Interleukin-1 is released at sites of human cutaneous allergic reactions

IL-1β and Allergy: Focusing on Its Role in Allergic Rhinitis

Allergic rhinitis (AR) is a chronic upper airway immune-inflammation response mediated by immunoglobulin E (IgE) to allergens and can seriously affect the quality of life and work efficiency. Previous studies have shown that interleukin-1β (IL-1β) acts as a key cytokine to participate in and promote the occurrence and development of allergic diseases. It has been proposed that IL-1β may be a potential biomarker of AR. However, its definitive role and potential mechanism in AR have not been fully elucidated, and the clinical sample collection and detection methods were inconsistent among different studies, which have limited the use of IL-1β as a clinical diagnosis and treatment marker for AR. This article systematically summarizes the research advances in the roles of IL-1β in allergic diseases, focusing on the changes of IL-1β in AR and the possible interventions. In addition, based on the findings by our team, we provided new insights into the use of IL-1β in AR diagnosis and treatment, in an attempt to further promote the clinical application of IL-1β in AR and other allergic diseases.

Effects of the Association between Photobiomodulation and Hyaluronic Acid Linked Gold Nanoparticles in Wound Healing

Healing is the process responsible for restoring the integrity of the body's internal or external structures when they rupture. Photobiomodulation (PBM) stands out as one of the most efficient resources in the treatment of epithelial lesions, as well as hyaluronic acid (HA), which has been emerging as a new molecule for the treatment of dermal and epidermal lesions. The biological application of gold nanoparticles (GNPs) shows promising results. This study aimed to investigate the possible anti-inflammatory and antioxidant effects of the association between PBM and GNPs-linked HA in an epithelial lesion model. Fifty Wistar rats were randomly distributed in the Control Group (CG); (PBM); (PBM + HA); (PBM + GNPs); (PBM + GNPs-HA). The animals were anesthetized, trichotomized, and induced to a surgical incision in the dorsal region. Topical treatment with HA (0.9%) and/or GNPs (30 mg/kg) occurred daily associated with 904 nm laser irradiation, dose of 5 J/cm², which started 24 h after the lesion and was performed daily until the seventh day. The levels of proinflammatory (IL1 and TNFα), anti-inflammatory (IL10 and IL4) and growth factors (FGF and TGFβ) cytokines and oxidative stress parameters were evaluated, besides histological analysis through inflammatory infiltrate, fibroblasts, new vessels, and collagen production area. Finally, for the analysis of wound size reduction, digital images were performed and subsequently analyzed by the IMAGEJ software. The treated groups showed a decrease in proinflammatory cytokine levels and an increase in anti-inflammatory cytokines. TGFβ and FGF levels also increased in the treated groups, especially in the combination therapy group (PBM + GNPs-HA). Regarding the oxidative stress parameters, MPO, DCF, and Nitrite levels decreased in the treated groups, as well as the oxidative damage (Carbonyl and Thiol groups). In contrast, antioxidant defense increased in the groups with the appropriate therapies proposed compared to the control group. Histological sections were analyzed where the inflammatory infiltrate was lower in the PBM + GNPs-HA group. The number of fibroblasts was higher in the PBM and PBM + HA treated groups, whereas collagen production was higher in all treated groups. Finally, in the analysis of the wound area contraction, the injury group presented a larger area in cm² compared to the other groups. Taken together, these results allow us to observe that the combination of PBM + GNPs-HA optimized the secretion of anti-inflammatory cytokines, proliferation and cell differentiation growth factors, and made an earlier transition to the chronic phase, contributing to the repair process.

Inducing type 2 immune response, induction of angiogenesis, and anti-bacterial and anti-inflammatory properties make Lacto-n-Neotetraose (LNnT) a therapeutic choice to accelerate the wound healing process

The healing process of non-healing and full-thickness wounds is currently facing some serious challenges. In such ulcers, losing a large part of skin causes a chronic infection due to the entrance of various pathogens in the wound bed. Moreover, poor vascularization, uncontrolled inflammation, and delayed re-epithelialization increase the healing time in patients suffering from such wounds. In this light, tissue engineering provides a wide range of strategies using a variety of biomaterials, biofactors and stem cells to decrease the healing time and restore the function of the damaged site. A suitable wound healing agent should possess some critical parameters such as inducing re-epithelialization, anti-inflammatory and anti-bacterial properties, and angiogenic capability. The Lacto-n-Neotetraose (LNnT) with chemical formula C26H45NO21 is an oligosaccharide present in human milk and soluble antigens extracted from Schistosoma mansoni eggs. It is reported that LNnT induces type 2 immune response (Th2 immunity). Th2 immunity promotes re-epithelialization, angiogenesis and wound contraction by recruiting the cells which produce Th2-related cytokines. Moreover, LNnT shows some special characteristics such as angiogenic capability, anti-inflammatory, and anti-bacterial effects which can address the mentioned challenges in the treatment of non-healing and full-thickness wounds. Here, we hypothesize that utilizing LNnT is an appropriate biofactor which would improve the healing process in full-thickness and non-healing wounds.

Changes in gene expression induced by histamine, fexofenadine and osthole: Expression of histamine H1 receptor, COX-2, NF-κB, CCR1, chemokine CCL5/RANTES and interleukin-1β in PBMC allergic and non-allergic patients

INTRODUCTION

Fexofenadine (FXF) is a third-generation antihistamine drug and osthole is assumed as a natural antihistamine alternative. This paper compares results of histamine, FXF and osthole impact on HRH-1, COX-2, NF-κB-p50, CCR1 mRNA expression. We also measured mRNA expression of IL-1β and CCL5/RANTES in incubated peripheral blood mononuclear cells (PBMC) to compared how histamine, FXF and osthole had influence on expression level and interacts on product secretion.

OBJECTIVE

The purpose was to investigate expression pattern in asthma PBMC.

METHODS

The cultures were treated 72h with FXF and osthole. We measured mRNA expression of histamine HRH-1, COX-2, NF-κB-p50, CCR1, IL-1β and CCL5/RANTES with Real-Time PCR (RT-PCR).

RESULTS

The present study suggest that osthole may be a potential inhibitor of histamine H₁ receptor activity. We also demonstrated that cells cultured with histamine increase COX-2 mRNA expression and osthole reduce it.

