Clinical consequences of targeting IL-17 and TH17 in autoimmune and allergic disorders

Effect of sublingual immunotherapy on clinical and laboratory autoimmunity

Background: There still are few data on the long-term safety of sublingual immunotherapy (SLIT). The aim of this study was to assess the appearance of autoimmune diseases in patients before and after SLIT. Materials & methods: New cases of autoimmune diseases were monitored. Patients in the SLIT group (n = 816) were compared with controls (n = 1096). Results: The new incidences of autoimmune diseases in the SLIT group were lower compared with the control group: 18 (2.2%) versus 58 (5.3%); p < 0.05. Systemic lupus erythematosus, psoriasis and Hashimoto appeared much more often in the control group. Conclusion: SLIT had no significant effect on the induction of autoimmune diseases.

1,25-dihydroxyvitamin D3 ameliorates lupus nephritis through inhibiting the NF-κB and MAPK signalling pathways in MRL/lpr mice

Background

Lupus nephritis (LN) is a common and serious complication of systemic lupus erythematosus (SLE). However, the aetiology and pathogenesis of LN remain unknown. 1,25-dihydroxyvitamin D3 [1,25-(OH)2-VitD3] is the active form of vitamin D, and it has been shown to perform important functions in inflammatory and immune-related diseases. In this study, we investigated the time-dependent effects of 1,25-dihydroxyvitamin D3 and explored the underlying mechanism in MRL/lpr mice, a well-studied animal model of LN.

Methods

Beginning at 8 weeks of age, 24-h urine samples were collected weekly to measure the levels of protein in the urine. We treated female MRL/lpr mice with 1,25-dihydroxyvitamin D3 (4 μg/kg) or 1% DMSO by intraperitoneal injection twice weekly for 3 weeks beginning at the age of 11 weeks. The mice were separately sacrificed, and serum and kidney samples were collected at the ages of 14, 16, 18, and 20 weeks to measure creatinine (Cr) levels, blood urea nitrogen (BUN) levels, histological damage, immunological marker (A-ds DNA, C1q, C3, IgG, IgM) levels, and inflammatory factor (TNF-α, IL-17, MCP-1) levels. Furthermore, the nuclear factor kappa B (NF-κB) and the mitogen-activated protein kinase (MAPK) signalling pathways were also assessed to elucidate the underlying mechanism.

Results

We found that MRL/lpr mice treated with 1,25-dihydroxyvitamin D3 displayed significantly attenuated LN. VitD3-treated mice exhibited significantly improved renal pathological damage and reduced proteinuria, BUN, SCr, A-ds DNA antibody and immune complex deposition levels (P < 0.05) compared with untreated MRL/lpr mice. Moreover, 1,25-dihydroxyvitamin D3 inhibited the complement cascade, inhibited the release of proinflammatory cytokines, such as TNF-α, IL-17, and MCP-1, and inhibited NF-κB and MAPK activation (P < 0.05).

Conclusion

1,25-dihydroxyvitamin D3 exerts a protective effect against LN by inhibiting the NF-κB and MAPK signalling pathways, providing a potential treatment strategy for LN. Interestingly, the NF-κB and MAPK signalling pathways are time-dependent mediators of LN and may be associated with lupus activity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02870-z.

Role of Th17 Cytokines in Airway Remodeling in Asthma and Therapy Perspectives

Airway remodeling is a frequent pathological feature of severe asthma leading to permanent airway obstruction in up to 50% of cases and to respiratory disability. Although structural changes related to airway remodeling are well-characterized, immunological processes triggering and maintaining this phenomenon are still poorly understood. As a consequence, no biotherapy targeting cytokines are currently efficient to treat airway remodeling and only bronchial thermoplasty may have an effect on bronchial nerves and smooth muscles with uncertain clinical relevance. Th17 cytokines, including interleukin (IL)-17 and IL-22, play a role in neutrophilic inflammation in severe asthma and may be involved in airway remodeling. Indeed, IL-17 is increased in sputum from severe asthmatic patients, induces the expression of "profibrotic" cytokines by epithelial, endothelial cells and fibroblasts, and provokes human airway smooth muscle cell migration in in vitro studies. IL-22 is also increased in asthmatic samples, promotes myofibroblast differentiation, epithelial-mesenchymal transition and proliferation and migration of smooth muscle cells in vitro. Accordingly, we also found high levels of IL-17 and IL-22 in a mouse model of dog-allergen induced asthma characterized by a strong airway remodeling. Clinical trials found no effect of therapy targeting IL-17 in an unselected population of asthmatic patients but showed a potential benefit in a sub-population of patients exhibiting a high level of airway reversibility, suggesting a potential role on airway remodeling. Anti-IL-22 therapies have not been evaluated in asthma yet but were demonstrated efficient in severe atopic dermatitis including an effect on skin remodeling. In this review, we will address the role of Th17 cytokines in airway remodeling through data from in vitro, in vivo and translational studies, and examine the potential place of Th17-targeting therapies in the treatment of asthma with airway remodeling.

