Glucocorticoids increase the synthesis of immunoglobulin E by interleukin 4-stimulated human lymphocytes

Impact of fucosyltransferase 1-mediated epidermal blood group antigen H on anti-inflammatory response in atopic dermatitis

The presence of the blood group H2 antigen on the membrane of red blood cells determines blood type O in individuals and this H2 antigen serves as a precursor to the A and B antigens expressed in blood types A and B, respectively. However, the specific involvement of ABH antigens in skin diseases is unknown. Therefore, we aim to investigate the expression of ABH antigens in skin tissue of patients with atopic dermatitis (AD) and MC903-induced AD-like mice. We demonstrated that the expression of ABH antigen is primarily located in the granular and horny layers of the skin in healthy control individuals. However, in patients with AD, the expression of the ABH antigen was absent or diminished in these layers, while the H2 antigen expression increased in the spinous layers of the affected skin lesions. Then, we investigated the biological function of blood group H antigen mediated by fucosyltransferase 1 (Fut1) in the skin, utilizing an AD mouse model induced by MC903 in wild-type (WT) and Fut1-knockout mice. After the application of MC903, Fut1-deficient mice, with no H2 antigen expression on their skin, exhibited more severe clinical signs, increased ear swelling, and elevated serum IgE levels compared with those of WT mice. Additionally, the MC903-induced thickening of both the epidermis and dermis was more pronounced in Fut1-deficient mice than that in WT mice. Furthermore, Fut1-deficient mice showed a significantly higher production of interleukin-4 (IL-4) and IL-6 in skin lesions compared with that of their WT counterparts. The expression of chemokines, particularly Ccl2 and Ccl8, was notably higher in Fut1-deficient mice compared with those of WT mice. The infiltration of CD4+ T cells, eosinophils, and mast cells into the lesional skin was significantly elevated in Fut1-deficient mice compared with that in WT mice. These findings demonstrate the protective role of H2 antigen expression against AD-like inflammation and highlight its potential therapeutic impact on AD through the regulation of blood group antigens.

B cells and the stressed brain: emerging evidence of neuroimmune interactions in the context of psychosocial stress and major depression

The immune system has emerged as a key regulator of central nervous system (CNS) function in health and in disease. Importantly, improved understanding of immune contributions to mood disorders has provided novel opportunities for the treatment of debilitating stress-related mental health conditions such as major depressive disorder (MDD). Yet, the impact to, and involvement of, B lymphocytes in the response to stress is not well-understood, leaving a fundamental gap in our knowledge underlying the immune theory of depression. Several emerging clinical and preclinical findings highlight pronounced consequences for B cells in stress and MDD and may indicate key roles for B cells in modulating mood. This review will describe the clinical and foundational observations implicating B cell-psychological stress interactions, discuss potential mechanisms by which B cells may impact brain function in the context of stress and mood disorders, describe research tools that support the investigation of their neurobiological impacts, and highlight remaining research questions. The goal here is for this discussion to illuminate both the scope and limitations of our current understanding regarding the role of B cells, stress, mood, and depression.

Topical Skullcapflavone II attenuates atopic dermatitis in a mouse model by directly inhibiting associated cytokines in different cell types

Skullcapflavone II (SFII), a flavonoid derived from Scutellaria baicalensis, is an anticancer agent. We aimed to validate SFII for atopic dermatitis (AD) therapy by demonstrating the anti-inflammatory effects of SFII in an AD mouse model produced by the topical application of the vitamin D3 analog MC903. We showed that topical treatment with SFII significantly suppressed MC903-induced serum IgE levels compared with topical hydrocortisone (HC) treatment. Topical SFII also prevents MC903-induced pruritus, skin hyperplasia, and inflammatory immune cell infiltration into lesional skin comparable to topical HC. In addition, MC903-induced immune cell chemoattractants and AD-associated cytokine production in skin lesions were effectively suppressed by topical SFII. The production of MC903-induced effector cytokines influencing T helper (Th)2 and Th17 polarization in lesioned skin is significantly inhibited by topical SFII. Furthermore, we showed that SFII can directly inhibit the production of AD-associated cytokines by human primary keratinocytes, mouse bone marrow-derived cells (BMDCs), and mouse CD4⁺ T cells in vitro. Lastly, we demonstrated that topical SFII more effectively suppressed serum IgE levels, the production of IL-4 and thymic stromal lymphopoietin (TSLP), and infiltration of CD4⁺ T cells and Gr-1⁺ cells (neutrophils) into lesion skin compared to topical baicalein (a flavonoid derived from Scutellaria baicalensis), which has anti-inflammatory effects. Taken together, our findings suggest that SFII may have promising therapeutic potential for this complex disease via the regulation of multiple AD-associated targets.

Daratumumab: Beyond Multiple Myeloma

Daratumumab (DARA) is the biological name of an Immunoglobulin G1k human monoclonal antibody. DARA the first-in-class therapy targeting CD38 expressing- plasma cells (PC) and plasma blasts. It has been approved for the treatment of multiple myeloma. It is also being examined in the setting of other hematologic malignancies. As DARA targets PCs, it could potentially be used to treat many other disease processes that are antibody mediated. In fact, several case reports and case series report experiences of using DARA to treat a variety of antibody-mediated disorderss. The aim of this review is to present a summary of the literature thus far regarding the application of DARA beyond its uses in multiple myeloma and other hematologic diseases. Specifically, we address uses of DARA as an immunologic modulator in various antibody mediated processes.

Keratinocytes control skin immune homeostasis through de novo-synthesized glucocorticoids

Glucocorticoids (GC), synthesized by the 11β-hydroxylase (Cyp11b1), control excessive inflammation through immunosuppressive actions. The skin was proposed to regulate homeostasis by autonomous GC production in keratinocytes. However, their immunosuppressive capacity and clinical relevance remain unexplored. Here, we demonstrate the potential of skin-derived GC and their role in the regulation of physiological and prevalent inflammatory skin conditions. In line with 11β-hydroxylase deficiency in human inflammatory skin disorders, genetic in vivo Cyp11b1 ablation and long-term GC deficiency in keratinocytes primed the murine skin immune system resulting in spontaneous skin inflammation. Deficient skin GC in experimental models for inflammatory skin disorders led to exacerbated contact hypersensitivity and psoriasiform skin inflammation accompanied by decreased regulatory T cells and the involvement of unconventional T cells. Our findings provide insights on how skin homeostasis and pathology are critically regulated by keratinocyte-derived GC, emphasizing the immunoregulatory potential of endogenous GC in the regulation of epithelial immune microenvironment.

