Potential role of interleukin-10-secreting regulatory T cells in allergy and asthma

The beneficial properties of marine polysaccharides in alleviation of allergic responses

Marine polysaccharides have been found as the principle component in cell wall structures of seaweeds or exoskeletons of crustaceans. Due to numerous pharmaceutical properties of marine polysaccharides such as antioxidant, anti-inflammatory, antiallergic, antitumor, antiobesity, antidiabetes, anticoagulant, antiviral, immunomodulatory, cardioprotective, and antihepatopathy activities, they have been applied in many fields of biomaterials, food, cosmetic, and pharmacology. Recently, several marine polysaccharides such alginate, porphyran, fucoidan, and chitin and its derivatives have been evidenced as downregulators of allergic responses due to enhancement of innate immune system, alteration of Th1/Th2 balance forward to Th1 cells, inhibition of IgE production, and suppression of mast cell degranulation. This contribution, therefore, focuses on antiallergic properties of marine polysaccharides and emphasizes their potential application as bioactive food ingredients as well as nutraceuticals for prevention of allergic disorders.

Protective effects of pogostone from Pogostemonis Herba against ethanol-induced gastric ulcer in rats

We examined the protective effect of pogostone (PO), a chemical constituent isolated from Pogostemonis Herba, on the ethanol-induced gastric ulcer in rats. Administration of PO at doses of 10, 20 and 40 mg/kg body weight prior to ethanol ingestion effectively protected the stomach from ulceration. The gastric lesions were significantly ameliorated by all doses of PO as compared to the vehicle group. Pre-treatment with PO prevented the oxidative damage and the decrease of prostaglandin E2 (PGE2) content. In addition, PO pretreatment markedly increased the mucosa levels of glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT), and decreased gastric malonaldehyde (MDA), relative to the vehicle group. In the mechanistic study, significant elevation of non-protein-sulfhydryl (NP-SH) was observed in the gastric mucosa pretreated by PO. Analysis of serum cytokines indicated that PO pretreatment obviously elevated the decrease of interleukin-10 (IL-10) level, while markedly mitigated the increment of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) secretions in ethanol-induced rats. Taken together, these results strongly indicate that PO could exert a gastro-protective effect against gastric ulceration, and the underlying mechanism might be associated with the stimulation of PGE2, improvement of antioxidant and anti-inflammatory status, as well as preservation of NP-SH.

The therapeutic potential of interleukin-10 in neuroimmune diseases

Neuroimmune diseases have diverse symptoms and etiologies but all involve pathological inflammation that affects normal central nervous system signaling. Critically, many neuroimmune diseases also involve insufficient signaling/bioavailability of interleukin-10 (IL-10). IL-10 is a potent anti-inflammatory cytokine released by immune cells and glia, which drives the regulation of a variety of anti-inflammatory processes. This review will focus on the signaling pathways and function of IL-10, the current evidence for insufficiencies in IL-10 signaling/bioavailability in neuroimmune diseases, as well as the implications for IL-10-based therapies to treating such problems. We will review in detail four pathologies as examples of the common etiologies of such disease states, namely neuropathic pain (nerve trauma), osteoarthritis (peripheral inflammation), Parkinson's disease (neurodegeneration), and multiple sclerosis (autoimmune). A number of methods to increase IL-10 have been developed (e.g. protein administration, viral vectors, naked plasmid DNA, plasmid DNA packaged in polymers to enhance their uptake into target cells, and adenosine 2A agonists), which will also be discussed. In general, IL-10-based therapies have been effective at treating both the symptoms and pathology associated with various neuroimmune diseases, with more sophisticated gene therapy-based methods producing sustained therapeutic effects lasting for several months following a single injection. These exciting results have resulted in IL-10-targeted therapeutics being positioned for upcoming clinical trials for treating neuroimmune diseases, including neuropathic pain. Although further research is necessary to determine the full range of effects associated with IL-10-based therapy, evidence suggests IL-10 may be an invaluable target for the treatment of neuroimmune disease. This article is part of a Special Issue entitled 'Neuroimmunology and Synaptic Function'.

Cohabitation with a sick partner increases allergic lung inflammatory response in mice

The bidirectional relationship between the nervous system and the immune system is relevant for homeostatic organism maintenance. Studies from our laboratory showed that 14days of cohabitation with a sick partner (injected with Ehrlich tumor cells-TAE) produced behavioral, neurochemical, endocrinological and immunological changes. This study analyzes the effects of cohabitation with an Ehrlich tumor-bearing animal on ovalbumin (OVA)-induced lung inflammatory response in mice. Pairs of male mice were divided into three groups: naïve, control and experimental. Animals of the naïve group were kept undisturbed being used for the assessment of basal parameters. One animal of each experimental and control pair of mice was immunized with OVA. On ED(0), these OVA-immunized animals received an OVA booster. At this day (D(0)) the experimental mice that were kept undisturbed were inoculated with 5×10(6) Ehrlich tumor cells; their immunized cage-mates were then referred as to CSP ("companion of sick partner"). The undisturbed mice of each control pair were i.p. treated on D(0) with 0.9% NaCl; their sensitized cage-mates were subsequently referred as CHP ("companion of health partner"). The OVA challenge was performed on CSP and CHP mice on ED(12) and ED(13); blood and tissue collection were performed on ED(14). Fourteen days after cohabitation, in comparison to the CHP mice, the CSP mice displayed the following: (1) an increased number of eosinophils and neutrophils in the BAL, (2) a decreased bone marrow cell count, (3) increased levels of IL-4 and IL-5 and decreased levels of IL-10 and IFN-γ in the BAL supernatant, (5) increased levels of IgG1-OVA, decreased levels of IgG2a-OVA and no changes in OVA-specific IgE in the peripheral blood, (6) increased expression of L-selectin in the BAL granulocytes, (7) decreased tracheal reactivity to methacholine measured in vitro, (8) no changes in plasma corticosterone levels and (9) increased levels of plasmatic noradrenaline. These results suggest that allergic lung inflammatory response exacerbation in CSP mice is a consequence of the psychological stress induced by forced cohabitation with the sick partner. Strong involvement of the sympathetic nervous system (SNS) through adrenaline and noradrenaline release and a shift of the Th1/Th2 cytokine profile toward a Th2 response were considered to be the mechanisms underlying the cell recruitment to the animal's airways.

Perforin, CD28 and CD95 expression in circulating CD4 and CD8 cells as predictors of head and neck (H&N) cancer patient survival

Long-term survival of H&N cancer patients has not improved significantly over the last 30 years. The possibility of using circulating blood cell phenotypes as a prognostic biomarker of H&N cancer patient was investigated in this study. Pre-treatment, circulating T lymphocyte subpopulations as well as the survival time of the patients in question were studied. Upregulated CD4+ perforin+ and CD8+ CD95+ but downregulated CD4+ CD28+ (p < 0.001) were detected in H&N cancer patients. With 3 years of follow-up time, an increase in the frequency of the pre-treatment, circulating CD4+ perforin+ cells and CD8+ perforin+ cells was showed to have reverse effects on the survival time in H&N cancer patients (p < 0.01). Detection of perforin+ frequency in CD4+ and CD8+ lymphocyte by FACS is fast, simple and cost-effective. A potential role of perforin expression in CD4+ and CD8+ cells as a prognostic biomarker for H&N cancer patient in the clinical setting was suggested.

