In situ changes in the relative abundance of human epidermal cytokine messenger RNA levels following exposure to the poison ivy/oak contact allergen urushiol

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.

The role of interleukin-1β in the immune response to contact allergens

Interleukin-1β (IL-1β) is an important pro-inflammatory cytokine that has an effect on almost every cell lineage in the body. By blocking IL-1β and investigating the IL-1β signaling pathway, several studies have demonstrated a central role of IL-1β in the response to contact allergens. This review summarizes the current literature regarding the basic immunological mechanisms mediated by IL-1β in the different phases of allergic contact dermatitis (ACD) and highlights potential IL-1β-targeted treatment options, which in the future may be relevant in the treatment of patients with ACD. This review is based primarily on studies using various mouse models and human in vitro studies, since clinical studies on the effect of IL-1β in ACD are lacking.

Interleukin 1-β, interleukin-1 receptor antagonist and vitamin D levels in children with atopic dermatitis

Introduction

Among the broad spectrum of cytokines, interleukin 1-β (IL-1β) has been implicated in induction and subsequent aggravation of skin lesions in atopic dermatitis (AD). A considerable body of evidence suggests that vitamin D status also influences the risk and/or severity of AD.

Material and methods

Fifty-seven children suffering from mild to severe AD were enrolled in the study. The control group consisted of 33 matched healthy children. In all the children serum concentrations of IL-1β/IL-1F2 and the interleukin-1 receptor antagonist IL-Ra/1F3 were measured. Serum 25(OH)D concentration was obtained for 49 patients with AD and all healthy children.

Results

In children with AD 59.2% of children had insufficiency, 24.5% had deficiency and 16.3% had a sufficient serum 25(OH)D level. In the control group 26.5%, 52.9% and 20% of participants had insufficiency/deficiency/sufficiency of 25(OH)D, respectively. The severity of AD was positively correlated with total IgE level, percentage and absolute count of eosinophils and IL-1Ra. IL-1β correlated with IL-1Ra.

Conclusions

In children with AD the serum vitamin D level was lower than in healthy children. The correlation between severity of AD and IL-1Ra may prove that inflammasome-dependent IL-1β is involved in immunopathogenesis of the disease. Further studies are needed on a larger population of children to confirm the role of this cytokine in development of AD.

IL-1β-dependent activation of dendritic epidermal T cells in contact hypersensitivity

Substances that penetrate the skin surface can act as allergens and induce a T cell-mediated inflammatory skin disease called contact hypersensitivity (CHS). IL-17 is a key cytokine in CHS and was originally thought to be produced solely by CD4(+) T cells. However, it is now known that several cell types, including γδ T cells, can produce IL-17. In this study, we determine the role of γδ T cells, especially dendritic epidermal T cells (DETCs), in CHS. Using a well-established model for CHS in which 2,4-dinitrofluorobenzene (DNFB) is used as allergen, we found that γδ T cells are important players in CHS. Thus, more IL-17-producing DETCs appear in the skin following exposure to DNFB in wild-type mice, and DNFB-induced ear swelling is reduced by ∼50% in TCRδ(-/-) mice compared with wild-type mice. In accordance, DNFB-induced ear swelling was reduced by ∼50% in IL-17(-/-) mice. We show that DNFB triggers DETC activation and IL-1β production in the skin and that keratinocytes produce IL-1β when stimulated with DNFB. We find that DETCs activated in vitro by incubation with anti-CD3 and IL-1β produce IL-17. Importantly, we demonstrate that the IL-1R antagonist anakinra significantly reduces CHS responses, as measured by decreased ear swelling, inhibition of local DETC activation, and a reduction in the number of IL-17(+) γδ T cells and DETCs in the draining lymph nodes. Taken together, we show that DETCs become activated and produce IL-17 in an IL-1β-dependent manner during CHS, suggesting a key role for DETCs in CHS.

Keratinocytes and cytokines

The skin has long been recognized as a major producer of cytokines, but the keratinocyte as principal epidermal cell has received less attention as potential source and target of cytokines. Nevertheless, keratinocytes produce a plethora of cytokines including interleukin (IL)-1, -6, -7, -8, -10, -12, -15, -18, and -20, and tumor necrosis factor alpha (TNF). The production by keratinocytes of pro-inflammatory (IL)-1, -6, -8, and TNF was recognized early and is well studied. Keratinocyte-derived IL-7 and -15 are considered to be significant in T-cell trafficking, possibly even in the pathogenesis of cutaneous T-cell lymphoma. Immunomodulatory IL-10 and -12 originating from keratinocytes are considered to be responsible for systemic effects, and IL-18 perhaps has a similar action. Keratinocytes were fairly recently recognized as being source or target of other IL-10 family members like IL-20 and IL-24 and the role of these cytokines in specific diseases is under investigation. In addition, a variety of cytokine receptors are present on keratinocytes like those for IL-4, -13, and -17 and to lesser degree IL-2. The ability to study the expression of cytokines by keratinocytes in vivo and in vitro using primary cells, immortalized cells or even organotypic culture systems offers many possibilities to further investigate the role of cytokine production in keratinocyte biology and disease.

Langerhans cells that express matrix metalloproteinase 9 increase in human dermis during sensitization to diphenylcyclopropenone in patients with alopecia areata

BACKGROUND

We know little of the initial events during the sensitization phase of contact allergy in humans. Alopecia areata (AA), a disease of unknown pathogenesis characterized by patchy hair loss, may be treated by inducing contact allergy to diphenylcyclopropenone (DPC), later followed by its topical application.