FCER2 T2206C variant associated with FENO levels in asthmatic children using inhaled corticosteroids: The PACMAN study

BACKGROUND

The FCER2 gene, via encoding of the CD23 receptor, plays an important role in the regulation of IgE responses. A genetic variant of the FCER2 gene (T2206C) was previously shown to be associated with IgE levels in asthmatic children. IgE sensitization has also been linked to increased levels of fractional exhaled nitric oxide (FENO).

OBJECTIVE

To investigate whether the FCER2 T2206C variant influences FENO levels in asthmatic children with a reported use of inhaled corticosteroids (ICS).

METHODS

This cross-sectional study involved 593 asthmatic children with a reported use of ICS, availability of FENO measurements and genotyping data on the FCER2 T2206C variant (rs28364072). An additive genetic model was assumed, and the association between the FCER2 T2206C variant and the log-transformed (ln) FENO levels was evaluated using linear regression analysis, adjusted for age, sex, adapted British Thoracic Society (BTS) treatment steps and atopy.

RESULTS

The mean age of the population was 9.1 ± 2.2 years, and the median of FENO levels was 13.0 ppb with an interquartile range (IQR) of (8.0-27.5 ppb). The minor allele (G) frequency of rs28364072 was 29.6%, and each extra copy of the G allele was significantly associated with a lower level of the geometric mean of FENO (log scale, β = -0.12, 95% CI: -0.23, -0.02).

CONCLUSION AND CLINICAL RELEVANCE

Our results showed that the FCER2 T2206C variant was significantly associated with lower FENO levels in carriers of the G allele. Nevertheless, this SNP contributed little to the variability in FENO levels in this patient population. Our findings contribute to the present knowledge on FENO in asthmatic children; however, future replication studies are required to establish the role of this gene in relation to FENO.

Phloxine O, a Cosmetic Colorant, Suppresses the Expression of Thymic Stromal Lymphopoietin and Acute Dermatitis Symptoms in Mice

Cosmetics are primarily applied to the skin; therefore, the association of cosmetic dyes with skin diseases or inflammation is a topic of great interest. Thymic stromal lymphopoietin (TSLP) is an interleukin 7-like cytokine that activates dendritic cells to promote Th2 inflammatory immune responses. TSLP is highly expressed in keratinocytes under inflammatory conditions, which suggests that it may play a critical role in the development of skin diseases, such as atopic dermatitis. Therefore, we investigated whether cosmetic dyes influenced the production of TSLP by keratinocytes. Phloxine O, also known as D&C Red No.27, is one of the most common red synthetic pigments and is widely used in colored cosmetics. Our results showed that Phloxine O downregulated phorbol 12-myristate 13-acetate-induced production of TSLP in a murine keratinocyte cell line (PAM212). Phloxine O also suppressed TSLP expression in KCMH-1 cells, which are mouse keratinocytes that constitutively produce high levels of TSLP. To investigate the in vivo effects of Phloxine O, we induced TSLP expression in mouse ear skin by topically applying MC903, a vitamin D3 analogue that is a well-known inducer of atopic dermatitis-like symptoms. Topical application of Phloxine O prevented MC903-induced TSLP production in mouse ear skin, attenuated the acute dermatitis-like symptoms and decreased serum IgE and histamine levels in mice. Suppression of TSLP expression by Phloxine O correlated with reduced expression of OX40 ligand and Th2 cytokines in mouse ear skin. Our results showed that Phloxine O may be beneficial to prevent dermatitis by suppressing the expression of TSLP and Th2 cytokines in skin.

Corticosteroids inhibit anti-IgE activities of specialized proresolving mediators on B cells from asthma patients

Specialized proresolving mediators (SPMs) promote the resolution of inflammation and exert beneficial effects in animal models of chronic inflammatory diseases, including asthma. Previously, we have shown that certain SPMs reduce IgE production in B cells from healthy individuals, which has a critical role in allergic asthma. Here, we investigated the effects of SPMs on B cell IgE production in asthma patients. Peripheral blood mononuclear cells from asthma patients were treated with 17-HDHA or RvD1, and IgE levels were measured. RvD1 and 17-HDHA dampened IgE production in B cells from most asthma patients, whereas B cells from a subset of patients taking oral steroids were refractory to SPM treatment. Molecular mechanisms underlying the interaction between corticosteroids and SPMs were investigated by treating B cells from nonasthmatic donors with corticosteroids in vitro. Corticosteroids blocked the inhibitory effects of 17-HDHA and RvD1 on B cell IgE production by abolishing the suppressive activity of these mediators on IgE class switching. Corticosteroids decreased the expression of transcriptional repressor Bcl-6 as well as its suppressive activity on epsilon germline transcription. We conclude that 17-HDHA and RvD1 can reduce IgE production in asthma patients not taking high doses of steroids but that corticosteroids interfere with the ability of B cells to respond to proresolving mediators.

Glucocorticoid inhibition of activation-induced cytidine deaminase expression in human B lymphocytes

We examined whether glucocorticoids could modulate the expression of activation-induced cytidine deaminase (AICDA), the principal regulator of the processes of immunoglobulin gene somatic hypermutation and class switch recombination in B lymphocytes. Treatment of human B cells with IL-4 and anti-CD40 antibody for 18-20h resulted in induction of expression of AICDA mRNA by over 10-fold. Dexamethasone at 10nM concentration inhibited AICDA induction by an average of 51.8% (p<0.0001). These effects of glucocorticoids were found to be dose dependent in the physiologic range and were reversible by co-treatment with a glucocorticoid receptor antagonist. Human B cell viability and proliferation were unaltered by glucocorticoid treatment. These data demonstrate that physiologic concentrations of glucocorticoids can act on human B lymphocytes through glucocorticoid receptor-mediated mechanisms to diminish the expression of AICDA, a key regulator of humoral immune responses.

Glucocorticoid-induced immunoglobulin E synthesis by peripheral blood mononuclear cells from allergic and nonallergic subjects

BACKGROUND

Glucocorticoids (GCS) have been shown to induce IgE synthesis in human peripheral blood mononuclear cells (PBMCs) and purified B cells in vitro. However, the differences in immunoglobulin E (IgE) response to GCS between allergic and non-allergic individuals and the mechanism this interaction have not been elucidated.