A novel and well tolerated mite allergoid subcutaneous immunotherapy: evidence of clinical and immunologic efficacy

Allergy to house dust mite is one of the most common causes of allergic rhinitis. A novel tyrosine-adsorbed, modified allergen product, Acarovac Plus, developed for the treatment of perennial mite allergy seeks to address the underlying cause of allergic rhinitis in this instance. One of two dosing regimens may be used, either the Conventional Regimen or the Cluster Regimen. We sought to compare the efficacy and safety of a specific immunotherapy, developed for the treatment of perennial mite allergy, administered under a Conventional and Clustered dosing schedule in patients with persistent allergic rhinitis. Thirty adult patients, between 18 and 65 years old, with allergic rhinitis and/or asthma secondary to hypersensitivity to Dermatophagoides pteronyssinus were administered with either conventional or cluster initial regime, with a final visit one week after the last dose administration. The efficacy to the Conventional and Cluster regimens was measured using a Nasal Challenge Test monitoring clinical symptoms and peak nasal inspiratory flow. Total IgE, serum-specific inmunoglobulins (IgE and IgG4) to Dermatophagoides pteronyssinus and relevant cytokines (IFN-γ, IL-4, IL-5, IL-10 and IL-13) were assessed. A Satisfaction Questionnaire (TSQM) was completed after each patient's final visit. The tolerability of the vaccine was assessed monitoring adverse reactions. No adverse events were recorded in either conventional or cluster regime. The specific Nasal Challenge Test led to a decrease in symptom scores and a significant decrease in mean nasal peak inspiratory flow drop was recorded in both dosing regimen groups. A significant increase in IgG4-specific antibody titres was assessed. No significant changes were observed in concentrations of total IgE, specific IgE or cytokines (IFN-γ, IL-4, IL-5, IL-10 and IL-13). Patients declared themselves most satisfied in relation to "Secondary effects", with high overall satisfaction in both groups. Cluster and conventional specific immunotherapy resulted in no adverse reaction(s) and led to similar improvements in immunological parameters, clinical efficacy (Nasal Challenge Test) and high overall satisfaction.

WNT16B from ovarian fibroblasts induces differentiation of regulatory T cells through β-catenin signal in dendritic cells

Treatment for cancer can induce a series of secreted factors into the tumor microenvironment, which can affect cancer progression. Wingless-type MMTV (mouse mammary tumor virus) integration site 16B (WNT16B) is a new member of the WNT family and has been reported to play growth-related roles in previous studies. In this study, we found WNT16B could be expressed and secreted into the microenvironment by human ovarian fibroblasts after DNA damage-associated treatment, including chemotherapy drugs and radiation. We also demonstrated that fibroblast-derived WNT16B could result in accumulation of β-catenin in dendritic cells and secretion of interleukin-10 (IL-10) and transforming growth factor beta (TGF-β), which contributed to the differentiation of regulatory T cells in a co-culture environment. These results shed light on the roles of WNT16B in immune regulation, especially in regard to cancer treatment.

Modulation of dendritic cell functions by viral IL-10 encoded by human cytomegalovirus

Human cytomegalovirus (HCMV), a clinically important β-herpesvirus, is a master of evasion and modulation of the host immune system, including inhibition of a number of dendritic cell (DC) functions. DCs play a central role in co-ordination of the immune response against pathogens and any disturbance of DCs functions can result in a cascade effect on a range of immune cells. Recently, the HCMV gene UL111A, which encodes viral homologs of human interleukin 10, has been identified as a strong suppressor of a number of DCs functions. In this mini review, we focus on HCMV-encoded viral IL-10-mediated inhibitory effects on DCs and implications for the development of an effective HCMV vaccine.

Helminths in the hygiene hypothesis: sooner or later?

There is increasing recognition that exposures to infectious agents evoke fundamental effects on the development and behaviour of the immune system. Moreover, where infections (especially parasitic infections) have declined, immune responses appear to be increasingly prone to hyperactivity. For example, epidemiological studies of parasite-endemic areas indicate that prenatal or early-life experience of infections can imprint an individual's immunological reactivity. However, the ability of helminths to dampen pathology in established inflammatory diseases implies that they can have therapeutic effects even if the immune system has developed in a low-infection setting. With recent investigations of how parasites are able to modulate host immune pathology at the level of individual parasite molecules and host cell populations, we are now able to dissect the nature of the host-parasite interaction at both the initiation and recall phases of the immune response. Thus the question remains - is the influence of parasites on immunity one that acts primarily in early life, and at initiation of the immune response, or in adulthood and when recall responses occur? In short, parasite immunosuppression - sooner or later?

Frequency of regulatory T-cell and hepatitis C viral antigen-specific immune response in recurrent hepatitis C after liver transplantation

INTRODUCTION

Regulatory T (Treg) and type 1 regulatory T (Tr1) cells facilitate hepatitis C virus (HCV) recurrence after orthotopic liver transplantation (OLT). However, their frequencies and effects on HCV-specific immune responses have not been well investigated.

METHODS

We determined Treg and Tr1 frequencies in OLT patients with hepatitis C and assessed their associations with HCV-specific T cell responses. These patients comprised the following groups: an early post-transplantation group (n=14); an OLT-chronic active hepatitis C group (n=14) with active hepatitis C (alanine aminotransferase of>upper limit of normal/positive for HCV-RNA); an OLT-persistently normal alanine aminotransferase group (n=12) without active hepatitis C (not interferon/positive for HCV-RNA); and an OLT-sustained viral response group (n=6) with sustained viral responses using interferon treatment (negative for HCV-RNA). The frequencies of HCV-specific CD4+ T cells that secreted interferon-γ were determined by enzyme-linked immunosorbent spot assay (except for the OLT early group).

RESULTS

Treg and Tr1 frequencies were low during the early post-transplantation period. OLT patients with sustained viral responses had lower Treg frequencies than those with chronic hepatitis C, whereas Tr1 frequencies were significantly reduced in OLT patients with persistently normal alanine aminotransferase levels compared to those with chronic hepatitis C (p<0.05). Treg frequencies positively correlated with HCV NS3 antigen-specific interferon-γ responses, which corresponded to HCV clearance.

CONCLUSIONS

Increased Treg frequencies and reduced HCV-NS3 antigen-specific responses recovered after viral eradication in post-OLT chronic hepatitis C patients. Reduced Tr1 frequencies were associated with hepatitis activity control, which may facilitate controlling chronic hepatitis C in patients after OLT.

IL-10 function, regulation, and in bacterial keratitis

The immune system protects the host from pathogenic microbes, but tight regulation of the evoked response is requisite to limit bystander damage. The interleukin (IL)-10 family of cytokines, composed of 9 members: IL-10, IL-19, IL-20, IL-22, IL-24, IL-26, and 3 distantly related members, IL-28A, IL-28B, and IL-29, plays a central role in this regulation. IL-10 family cytokines emerged before the adaptive immune response and elicit diverse host defense mechanisms, especially from epithelial cells during an infection. IL-10 family cytokines are also essential for maintenance and integrity of tissue epithelial layers. These cytokines promote innate immune responses from tissue epithelia that limit the damage caused by both viral and bacterial infections. They also facilitate tissue healing after infection/inflammation. In this regard, IL-10 suppresses pro-inflammatory responses, limiting tissue disruption resulting from an inflammatory response. Thus, a central functional theme of IL-10 family cytokines is their role in tissue protection. This review focuses on IL-10, the founding member of this family of cytokines, and integrates recent data on the function and regulation of IL-10 during bacterial infections. Emphasis is placed on the role of IL-10 in Pseudomonas aeruginosa keratitis and the subsequent infectious/inflammatory processes evoked.