CONCLUSION

Allergy remains one of the most common chronic diseases in Europe and it is rapidly approaching epidemic proportions; with current predictions estimating that the number of allergy-afflicted will equal the healthy population by 2020. It is therefore paramount to find new pharmaceuticals which successfully combat allergic disease.

Different activation signals induce distinct mast cell degranulation strategies

Mast cells (MCs) influence intercellular communication during inflammation by secreting cytoplasmic granules that contain diverse mediators. Here, we have demonstrated that MCs decode different activation stimuli into spatially and temporally distinct patterns of granule secretion. Certain signals, including substance P, the complement anaphylatoxins C3a and C5a, and endothelin 1, induced human MCs rapidly to secrete small and relatively spherical granule structures, a pattern consistent with the secretion of individual granules. Conversely, activating MCs with anti-IgE increased the time partition between signaling and secretion, which was associated with a period of sustained elevation of intracellular calcium and formation of larger and more heterogeneously shaped granule structures that underwent prolonged exteriorization. Pharmacological inhibition of IKK-β during IgE-dependent stimulation strongly reduced the time partition between signaling and secretion, inhibited SNAP23/STX4 complex formation, and switched the degranulation pattern into one that resembled degranulation induced by substance P. IgE-dependent and substance P-dependent activation in vivo also induced different patterns of mouse MC degranulation that were associated with distinct local and systemic pathophysiological responses. These findings show that cytoplasmic granule secretion from MCs that occurs in response to different activating stimuli can exhibit distinct dynamics and features that are associated with distinct patterns of MC-dependent inflammation.

Plant chitinase III Ziz m 1 stimulates multiple cytokines, most predominantly interleukin-13, from peripheral blood mononuclear cells of latex-fruit allergic patients

BACKGROUND

Indian jujube is a fruit abundantly cultivated in Taiwan. Its major allergen in latex-fruit syndrome is Ziz m 1 of the chitinase III family. The Ziz m 1 Pichia (rZiz m 1-P) has chitinase activity but not Ziz m 1 E. coli (rZiz m 1-E).

OBJECTIVE

This study examined whether plant chitinase III, using rZiz m 1-P and rZiz m 1-E, can stimulate allergic inflammation similar to that of mammalian chitinases.

METHODS

Five patients allergic to latex-Indian jujube and five nonallergic controls were evaluated. Their peripheral blood mononuclear cells (PBMC) were cultured with rZiz m 1-E or rZiz m 1-P and pulsed with phorbol 12-myristate 13-acetate. Eleven cytokines were measured by FlowCytomix human Th1/Th2 plex kit and interleukin (IL)-13 by sandwich enzyme-linked immunosorbent assay (ELISA).

RESULTS

Interleukin-13 significantly increased in rZiz m 1-P stimulated PBMC of allergic subjects but was undetectable when stimulated with rZiz m 1-E. The stimulation index significantly increased in IL-13 (380.6 ± 77.33 vs 13.70 ± 6.92), IL-5 (6.70 ± 0.59 vs 0.70 ± 0.37), IL-1β (32.70 ± 0.83 vs 2.10 ± 1.29), and tumor necrosis factor beta (TNF-β) (17.10 ± 2.66 vs 1.50 ± 0.66) between allergic and nonallergic subjects after rZiz m 1-P stimulation. There was no difference in terms of IL-2, IFN-γ, IL-8, and TNF-α production.

CONCLUSIONS

The biological function of chitinase activity is required for Ziz m 1 to induce a Th2-specific immune response. This is the first report on PBMC responses of latex-fruit syndrome subjects toward an active exogenous plant class III chitinase that can stimulate multiple cytokines, especially IL-13, from allergic subjects. This implies the role of cross-reactive food allergens in propagating allergic inflammation among allergic subjects.

The significant role of mast cells in cancer

Mast cells (MC) are a bone marrow-derived, long-lived, heterogeneous cellular population that function both as positive and negative regulators of immune responses. They are arguably the most productive chemical factory in the body and influence other cells through both soluble mediators and cell-to-cell interaction. MC are commonly seen in various tumors and have been attributed alternatively with tumor rejection or tumor promotion. Tumor-infiltrating MC are derived both from sentinel and recruited progenitor cells. MC can directly influence tumor cell proliferation and invasion but also help tumors indirectly by organizing its microenvironment and modulating immune responses to tumor cells. Best known for orchestrating inflammation and angiogenesis, the role of MC in shaping adaptive immune responses has become a focus of recent investigations. MC mobilize T cells and antigen-presenting dendritic cells. They function as intermediaries in regulatory T cells (Treg)-induced tolerance but can also modify or reverse Treg-suppressive properties. The central role of MC in the control of innate and adaptive immunity endows them with the ability to tune the nature of host responses to cancer and ultimately influence the outcome of disease and fate of the cancer patient.

Development and characterization of new inhibitors of the human and mouse hematopoietic prostaglandin D(2) synthases

The hematopoietic prostaglandin D(2) synthase has a proinflammatory effect in a range of diseases, including allergic asthma, where its product prostaglandin D(2) (PGD(2)) has a role in regulating many of the hallmark disease characteristics. Here we describe the development and characterization of a novel series of hematopoietic prostaglandin D(2) synthase inhibitors with potency similar to that of known inhibitors. Compounds N-benzhydryl-5-(3-hydroxyphenyl)thiophene-2-carboxamide (compound 8) and N-(1-amino-1-oxo-3-phenylpropan-2-yl)-6-(thiophen-2-yl)nicotinamide (compound 34) demonstrated low micromolar potency in the inhibition of the purified enzyme, while only 34 reduced Toll-like receptor (TLR) inducible PGD(2) production in both mouse primary bone marrow-derived macrophages and the human megakaryocytic cell line MEG-01S. Importantly, 34 demonstrated a greater selectivity for inhibition of PGD(2) synthesis versus other eicosanoids that lie downstream of PGH(2) (PGE(2) and markers of prostacyclin (6-keto PGF(1alpha)) and thromboxane (TXB(2))) when compared to the known inhibitors HQL-79 (compound 1) and 2-phenyl-5-(1H-pyrazol-3-yl)thiazole (compound 2). Compound 34 therefore represents a selective hematopoietic prostaglandin D(2) synthase inhibitor.