OBJECTIVE

We aimed to compare the effect of GCS (budesonide) on interleukin (IL)-4-driven IgE production in vitro in allergic and non allergic subjects and assess the engagement of intracellular mechanisms.

METHODS

The study included 22 patients with allergic asthma and/or allergic rhinitis and 24 healthy volunteers. PBMCs were cultured for 11 days with IL-4 and budesonide and IgE concentrations in supernatants were assessed by immunoassays. T and B cell markers were assessed by flow cytometry.

RESULTS

Budesonide enhanced IgE synthesis to higher extent in healthy donors than in allergic patients (mean increase of 16.5 vs 6.3 kU/L, P< .05 respectively) acting through glucocorticoid receptor. Budesonide significantly increased lymhoplasmocytoid cells percentage in both media-controlled (2.5-fold increase) and IL-4-stimulated PBMCs (2-fold increase). Added to IL-4 budesonide decreased the percentage of both T cells and CD40L(+) T cells, but strongly increased the percentage of B cells. Protein tyrosine kinase (PTK) inhibitor decreased, but NF-κB and protein kinase A (PKA) inhibitors expressed modulatory effects on budesonide-induced IgE synthesis.

CONCLUSIONS

Budesonide-induced IgE generation in PBMCs differs in magnitude and seems to involve different mechanisms in atopic and non-atopic subjects.

Predictors of poor response during asthma therapy differ with definition of outcome

AIMS

To evaluate phenotypic and genetic variables associated with a poor long-term response to inhaled corticosteroid therapy for asthma, based independently on lung function changes or asthma exacerbations.

MATERIALS & METHODS

We tested 17 phenotypic variables and polymorphisms in FCER2 and CRHR1 in 311 children (aged 5-12 years) randomized to a 4-year course of inhaled corticosteroid during the Childhood Asthma Management Program (CAMP).

RESULTS

Predictors of recurrent asthma exacerbations are distinct from predictors of poor lung function response. A history of prior asthma exacerbations, younger age and a higher IgE level (p < 0.05) are associated with recurrent exacerbations. By contrast, lower bronchodilator response to albuterol and the minor alleles of RS242941 in CRHR1 and T2206C in FCER2 (p < 0.05) are associated with poor lung function response. Poor lung function response does not increase the risk of exacerbations and vice versa (p = 0.72).

CONCLUSION

Genetic and phenotypic predictors of a poor long-term response to inhaled corticosteroids differ markedly depending on definition of outcome (based on exacerbations vs lung function). These findings are important in comparing outcomes of clinical trials and in designing future pharmacogenetic studies.

How stress and anxiety can alter immediate and late phase skin test responses in allergic rhinitis

Allergic rhinitis (AR) is the fifth most common chronic disease, and the association between allergic disorders and anxiety is well-documented. To investigate how anxiety and stressors modulate skin prick test (SPT) responses and associated inflammatory responses, 28 men and women with AR were selected by clinical history and skin test responses. The participants were admitted twice to a hospital research unit for 4h in a crossover trial. Changes in SPT wheals were assessed before and after a standardized laboratory speech stressor, as well as again the following morning; skin responses assessed twice during a lab session without a stressor and again the following morning served as the contrast condition. Anxiety heightened the magnitude of allergen-induced wheals following the stressor. As anxiety increased, SPT wheal diameters increased after the stressor, compared to a slight decrease following the control task. Anxiety also substantially enhanced the effects of stress on late phase responses: even skin tests performed the day after the stressor reflected the continuing impact of the speech stressor among the more anxious participants. Greater anxiety was associated with more IL-6 production by Con A-stimulated leukocytes following the stressor compared to the control visit. The data suggest that stress and anxiety can enhance and prolong AR symptoms.

FCER2: a pharmacogenetic basis for severe exacerbations in children with asthma

BACKGROUND

Although inhaled corticosteroids (ICSs) generally protect against severe exacerbations in asthma, they may result in elevated IgE levels, which are associated with exacerbations.

OBJECTIVE

To determine whether variation in the low-affinity IgE receptor gene, FCER2, is associated with severe exacerbations defined as emergency department visits and/or hospitalizations in patients with asthma on ICSs.

METHODS

We resequenced, then genotyped 10 FCER2 single nucleotide polymorphisms (SNPs) in 311 children randomized to inhaled budesonide as part of the Childhood Asthma Management Program. We evaluated the association of FCER2 variants with IgE levels and presence or absence of severe exacerbations over the 4-year clinical trial. We also evaluated differences in cellular expression of the novel FCER2 SNP, T2206C.

RESULTS

In white subjects, 3 FCER2 SNPs were significantly associated (P < .05) with elevated 4-year IgE level; each was also associated with increased severe exacerbations. Final multivariable models demonstrated associations between T2206C and severe exacerbations in both white and African American children (hazard ratio, 3.95; 95% CI, 1.64-9.51; and hazard ratio, 3.08; 95% CI, 1.00-9.47), despite ICS use. Interaction models supported a true gene-environment effect in white subjects (interaction P = .004). T2206C was also associated with decreased FCER2 expression (P = .02).

CONCLUSION

FCER2 predicts the likelihood of treatment protocol success in asthma. The associations of T2206C with IgE level, severe exacerbations, and FCER2 expression may provide a mechanistic basis for the observed findings.

CLINICAL IMPLICATIONS

Genetic variation in FCER2 may help form a prognostic model for ICS response in asthma.

BCR ligation antagonizes the IL-21 enhancement of anti-CD40/IL-4 plasma cell differentiation and IgE production found in low density human B cell cultures

We sought to discover the mechanisms explaining increased IgE production seen at low cell densities when IL-21 is added to human B cell cultures activated with anti-CD40 and IL-4. When cells were cultured in the absence of BCR ligation, qPCR demonstrated dramatic increases in mRNA for the plasma cell transcription factors BLIMP1 and XBP1. Furthermore, a majority of viable cells expressed high levels of CD38 while losing expression of surface IgD. In contrast, in the presence of BCR stimulation, both the XBP1 mRNA levels and CD38 cell surface expression were markedly reduced, and a large population of cells retained IgD expression, indicating reduced plasma cell differentiation. IgE levels were reduced in the BCR stimulated cultures by 90%, while IgG4 levels remained unchanged. In summary, IL-21 enhances IgE production at low densities through stimulating cell division and plasma cell differentiation and this activity is reduced upon BCR cross-linking.