Interleukin-17-A multifaceted cytokine in viral infections

Viral infections are a major threat to the human population due to the lack of selective therapeutic measures. The morbidity and mortality reported worldwide are very alarming against viral pathogens. The proinflammatory environment is required for viral inhibition by initiating the host immune response. The host immune response fights these pathogens by secreting different cytokines. Interleukin-17 (IL-17) a proinflammatory cytokine mainly produced by T helper type 17 cells, plays a vital role in the regulation of host immune response against various pathogens, including viruses. However, dysregulated production of IL-17 induces chronic inflammation, autoimmune disorders, and may lead to cancer. Recent studies suggest that IL-17 is not only involved in the antiviral immune response but also promotes virus-mediated illnesses. In this review, we discuss the protective and pathogenic role of IL-17 against various viral infections. A detailed understanding of IL-17 during viral infections could contribute to improve therapeutic measures and enable the development of an efficient and safe IL-17 based immunotherapy.

Role of interleukin-17 in human papillomavirus infection and associated malignancies

Human papillomavirus infection is among the leading viral infections in the world, causing severe mortality and morbidity. The virus mainly targets the female genital tract-cervix, vulva, anus but it is also reported to infect the lungs and oropharyngeal region of the body. The host immune response plays a vital role in the persistence of viral infection. Interleukin 17 (IL-17) is mainly secreted by Th17 cells and mediates the immune response that enhances the disease severity in HPV infection. IL-17 is reported to promote lesions and tumour progression by creating a hyperinflammatory condition leading to cancer. The current minireview summarizes the pathogenic role of IL-17 in HPV infection and HPV-induced malignancies. Further study on IL-17 associated pathology of HPV infection would be useful in developing therapeutic measures.

Immune regulations by 14-3-3: A misty terrain

The 14-3-3 proteins are known for their functions related to the cell cycle and play a prominent role in cancer-related diseases. Recent studies show that 14-3-3 proteins are also regulators of immune responses and are involved in the pathogenesis of autoimmune and infectious diseases. This focused review highlights the significant and recent studies on how 14-3-3 proteins influence innate and adaptive immune responses; specifically, their roles as immunogens and cytokine signaling regulators are discussed. These revelations have added numerous questions to the pre-existing list of challenges, including understanding the 14-3-3 proteins' mechanism of immunogenicity to dissecting the isoform-specific immune regulations.

Coxiella burnetii Whole Cell Vaccine Produces a Th1 Delayed-Type Hypersensitivity Response in a Novel Sensitized Mouse Model

Q-VAX®, a whole cell, formalin-inactivated vaccine, is the only vaccine licensed for human use to protect against Coxiella burnetii, the cause of Q fever. Although this vaccine provides long-term protection, local and systemic reactogenic responses are common in previously sensitized individuals which prevents its use outside of Australia. Despite the importance of preventing these adverse reactions to develop widely accepted, novel vaccines against C. burnetii, little is understood about the underlying cellular mechanisms. This is mostly attributed to the use of a guinea pig reactogenicity model where complex cellular analysis is limited. To address this, we compared three different mouse strains develop a model of C. burnetii whole cell vaccine reactogenic responses. SKH1 and C57Bl/6, but not BALBc mice, develop local granulomatous reactions after either infection- or vaccine-induced sensitization. We evaluated local and systemic responses by measuring T cell populations from the vaccination site and spleen during elicitation using flow cytometry. Local reaction sites showed influx of IFNγ+ and IL17a+ CD4 T cells in sensitized mice compared with controls and a reduction in IL4+ CD4 T cells. Additionally, sensitized mice showed a systemic response to elicitation by an increase in IFNγ+ and IL17a+ CD4 T cells in the spleen. These results indicate that local and systemic C. burnetii reactogenic responses are consistent with a Th1 delayed-type hypersensitivity. Our experiments provide insights into the pathophysiology of C. burnetii whole cell vaccine reactogenicity and demonstrate that C57Bl/6 and SKH1 mice can provide a valuable model for evaluating the reactogenicity of novel C. burnetii vaccine candidates.

The Effects of Maternal Smoking on Pregnancy and Offspring: Possible Role for EGF?

Cigarette smoke exposure during pregnancy and lactation is associated with adverse pregnancy outcomes. Here, we investigated the effects of maternal smoke exposure on pregnancy and offspring immunity and explored whether, epidermal growth factor (EGF), an important growth-promoting factor in human colostrum and milk, might be a possible missing link in maternal smoke exposure and changes in infants’ immune responses. Pregnant BALB/c mice were exposed to either cigarette smoke or air during gestation and lactation, and effects on pulmonary inflammation in dams and immune responses in offspring were examined. Maternal smoke exposure increased airway hyperresponsiveness and accumulation of inflammatory cells in the lungs of pregnant dams compared to non-pregnant dams. The E-cadherin protein expression was reduced in mammary glands of cigarette smoke-exposed pregnant dams. EGF levels were higher in mammary glands and serum of smoke-exposed pregnant dams compared to air-exposed pregnant dams. Offspring from cigarette smoke-exposed dams exhibited elevated levels of IL-17A, MCP-1, IL-22, and IL-13 in anti-CD3 stimulated spleen cell culture supernatants. EGF levels were also increased in serum of offspring from smoke-exposed dams. A positive correlation was observed between serum EGF levels and neutrophil numbers in bronchoalveolar lavage fluid of the dams. Interestingly, IL-17A, MCP-1, IL-22, IL13, and IFN-γ levels in anti-CD3 stimulated spleen cell culture supernatants of male pups also showed a positive correlation with EGF serum levels. In summary, our results reveal that maternal smoke exposure predisposes dams to exacerbated airway inflammation and offspring to exacerbated immune responses and both phenomena are associated with elevated EGF concentrations.

