated that leukocyte recruitment in the late phase had a different adhesive profile (mainly α₄-integrin). Complete blockade of E- and P-selectin within the first 2 h of leukocyte–endothelial cell interactions (but not later) eliminated selectin-independent leukocyte recruitment at 24 h. Despite the predominance of neutrophils in the early phase, specific elimination of CD4⁺ lymphocytes in the early phase eliminated the late response. CD4⁺ lymphocytes homed to skin via E- and P-selectin within the early phase and induced the late phase response. Addition of these same CD4⁺ lymphocytes 2 h after antigen challenge was too late for these cells to home to the skin and induce late phase responses. Our data clearly demonstrate that the antigen-challenged microenvironment is only accessible to CD4⁺ lymphocytes for the first 2 h, and that this process is essential for the subsequent recruitment of other leukocyte populations in late phase responses.

Systemic and mucosal responses to oral administration of excretory and secretory antigens from Giardia intestinalis

Giardia, a flagellated protozoan that infects the upper small intestine of its vertebrate host, is the most common parasitic protist responsible for diarrhea worldwide. Molecules released by the parasite, particularly excretory and secretory antigens, seemed to be associated with pathogenesis as well as with the expression of Giardia virulence. In the present work, we examined the effect of oral administration of Giardia intestinalis excretory and secretory antigens on systemic and local antibody response as well as on mucosal injuries in BALB/c mice. Significant titers of serum-specific immunoglobulin G1 (IgG1) and specific IgG2a were observed. Systemic and mucosal specific IgA antibodies were also recorded. A transient production of serum-specific IgE antibody and high total IgE levels were also detected, suggesting the presence in excretory and secretory proteins of factors promoting a specific IgE response. The sera of excretory and secretory antigen-treated mice recognized proteins of 50 and 58 kDa as well as electrophoretic bands of 15, 63, and 72 kDa that could support a proteinase activity. The in vitro exposure of G. intestinalis trophozoites to heat-inactivated sera from mice orally inoculated with excretory and secretory antigens induced a decrease of growth, revealing a complement-independent inhibitory activity of specific serum antibodies. Furthermore, histological evaluation performed on the small and large intestines revealed moderate to acute histological changes comparable to those observed in natural or experimental Giardia infection characterized by eosinophilic infiltration, hypercellularity, and enterocytic desquamation. The present results suggested that Giardia excretory and secretory antigens stimulate a preferential Th2 response, which is probably involved in the intestinal alterations associated with giardiasis.

Stimulation of human bronchial epithelial cells by IgE-dependent histamine-releasing factor

An IgE-dependent histamine-releasing factor (HRF p23; also known as translationally controlled tumor protein or p23) stimulates the release of histamine, IL-4, and IL-13 from a subpopulation of highly allergic donor basophils. It has also been shown to act as a chemoattractant for eosinophils. To elucidate novel functions of HRF p23 in airway inflammation, we examined the effects of human recombinant HRF p23 (hrHRF) on bronchial epithelium and found that hrHRF stimulated the secretions of IL-8 and granulocyte/macrophage colony-stimulating factor by both primary cultures of human bronchial epithelial cells and BEAS-2B cells. In response to hrHRF, these cells induced IL-8 mRNA expression within 4 h. H2O2, but not IL-1 beta or tumor necrosis factor-alpha, stimulated secretion of HRF p23 by BEAS-2B cells, suggesting that oxidative stress may trigger the release of HRF p23 from bronchial epithelial cells. Bronchoalveolar lavage (BAL) from healthy volunteers contained only trivial or undetectable amounts of HRF p23. Significantly higher amounts of HRF p23 were recovered from BAL fluid taken from asthmatic patients, and the amounts of HRF p23 were further elevated in patients with idiopathic eosinophilic pneumonia. Our results demonstrate for the first time that HRF p23 can stimulate nonimmune epithelium. HRF p23 derived from bronchial epithelial cells may regulate complex cytokine networks in eosinophil-dependent inflammation of the human airway.

Effect of a topical steroid on gene expressions for chemokines in mice with contact hypersensitivity

Effects of a topical corticosteroid drug, diflucortolone valerate, on the mRNA expressions for four CC- and four CXC-chemokines, which have been reported to be associated with recruitment of different kinds of proinflammatory and inflammatory cells, were investigated by RT-PCR in mice with 2,4,6-trinitrochlorobenzene (TNCB)-induced contact hypersensitivity (CHS) response. All of the eight gene expressions were clearly up-regulated in the lesion site of the CHS response up to 24 h post-challenge of TNCB at which ear swelling response reached a peak, so that heavy infiltration of inflammatory cells consisting mainly of mononuclear cells and neutrophils was likely induced by these chemokines. Topical treatment with diflucortolone valerate suppressed completely the infiltrates as well as the ear swelling response. In addition, the up-regulation of gene expressions for these eight chemokines were suppressed by the treatment, indicating that the corticosteroid drug attenuates the expression of chemokine genes essential for orientating nonspecific skin response to hapten-specific CHS response through the recruitment of inflammatory cells from the circulation into the tissue site.

Eotaxin-2 and IL-5 cooperate in the lung to regulate IL-13 production and airway eosinophilia and hyperreactivity

BACKGROUND

Eotaxin-2 is a member of the eotaxin subfamily of CC chemokines that display eosinophil-specific, chemotactic properties and has been associated with allergic disorders. However, the contribution of eotaxin-2 to the development of defined pathogenic features of allergic disease remains to be defined.

OBJECTIVE

We sought to determine whether eotaxin-2 was a cofactor with IL-5 for the regulation of pulmonary eosinophilia and to identify the combined role of these molecules in the induction of phenotypic characteristics of allergic lung disease.

METHODS

We instilled recombinant eotaxin-2 into the airways of wild-type mice that had been treated systemically with IL-5 or into IL-5-transgenic mice and characterized pulmonary eosinophil numbers, IL-13 production, and airway hyperreactivity (AHR) to methacholine. Mice deficient in the IL-4 receptor alpha-chain, IL-13, and signal transducers and activators of transcription 6 or mice treated with anti-CCR3 monoclonal antibody were also used.

RESULTS

Eotaxin-2 and IL-5 cooperatively promoted eosinophil accumulation, IL-13 production, and AHR to methacholine. Neither eotaxin-2 nor IL-5 alone induced these features of allergic disease. IL-13 production was critically dependent on eotaxin-2- and IL-5-regulated eosinophilia, which predisposed to the development of AHR. AHR was dependent on IL-13 and signaling through the IL-4R alpha-chain and signal transducers and activators of transcription 6 pathways and the presence of eosinophils in the lung.

CONCLUSION

These investigations demonstrate important cooperativity between eotaxin-2, IL-5, and IL-13 signaling systems and eosinophils for the development of hallmark features of allergic disease of the lung.