Prophylactic role for complementary and alternative medicine in perinatal programming of adult health

BACKGROUND

The health status of an individual in adulthood is proposed to be determined by events occurring in the prenatal and early postnatal period. A common early life event proven to have long lasting effects on the developing fetus is stress, including pain. Exposure of fetal and neonatal infants to repetitive psychological (e.g., maternal stress) or physiological (e.g., pain, infection, and noise) stress during this period is proposed to alter mechanisms involved in the regulation of stress, immunological maturation, pain perception, and cognition. Such changes, which persist into adulthood, may occur via alterations in the development of the hypothalamic-pituitary-adrenal (HPA) axis. This process is typically referred to as 'perinatal programming'. Ontogenic alterations in the development of the HPA-axis have been related to a number of adult pathologies such as cardiovascular disease, type 2 diabetes, asthma, as well as psychopathologies such as anxiety and depression.

OBJECTIVE

In this review, the effectiveness of complementary and alternative medicine (CAM), such as music, dietary supplements, massage and aromatherapy, in reducing perinatal stress in mothers and infants is examined. An emphasis is placed on these therapies as preventative measures which may be of value to individuals at risk of developing disease profiles associated with the consequences of adverse perinatal programming. The widening interest in perinatal programming and CAM suggests the potential for CAM to become a valuable tool in offsetting negative adult health outcomes resulting from perinatal programming associated with adverse gestational early life environments.

Psychological stress affects response to sublingual immunotherapy in asthmatic children allergic to house dust mite

While the clinical and immunologic efficacy of sublingual immunotherapy (SLIT) in allergic diseases has been extensively demonstrated, some patients display a poor clinical response. Psychological stress has been shown to play a role in atopy and also to affect response to immunomodulating therapies such as vaccination with microbial antigens. This study addresses the possibility of response to SLIT being affected by psychological stress. Forty children with mild asthma caused by allergy to Dermatophagoides pteronyssinus and farinae were subjected to SLIT and then divided after 6 months into two groups based on the results of the stress integrated measure (SIM) test: group 1 (24 stressed patients, mean SIM value of 60.1) and group 2 (16 non-stressed patients, mean SIM value of 7.6). There was also a higher prevalence of psychosocial stressing factors (divorced/absent parents, low income households, non-working parents) among stressed patients. The symptom score, peak expiratory flow (PEF), forced expiratory volume in 1 s (FEV(1)) and serum eosinophie cationic protein (ECP) concentration were evaluated at both times. The serum concentration of neuroendocrine parameters [prolactin, cortisol, adrenocorticotropic hormone (ACTH)] was also measured after 6 months of therapy. While all the clinical parameters and ECP concentration improved after SLIT, symptom score, PEF and ECP showed a significantly greater improvement in non-stressed patients. The concentration of neuroendocrine parameters was significantly increased in stressed patients. Our findings show that psychological stress can affect response to SLIT also in allergic subjects and are consistent with data recently reported showing a correlation between stress and poor response to antimicrobial vaccines. Our data also suggest that stress evaluation may become a useful prognostic factor in immunotherapy.

Perceived control and immune and pulmonary outcomes in children with asthma

OBJECTIVE

This study tested the relationships between perceived control and biological processes relevant to asthma in children.

METHODS

Forty children diagnosed with asthma completed the Children's Health Locus of Control (CHLC) scale. Participants also completed pulmonary function testing, measuring forced vital capacity (FVC), and forced expiratory volume in 1 second (FEV1). Blood was drawn to assess immune markers associated with asthma. Specifically, stimulated production of the cytokines interleukin 4 (IL-4), interleukin-5 (IL-5), interleukin-13 (IL-13), interferon-gamma (IFN-gamma), as well as eosinophil count, was measured. At home, participants completed peak expiratory flow rate (PEFR) measures to monitor their daily pulmonary function.

RESULTS

Higher levels of perceived control were associated with significantly better FVC, FEV1, and PEFR variability. Higher levels of perceived control were also associated with decreased production of asthma-related cytokines, including IL-4, IL-5, and IL-13.

CONCLUSION

These results suggest that psychological processes such as perceived control may play an important role in asthma-related biological processes among children with asthma.

Anti-CD23

CD23, the low-affinity immunoglobulin (Ig)E receptor (FcepsilonRII), is widely distributed on the surface of various human cells. CD23 mediates numerous IgE-related immune responses (including allergen focusing) by enhancing IgE antigen complex presentation, regulating IgE synthesis, influencing cell differentiation and growth of both B- and T-cells, and stimulating production of pro-inflammatory mediators from monocytes/macrophages, eosinophils, and even airway smooth muscle cells. Both membrane and soluble CD23 play an important role in allergic reactions. Cellular contacts and cytokines modulate its expression in a concerted manner as needed for allergic reactions. Expression of CD23 and soluble CD23 has been associated with allergic diseases. Targeting CD23 with monoclonal antibody (MAb) is a promising candidate therapy in allergic diseases. A newly developed agent known as Lumiliximab, which is an anti-CD23 MAb (Lumiliximab), was demonstrated to be a well-tolerated agent in a phase I clinical trial (a placebo-controlled study with allergic asthma). Adverse events were mild, and no relationship was apparent between the dose of Lumilixilab and the frequency, severity, or type of event. Sustained and dose-dependent decreases in mean serum total IgE concentrations were noted. The serum half-life of Lumilixilab increased from 2 to 10 d with increasing doses. Blocking antigen presentation, preventing costimulation signals, and reducing production of pro-inflammatory mediators are some of the potential mechanisms involved for anti-CD23 activity. Although the safety and clinical efficacy of Lumilixilab in allergic asthma and rhinitis require confirmation, the observed data imply that anti-CD23 is a promising candidate therapy option for future treatment of allergic diseases.

Stress system--organization, physiology and immunoregulation

Stress is defined as a state of threatened homeostasis. The principal effectors of the stress system include corticotropin-releasing hormone, arginine vasopressin, the glucocorticoids, and the catecholamines norepinephrine and epinephrine. Activation of the stress system leads to adaptive behavioral and physical changes. The principal stress hormones glucocorticoids and catecholamines affect major immune functions such as antigen presentation, leukocyte proliferation and traffic, secretion of cytokines and antibodies, and selection of the T helper (Th) 1 versus Th2 responses. A fully fledged systemic inflammatory reaction results in stimulation of the stress response, which in turn, through induction of a Th2 shift protects the organism from systemic overshooting with Th1/pro-inflammatory cytokines. Stress is often regarded as immunosuppressive, but recent evidence indicates that stress hormones influence the immune response in a less monochromatic way--systemically they inhibit Th1/pro-inflammatory responses and induce a Th2 shift, whereas in certain local responses they promote pro-inflammatory cytokine production and activation of the corticotropin-releasing hormone-mast cell-histamine axis. Through this mechanism a hyper- or hypoactive stress system associated with abnormalities of the systemic anti-inflammatory feedback and/or hyperactivity of the local pro-inflammatory factors may play a role in the pathogenesis of chronic inflammation and immune-related diseases.