IL-1 and Allergy

IL-1 is a well-characterized proinflammatory cytokine that is involved in host defense and autoimmune diseases. IL-1 can promote activation of T cells, including Th1 cells, Th2 cells and Th17 cells, and B cells, suggesting that IL-1 may contribute to the development of various types of T-cell-mediated diseases. This report reviews and discusses the role of IL-1 in the pathogenesis of allergic diseases based on studies using IL-1-related gene-deficient mice.

The controversial role of mast cells in tumor growth

Mast cells (MCs) were first described by Paul Ehrlich (Beiträge zur Theorie und Praxis der Histologischen Färbung, Thesis, Leipzig University, 1878). They have long been implicated in the pathogenesis of allergic reactions and protective responses to parasites. However, their functional role has been found to be complex and multifarious. MCs are also involved in various cell-mediated immune reactions and found in tissues from multiple disease sites, and as a component of the host reaction to bacteria, parasite, and even virus infections. They also participate in angiogenic and tissue repair processes after injury. The importance of a possible functional link between chronic inflammation and cancer has long been recognized. As most tumors contain inflammatory cell infiltrates, which often include plentiful MCs, a possible contribution of these cells to tumor development has emerged. In this review, general biology of mast cells, their development, anatomical distribution, and phenotype as well as their secretory products will first be discussed. The specific involvement of MCs in tumor biology and tumor fate will then be considered, with particular emphasis on their capacity to stimulate tumor growth by promoting angiogenesis and lymphangiogenesis. Finally, it is suggested that mast cells may serve as a novel therapeutic target for cancer treatment.

Eosinophil function in allergic inflammation: from bone marrow to tissue response

The role of the eosinophil in the pathophysiology of allergy and asthma has been the focus of intense interest during the past two decades. Although the presence of eosinophils in humans with allergy and asthma is well established, the precise role of this cell in human and animal tissue response is still unclear. However, recent developments in research on many organ systems have provided novel insights into the possible underlying role of the eosinophil in both allergic and nonallergic inflammation. In this review, we examine the pathways associated with eosinophil recruitment and activation, and discuss these findings with reference to clinically defined categories.

Eosinophils and atopic dermatitis

In spite of the progress regarding the description of immunological phenomena associated with atopic dermatitis (AD), the pathogenesis of this disease still remains unclear. The presence of eosinophils in the inflammatory infiltrate of AD has long been established. Eosinophil numbers as well as eosinophil granule protein levels in peripheral blood are elevated in most AD patients and appear to correlate with disease activity. Moreover, eosinophil granule proteins, which possess cytotoxic activity, are deposited in the skin lesions. These observations indicate a role of eosinophils in the pathogenesis of AD. Furthermore, AD is associated with increased production of T helper 2 cytokines including interleukin (IL)-5, which specifically acts on eosinophils, resulting in accelerated eosinophilopoiesis, chemotaxis, cell activation, and delayed apoptosis. Therefore, IL-5 is an interesting target for experimental therapy in this inflammatory disorder of the skin. Such studies might result in new insights into the pathogenetic role of eosinophils in AD.

Autocrine regulation of airway smooth muscle responsiveness

Bronchial asthma is characterized by airway inflammation, exaggerated airway narrowing to bronchoconstrictor agonists, and attenuated beta-adrenoceptor-mediated airway relaxation. Various cytokines/chemokines have been implicated in the pathogenesis of the airway inflammatory response, and certain cytokines, most notably including specific Th2-type cytokines and IL-1beta, have been shown to directly regulate airway smooth muscle (ASM) responsiveness. Recent evidence supports the concept that the ASM itself has the capacity to endogenously express a number of these cytokines under specific conditions of ASM sensitization. Moreover, these cytokines were found to act in an autocrine manner on the ASM to evoke the 'pro-asthmatic' phenotype of altered airway responsiveness. This cytokine-driven autocrine signaling mechanism in ASM may be triggered by either Fc receptor activation in the atopic (IgE-mediated) sensitized state or by ASM exposure to specific viral respiratory pathogens, most notably including rhinovirus. Furthermore, the autocrine-induced changes in ASM responsiveness are attributed to altered receptor-coupled transmembrane signaling in the sensitized ASM, resulting in perturbed expression and release of second messenger molecules that regulate ASM contraction and relaxation. Collectively, this evidence identifies mechanisms intrinsic to the ASM itself, including autocrine pro-inflammatory signaling and altered receptor/G protein-coupled second messenger activation, that importantly contribute to phenotypic expression of the changes in ASM responsiveness that characterize the asthmatic state.

Mechanisms of eosinophil recruitment and activation

The role of the eosinophil in the pathophysiology of allergy and asthma has been the focus of intense interest during the last two decades. While the presence of eosinophils in humans with allergy and asthma is well established, the precise role of this cell in humans and in animal models is less clear. However, recent developments in research on many organ systems have provided novel insights into the possible underlying role of the eosinophil in both allergic and nonallergic inflammation. This review examines the pathways associated with eosinophil recruitment and activation and discusses these findings, with reference to clinically defined categories.

Secretion of interleukin-1 receptor antagonist from human mast cells after immunoglobulin E-mediated activation and after segmental antigen challenge

Mast cells produce substances with antiinflammatory properties in addition to their capacity to release proinflammatory mediators. To further probe the antiinflammatory aspect of mast-cell function we investigated the ability of human mast cells (huMCs) to produce interleukin (IL)-1 receptor antagonist (IL-1ra) in response to high-affinity Fc receptor for immunoglobulin E (Fcalpha RI) aggregation, and examined IL-1ra in bronchoalveolar lavage fluid (BALF) to determine whether it might be of mast-cell origin. Using a ribonuclease protection assay, flow cytometry, and enzyme-linked immunosorbent assay (ELISA), IL-1ra message and protein were found to be constitutively expressed in cultured huMCs. Upon stimulation through Fcalpha RI, IL-1ra message was upregulated in huMCs and IL-1ra protein secreted from cultured huMCs and isolated human lung mast cells. By immunoblot analysis, huMCs were found to produce the 17-kD form of IL-1ra and the presence of IL-1ra in human lung mast cells was confirmed by immunohistochemistry. In BALF obtained from allergic asthmatic subjects, IL-1ra production increased after specific antigen challenge, with the 17-kD isoform of IL-1ra predominating. These findings demonstrate that huMCs produce and release IL-1ra after Fcalpha RI aggregation, which may contribute to a local inhibition of IL-1-dependent effects on inflammation in the lung.