Mechanisms of allergen-specific immunotherapy: multiple suppressor factors at work in immune tolerance to allergens

Allergen-specific immunotherapy (AIT) has been used for more than 100 years as a desensitizing therapy for IgE-mediated allergic diseases and represents a potentially curative way of treatment. The mechanisms of action of AIT include the induction of very early desensitization of mast cells and basophils; generation of regulatory T and regulatory B (Breg) cell responses; regulation of IgE and IgG4; decreases in numbers and activity of eosinophils and mast cells in mucosal allergic tissues; and decreases in the activity of basophils in circulation. Skewing of allergen-specific effector T and effector B cells to a regulatory phenotype appears as a key event in the course of AIT and normal immune response to allergens. Recently, inducible IL-10-secreting Breg cells were also demonstrated to contribute to allergen tolerance through suppression of effector T cells and selective induction of IgG4 isotype antibodies. Allergen-specific regulatory T and Breg cells orchestrate a general immunoregulatory activity, which can be summarized as suppression of cytokines from inflammatory dendritic cells; suppression of effector TH1, TH2, and TH17 cells; suppression of allergen-specific IgE and induction of IgG4; and suppression of migration of mast cells, basophils, eosinophils, and effector T cells to tissues. A detailed knowledge of the mechanisms of AIT is not only important in designing the prevention and treatment of allergic diseases but might also find applications in the treatment of autoimmune diseases, organ transplantation, chronic infection, and cancer.

The Vitamin D Antenatal Asthma Reduction Trial (VDAART): rationale, design, and methods of a randomized, controlled trial of vitamin D supplementation in pregnancy for the primary prevention of asthma and allergies in children

There is intense interest in the role of vitamin D in the development of asthma and allergies. However, studies differ on whether a higher vitamin D intake or status in pregnancy or at birth is protective against asthma and allergies. To address this uncertainty, the Vitamin D Antenatal Asthma Reduction Trial (VDAART) was developed. VDAART is a randomized, double-blind, placebo-controlled trial of vitamin D supplementation in pregnant women to determine whether prenatal supplementation can prevent the development of asthma and allergies in women's offspring. A secondary aim is to determine whether vitamin D supplementation can prevent the development of pregnancy complications, such as preeclampsia, preterm birth, and gestational diabetes. Women were randomized to the treatment arm of 4000IU/day of vitamin D3 plus a daily multivitamin that contained 400IU of vitamin D3 or the placebo arm of placebo plus a multivitamin that contained 400IU daily of vitamin D3. Women who were between the gestational ages of 10 and 18 weeks were randomized from three clinical centers across the United States - Boston Medical Center, Washington University in St. Louis, and Kaiser Permanente Southern California Region (San Diego, CA). Supplementation took place throughout pregnancy. Monthly monitoring of urinary calcium to creatinine ratio was performed in addition to medical record review for adverse events. Offspring are being evaluated quarterly through questionnaires and yearly during in-person visits until the 3rd birthday of the child. Ancillary studies will investigate neonatal T-regulatory cell function, maternal vaginal flora, and maternal and child intestinal flora.

Enhanced glucocorticoid-induced leucine zipper in dendritic cells induces allergen-specific regulatory CD4(+) T-cells in respiratory allergies

BACKGROUND

Respiratory allergies rely on a defect of IL-10-secreting regulatory CD4(+) T-cells (IL-10-Tregs ) leading to excessive Th2-biased immune responses to allergens. According to clinical data, the restoration of allergen-specific IL-10-Tregs is required to control respiratory allergies and cure patients. The discovery of mechanisms involved in the generation of IL-10-Tregs will thus help to provide effective treatments. We previously demonstrated that dendritic cells (DCs) expressing high levels of the glucocorticoid-induced leucine zipper protein (GILZ) generate antigen-specific IL-10-Tregs .

OBJECTIVE

We suspect a defective expression of GILZ in the DCs of respiratory allergic patients and speculate that increasing its expression might restore immune tolerance against allergens through the induction of IL-10-Tregs .

METHODS

We assessed GILZ expression in blood DCs of patients and healthy nonallergic donors by qPCR. We compared the ability of patients' DCs to induce allergen-specific IL-10-Tregs before and after an in vivo up-regulation of GILZ expression by steroid administration, steroids being inducers of GILZ.

RESULTS

We report lower levels of GILZ in DCs of respiratory allergic patients that return to normal levels after steroid administration. We show that patients' DCs with increased levels of GILZ generate allergen-specific IL-10-Tregs again. We further confirm unequivocally that GILZ is required in patients' DCs to activate these IL-10-Tregs .

CONCLUSION

This proof of concept study shows that the re-establishment of GILZ expression in patients' DCs to normal levels restores their capacity to activate allergen-specific IL-10-Tregs . We thus highlight the up-regulation of GILZ in DCs as a new interventional approach to restore the immune tolerance to allergens.

Phase I/II study of oral immunotherapy with Cry j1-galactomannan conjugate for Japanese cedar pollinosis

OBJECTIVE

Among many immunotherapeutic approaches, oral immunotherapy (OIT) is thought to be an effective route for desensitization against a variety of allergens. However, there is little evidence that OIT is effective for airway allergic diseases such as pollen allergy. Thus, in the present study, we assessed the safety, efficacy and immune response of OIT using the Cry j1-galactomannan conjugate for Japanese cedar pollen allergy.

METHODS

An open trial was conducted over a period of 4 months. The OIT group comprised of 23 subjects. Treatment was initiated 1 month before the estimated pollen season and continued for 1 month. The control group (the pharmacological treatment group without OIT) comprised of 11 subjects. The symptoms and medication score, levels of allergen-specific serum antibodies, cellular components of lymphocytes and cytokine production from peripheral blood mononuclear cells (PBMCs) were evaluated throughout the pollen season.

RESULTS

The participants receiving OIT treatment showed significant improvements in total symptom scores and symptom-medication scores during the pollen season compared with the control group. The levels of allergen-specific serum IgG4 and IL-10 production in PBMCs were significantly increased in the OIT group compared with that in the control group. Importantly, no severe adverse effects were observed in the participants receiving OIT treatment.

CONCLUSION

Short-term OIT using the Cry j1-galactomannan conjugate is effective, relatively safe and induces tolerant immune responses such as increased allergen-specific serum IgG4 and IL-10 production in PBMCs. These results suggest that OIT using allergen-galactomannan conjugates may provide a rapid, effective, and safe immunotherapy regimen for cedar pollen allergy.

Passive transfer of tumour-derived MDSCs inhibits asthma-related airway inflammation

Myeloid-derived suppressor cells (MDSCs), a heterogeneous population including myeloid progenitor and immature myeloid cells, are known to inhibit T cell responses. The issue of whether tumour-derived MDSCs regulate the immune response in an asthma environment is currently unclear. Here, we have reported that tumour-derived MDSCs shift the balance back to normal in a Th2-dominant asthmatic environment. In an ovalbumin (OVA)-induced mouse asthma model, injected tumour-derived MDSCs were recruited to the lungs of asthmatic mice by CC chemokine ligand 2 (CCL2). MDSCs transferred into asthmatic mice via i.v. injection suppressed the infiltration of inflammatory cells into the lung, the Th2 cytokine, IL-4, concentration in bronchial lavage fluid and the serum level of OVA-specific IgE. Increased TGF-β1 production in the lung was detected after transfer of MDSCs. The inhibitory effects of MDSCs were reversed upon treatment with an anti-TGF-β1 antibody, suggesting dependence of these activities on TGF-β1. Our findings imply that tumour-derived MDSCs inhibit the Th2 cell-mediated response against allergen in a TGF-β1-dependent manner. Based on the collective results, we propose that asthma may be effectively targeted using a novel MDSC-based cell therapy approach.