Prevalence of atopic diseases and the use of topical corticosteroids. Is there any connection?

The prevalence of atopic diseases (atopic dermatitis, bronchial asthma, allergic rhinitis) has considerably increased for the last 40 years. This tendency has coincided with the beginning of the epoch of the use of the topical corticosteroids, which have a potent immunomodulation action. This fact itself as well as a number of research results has allowed to formulate the following hypothesis: the use of topical corticosteroids in children of early age contributes to the increase of prevalence of atopic diseases in the developed countries. The offered hypothesis can explain lower prevalence of atopic diseases in rural areas and in children from families with the anthroposophic life style. In other side this hypothesis also capable to give explanation of increased level of atopic diseases among people with high socioeconomic level and in children from 1 child families. It is of a note that corticosteroids use in developing countries is limited due to economic reasons and active use of complementary medicine. If the proposed hypothesis is correct, a revision of the therapeutic approaches is necessary concerning the attitude towards application of topical corticosteroids in children suffering from various forms of eczema. The direct proof of this hypothesis can be found during prospective studies.

Molecular mechanisms of glucocorticoids in the control of inflammation and lymphocyte apoptosis

The immune system must be tightly controlled not only to guarantee efficient protection from invading pathogens and oncogenic cells but also to avoid exaggerated immune responses and autoimmunity. This is achieved through interactions amongst leukocytes themselves, by signals from stromal cells and also by various hormones, including glucocorticoids. The glucocorticoids are a class of steroid hormones that exert a wide range of anti-inflammatory and immunosuppressive activities after binding to the glucocorticoid receptor. The power of these hormones was acknowledged many decades ago, and today synthetic derivatives are widely used in the treatment of inflammatory disorders, autoimmunity and cancer. In this review, we summarize our present knowledge of the molecular mechanisms of glucocorticoid action, their influence on specific leukocytes and the induction of thymocyte apoptosis, with an emphasis on how molecular genetics has contributed to our growing, although still incomplete, understanding of these processes.

Rebound phenomenon to systemic corticosteroid in atopic dermatitis

Three patients with atopic dermatitis, one boy and two girls, aged between 6 and 17 years, presented eczematous skin, pruritus, scarifications, lichenification and a family history of atopy. During exacerbations, the patients sought emergency care and were prescribed oral corticosteroids for a period of approximately 15 days. Initially, the patients improved but after cessation of therapy or dose reduction, marked worsening occurred with the development of lesions with extreme pruritus, several confluent lesions, scarification and intense exudates, as well as fever and dehydration. The patients' condition was so severe that two were admitted to the allergy unit. The medication was withdrawn and intravenous hydration was administered, together with hydrating skin creams and antihistamine therapy. In addition, weak topical corticosteroids were applied on the most severely affected areas. All three patients progressively improved. We conclude that the patients with atopic dermatitis described herein presented a rebound phenomenon after the use of corticosteroids. We believe that systemic corticosteroids may exacerbate the acute phase of atopic dermatitis, mediated by IgE, accentuating the Th2 pattern in these patients.

Neuroendocrine mechanisms of immune dysregulation: applications to allergy and asthma

OBJECTIVE

To review the current information and hypotheses related to the underlying mechanisms that link psychological stress and asthma activity via a neuroimmune network dysfunction that may manifest as increased morbidity of immune diseases, such as asthma.

DATA SOURCES

Literature searches of MEDLINE for published human and animal studies and review articles published in English-language periodicals. Keywords searched included individual and various combinations of psychoneuroimmunology, neuroimmune, neuroimmunology, stress, immunity, allergy, asthma, and inflammation. Both review articles and specific hypothesis-driven articles that focused on immune effects of stress were included. Manuscripts that focused on animal studies were excluded from this review.

STUDY SELECTION

Representative studies that reflect the consensus of the field based on the expert opinion of the author.

RESULTS

This article demonstrates the established relationships between the neuroendocrine and immune systems and the impact of both acute and chronic psychological stress on neuroendocrine and immune network function. The adverse impact of stress appears to occur more on immune dysregulation rather than immune suppression.

CONCLUSION

Psychological stress, allergy and asthma morbidity, and allergy and asthma incidence are all steadily increasing in our society. Establishing a firm relationship can provide a possible new therapeutic direction for evaluation and management of difficult-to-treat patients and possible prophylactic strategies in susceptible populations.

Overview of the actions of glucocorticoids on the immune response: a good model to characterize new pathways of immunosuppression for new treatment strategies

Glucocorticoids have been used for over 50 years in the treatment of inflammatory and autoimmune diseases and in preventing graft rejection. Today, knowledge of their molecular, cellular, and pharmacological properties allows a better understanding of glucocorticoid-mediated immunosuppression. Glucocorticoids exert both negative and positive effects with a dynamic and bi-directional spectrum of activities on various limbs and components of the immune response. They modulate genes involved in the priming of the innate immune response, while their actions on the adaptive immune response are to suppress cellular (Th1) immunity and promote humoral (Th2) immunity. Interestingly, glucocorticoids can also induce tolerance to specific antigens by influencing dendritic cell maturation and function and promoting the development of regulatory high IL-10-producing T cells. The ex vivo therapeutic use of glucocorticoids could therefore represent an adjuvant treatment to cell therapy in autoimmune diseases, avoiding the long-term deleterious adverse effects of glucocorticoids. Thus, the panoramic view of glucocorticoid actions on the immune system provides an interesting model for characterizing important biological pathways of immunosuppression.