Keratins and the keratinocyte activation cycle

In wound healing and many pathologic conditions, keratinocytes become activated: they turn into migratory, hyperproliferative cells that produce and secrete extracellular matrix components and signaling polypeptides. At the same time, their cytoskeleton is also altered by the production of specific keratin proteins. These changes are orchestrated by growth factors, chemokines, and cytokines produced by keratinocytes and other cutaneous cell types. The responding intracellular signaling pathways activate transcription factors that regulate expression of keratin genes. Analysis of these processes led us to propose the existence of a keratinocyte activation cycle, in which the cells first become activated by the release of IL-1. Subsequently, they maintain the activated state by autocrine production of proinflammatory and proliferative signals. Keratins K6 and K16 are markers of the active state. Signals from the lymphocytes, in the form of Interferon-gamma, induce the expression of K17 and make keratinocytes contractile. This enables the keratinocytes to shrink the provisional fibronectin-rich basement membrane. Signals from the fibroblasts, in the form of TGF-beta, induce the expression of K5 and K14, revert the keratinocytes to the healthy basal phenotype, and thus complete the activation cycle.

Cellular and immunologic mechanisms in atopic dermatitis

Atopic dermatitis is a chronic inflammatory skin disease that is frequently associated with respiratory allergies. Atopic dermatitis develops as a result of a complex interrelationship of environmental, immunologic, genetic, and pharmacologic factors. Efforts to understand the relative contributions of these factors have led to research seeking to identify the relevant effector cells and mediators involved in the pathogenesis of atopic dermatitis. These factors include the pattern of local cytokine release, the differentiation of helper T cells, multiple roles of IgE, skin-directed cell responses, infectious agents, and superantigens. This article reviews these cellular and immunologic mechanisms underlying atopic dermatitis and discusses how an understanding of their role in the inflammatory process may lead to improved treatments for atopic dermatitis.

Glucocorticosteroids rapidly inhibit allergen-induced expression of E-selectin in vitro in a mucosal model of allergic rhinitis

BACKGROUND

Transendothelial migration of cells to sites of inflammation is a hallmark of the allergic reaction. The adhesion cascade involves the initial expression of the adhesion molecule E-selectin on endothelial cells. The aim of the study was to determine the efficacy of a 30-min preincubation of the glucocorticosteroids (GCS) fluticasone, prednisolone, and fluocortin butyl on allergen- and interleukin (IL)-1beta-induced E-selectin expression in allergic rhinitis.

METHODS

Freshly taken nasal inferior turbinate mucosa of 19 subjects with allergic rhinitis was cut into small cubes and preincubated for 30 min with prednisolone (n = 6), fluticasone (n = 5), and fluocortin butyl (n = 3) in different concentrations, followed by allergen exposure at a concentration of 1000 BU/ml for 1 and 2 h. Additionally, fluticasone-preincubated tissues were exposed to recombinant human rhIL-1beta (n = 5) at a concentration of 2 pg/ml. The expression of E-selectin was assessed by immunohistochemistry (APAAP technique) and computerized image evaluation.

RESULTS

In this model, E-selectin expression was significantly upregulated by allergen and rhIL- 1beta within 1 and 2 h. After 30-min preincubation with prednisolone and fluocortin butyl at drug concentrations of 10-8 mol/1, we found a significant (> or = 50%) reduction of the E-selectin expression after 1 and 2 h. Allergen-induced E-selectin expression was nearly abolished at concentrations of 10-5 (prednisolone) and 10-4 mol/l (fluocortin butyl). Fluticasone significantly inhibited E-selectin expression by > or = 50% at concentrations of 10-14 and 10-12 mol/l after 1 and 2 h, and abolished E-selectin induction at concentrations of 10-12 and 10-10 mol/l, respectively. Exposure of mucosal cubes to rhIL-lbeta (n = 5) also induced rapid upregulation of E-selectin expression, an effect which could be only partially suppressed by fluticasone preincubation at concentrations of 10-l0 mol/l.

CONCLUSIONS

Allergen-induced E-selectin expression is significantly and rapidly inhibited by GCS preincubation, fluticasone being more potent than prednisolone and fluocortin butyl. We suggest that this rapid effect is mainly indirect, possibly by inhibition of allergen-induced cytokine release.

Inhibition of eosinophilic inflammation in allergen-challenged, IL-1 receptor type 1–deficient mice is associated with reduced eosinophil rolling and adhesion on vascular endothelium

To determine the relative in vivo importance of IL-1 release after allergen challenge to the subsequent endothelial adhesion and recruitment of eosinophils, the authors used ovalbumin sensitization and inhalation challenge to induce airway eosinophilia in IL-1 receptor type 1-deficient and control wild-type mice. Bronchoalveolar lavage (BAL) eosinophil recruitment in IL-1 receptor type 1-deficient mice challenged with ovalbumin (24.3% ± 6.3% BAL eosinophils) was significantly reduced compared with wild-type mice (63.7% ± 2.5% BAL eosinophils). To determine whether the inhibition of eosinophil adhesion to vascular endothelium contributed to the inhibition of eosinophil recruitment in IL-1 receptor type 1-deficient mice, the authors used intravital microscopy to visualize the rolling and firm adhesion of fluorescence-labeled mouse eosinophils in the microvasculature of the allergen-challenged mouse mesentery. Eosinophil rolling, eosinophil firm adhesion to endothelium, and transmigration across endothelium (peritoneal eosinophils) were significantly inhibited in allergen-challenged IL-1 receptor type 1-deficient mice compared with wild-type mice. Overall, these studies demonstrate that cytokines such as IL-1, released after allergen challenge, are important in the induction of endothelial cell adhesiveness, a prerequisite for the recruitment of circulating eosinophils. (Blood. 2000;95:263-269)

Inhibition of eosinophilic inflammation in allergen-challenged, IL-1 receptor type 1–deficient mice is associated with reduced eosinophil rolling and adhesion on vascular endothelium