Characterization of human CD39+ Th17 cells with suppressor activity and modulation in inflammatory bowel disease

Induced regulatory T-cells (iT-reg) and T helper type 17 (Th17) in the mouse share common CD4 progenitor cells and exhibit overlapping phenotypic and functional features. Here, we show that human Th17 cells endowed with suppressor activity (supTh17) can be derived following exposure of iT-reg populations to Th17 polarizing conditions. In contrast to “pathogenic” Th17, supTh17 display immune suppressive function and express high levels of CD39, an ectonucleotidase that catalyzes the conversion of pro-inflammatory extracellular nucleotides ultimately generating nucleosides. Accordingly, supTh17 exhibit nucleoside triphosphate diphosphohydrolase activity, as demonstrated by the efficient generation of extracellular AMP, adenosine and other purine derivatives. In addition supTh17 cells are resistant to the effects of adenosine as result of the low expression of the A2A receptor and accelerated adenosine catalysis by adenosine deaminase (ADA). These supTh17 can be detected in the blood and in the lamina propria of healthy subjects. However, these supTh17 cells are diminished in patients with Crohn’s disease. In summary, we describe a human Th17 subpopulation with suppressor activity, which expresses high levels of CD39 and consequently produces extracellular adenosine. As these uniquely suppressive CD39⁺ Th17 cells are decreased in patients with inflammatory bowel disease, our findings might have implications for the development of novel anti-inflammatory therapeutic approaches in these and potentially other immune disorders.

Vitamin D, the immune system and asthma

The effects of vitamin D on bone metabolism and calcium homeostasis have long been recognized. Emerging evidence has implicated vitamin D as a critical regulator of immunity, playing a role in both the innate and cell-mediated immune systems. Vitamin D deficiency has been found to be associated with several immune-mediated diseases, susceptibility to infection and cancer. Recently, there has been increasing interest in the possible link between vitamin D and asthma. Further elucidation of the role of vitamin D in lung development and immune system function may hold profound implications for the prevention and treatment of asthma.

The role of complement in tumor growth

Complement is a central part of the immune system that has developed as a first defense against non-self cells. Neoplastic transformation is accompanied by an increased capacity of the malignant cells to activate complement. In fact, clinical data demonstrate complement activation in cancer patients. On the basis of the use of protective mechanisms by malignant cells, complement activation has traditionally been considered part of the body's immunosurveillance against cancer. Inhibitory mechanisms of complement activation allow cancer cells to escape from complement-mediated elimination and hamper the clinical efficacy of monoclonal antibody-based cancer immunotherapies. To overcome this limitation, many strategies have been developed with the goal of improving complement-mediated effector mechanisms. However, significant work in recent years has identified new and surprising roles for complement activation within the tumor microenvironment. Recent reports suggest that complement elements can promote tumor growth in the context of chronic inflammation. This chapter reviews the data describing the role of complement activation in cancer immunity, which offers insights that may aid the development of more effective therapeutic approaches to control cancer.

Defective IL-10 expression and in vitro steroid-induced IL-17A in paediatric severe therapy-resistant asthma

BACKGROUND

Understanding of immune mechanisms underpinning asthma has emerged from studies in adults. It is increasingly recognised, both immunologically and in the development of novel therapies, that adult responses cannot be used accurately to predict those of children.

METHODS

Using a well-defined paediatric cohort of severe therapy-resistant asthma (STRA) patients, we investigated cytokine profiles in the airway by analysis of bronchoalveolar lavage fluid. The in vitro capacity of peripheral blood mononuclear cells (PBMCs) for cytokine production was also assessed following polyclonal T cell activation in culture, in the absence or presence of dexamethasone and 1α,25-dihydroxyvitamin D3.

RESULTS

Children with both moderate and STRA had significantly diminished levels of anti-inflammatory interleukin (IL)-10 in airway lavage samples when compared with non-asthmatic controls (p<0.001). Their PBMCs also demonstrated significantly impaired capacity to secrete IL-10 in culture (p<0.001). Dexamethasone regulated the balance between PBMC IL-10 and IL-13 production, increasing IL-10 secretion (p<0.001) and decreasing IL-13 (p<0.001) but unexpectedly enhanced IL-17A production in all groups-most strikingly in the STRA cohort (p<0.001). The inclusion of the active form of vitamin D, 1α,25-dihydroxyvitamin D3, in culture enhanced dexamethasone-induced IL-10 (p<0.05) without marked effects on IL-13 or IL-17A production. Furthermore, systemic vitamin D status directly correlated with airway IL-10 (r=0.6, p<0.01).

CONCLUSIONS

These findings demonstrate reduced peripheral and local IL-10 synthesis in paediatric asthma, and support therapeutic augmentation of low circulating vitamin D in severe, difficult-to-treat asthma, in order to correct impaired IL-10 levels. Conversely, steroids enhanced IL-17A levels, and therefore any steroid-sparing properties of vitamin D may have additional benefit in STRA.

The cell-to-cell coordination between activated T cells and CpG-stimulated macrophages synergistically induce elevated levels of IL-10 via NF-κB1, STAT3, and CD40/CD154

Background

Studies into the regulation of interleukin-10 (IL-10), have focused only on the molecular or single-cell level. The cues that induce IL-10 in the context of cell-to-cell communication are scarce. To fill this gap, this study elucidates the cell-to-cell interaction dependent regulation of IL-10.

Results

The simultaneous activation of CD4⁺ T cells via CD3/CD28 and stimulation of macrophages via CpG and their intercellular communication with each other in the same microenvironment is necessary to induce a synergistic expression of IL-10. NF-κB1, ERK, and STAT3 are positive regulators of this cell-to-cell communication mediated molecular change of IL-10 induction. Strikingly, the activation of CD40/CD154 signaling is a negative regulator of IL-10 levels by CD3/CD28/CpG.

Conclusions

These findings are of prominence as CD3/CD28/CpG treatment can induce the anti-inflammatory cytokines IL-10 and IL-30, and the activation or inhibition of the CD40/CD154 acts as molecular rheostat of the expression of IL-10 or IL-30. More importantly, this not only serves as an example of IL-10 regulation at the cellular via coordination of two signals from two cell types, but these findings also lay the molecular and cellular groundwork for future studies to investigate how to manipulate IL-10 or IL-30 production during inflammation, cancer, or autoimmune diseases.

The effect of inflammatory cytokines in alcoholic liver disease

Alcohol is the most common cause of liver disease in the world. Chronic alcohol consumption leads to hepatocellular injury and liver inflammation. Inflammatory cytokines, such as TNF-α and IFN-γ, induce liver injury in the rat model of alcoholic liver disease (ALD). Hepatoprotective cytokines, such as IL-6, and anti-inflammatory cytokines, such as IL-10, are also associated with ALD. IL-6 improves ALD via activation of the signal transducer and activator of transcription 3 (STAT3) and the subsequent induction of a variety of hepatoprotective genes in hepatocytes. IL-10 inhibits alcoholic liver inflammation via activation of STAT3 in Kupffer cells and the subsequent inhibition of liver inflammation. Alcohol consumption promotes liver inflammation by increasing translocation of gut-derived endotoxins to the portal circulation and activating Kupffer cells through the LPS/Toll-like receptor (TLR) 4 pathways. Oxidative stress and microflora products are also associated with ALD. Interactions between pro- and anti-inflammatory cytokines and other cytokines and chemokines are likely to play important roles in the development of ALD. The present study aims to conduct a systemic review of ALD from the aspect of inflammation.

Therapeutic effects and immunomodulation of suanbo mineral water therapy in a murine model of atopic dermatitis

Background

Balneotherapy is widely used as an alternative treatment modality for AD. Although the clinical benefit of some mineral waters has been established, their mechanisms of action in alleviating AD are only partly understood.