Transient corticosteroid treatment permanently amplifies the Th2 response in a murine model of asthma

Corticosteroids (CS) remain the most efficacious pharmacotherapeutic option for the management of asthma. Although the acute anti-inflammatory effects of CS treatment have been amply documented both clinically and experimentally, recent human data intimate that exposure to CS may be associated with retrograde immune phenomena, including enhanced synthesis of IgE in vivo and elevated Th2 cytokine production in vitro. We have investigated the long-term immunologic effects of CS treatment in a murine model of allergic airway inflammation. CS treatment during initial exposure to OVA or upon long-term Ag rechallenge remarkably attenuated eosinophilic airway inflammation and airway hyperresponsiveness. Interestingly, however, Th2 cytokine production by cultured splenocytes from CS-treated mice was significantly elevated, while IFN-gamma synthesis was depressed. Moreover, mice rechallenged with OVA several weeks after CS intervention during allergic sensitization not only developed airway inflammation, but also exhibited enhanced Th2 cytokine production in lymphoid tissues and OVA-specific IgE in serum. This amplification of the systemic immune response was associated with an intact APC compartment during CS-conditioned sensitization to OVA. These data indicate that immune processes underlying the allergic phenotype remain impervious to CS treatment and raise the possibility that treatment with CS during sensitization may amplify elements of the allergen-specific immune response.

Behavioural endocrine immune-conditioned response is induced by taste and superantigen pairing

Administration of bacterial superantigen, such as staphylococcal enterotoxin B (SEB), induces in vivo stimulation of T cell proliferation and cytokine production such as interleukin-2 (IL-2). It has been previously reported that SEB administration induces fever, c-Fos expression in the brain, and hypothalamus-pituitary-adrenal axis activation, demonstrating that the brain is able to sense and respond to SEB. Previously it had been shown that immune functions can be behaviourally conditioned pairing a novel gustatory stimulus together with an immunomodulatory drug or an antigen. We designed an experimental protocol using Dark Agouti rats in which saccharin taste, as conditioned stimulus, was paired with an i.p. injection of SEB (2 mg/kg), as unconditioned stimulus. Six days later, when conditioned animals were re-exposed to the conditioned stimulus they displayed strong conditioned taste avoidance to the saccharin. More importantly, re-exposure to the conditioned stimulus significantly increased IL-2, interferon-gamma and corticosterone plasma levels, in comparison with conditioned animals which had not been re-exposed to saccharin taste. These results demonstrate a behavioural-immune-endocrine conditioned response using a superantigen as unconditioned stimulus. In addition, they illustrate the brain abilities to mimic the unconditioned effects of a superantigen by yet unknown mechanisms.

Stress, leukocyte trafficking, and the augmentation of skin immune function

Delayed type hypersensitivity (DTH) reactions represent cell-mediated immune responses that exert important immunoprotective (resistance to viruses, bacteria, and fungi) or immunopathologic (allergic or autoimmune hypersensitivity) effects. We have used the skin DTH response as an in vivo model to study neuro-endocrine-immune interactions. We hypothesized that just as an acute stress response prepares the cardiovascular and musculoskeletal systems for fight or flight, it may also prepare the immune system for challenges (e.g., wounding) that may be imposed by a stressor (e.g., an aggressor). Studies showed that acute (2 hours) stress experienced before primary or secondary cutaneous antigen exposure induces significantly enhanced skin DTH. This enhancement involves innate as well as adaptive immune mechanisms. Adrenalectomy eliminates the stress-induced enhancement of DTH. Acute administration of physiological concentrations of corticosterone and/or epinephrine to adrenalectomized animals enhances skin DTH. Compared with those in controls, DTH sites from acutely stressed or hormone-injected animals show significantly greater erythema and induration, numbers of infiltrating leukocytes, and levels of cytokine gene expression. In contrast to acute stress, chronic stress is immunosuppressive. Chronic exposure to corticosterone or acute exposure to dexamethasone significantly suppresses skin DTH. These results suggest that during acute stress, endogenous stress hormones enhance skin immunity by increasing leukocyte trafficking and cytokine gene expression at the site of antigen entry. Elucidation of mechanisms mediating a stress-induced enhancement of skin immune function is important because such immunoenhancement can have protective (wound healing, resistance to infection) or pathological (allergic or autoimmune hypersensitivity) consequences.

Glucocorticoids enhance interleukin-4 production to neo-antigen (hyaluronidase) in children immunocompromised with cytostatic drugs

Immunoglobulin E (IgE)-mediated immediate-type allergic reactions to hyaluronidase have been observed in children with central nervous system (CNS) tumors. Glucocorticoids, used as therapy for brain edema, are discussed controversially as T helper 2 (Th2) stimulatory factors. In this study we investigated the role of glucocorticoids on a Th2 cytokine-promoting effect in children with CNS tumors. Peripheral blood mononuclear cells (PBMCs) from: 29 children suffering from malignant brain tumors, of whom 23 received short-term glucocorticoid treatment (for 3-4 days) during the course of chemotherapy; 18 children with nephrotic syndrome or renal transplantation receiving long-term glucocorticoid treatment; and 13 healthy children, were incubated with phytohemagglutinin (PHA) and/or anti-CD28 monoclonal antibody (mAb) and, in a second approach, with hyaluronidase. The concentrations of Th cell-mediated cytokines - interleukin (IL)-4, IL-10, and interferon-gamma (IFN-gamma) - were measured in supernatants. The IL-4 production of PBMCs incubated with PHA/anti-CD28 mAb from children with repeated co-administration of glucocorticoids, hyaluronidase, and cytostatic drugs (median: 249.9 pg/ml; range: 234.4-261.7) was significantly higher (p < 0.0001) than IL-4 production of PBMC from children of all the other groups (median: 86.18; range: 16.0-212.5). There was no significant difference in the levels of IL-10 and IFN-gamma within the groups. PBMCs stimulated only with hyaluronidase failed to produce detectable levels of cytokines. The results of this study indicate that repeated co-administration of glucocorticoids and hyaluronidase (a neo-antigen) enhance IL-4 production in vitro and thus may induce the production of specific IgE antibodies in children immunocompromised with cytostatic drugs. Hyaluronidase itself does not stimulate in vitro IL-4 synthesis in PBMCs of children receiving cytostatic drugs.

Protective and curative effects of topically applied CX-659S, a novel diaminouracil derivative, on chronic picryl chloride-induced contact hypersensitivity responses

BACKGROUND

CX-659S, a newly discovered anti-inflammatory compound, exerts inhibitory effects against acute contact hypersensitivity responses (CHRs) induced by picryl chloride (PC), oxazolone and dinitrochlorobenzene. The murine model of chronic CHR induced by repeated application of PC is known to mimic many, if not all, events occurring within the lesional skin of patients with atopic dermatitis (AD).

OBJECTIVES

To investigate the ability of CX-659S to inhibit PC-induced chronic CHR in mice.