To determine the relative in vivo importance of IL-1 release after allergen challenge to the subsequent endothelial adhesion and recruitment of eosinophils, the authors used ovalbumin sensitization and inhalation challenge to induce airway eosinophilia in IL-1 receptor type 1-deficient and control wild-type mice. Bronchoalveolar lavage (BAL) eosinophil recruitment in IL-1 receptor type 1-deficient mice challenged with ovalbumin (24.3% ± 6.3% BAL eosinophils) was significantly reduced compared with wild-type mice (63.7% ± 2.5% BAL eosinophils). To determine whether the inhibition of eosinophil adhesion to vascular endothelium contributed to the inhibition of eosinophil recruitment in IL-1 receptor type 1-deficient mice, the authors used intravital microscopy to visualize the rolling and firm adhesion of fluorescence-labeled mouse eosinophils in the microvasculature of the allergen-challenged mouse mesentery. Eosinophil rolling, eosinophil firm adhesion to endothelium, and transmigration across endothelium (peritoneal eosinophils) were significantly inhibited in allergen-challenged IL-1 receptor type 1-deficient mice compared with wild-type mice. Overall, these studies demonstrate that cytokines such as IL-1, released after allergen challenge, are important in the induction of endothelial cell adhesiveness, a prerequisite for the recruitment of circulating eosinophils. (Blood. 2000;95:263-269)

IL-1 receptor-type expression in relation to atopy

BACKGROUND

IL-1 has 2 receptors, type I (IL-1RI) and type II (IL-1RII), which have 2 forms each, membrane (m) and soluble (s). When IL-1 binds to mIL-1RI, the active receptor, an inflammatory response is initiated, which does not occur when IL-1 binds to mIL-1RII, the decoy receptor. Both sIL-1RI and sIL-1RII function as IL-1-mopping mechanisms. We hypothesized that the ratio of active (mIL-1RI) to inactive (mIL-1RII, sIL-1RI, and sIL-1RII) receptors is important in determining the amount of inflammation produced in allergic reactions.

OBJECTIVE

Our aim was to compare the concentrations of mIL-1RI and mIL-1RII on cultured PBLs and sIL-1RI, sIL-1RII, and IL-1beta in sera and supernatants of cultured PBMCs from atopic and nonatopic subjects.

METHODS

The membrane receptors, soluble receptors, and IL-1beta concentrations were measured by ELISA with specific mAbs.

RESULTS

Although there was no difference in the level of serum IL-1beta between the 2 groups, PBMCs from atopic persons spontaneously secreted higher levels of IL-1beta than those from nonatopic donors (P < .05). PBLs from atopic subjects compared with those from nonatopic individuals expressed higher mIL-1RI (P < .0001) and mIL-1RII (P < .05). Levels of both the soluble receptors from both serum (P < .0001) and PBMCs (P < .05) of nonatopic donors were higher than those found in atopic donors.

CONCLUSION

This augmentation of mIL-1RI concomitant with a reduction in soluble receptors may be an important contributory factor to the inflammation that occurs with allergen exposure.

Chemical mediators in atopic dermatitis: involvement of leukotriene B4 released by a type I allergic reaction in the pathogenesis of atopic dermatitis

BACKGROUND

The mediators produced from a type I allergic reaction have not yet been able to explain the pathogenesis of atopic dermatitis (AD).

OBJECTIVE

The purpose of this study was to elucidate the involvement of leukotriene (LT) B4 produced from a type I allergic reaction in the pathogenesis of AD.

METHOD

The release of LTB4 was measured both in vitro, in passively sensitized and antigen-challenged human skin slices, as well as in vivo, in skin chambers on patients with AD.

RESULTS

LTB4 was released from in vitro human skin by stimulation of the antigen (54.9 +/- 14.6 pg/g wet weight of skin by antigen challenge and 28.0 +/- 11.1 pg/g in control skin, P <.002). Antigen-specific release of LTB4 and histamine was also observed in vivo in nonlesional skin from the patients with AD by using the skin chamber technique.

CONCLUSION

LTB4 release during type I allergic reaction in human skin has been determined in vitro. The released LTB4 possibly contributes to cellular response at the acute inflammatory lesion of AD.

Biologic activities of IL-1 and its role in human disease

The role of the polypeptide proinflammatory cytokine IL-1 family represents a group of proteins that have contrasting and synergistic biologic responses. IL-1alpha and beta and their precursor forms are heavily involved in the enhancement of inflammation and host defense. Within this family of gene products, there is also a naturally occurring receptor antagonist, IL-1ra, as well as a family of receptor proteins that have differential signaling functions and activities. The study of these proteins in human disease, including allergic disease and type 1 hypersensitivity responses, has led to a better understanding of the underlying general inflammation associated with these syndromes and has provided opportunities to look at new forms of intervention in allergic disease and asthma.

Comparison of inflammatory events in skin sites with and without cutaneous late-phase reactions after prominent immediate IgE-mediated responses

BACKGROUND

A number of inflammatory events have been detected in skin chambers overlying sites of developing late-phase reactions (LPR) to pollen antigens in sensitive subjects. However, the pathogenic significance of such events is still unclear.

OBJECTIVE

We sought to compare inflammatory responses and cytokine levels in skin chambers that overlie sites of antigen challenge in individuals with and individuals without LPRs after immediate wheal responses of similar intensity.

RESULTS

Early histamine releases at antigen sites were similar in eight subjects with LPR (+/+ group) and eight subjects without LPR (+/- group). However, histamine releases during hours 2 through 5 of antigen challenge were significantly greater in the +/+ subjects than in the +/- subjects. Total exuding leukocytes; percent eosinophils; and levels of eosinophil cationic protein, lactoferrin, and IL-8 were significantly greater at antigen versus buffer control challenge sites in both the +/+ and +/- groups, with no significant differences between the groups. IL-1 and IL-6 levels were not greater at antigen sites than at buffer sites.

CONCLUSIONS

The only significantly greater antigen-induced response detected in +/+ subjects than in +/- subjects was in later histamine release, which is possibly a marker of other inflammatory responses because histamine itself does not induce LPRs. Other inflammatory events assessed may be somewhat greater in +/+ subjects, but not significantly so.