Objective

The clinical modification and immunomodulatory or anti-inflammatory effects of mineral water from the Suanbo hot springs on the differentiation and cytokine production of Th1, Th2, and regulatory T cells (T_reg) were investigated using spleen, skin tissue, and serum from NC/Nga mice.

Methods

The therapeutic effects of bathing in mineral water in a Dermatophagoides farinae body extract ointment (Dfb ointment)-induced AD mouse model were assessed by measuring the modified Scoring atopic dermatitis (SCORAD) index scores, transepidermal water loss (TEWL), histological and immunohistochemical changes of the skin lesion, serum levels of interferon (IFN)-γ, interleukin (IL)-4, IL-5 and immunoglobulin E, mRNA expression of IFN-γ, IL-4 and IL-5 of dorsal skin, and helper T cell differentiation in the spleen.

Results

Bathing in mineral water significantly reduced the modified SCORAD index scores, TEWL, epidermal hyperplasia, and inflammatory cell infiltration. IL-4 production and Th2 cell differentiation showed a decreasing tendency with mineral water bathing, but the Th1 cells did not. On the contrary, differentiation to T_reg cells was promoted with mineral water bathing.

Conclusion

Balneotherapy not only has anti-inflammatory activity, but also shows positive effects on cutaneous barrier homeostasis. These results suggest that the favorable effects of balneotherapy may be mediated by modifying the Th2 response, and possibly in part by inducing T_reg cell differentiation.

Alveolar macrophages are critical for the inhibition of allergic asthma by mesenchymal stromal cells

Multipotent mesenchymal stromal cells (MSCs) possess reparative and immunoregulatory properties, making them attractive candidates for cellular therapy. However, the majority of MSCs administered i.v. encounter a pulmonary impasse and soon disappear from the lungs, raising the question of how they induce such durable immunosuppressive effects. Using a mouse model of allergic asthma, we show that administration of MSCs isolated from human bone marrow, umbilical cord, or adipose tissue provoked a pronounced increase in alveolar macrophages and inhibited hallmark features of asthma, including airway hyperresponsiveness, eosinophilic accumulation, and Th2 cytokine production. Importantly, selective depletion of this macrophage compartment reversed the therapeutic benefit of MSC treatment on airway hyperresponsiveness. Our data demonstrate that human MSCs exert cross-species immunosuppressive activity, which is mediated by alveolar macrophages in allergic asthma. As alveolar macrophages are the predominant immune effector cells at the air-tissue interface in the lungs, this study provides a compelling mechanism for durable MSC effects in the absence of sustained engraftment.

Fish oil has beneficial effects on allergen-induced airway inflammation and hyperreactivity in mice

Background

Fish oil (FO) is rich in n-3 polyunsaturated fatty acids (PUFA), which have been suggested to be anti-inflammatory and are associated with improvement of several inflammatory diseases. In this study, we investigated the influence of FO on allergen-induced lung inflammation and airway hyperreactivity in mice.

Methods

Male A/J mice were fed either a standard-chow (SC) or a FO diet (FO) for 8 weeks. After 4 weeks, each group was further randomized for ovalbumin (SC-OVA and FO-OVA) or saline (SC-SAL and FO-SAL) challenge. Resistance and elastance were measured at baseline and after aerosolized methacholine, 24h after the last challenge. Bronchoalveolar lavage (BAL) was performed for leukocyte counts. Lung tissue mucus deposition, peribronchiolar matrix deposition and eosinophil infiltration were quantified. Serum immunoglobulin E (IgE) and IgG1 (ref 2.2), lung IL-4, IL-5, IL-10, IL-13, IL-17, INFγ and eotaxin-1 and 2 were detected by ELISA and nuclear factor kappa B (NFκB), GATA-3 and peroxisome proliferator-activated receptor gamma (PPARγ) expression was measured by Western blot.

Results

Levels of serum IgE and IgG1 were significantly higher in OVA sensitized mice. OVA challenge resulted in increased eosinophil infiltration, increased inflammatory cytokine production, peribronchiolar matrix and mucus deposition and airway hyperreactivity to aerosolized methacholine. Elevated lung NFκB and GATA-3 expression was noted in OVA-challenged mice. These changes were attenuated in mice fed with FO diet. Higher PPARγ expression was also detected in the lungs from the FO-fed groups.

Conclusion

Our results demonstrate that FO intake attenuated classical asthma features by suppressing the systemic sensitization, thus providing evidence that FO might be a prophylactic alternative for asthma prevention.

Evaluation of T cell function in allergic disease

T lymphocytes play positive and negative roles in the pathogenesis of allergic disease. Isolation and functional characterization of T lymphocyte subpopulations is an important aspect of understanding allergy models and allergy therapies. Measurement of the T cell surface proteins and T cell proliferation can provide insight into T cell activation. T cell function and the identities of T cell subsets can be determined by measuring cytokine production, either via intracellular cytokine staining or ELISPOT. This chapter outlines protocols for T cell isolation as well as the evaluation of surface protein expression, proliferation, intracellular cytokine staining, and ELISPOT.

The IL-10/STAT3-mediated anti-inflammatory response: recent developments and future challenges

Inflammation is a fundamental response of the immune system whose successful termination involves the elimination of the invading pathogens, the resolution of inflammation and the repair of the local damaged tissue. In this context, the interleukin 10 (IL-10)-mediated anti-inflammatory response (AIR) represents an essential homeostatic mechanism that controls the degree and duration of inflammation. Here, we review recent work on the mechanistic characterization of the IL-10-mediated AIR on multiple levels: from the cataloguing of the in vivo genomic targets of STAT3 (the transcription factor downstream of IL-10) to the identification of specific co-factors that endow STAT3 with genomic-binding specificity, and how genomic and computational methods are being used to elucidate the regulatory mechanisms of this essential physiological response in macrophages.

In vitro effects of CpG oligodeoxynucleotides delivered by gelatin nanoparticles on canine peripheral blood mononuclear cells of atopic and healthy dogs - a pilot study

BACKGROUND

Cytosine-phosphate-guanine (CpG) oligodeoxynucleotides offer a novel promising immunotherapeutic approach for atopic dermatitis (AD) both in humans and animals. Gelatin nanoparticles (GNP) enhance and prolong CpG-associated immunomodulatory effects and minimize adverse effects both in vitro and in vivo. Information about the effects of this combination in dogs is lacking.

HYPOTHESIS/OBJECTIVES

The aim of this study was to evaluate immunological effects of CpG coupled to GNP on canine peripheral blood mononuclear cells (PBMCs) in vitro.

ANIMALS

Eight dogs with AD, diagnosed by standard criteria and with a concurrent immediate hypersensitivity to house dust mites were included. Control samples were taken from eight healthy, age-matched control dogs without history or evidence of cutaneous or systemic illness.

METHODS

Peripheral blood mononuclear cells of healthy and allergic dogs were incubated with CpG-GNP and the uptake of CpG-GNP was demonstrated using confocal laser scanning microscopy. Cell culture supernatant concentrations of interferon gamma (IFN-γ), interleukin (IL)-4, IL-6 and IL-10 were measured by Canine Cytokine Milliplex.

RESULTS

No significant changes in IFN-γ and IL-4 were found when comparing PBMCs incubated with CpG and CpG-GNP with the negative controls in atopic and healthy dogs. Interleukin-6 was not detected in any of the groups. However, a statistically significant increase in IL-10 concentration was found after 24 h stimulation with CpG-GNP compared with CpG alone both in atopic and healthy dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

As IL-10 is considered an immunosuppressive cytokine playing a key role in peripheral tolerance; the reported CpG-GNP formulation could be a new approach in allergy treatment.