METHODS

The protective and curative effects of CX-659S were tested on PC-treated ears of BALB/c mice, and were compared with those of prednisolone. Effects were quantified by measurements of ear thickness, serum IgE and cytokine mRNA expression.

RESULTS

Both protectively applied and curatively applied CX-659S significantly inhibited increases in ear thickness and total serum IgE. Inhibition was dose-dependent. Although protectively applied prednisolone showed similar activities to CX-659S against chronic CHR, curatively applied prednisolone did not affect the serum IgE level despite inhibiting increases in ear thickness and inflammatory cell infiltration. Consistent with these results, CX-659S reduced mRNA expression of interleukin (IL)-4 and IL-10 but not of interferon (IFN)-gamma, whereas prednisolone inhibited not only mRNA expression of IL-4 and IL-10 but also that of IFN-gamma in the ear lesion. In contrast to prednisolone, CX-659S did not show any side-effect such as atrophy, alopecia or telangiectasia.

CONCLUSIONS

CX-659S is the first promising compound having inhibitory activities against chronic CHR accompanied by a diminishing effect on elevated serum IgE, without any other side-effect. Therefore, CX-659S may be a promising candidate for management of patients with recurring AD who require long-term therapy.

Antinuclear autoantibodies (ANA) in Gulf War-related illness and chronic fatigue syndrome (CFS) patients

It is established that veterans of the 1991 Gulf War have an increased frequency of experiencing multiple symptoms. The underlying mechanism of these ailments is unclear, although they do not correspond to any clearly defined syndrome. The most common symptoms overlap with those of chronic fatigue syndrome (CFS). CFS was recently associated with a novel subtype of antinuclear autoantibody (ANA) that reacts with nuclear envelope (NE) antigens. NE autoantibodies are not known to be linked with any distinct clinical condition, but have been observed in patients with unusual mixed chronic autoimmune disorders and connective tissue diseases. In this study we examined whether NE ANAs are a feature of patients with CFS and symptomatic Gulf War veterans (sGWV). We studied the prevalence of ANA in 130 sGWV, 90 well Gulf War veterans (wGWV), 128 symptomatic Bosnia and Era veterans (sBEV), 100 CFS patients, and 111 healthy control subjects matching for age and sex. We found no significant difference in the prevalence of ANAs between any of the groups. None of the patients/or veterans we studied had ANA of the NE type. Our results show that multisymptom illness due to CFS or related to Gulf War service is not associated with antinuclear autoimmunity.

Annexin 1 (lipocortin 1) mimics inhibitory effects of glucocorticoids on testosterone secretion and enhances effects of interleukin-1beta

Annexin 1 is an important mediator of glucocorticoid action in the hypothalamo-pituitary axis; however, little is known of its role in mediating glucocorticoid actions in the peripheral endocrine organs. Accordingly, we have carried out a preliminary study to investigate the effects of annexin 1 in vitro on the testicular secretion of testosterone, a process inhibited by both glucocorticoids and interleukin-1beta (IL-1beta). Luteinizing hormone (LH) and forskolin stimulated the release of testosterone from dispersed murine testicular cells in vitro. Their effects were reduced in cells from mice pretreated with dexamethasone (DEX). Similarly, preincubation of testicular cells from untreated mice with DEX, corticosterone, or 11-dehydrocorticosterone reduced LH-stimulated testosterone release, as did the 11beta-hydroxysteroid dehydrogenase inhibitors, glycyrrhetinic acid and carbenoxolone. The inhibitory actions of the steroids were mimicked by annexin 1(1-188) (ANXA1(1-188)) (a stable annexin 1 analog). IL-1beta produced a marked decrease in the response to LH, which was blocked by indomethacin, a nonselective cyclooxygenase inhibitor and an additive effect with DEX and ANXA1(1-188). These results confirm reports that glucocorticoids and IL-1beta inhibit LH-stimulated testosterone release from mouse testicular cells. They also show, for the first time, that the effects of the steroids are mimicked by annexin 1 and that, in contrast to their mutually antagonistic effects in the neuroendocrine system, IL-1beta and annexin 1 exert additive actions in the testis.

Corticosteroid inhibits IL-4 signaling through down-regulation of IL-4 receptor and STAT6 activity

Corticosteroids are potent anti-inflammatory and immunosuppressive agents which down-regulate cytokine production and action. Yet, contradictory results have been reported for their effects on the interleukin (IL)-4-mediated response. Using type II Fc receptor for IgE/CD23 as a target gene, here we report that corticosteroids at 10(-4)-10(-6) M inhibit the IL-4 signaling pathway in human primary immune cells by down-regulation of the IL-4-induced IL-4 receptor expression and STAT6 activation. Although functional antagonism between steroid receptor and STAT6 for their transcriptional activity has been recently described, this is the first report that steroid inhibits the IL-4-induced STAT6 activity at the level of tyrosine phosphorylation and target DNA binding.

Molecular mechanisms of immunomodulatory activity of glucocorticoids

The development and function of cells in the immune system are regulated by many intrinsic and extrinsic factors. One class of molecule that affects immune cells belongs to the neuroendocrine system and the best-studied mediators in this category are glucocorticoids. These are small lypophilic molecules that participate in a wide number of normal and pathologic processes. This paper concentrates on their physiologic and pharmacologic effects on the immune response.

Gene profiling reveals unknown enhancing and suppressive actions of glucocorticoids on immune cells

Glucocorticoids continue to be the major immunomodulatory agents used in clinical medicine today. However, their actions as anti-inflammatory and immunosuppressive drugs are both beneficial and deleterious. We analyzed the effect of glucocorticoids on the gene expression profile of peripheral blood mononuclear cells from healthy donors. DNA microarray analysis combined with quantitative TaqMan PCR and flow cytometry revealed that glucocorticoids induced the expression of chemokine, cytokine, and complement family members as well as of newly discovered innate immune-related genes, including scavenger and Toll-like receptors. In contrast, glucocorticoids repressed the expression of adaptive immune-related genes. Simultaneous inhibitory and stimulatory effects of glucocorticoids were found on inflammatory T helper subsets and apoptosis-related gene clusters. In cells activated by T cell receptor cross-linking, glucocorticoids down-regulated the expression of specific genes that were previously up-regulated in resting cells, suggesting a potential new mechanism by which they exert positive and negative effects. Considering the broad and continuously renewed interest in glucocorticoid therapy, the profiles we describe here will be useful in designing more specific and efficient treatment strategies.