OBJECTIVES

To learn more about the initial events during sensitization in human skin, we studied the early events during induction of contact allergy to DPC in patients with AA.

METHODS

DPC 2% and sodium lauryl sulphate (SLS) 4% were applied on the backs of eight patients with AA. Punch biopsies were taken 6 and 24 h after application. The biopsies were snap-frozen and cryostat sections were evaluated with immunohistochemistry using antibodies against CD1a, HLA-DR, CD3, CD54 and matrix metalloproteinase 9 (MMP-9).

RESULTS

After 24 h all subjects exhibited erythema on the DPC-treated areas. Histological evaluation of biopsies from these areas showed hydropic degeneration and a significantly increased number of MMP-9+ cells in the dermis (P < 0.0005). The MMP-9+ cells were identified with double immunofluorescence staining as CD1a + Langerhans cells. The expression of the other markers studied remained unaltered irrespective of treatment, including treatment with SLS.

CONCLUSIONS

Our findings show that DPC induces an irritant reaction leading to an increased number of MMP-9+ CD1a+ cells in the dermis during the initial phase of sensitization.

Rhus (Toxicodendron) dermatitis

This article reviews the current fund of knowledge on poison ivy, poison oak, and poison sumac dermatitis. It is intended as a global summary to provide the primary care provider with the required information and sources for more esoteric academic pursuits. Toxicodendron characteristics, morphology, and biology are reviewed. The overall medical impact is delineated as well as the clinical manifestations, pathophysiology, prevention, and treatment. Historical perspectives are mentioned throughout, as are future trends in research.

Epidermal cytokines IL-1beta, TNF-alpha, and IL-12 in patients with atopic dermatitis: response to application of house dust mite antigens

Epidermal cytokines such as interleukin (IL)-1beta, tumor necrosis factor-alpha, and IL-12 have been described to play a crucial role in the induction and elicitation phase of allergic contact dermatitis upon exposure to haptens. In this study we asked whether these cytokines may also play a role in the epidermis of patients with atopic dermatitis after the application of house dust mite antigens (HDM) to their skin. Epidermal samples were collected by scraping healthy appearing skin of atopic patients and healthy individuals 8 h after the application of an extract of HDM. Sodium lauryl sulfate and saline served as controls. Reverse transcriptase-polymerase chain reaction was performed for IL-1beta, tumor necrosis factor-alpha, IL-12 p35, and IL-12 p40. Exposure to HDM led to a significant upregulation of mRNA of these cytokines in atopic patients only. Whereas IL-1beta and tumor necrosis factor-alpha also showed an upregulation in part of these patients after exposure to the irritant sodium lauryl sulfate, IL-12 p40 mRNA was exclusively enhanced by the application of the allergen. In contrast to IL-12 p40, IL-12 p35 mRNA was not detectable in significant amounts. Interestingly, also in untreated, normal appearing skin of atopic individuals (n = 16), the levels of these cytokines were higher than in normal individuals (n = 8), possibly explaining the increased skin irritability of atopic individuals. Finally, comparing epidermal cytokines in the skin of patients who developed a positive allergen patch test to those who stayed negative, suggests that only expression of IL-1beta mRNA may be a predictive marker for the development of a positive patch test reaction to HDM.

The cytokines NAP-1 (IL-8), MCP-1, IL-1 beta, and GRO in rabbit inflammatory skin lesions produced by the chemical irritant sulfur mustard

Developing and healing dermal inflammatory lesions were produced in rabbits by the topical application of dilute sulfur mustard (SM), the military vesicant. In tissue sections of such lesions, cells containing the mRNA of important cytokines were identified with in situ hybridization techniques. These cytokines were neutrophil attractant/activation protein-1 (NAP-1 (also called IL-8), monocyte chemoattractant (activating) protein 1 (MCP-1), interleukin 1 (beta) (IL-1 (beta)), and GRO (a growth factor and chemokine). Mononuclear cells (mainly macrophages and activated fibroblasts) contained the mRNA of all four of these cytokines. A higher percentage of cytokine-producing mononuclear cells (macrophages and activated fibroblasts) was present in lesions at 2 days (their peak size) than at 6 days, when they were almost healed. Granulocytes emigrated from the bloodstream, passed through the lesions, and were the major constituent of the protective crust. This sequence correlated with the distribution of cells able to produce NAP-1: At 2 days and 6 days, the mononuclears that contained messenger RNA for this granulocyte chemoattractant were found mainly in the upper part of the dermis. At 2 days and 6 days, cells containing the mRNA of IL-1, a primary cytokine, were also found predominantly in the upper dermis, i.e., nearest the site of injury. In contrast, mononuclears containing the mRNA of MCP-1 (a monocyte chemoattractant), and the mRNA of GRO (a granulocyte chemoattractant) were more equally distributed throughout the dermis. SM stimulated hair follicle epithelial cells to up-regulate GRO mRNA and, to a lesser degree, NAP-1 mRNA. Apparently, the irritation produced by SM directly or indirectly induces such epithelial cells to manufacture these growth factors. In the rabbit, hair follicles are known to be the main source of new epithelial cells after the covering epithelium has been destroyed. Therefore, GRO is probably a major autocrine-paracrine stimulus for such repair. A brief review of the role of cytokines in dermal inflammation is presented.