Cytokines as targets for the inhibition of eosinophilic inflammation

Eosinophilic inflammation is thought to play a central role in the pathogenesis of asthma. The immunoregulatory effects of interleukin (IL)-4, IL-5 and immunoglobulin (Ig)E suggest that these molecules play key roles in the effector function of eosinophils and mast cells. IL-4 regulates the development of CD4+ TH2-type cells, which elicit essential signals through IL-4 and IL-5 for the regulation of IgE production and eosinophilia, respectively. IL-5-regulated pulmonary eosinophilia and airways dysfunction can also occur independently of IL-4 and allergen-specific Igs. Such IL-4-independent pathways may also play a substantive role in the aetiology of asthma. Thus, evidence is now emerging that allergic airways disease is regulated by humoral and cell-mediated components. The essential and specific role of IL-5 in regulating eosinophilia, and the subsequent involvement of this leukocyte in the induction of lung damage and airways dysfunction, identifies IL-5 as a primary therapeutic target for the relief of airways dysfunction in asthma.

Cytokine levels and inflammatory responses in developing late-phase allergic reactions in the skin

BACKGROUND

Cytokines could play roles in the attraction of leukocytes into sites of IgE-mediated late-phase reactions (LPR) or in the activation of such cells at the sites. Previous studies found increased release of IL-6, IL-1, and granulocyte-macrophage colony-stimulating factor into skin chambers overlying allergen-challenged sites, mainly after 6 hours when LPR are already well-developed.

OBJECTIVE

To compare levels of several cytokines with inflammatory responses in skin chambers overlying developing LPRs.

METHODS

Skin chambers were appended to denuded blister bases in 15 sensitive subjects, then challenged over a 5-hour period with pollen allergens (Ag) or buffer control (B). Levels of several chemotactic cytokines, eosinophil cationic product (released from eosinophils), and lactoferrin (released from neutrophils) were measured and leukocyte accumulation was assessed.

RESULTS

Levels of the chemokines IL-8, RANTES, and monocyte chemotactic protein-1 (but not IL-1, IL-6, or granulocyte-macrophage colony-stimulating factor) were significantly higher at Ag-challenge sites than at B-challenge sites. IL-5 was not detected. In individual chamber fluids at Ag-challenge sites, (1) IL-8 levels correlated strongly with levels of lactoferrin but not with eosinophil cationic protein levels; (2) RANTES levels correlated with numbers of eosinophils but not with eosinophil cationic protein levels; and (3) levels of monocyte chemotactic protein-1 correlated weakly with histamine released after the first hour.

CONCLUSIONS

During LPRs developing during the first 5 hours of Ag challenge, there is increased local release of several chemokines, which could play roles in the observed attraction and subsequent activation of leukocytes and continued histamine release observed at such sites.

Recent developments in the treatment of atopic eczema

Atopic eczema remains a therapeutic challenge. However, new developments in the understanding of the pathogenesis of this complex disease have prompted new therapeutic strategies. This review focuses on recently described treatment modalities for atopic eczema that are currently available or under investigation. The effectiveness of phototherapy, cytokines, and immunosuppressive drugs is evaluated. In addition, some new and promising but still experimental approaches are discussed.

Evidence that enhanced nasal reactivity to bradykinin in patients with symptomatic allergy is mediated by neural reflexes

OBJECTIVE

The aim of this study was to determine whether allergic inflammation induces nasal hyperreactivity to bradykinin by enhancing neuronal responsiveness.

METHODS

We compared the response to localized, unilateral nasal challenge with bradykinin in patients with perennial allergic rhinitis and nonallergic subjects, and in patients with seasonal allergic rhinitis challenged in and out of season. Weights of secretions from each nostril were recorded, and levels of albumin and lactoferrin in secretions recovered from each nostril were assayed. Contralateral administration of atropine (0.32 mg) was used to evaluate the role of cholinergic reflexes in nasal hyperresponsiveness to bradykinin.

RESULTS

In patients with symptomatic allergy, bradykinin induced greater symptom scores than in asymptomatic atopic or nonallergic control subjects. Moreover, bradykinin caused sneezing in a majority of patients with symptomatic allergy but in none of the asymptomatic atopic or nonallergic control subjects. Only patients with symptomatic allergy showed dose-dependent bilateral increases in secretion weights and levels of the serous glandular marker, lactoferrin. In contrast, bradykinin induced similar increases in ipsilateral, but not contralateral, levels of albumin in all patient populations. Atropine inhibited contralateral secretion and lactoferrin production (p < 0.05) in patients with symptomatic allergy.

CONCLUSION

The induction of sneezing and of atropine-inhibitable contralateral glandular secretion demonstrates that allergic inflammation causes nasal hyperreactivity to bradykinin, at least in part, by enhancing neuronal responsiveness.

Glucocorticosteroid inhibition of cytokine production: relevance to antiallergic actions

We believe that there are the following four classes of glucocorticoid-sensitive cytokines that are involved in cell recruitment: (1) those that activate endothelium nonspecifically; (2) those that activate endothelium specifically; (3) those that activate, prime, and prolong the survival of eosinophils; and (4) those that stimulate movement of cells up into the epithelium. Glucocorticoids inhibit the generation of these cytokines and thereby prevent several different aspects of inflammation, including the activation and recruitment of inflammatory cells (eosinophils, basophils, and lymphocytes) and the release of inflammatory mediators. We believe such pleiotropic actions account for the efficacy and widespread use of glucocorticoids in the treatment of asthma.

Cytokine treatment of mast-cell-mediated skin diseases

Cytokines released by mast cells as well as their effects on mast cell functions appear to be of major importance in the pathogenesis of mast cell mediated skin diseases. In addition, the identification of some key mediators which were found to play a crucial in vivo rôle in certain disease states may allow the development of new therapeutic strategies using cytokines or cytokine antagonists for the treatment of inflammatory skin diseases. So far, encouraging results have been obtained when diseases with mast cell involvement such as atopic eczema or mastocytosis have been treated with different IFNs. Future trials using IFNs and other newly detected cytokines or their antagonists are required to establish effective therapy regimens.