Medroxyprogesterone acetate enhances in vivo and in vitro antibody production

In the present study we examine the effects of medroxyprogesterone acetate (MPA) on the specific antibody secretion to T-dependent antigens. Our results show that the in vivo administration of MPA to mice, 7 or 90 days before immunization with sheep red blood cells (SRBC), significantly enhanced both, primary and secondary antibody responses, without affecting delayed-type hypersensitivity (DTH). These effects could be counteracted by the anti-progestin onapristone or ZK 98299 (ZK) suggesting that MPA interacted with progesterone (PRG) receptors to increase B-cell response. To better understand the mechanisms involved in MPA activity we carried out cultures of splenocytes, bone marrow cells or lymph node cells from immunized mice in the presence of MPA, and evaluated the amount of antibody release to supernatants. We found that low doses of MPA (10(-9) M and 10(-10) M) significantly enhanced the in vitro production of specific immunoglobulin G (IgG) antibodies, an effect that appears to involve the interaction of the progestin with PRG receptors, as judged by the inhibition of MPA effects with ZK (10(-8) M) or RU486 (10(-9) M). These receptors were detected by flow cytometry analysis in a proportion of T lymphocytes. Because MPA did not increase the number of immunoglobulin-secreting cells, our findings suggest that MPA enhanced the capacity of individual cells to produce specific immunoglobulin.

Towards a unified model of neuroendocrine-immune interaction

Although the neuroendocrine system has immunomodulating potential, studies examining the relationship between stress, immunity and infection have, until recently, largely been the preserve of behavioural psychologists. Over the last decade, however, immunologists have begun to increasingly appreciate that neuroendocrine-immune interactions hold the key to understanding the complex behaviour of the immune system in vivo. The nervous, endocrine and immune systems communicate bidirectionally via shared messenger molecules variously called neurotransmitters, cytokines or hormones. Their classification as neurotransmitters, cytokines or hormones is more serendipity than a true reflection of their sphere of influence. Rather than these systems being discrete entities we would propose that they constitute, in reality, a single higher-order entity. This paper reviews current knowledge of neuroendocrine-immune interaction and uses the example of T-cell subset differentiation to show the previously under-appreciated importance of neuroendocrine influences in the regulation of immune function and, in particular, Th1/Th2 balance and diurnal variation there of.

Immediate and longterm effects of immune stimulation: hypothesis linking the immune response to subsequent physical and psychological wellbeing

We hypothesize that antigenic stimuli in susceptible persons during key developmental life stages alters neuroendocrine-immune organization and leads to the development of aberrant immune and neuroendocrine responses to subsequent environmental stressors, with longterm physical and psychological consequences. The release of interleukin-1beta (IL-1beta) and other proinflammatory cytokines associated with the immune response during times when individuals are most vulnerable to the effects of environmental influences activates the hypothalamic-pituitary-adrenal (HPA) axis and leads to maladaptive responses to subsequent stressors. The primed HPA axis is reactivated by proinflammatory cytokines, resulting in the secretion of corticotropin-releasing hormone (CRH) and cortisol, followed by physical and psychological effects that feedback on the HPA axis to produce an array of outcomes affecting general wellbeing. Through the release of histamine and other mediators and their effects on the mast cell-leukocyte cytokine cascade, immune stimuli in susceptible persons increase allergic inflammation and magnify stressors' effects through the release of HPA-axis-activating cytokines, such as IL-1beta, that drive the axis and reinforce the physiological and behavioral effects. Thus, specific proinflammatory cytokines and allergic reactions initiate, promote, and maintain immune-stimulus-associated HPA axis activity, and with CRH and cortisol, participate in a positive feedback loop, resulting in aberrant, maladaptive responses to physical or psychological stressors, with outcomes such as depression, hyperalgesia, and pain-related behavior.

Immunoendocrinologic abnormalities in human immunodeficiency virus infection

Alterations in the production of adrenal steroids and a complex pattern of dysregulation in cytokine profiles accompany the progression of HIV infection. Cortisol levels increase in HIV infection, while those of dehydroepiandrosterone (DHEA), a physiologic antagonist of the immunoregulatory activities of cortisol, decrease. A shift from type-1 to type-2 cytokine production is also detected in most patients during disease progression. This shift is summarized as a defective production of interferon gamma (IFN gamma), interleukin-2 (IL), and IL-12 accompained by increased production of IL-4, IL-5, IL-6, and IL-10. IFN gamma and IL-2 are suppressed, while the generation of IL-4 is stimulated by cortisol and pharmacological doses of glucocorticoids (GC). GC and IL-4 stimulate the differentiation of B lymphocytes into IgE-producing plasma cells, the concentration of which augments in HIV infection. Finally, GC induces programmed cell death (PCD) in a variety of different cells, including mature T lymphocytes. Because (1) TH1 but not TH2 undergo rapid Fas-mediated PCD upon antigen-stimulation, and (2) TH2 clones preferentially survive in vitro cell cultures, the progressive shift from type-1 to type-2 cytokine production observed in HIV infection could be at least partially provoked by the increase in the production of cortisol and the reduction of DHEA. Progression of HIV infection to AIDS can be controlled by highly active antiretroviral therapy (HAART); HAART drastically reduces HIV plasma viremia, but is less effective in immune reconstitution. Additionally HAART is associated in a sizable portion of patients by complex lypodistropyc phenomena that often involve the endocrine system.

Altered glucocorticoid regulation of the immune response in the chronic fatigue syndrome

It is increasingly recognized that glucocortiocoids (GCs) can have subtle modulatory effects in immunoregulation rather than having generalized immunosuppressive effects. GCs suppress Th1 cells and cellular immunity, but may favor Th2 responses and humoral immunity. The chronic fatigue syndrome (CFS) appears to be associated with a disturbed HPA-axis. Moreover, CFS patients show several immunological changes suggestive of decreased cellular immunity. It is postulated herein that in CFS patients a decreased Th1/Th2 balance may be the result of selective effects of GC on the IL-10/IL-12 regulatory circuit.

Regulation of allergic airways inflammation by cytokines and glucocorticoids

Cytokines mediate the allergic inflammatory response of the airways, and glucocorticosteroids ameliorate allergy symptoms by regulating cytokine expression. Recent studies provide insight into the manner by which cytokines work together to mediate allergic airway disease. Real progress has also been gained in our understanding of subcellular mechanisms of allergic inflammation, particularly the role of transcription factors in regulating the expression of specific cytokine profiles and the differentiation of the TH2 subset. This article provides an update of recently reported findings in this field and highlights emerging concepts of allergic inflammation.