Exosomes with membrane-associated TGF-β1 from gene-modified dendritic cells inhibit murine EAE independently of MHC restriction

We have previously demonstrated that exosomes from dendritic cells (DCs) secreting TGF-β1 (sTGF-β1-EXOs) delay the development of murine inflammatory bowel disease (IBD). In this study, we isolated exosomes from DCs expressing membrane-associated TGF-β1 (mTGF-β1-EXOs) and found mTGF-β1-EXOs had more potent immunosuppressive activity than sTGF-β1-EXOs in vitro. Treatment of mice with mTGF-β1-EXOs inhibited the development and progression of myelin oligodendrocyte glycoprotein (MOG) peptide-induced EAE even after disease onset. Treatment of mice with mTGF-β1-EXOs also impaired Ag-specific Th1 and IL-17 responses, but promoted IL-10 responses ex vivo. Treatment with mTGF-β1-EXOs decreased the frequency of Th17 cells in EAE mice, which might be associated with the down-regulation of the p38, ERK, Stat3, and NF-κB activation and IL-6 expression in DCs. Treatment with mTGF-β1-EXOs maintained the regulatory capacity of Treg cells, and adoptive transfer of CD4(+)Foxp3(+)Treg cells from mTGF-β1-EXO-treated EAE mice dramatically prevented the development of EAE in the recipients. Moreover, treatment with mTGF-β1-EXOs from C57BL/6 mice effectively prevented and inhibited proteolipid protein (PLP) peptide-induced EAE in BALB/c mice. These results indicate that mTGF-β1-EXOs possess powerful immunosuppressive ability and can effectively inhibit the development and progression of EAE in different strains of mice.

Intranasal, liposome-adjuvanted cockroach allergy vaccines made of refined major allergen and whole-body extract of Periplaneta americana

BACKGROUND

Cockroach (CR) allergens frequently cause severe asthma in CR-sensitized subjects. Allergen-specific immunotherapy causes a shift of allergic Th2 responses towards Th1 and/or regulatory T cell (Treg) responses which reduce airway inflammation and prevent disease progression. Data are relatively limited on immunotherapy via CR allergy vaccine.

METHODS

The therapeutic efficacy of an intranasal liposome-adjuvant vaccine made of a refined Periplaneta americana arginine kinase (AK) was compared to the liposome-entrapped P. americana crude extract (CRE) vaccine. Adult BALB/c mice were rendered allergic to CRE. Three allergic mouse groups were immunized intranasally on alternate days with 8 doses of liposome-entrapped CRE (L-CRE), liposome-entrapped AK and placebo, respectively. One week later, all mice received a nebulized CRE provocation. Evaluation of vaccine efficacy was performed 1 day after provocation.

RESULTS

Liposome-entrapped native AK attenuated airway inflammation after the CRE provocation and caused a shift of allergic Th2 to Th1 and Treg responses. The L-CRE also induced a shift from the Th2 to the Th1 response but did not induce a Treg response and could not attenuate the airway inflammation upon allergen reexposure.

CONCLUSIONS

Intranasal liposome-adjuvant CR allergy vaccine containing native AK (Per a 9) is better than L-CRE in attenuating allergic airway inflammation. The findings of this study not only document a more comprehensive and beneficial immune response induced by the refined allergen vaccine but also raise the point that the shift from the Th2 to the Th1 response alone might not correlate with improved airway histopathology, clinical outcome and quality of life.

The effect of decellularization of tracheal allografts on leukocyte infiltration and of recellularization on regulatory T cell recruitment

Tracheal transplantation without immunosuppressive therapy has been accomplished with a tissue-engineering approach using decellularized biological scaffolds in combination with recipient progenitor cells. The mechanisms of immune response directed towards these tracheal allografts have not been fully determined. In this study, we evaluated the immunogenicity of these grafts at the protein level, and functionally, in vitro and in vivo in a large animal model. Long-segment circumferential tracheal allografts were decellularized using two different protocols and recellularized using recipient mesenchymal stromal cells (MSC) and tracheal epithelial progenitor cells (TEC). Residual MHCI and MHCII immunostaining was found surrounding the submucosal glands despite cyclical decellularization. In an in vitro lymphocyte proliferation assay, CD4+ T cells continued to proliferate on decellularized pieces and this proliferation was inhibited by co-culture with autologous MSC. Allografts were heterotopically transplanted under a muscle flap in the neck of the recipients and decellularization was found to delay leukocyte infiltration but resulted in eventual cartilage degradation. Recellularization prevented this infiltration up to 3 weeks post-transplantation and allowed for preservation of the cartilage. The immune cells found within these grafts included a significant number of CD4+CD25+Foxp3+ regulatory T cells. Furthermore, gene expression of anti-inflammatory cytokines, such as IL-10 and TGF-β1, involved in proliferation, differentiation and function of regulatory T cells was found in these grafts. These results indicate that the immunological modification induced by recellularized tracheal scaffolds is an active process involving the recruitment of immunosuppressive cells, rather than simply the removal of donor-derived antigenic components.

Mechanisms underlying helper T-cell plasticity: implications for immune-mediated disease

CD4 helper T cells are critical for proper immune cell homeostasis and host defense but are also major contributors to immune and inflammatory disease. Arising from a simple biphasic model of differentiation (ie, TH1 and TH2 cells). A bewildering number of fates seem possible for helper T cells. To what extent different helper cell subsets maintain their characteristic gene expression profiles or exhibit functional plasticity is a hotly debated topic. In this review we will discuss how the expression of "signature cytokines" and "master regulator" transcription factors do not neatly conform to a simple helper T-cell paradigm. Although this might seem confusing, the good news is that the newly recognized complexity fits better with our understanding of immunopathogenesis. Finally, we will discuss factors, including epigenetic regulation and metabolic alterations, that contribute to helper cell specificity and plasticity.

IL-10-producing lymphocytes in inflammatory disease

IL-10 is an anti-inflammatory cytokine that plays a significant role in controlling inflammation and modulating adaptive immune responses that cause tissue damage. IL-10-producing lymphocytes contribute to the delicate balance between inflammation and immunoregulation, and are thus regarded as a kind of "regulatory cells." Dysregulation of these cells is linked with susceptibility to numerous inflammatory diseases. In this review, we summarized what is known about the regulatory effects of IL-10 produced by lymphocytes, including T cells, B cells and natural killer cells, in inflammatory diseases. We hope to augment immune responses or prevent immunopathology through making some small changes in the levels of IL-10 produced by lymphocytes, or in the cellular location where it is produced.

Lung-resident tissue macrophages generate Foxp3+ regulatory T cells and promote airway tolerance

Airway tolerance is the usual outcome of inhalation of harmless antigens. Although T cell deletion and anergy are likely components of tolerogenic mechanisms in the lung, increasing evidence indicates that antigen-specific regulatory T cells (inducible Treg cells [iTreg cells]) that express Foxp3 are also critical. Several lung antigen-presenting cells have been suggested to contribute to tolerance, including alveolar macrophages (MØs), classical dendritic cells (DCs), and plasmacytoid DCs, but whether these possess the attributes required to directly promote the development of Foxp3(+) iTreg cells is unclear. Here, we show that lung-resident tissue MØs coexpress TGF-β and retinal dehydrogenases (RALDH1 and RALDH 2) under steady-state conditions and that their sampling of harmless airborne antigen and presentation to antigen-specific CD4 T cells resulted in the generation of Foxp3(+) Treg cells. Treg cell induction in this model depended on both TGF-β and retinoic acid. Transfer of the antigen-pulsed tissue MØs into the airways correspondingly prevented the development of asthmatic lung inflammation upon subsequent challenge with antigen. Moreover, exposure of lung tissue MØs to allergens suppressed their ability to generate iTreg cells coincident with blocking airway tolerance. Suppression of Treg cell generation required proteases and TLR-mediated signals. Therefore, lung-resident tissue MØs have regulatory functions, and strategies to target these cells might hold promise for prevention or treatment of allergic asthma.