Potential role of interleukin-1 in allergen-induced late asthmatic reactions in guinea pigs: suppressive effect of interleukin-1 receptor antagonist on late asthmatic reaction

Interleukin (IL)-1 is a pluripotential proinflammatory cytokine and is thought to be involved in the pathogenesis of bronchial asthma and late asthmatic reactions (LARs). To determine whether IL-1 plays a role in LAR, guinea pigs sensitized with Ascaris antigen were used. We evaluated IL-1 production by immunostaining with anti-IL-1 beta antibody and elucidated the action of IL-1 in LAR with recombinant IL-1 receptor antagonist. Immunostaining revealed that IL-1 beta-like immunoreactivity-positive cells increased in the airway walls and in bronchoalveolar lavage fluid after the antigen challenge. IL-1 receptor antagonist protein pretreatment reduced the generation of LAR in terms of pulmonary resistance. IL-1 receptor antagonist protein pretreatment did not change cellular components but reduced the percentage of hypodense eosinophils in bronchoalveolar lavage fluid. We also studied the direct effect of recombinant human IL-1 beta on pulmonary resistance and eosinophil activity measured as released eosinophil peroxidase activity. Recombinant human IL-1 beta did not change pulmonary resistance but primed eosinophils to release eosinophil peroxidase activity in response to platelet activating factor. Therefore these results suggest that IL-1 was produced in sensitized pulmonary tissue of guinea pigs by allergen exposure and played a role in the generation of LAR, at least partially by modulating the activation of eosinophils.

Reduction of inflammation and pyrexia in the rat by oral administration of SDZ 224-015, an inhibitor of the interleukin-1 beta converting enzyme

1. The aim of this study was to determine whether a synthetic inhibitor of the interleukin-1 beta converting enzyme (ICE) displays oral activity in models of inflammation. 2. To this end, the ICE inhibitor, SDZ 224-015, was examined in rat paw oedema, pyrexia and nociception tests. 3. SDZ 224-015 (0.3-300 micrograms kg-1) potently reduced carrageenin-induced paw oedema, with an oral ED50 of approximately 25 micrograms kg-1. This effect was independent of endogenous glucocorticoid, as shown by retention of activity upon adrenalectomy. 4. Pyrexia induced by lipopolysaccharide (0.1 mg kg-1 s.c.) or by interleukin-1 beta (100 ng i.v.) was also reduced, over a similar dose-range to oedema (oral ED50s 11 micrograms kg-1 and 4 micrograms kg-1 respectively). 5. SDZ 224-015 (0.2-5 mg kg-1, p.o.) displayed analgesic activity in the Randall-Selitto yeast-inflamed paw pressure test, significant at a dose of 1 mg kg-1, p.o. 6. Thus, SDZ 224-015 has potent oral activity in several acute models for inflammation, suggesting that ICE inhibitors may constitute a novel type of anti-inflammatory agent.

Tumour necrosis factors and several interleukins inhibit the growth and modulate the antigen expression of normal human melanocytes in vitro

In the present study the action of various cytokines as regulators of human melanocyte growth and differentiation was examined in vitro. Primary melanocyte cultures were obtained in complete medium free of 12-O-tetradecanoylphorbol-13-acetate or serum. First passage melanocytes were treated with various concentrations of recombinant tumour necrosis factor alpha and beta (rTNF-alpha, rTNF-beta), as well as with various recombinant interleukins (rIL-1a, rIL-1b, rIL-2, rIL-3, rIL-4 and rIL-6) for 6 days in complete medium and for 6 and 12 days in a mitogen-reduced medium variant. The 4-methylumbelliferyl heptanoate fluorometric microassay and Ki-67 staining were used for assessing cell proliferation, and the immunophenotype was evaluated using various monoclonal antibodies. Melanocyte proliferation in complete medium was inhibited by rTNF-alpha (-24%), rTNF-beta (-17%), rIL-1a (-21%), rIL-1b (-18%) and rIL-6 (-29%); in contrast, rIL-2, rIL-3 and rIL-4 had no antiproliferative effect. Measurements of Ki-67-positive nuclei confirmed these results. In the reduced medium variant, none of the above cytokines inhibited melanocyte proliferation. Recombinant TNF-alpha and rTNF-beta markedly reduced the expression of the pigment cell-associated antigens HMB-45 and K.1.2, and they enhanced the expression of VLA-2, ICAM-1 and HLA class I antigens and strongly induced HLA-DR. Similar changes were induced by rIL-1a, rIL-b and rIL-6, and rIL-2 decreased the expression of HLA class I antigens and of ICAM-1. In conclusion, several cytokines inhibited the growth and modulated the phenotype of melanocytes in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

Proinflammatory cytokines in allergic rhinitis

Allergic diseases such as allergen-induced rhinitis represent an inflammatory reaction that is characterized by the chemotaxis and activation of various cell populations. A high degree of cell-to-cell communication is needed to orchestrate this inflammatory immune response. A variety of cytokines and adhesion receptors seem to play an important role in the allergic late phase reaction. Here we demonstrate that proinflammatory cytokines such as interleukin(IL)-1, IL-8 and TNF-alpha (tumor necrosis factor-alpha) can be detected in nasal secretions and mucosa by enzyme-linked immunosorbent assay and immunohistochemistry. The increased expression of adhesion receptors in mucosa specimens of patients with seasonal allergic rhinitis points to their role in regulating the cellular migration and probably represents a key event in allergic inflammation. We established an in vitro model using freshly taken nasal mucosa to study the induction of adhesion receptors by proinflammatory cytokines. E-selectin, an endothelial receptor, was strongly upregulated by IL-1 beta, TNF-alpha and allergen. The induction due to allergen exposure of the mucosa was markedly inhibited by soluble cytokine receptors (sIL-1R, TNF-BP) or by a receptor antagonist (IL-1ra) and prednisolone, These findings indicate that proinflammatory cytokines may be key factors for the upregulation of adhesion processes in human nasal mucosa and the activation of various cell populations involved in the allergic inflammation. They therefore represent a main target for new therapeutic strategies.

Mechanisms of the human allergic response. Clinical implications

During the past decade, there have been enormous strides made in our understanding of the mechanisms underlying the human allergic response. In particular, interleukin-4 and interleukin-5 play a critical role in this process. This article details the understanding of the mechanisms underlying the regulation of allergic response, which is critical to the development of new treatment of allergic diseases.

Anaphylactic colonic hypersecretion in cow's milk sensitized guinea-pigs depends upon release of interleukin-1, prostaglandins and mast cell degranulation

METHODS

The effect of beta-lactoglobulin (beta-LGI) challenge on net water movements into the proximal colon and the role of Interleukin-1 (IL-1), prostaglandins and mast cell degranulation on the challenge-induced net water changes were assessed in vivo using isolated colonic loops in anaesthetized guinea-pigs immunized to bovine milk.