Characterisation of CD154+ T cells following ex vivo birch allergen stimulation defines a close relationship between T cell subsets in healthy volunteers

BACKGROUND

Allergic sensitisation has been ascribed to a dysregulated relationship between allergen-specific Th1, Th2 and regulatory T cells. We hypothesised that the relationship between these T cell subsets could be better defined using a short-term allergen stimulation system followed by direct analysis of CD154-positive T cells. Using peripheral blood samples from birch pollinosis patients and healthy non-atopic controls, we sought to explore the frequencies and phenotype of birch-stimulated CD154-positive T helper cells following ex vivo birch allergen stimulation.

RESULTS

Activated CD154-positive Th1, Th2 and Tr1-like cells, that co-expressed IFNγ, IL-4 and IL-10 respectively, were identified in both birch-allergic and non-allergic participants. We observed a close correlation between Th1, Th2 and Tr1-like cell frequency in non-allergic volunteers, such that the three parameters increased together to maintain a low Th2: Th1 ratio. The relationship between Th1, Th2 and Tr1-like responses was dysregulated in birch-allergic patients, with abrogation of the IL-10 response and a higher Th2: Th1 ratio. A close correlation was observed between Th2 cell frequency and the absolute concentration of birch-specific IgE within the birch-allergic group, and we confirmed previous reports of a more differentiated T cell phenotype in allergic subjects.

CONCLUSIONS

The findings demonstrate an important balance between IFNγ, IL-4 and IL-10 T cell responses to birch allergen in health, where Th2 responses to allergens were frequently observed, but apparently balanced by Th1 and regulatory responses. The detection of CD154 positive T cells after short-term antigen stimulation may be a useful method for the detection of T cell responses to allergens when cost, speed and convenience are priorities.

Severe and uncontrolled adult asthma is associated with vitamin D insufficiency and deficiency

BACKGROUND

Vitamin D has effects on the innate and adaptive immune system. In asthmatic children low vitamin D levels are associated with poor asthma control, reduced lung function, increased medication intake, and exacerbations. Little is known about vitamin D in adult asthma patients or its association with asthma severity and control.

METHODS

Clinical parameters of asthma control and 25-hydroxyvitamin D (25(OH)D) serum concentrations were evaluated in 280 adult asthma patients (mean ± SD: 45.0 ± 13.8 yrs., 40% male, FEV1 74.9 ± 23.4%, 55% severe, 51% uncontrolled).

RESULTS

25(OH)D concentrations in adult asthmatics were low (25.6 ±11.8 ng/ml) and vitamin D insufficiency or deficiency (vitamin D <30 ng/ml) was common (67%). 25(OH)D levels were related to asthma severity (intermittent: 31.1 ± 13.0 ng/ml, mild: 27.3 ± 11.9 ng/ml, moderate: 26.5 ± 12.0 ng/ml, severe: 24.0 ± 11.8 ng/ml, p = 0.046) and control (controlled: 29.5 ± 12.5 ng/ml, partly controlled 25.9 ± 10.8 ng/ml, uncontrolled: 24.2 ± 11.8 ng/ml, p = 0.030). The frequency of vitamin D insufficiency or deficiency was significantly higher in patients with severe or uncontrolled asthma and was associated with a lower FEV1 (vitamin D <30 vs. ≥30 ng/ml 2.3 ± 0.9 L vs. 2.7 ± 1.0 L, p = 0.006), higher levels of exhaled NO (45 ± 46 ppb vs. 31 ± 37 ppb, p = 0.023), a higher BMI (28.3 ± 6.2 vs. 25.1 ± 3.9, p < 0.001), and sputum eosinophilia (5.1 ± 11.8% vs. 0.5 ± 1.0%, p = 0.005). The use of oral corticosteroids or sputum eosinophilia was associated with a 20% or 40% higher risk of vitamin D insufficiency or deficiency.

CONCLUSIONS

25(OH)D levels below 30 ng/ml are common in adult asthma and most pronounced in patients with severe and/or uncontrolled asthma, supporting the hypothesis that improving suboptimal vitamin D status might be effective in prevention and treatment of asthma.

Oral glucocorticoids diminish the efficacy of allergen-specific immunotherapy in experimental feline asthma

Allergen-specific rush immunotherapy (RIT) shows promise in treating asthma; however, pet cats will likely require at least initial concurrent glucocorticoids (GCs) to control serious clinical signs. How the immunosuppressive effects of GCs would impact RIT in cats is unknown. The hypothesis of this study was that oral, but not inhaled GCs will diminish the efficacy of RIT in experimental feline asthma. Cats (n=6/group) were sensitized using Bermuda grass allergen (BGA) and randomized to receive BGA-specific RIT for 9 months with an oral GC (prednisolone 10mg daily), inhaled GC (fluticasone 220 μg twice daily), or placebo administered for the first 6 months. Bronchoalveolar lavage fluid (BALF) percent eosinophils and other immunological assays were performed. Eosinophilic airway inflammation was suppressed in all groups at month 6 of RIT (group mean ± SD, 5 ± 2%, 13 ± 4%, and 7 ± 2% for oral GC, inhaled GC, and placebo, respectively; P=0.291). BALF percent eosinophils significantly increased over time only in oral GC/RIT cats between months 6 and 9 (P=0.031). Placebo/RIT cats had significant decreases over time in BGA-specific serum IgE (P=0.031). Concentration of interleukin (IL)-5 in BALF significantly increased over time in inhaled GC/RIT cats (P=0.031). No significant differences were found between groups at month 6 or over time in each group for BGA-specific lymphocyte blastogenesis, percent blood T regulatory cells, or number of IL-10-producing cells. Given the significant increase of airway eosinophilia over time in RIT cats initially treated with an oral GC, inhaled GCs might be better for dampening eosinophilic inflammation until RIT normalizes the dysregulated immune system.

Reduced expression of galectin-1 and galectin-9 by leucocytes in asthma patients

Accumulating evidence shows that galectins play roles in the initiation and resolution phases of inflammatory responses by promoting anti- or proinflammatory effects. This study investigated the presence of three members of the galectin family (galectin-1, -3 and -9) in induced sputum samples of asthma patients, as well as their possible implication in the immunopathogenesis of human asthma. Levels of interleukin (IL)-5, IL-13, and galectins were determined in leucocytes isolated from induced sputum samples by reverse transcription-polymerase chain reaction (RT-PCR) immunofluorescence and flow cytometry. High levels of IL-5 and IL-13 mRNA were detected in sputum cells from asthma patients. In parallel, immunoregulatory proteins galectin-1 and galectin-9 showed a reduced expression on macrophages from sputum samples compared with cells from healthy donors. In-vitro immunoassays showed that galectin-1 and galectin-9, but not galectin-3, are able to induce the production of IL-10 by peripheral blood mononuclear cells from healthy donors. These findings indicate that macrophages from sputum samples of asthma patients express low levels of galectin-1 and galectin-9, favouring the exacerbated immune response observed in this disease.

Recognition of self-heat shock protein 60 by T cells from patients with atopic dermatitis

Heat shock protein 60 (hsp60) is a highly conserved stress protein and target of self-reactive T cells in various inflammatory diseases. Not much is known about a possible role in atopic disease. As atopic diseases are considered to be the result of a disturbance in the balance between T helper cells type 2 and regulatory T cells, it is of interest to know whether hsp60 acts as a bystander antigen in atopic disease. Our aim was to investigate whether hsp60 is involved in the chronicity of inflammation of atopic dermatitis (AD). We studied the expression of hsp60 in skin tissue of adults with AD by immunohistochemistry. Peripheral blood mononuclear cells (PBMC) of children with AD were cultured with hsp60 and proliferative responses, cytokine secretion, surface markers, and functional assays were compared to responses of PBMC of healthy controls (HC). Hsp60 was detected more in lesional skin of AD patients compared to nonlesional skin. Furthermore, PBMC of children with AD proliferated more strongly in response to hsp60 compared to HC. hsp60-reactive T cells of atopic children produced high levels of IFNγ and low levels of IL-10. In vitro activation with hsp60 leads to the induction of CD4(+)CD25(bright) T cells expressing FOXP3 in both HC as well as in atopic children. However, despite their regulatory phenotype, hsp60-induced CD4(+)CD25(bright)CD127(-)FOXP3(+) T cells of AD patients were incapable of suppressing effector T cells in vitro. hsp60 is recognized by proinflammatory (IFNγ high, IL-10 low) T cells in atopic patients and is more present in lesional AD skin. This suggests that hsp60-specific T cell responses contribute to local inflammation in AD.

Patient-tailored modulation of the immune system may revolutionize future lung cancer treatment

Cancer research has devoted most of its energy over the past decades on unraveling the control mechanisms within tumor cells that govern its behavior. From this we know that the onset of cancer is the result of cumulative genetic mutations and epigenetic alterations in tumor cells leading to an unregulated cell cycle, unlimited replicative potential and the possibility for tissue invasion and metastasis. Until recently it was often thought that tumors are more or less undetected or tolerated by the patient’s immune system causing the neoplastic cells to divide and spread without resistance. However, it is without any doubt that the tumor environment contains a wide variety of recruited host immune cells. These tumor infiltrating immune cells influence anti-tumor responses in opposing ways and emerges as a critical regulator of tumor growth. Here we provide a summary of the relevant immunological cell types and their complex and dynamic roles within an established tumor microenvironment. For this, we focus on both the systemic compartment as well as the local presence within the tumor microenvironment of late-stage non-small cell lung cancer (NSCLC), admitting that this multifaceted cellular composition will be different from earlier stages of the disease, between NSCLC patients. Understanding the paradoxical role that the immune system plays in cancer and increasing options for their modulation may alter the odds in favor of a more effective anti-tumor immune response. We predict that the future standard of care of lung cancer will involve patient-tailor-made combination therapies that associate (traditional) chemotherapeutic drugs and biologicals with immune modulating agents and in this way complement the therapeutic armamentarium for this disease.

Single systemic administration of Ag85B of mycobacteria DNA inhibits allergic airway inflammation in a mouse model of asthma

The immune responses of T-helper (Th) and T-regulatory cells are thought to play a crucial role in the pathogenesis of allergic airway inflammation observed in asthma. The correction of immune response by these cells should be considered in the prevention and treatment of asthma. Native antigen 85B (Ag85B) of mycobacteria, which cross-reacts among mycobacteria species, may play an important biological role in host–pathogen interaction since it elicits various immune responses by activation of Th cells. The current study investigated the antiallergic inflammatory effects of DNA administration of Ag85B from Mycobacterium kansasii in a mouse model of asthma. Immunization of BALB/c mice with alum-adsorbed ovalbumin followed by aspiration with aerosolized ovalbumin resulted in the development of allergic airway inflammation. Administration of Ag85B DNA before the aerosolized ovalbumin challenge protected the mice from subsequent induction of allergic airway inflammation. Serum and bronchoalveolar lavage immunoglobulin E levels, extent of eosinophil infiltration, and levels of Th2-type cytokines in Ag85B DNA-administered mice were significantly lower than those in control plasmid-immunized mice, and levels of Th1-and T-regulatory-type cytokines were enhanced by Ag85B administration. The results of this study provide evidence for the potential utility of Ag85B DNA inoculation as a novel approach for the treatment of asthma.

Pretreatment with glycomacropeptide reduces allergen sensitization, alleviates immediate cutaneous hypersensitivity and protects from anaphylaxis

Allergic disorders are characterized by the involvement of allergen-specific immunoglobulin (Ig)E antibodies and T helper type 2 (Th2) cells. The search for new therapies for allergic diseases has been the primary focus of interest for many investigators in recent years. Glycomacropeptide (GMP) is a biologically active component of milk that exhibits a range of immunomodulatory functions. We examined whether oral administration of GMP could affect the development of allergic sensitization and the severity of immediate cutaneous hypersensitivity reactions and of anaphylaxis. Rats treated with or without GMP were ovalbumin (OVA)-sensitized and several indicators of allergy were evaluated. Pretreatment with GMP resulted in reduction of antigen-specific IgE titre in rats when sensitized with OVA. GMP administration also markedly suppressed the proliferative response of splenocytes to antigen and the production of interleukin (IL)-13 by splenocytes of sensitized animals. In addition, GMP pretreatment attenuated the intensity of the immediate cutaneous reaction induced by antigen and protected the sensitized rats from severe anaphylaxis. These data demonstrate, for the first time, that the administration of GMP prevents allergen sensitization and reduces the severity of the early-phase reaction induced by antigen in cutaneous hypersensitivity and in anaphylaxis. GMP may be used as a novel prophylactic agent for the control of allergic diseases.

The role of different subsets of regulatory T cells in immunopathogenesis of rheumatoid arthritis

Rheumatoid arthritis (RA) is a common autoimmune disease and a systemic inflammatory disease which is characterized by chronic joint inflammation and variable degrees of bone and cartilage erosion and hyperplasia of synovial tissues. Considering the role of autoreactive T cells (particularly Th1 and Th17 cells) in pathophysiology of RA, it might be assumed that the regulatory T cells (Tregs) will be able to control the initiation and progression of disease. The frequency, function, and properties of various subsets of Tregs including natural Tregs (nTregs), IL-10-producing type 1 Tregs (Tr1 cells), TGF-β-producing Th3 cells, CD8⁺ Tregs, and NKT regulatory cells have been investigated in various studies associated with RA and collagen-induced arthritis (CIA) as experimental model of this disease. In this paper, we intend to submit the comprehensive information about the immunobiology of various subsets of Tregs and their roles and function in immunopathophysiology of RA and its animal model, CIA.

Sublingual Immunotherapy Induces Regulatory Function of IL-10-Expressing CD4(+)CD25(+)Foxp3(+) T Cells of Cervical Lymph Nodes in Murine Allergic Rhinitis Model

Sublingual immunotherapy (SLIT) has been considered to be a painless and efficacious therapeutic treatment of allergic rhinitis which is known as type I allergy of nasal mucosa. Nevertheless, its mechanisms need to be further investigated. In this study, we constructed an effective murine model of sublingual immunotherapy in allergic rhinitis, in which mice were sublingually administered with ovalbumin (OVA) followed by intraperitoneal sensitization and nasal challenge of OVA. Sublingually treated mice showed significantly decreased specific IgE responses as well as suppressed Th2 immune responses. Sublingual administration of OVA did not alter the frequency of CD4⁺CD25⁺ regulatory T cells (Tregs), but led to upregulation of Foxp3- and IL-10-specific mRNAs in the Tregs of cervical lymph nodes (CLN), which strongly suppressed Th2 cytokine production from CD4⁺CD25⁻ effector T cells in vitro. Furthermore, sublingual administration of plasmids encoding the lymphoid chemokines CCL19 and CCL21-Ser DNA together with OVA suppressed allergic responses. These results suggest that IL-10-expressing CD4⁺CD25⁺Foxp3⁺ Tregs in CLN are involved in the suppression of allergic responses and that CCL19/CCL21 may contribute to it in mice that received SLIT.