RESULTS

beta-lactoglobulin challenge infused into the colonic loop during 30 min reversed the net water flux into a net secretion during the period of antigen infusion. Doxantrazole, a mast cell stabilizing agent, administered 120 min before challenge infusion, suppressed challenge-induced hypersecretion. Similarly recombinant IL-1 receptor antagonist protein abolished the antigen-induced colonic secretory effect. Indomethacin, a prostaglandin synthesis inhibitor, administered 20 min prior to antigen infusion, significantly (P < 0.05) reduced, but did not abolish, the challenge-induced colonic secretory effect.

CONCLUSIONS

These results suggest that IL-1 plays an important role in antigen challenge-induced colonic hypersecretion which involves mast cell degranulation and prostaglandin release.

Effects of human recombinant interleukins on stimulation-evoked noradrenaline overflow from the rat perfused spleen

Experiments were carried out in the isolated spleen of the rat to study in a lymphoid organ the influence of interleukins (ILs) on noradrenaline release. Spleens were perfused with Tyrode's solution and the overflow of endogenous noradrenaline was determined by HPLC with electrochemical detection. Perivascular electrical stimulation (4 or 10 Hz, 20-28 mA, 2 min) caused an increase in noradrenaline overflow and in perfusion pressure, both of which were markedly reduced by perfusion with Ca(2+)-free solution, abolished by tetrodotoxin, unaffected by hexamethonium, and subject to alpha 2-adrenoceptor- and muscarinic receptor-mediated modulation as shown by the effects of rauwolscine and methacholine. Human recombinant IL-1 beta and IL-2 and mouse recombinant IL-2 10 ng/ml failed to affect the evoked overflow of noradrenaline after an exposure time of 15 min. In contrast, human recombinant IL-1 beta and IL-2 0.1 ng/ml reduced the evoked overflow after exposure for 80 min; the inhibition tended to increase 30 min later despite washout. Murine recombinant IL-2 1.2 ng/ml caused no change after contact with the tissue for 80 min but there was an inhibition 30 min later after washout. Human recombinant IL-6 (0.1 ng/ml) caused no significant change. The inhibitory effect of low concentrations of IL-1 beta and IL-2 supports the idea that locally produced mediators of the immune system may affect neuronal function.

The effect of immunotherapy on the cutaneous late phase response to antigen

BACKGROUND

This study used the skin chamber model to evaluate prospectively the effect of immunotherapy (IT) on the cutaneous early and late phase response (LPR) to epicutaneous antigen challenge.

METHODS

Nine subjects with allergic rhinitis were studied at three time points: before starting IT, after 3 months of IT, and after 6 months of IT. Skin chamber histamine content was measured hourly for 12 hours, and cell counts performed hourly during hours 6 to 12. An intradermal skin test was placed, and the reaction was measured hourly for 12 hours. Skin biopsy specimens were obtained 8 hours after intradermal placement and evaluated for cellular infiltrate and major basic protein deposition. Serum antigen-specific IgG and IgE levels were measured at each time point to confirm physiologic effect of IT.

RESULTS

Six months of IT significantly (p < 0.05) decreased both early and LPR skin test reactivity and skin chamber histamine for hours 1 to 3, 4 to 6, and 9 to 12. Skin chamber LPR cellular influx decreased significantly (p < 0.05) for neutrophils only. Decrease in LPR histamine after 6 months of IT was significantly correlated with both decrease in mononuclear cells (R2 = 0.817, p = 0.002) and decrease in neutrophils (R2 = 0.813, p = 0.009). Also significantly correlated were decrease in LPR skin test reactivity, with percent change in skin chamber mononuclear cells (R2 = 0.800, p = 0.009) and decrease in early skin test reactivity (R2 = 0.675, p = 0.01). Biopsy specimens showed no consistent change in either dermal cellular infiltrate or deposition of major basic protein.

CONCLUSION

IT significantly attenuates cutaneous histamine release and skin test reactivity and is accompanied by a decrease in skin chamber LPR neutrophil influx without significantly altering the dermal infiltrate at 8 hours.

The late-phase reaction: role of IgE, its receptor and cytokines

Late phase IgE-mediated reactions (LPR) likely play a major role in the pathogenesis of chronic allergic diseases. Although a number of cellular and humoral alterations in LPR sites have been described recently, the pathogenesis of the LPR is still unclear. LPR follow IgE-mediated but not opiate-induced mast-cell activation suggesting different patterns of mast cell mediator release and/or additional effects of the antigen-IgE interaction. Granulocyte accumulation in developing LPR is accompanied by altered expression of adhesion molecules on local vascular endothelium. Lymphocytes and the cytokines they produce play an important role in developing and perpetuating LPR. These findings point to the likely complex pathogenesis of LPR with implications for the therapy of allergic diseases.

Cutaneous late-phase response in food-allergic children and adolescents with atopic dermatitis

Food hypersensitivities contribute to disease exacerbation in a sub-group of children with atopic dermatitis (AD). It has been shown that only selected foods are capable of causing clinical reactions when ingested, whereas other foods, to which the patient is equally sensitive by skin-prick testing, may be tolerated. The purpose of this study was to examine the cutaneous late-phase response (LPR) to food antigens in food-allergic patients with AD and to determine if the skin reacted differently to 'relevant foods' (foods eliciting positive skin-prick tests and positive oral challenges) than to 'non-relevant foods' (foods eliciting positive skin tests but negative oral challenges). Using blister chambers adfixed to the skin, six children with AD were challenged epicutaneously with foods to which they had previously been shown to be sensitive. Histamine and PGD2 were measured hourly for 10-12 hr in parallel with quantitation of the cellular traffic. There appeared to be no difference in any of the measured parameters between relevant foods and non-relevant foods, and the patterns of the LPR cells and mediators were similar to those previously described with aero-allergens in patients with respiratory allergy. Histamine rose to 13.0 +/- 24 ng/ml (P < 0.005) during the first hours, declined to < 1 ng/ml by the fifth hour, and then rose a second time to 6.72 +/- 3.4 ng/ml (P < 0.05) during the 12th hour. PGD2 rose to an average of 312 pg/ml (P < 0.05) during the first 3 hr followed by a decline to baseline.(ABSTRACT TRUNCATED AT 250 WORDS)