Oxidative Imbalance as a Crucial Factor in Inflammatory Lung Diseases: Could Antioxidant Treatment Constitute a New Therapeutic Strategy?

Inflammatory lung disease results in a high global burden of death and disability. There are no effective treatments for the most severe forms of many inflammatory lung diseases, such as chronic obstructive pulmonary disease, emphysema, corticosteroid-resistant asthma, and coronavirus disease 2019; hence, new treatment options are required. Here, we review the role of oxidative imbalance in the development of difficult-to-treat inflammatory lung diseases. The inflammation-induced overproduction of reactive oxygen species (ROS) means that endogenous antioxidants may not be sufficient to prevent oxidative damage, resulting in an oxidative imbalance in the lung. In turn, intracellular signaling events trigger the production of proinflammatory mediators that perpetuate and aggravate the inflammatory response and may lead to tissue damage. The production of high levels of ROS in inflammatory lung diseases can induce the phosphorylation of mitogen-activated protein kinases, the inactivation of phosphoinositide 3-kinase (PI3K) signaling and histone deacetylase 2, a decrease in glucocorticoid binding to its receptor, and thus resistance to glucocorticoid treatment. Hence, antioxidant treatment might be a therapeutic option for inflammatory lung diseases. Preclinical studies have shown that antioxidants (alone or combined with anti-inflammatory drugs) are effective in the treatment of inflammatory lung diseases, although the clinical evidence of efficacy is weaker. Despite the high level of evidence for the efficacy of antioxidants in the treatment of inflammatory lung diseases, the discovery and clinical investigation of safer, more efficacious compounds are now a priority.

RhoA and Cdc42 in T cells: Are they targetable for T cell-mediated inflammatory diseases?

Many inflammatory diseases are not curable, necessitating a better understanding of their pathobiology that may help identify novel biological targets. RhoA and Cdc42 of Rho family small GTPases regulate a variety of cellular functions such as actin cytoskeletal organization, cell adhesion, migration, proliferation, and survival. Recent characterization of mouse models of conditional gene knockout of RhoA and Cdc42 has revealed their physiological and cell type-specific roles in a number of cell types. In T lymphocytes, which play an important role in the pathogenesis of most, if not all, of the inflammatory diseases, we and others have investigated the effects of T cell-specific knockout of RhoA and Cdc42 on T cell development in the thymus, peripheral T cell homeostasis, activation, and differentiation to effector and regulatory T cells, and on T cell-mediated allergic airway inflammation and colitis. Here we highlight the phenotypes resulting from RhoA and Cdc42 deletion in T cells and discuss whether pharmacological targeting of RhoA and Cdc42 is feasible in treating asthma that is driven by allergic airway inflammation and colitis.

14-3-3ζ-TRAF5 axis governs interleukin-17A signaling

IL-17A is a therapeutic target in many autoimmune diseases. Most nonhematopoietic cells express IL-17A receptors and respond to extracellular IL-17A by inducing proinflammatory cytokines. The IL-17A signal transduction triggers two broad, TRAF6- and TRAF5-dependent, intracellular signaling pathways to produce representative cytokines (IL-6) and chemokines (CXCL-1), respectively. Our limited understanding of the cross-talk between these two branches has generated a crucial gap of knowledge, leading to therapeutics indiscriminately blocking IL-17A and global inhibition of its target genes. In previous work, we discovered an elevated expression of 14-3-3 proteins in inflammatory aortic disease, a rare human autoimmune disorder with increased levels of IL-17A. Here we report that 14-3-3ζ is essential for IL-17 signaling by differentially regulating the signal-induced IL-6 and CXCL-1. Using genetically manipulated human and mouse cells, and ex vivo and in vivo rat models, we uncovered a function of 14-3-3ζ. As a part of the molecular mechanism, we show that 14-3-3ζ interacts with several TRAF proteins; in particular, its interaction with TRAF5 and TRAF6 is increased in the presence of IL-17A. In contrast to TRAF6, we found TRAF5 to be an endogenous suppressor of IL-17A-induced IL-6 production, an effect countered by 14-3-3ζ. Furthermore, we observed that 14-3-3ζ interaction with TRAF proteins is required for the IL-17A-induced IL-6 levels. Together, our results show that 14-3-3ζ is an essential component of IL-17A signaling and IL-6 production, an effect that is suppressed by TRAF5. To the best of our knowledge, this report of the 14-3-3ζ-TRAF5 axis, which differentially regulates IL-17A-induced IL-6 and CXCL-1 production, is unique.

CIP2A Constrains Th17 Differentiation by Modulating STAT3 Signaling

Cancerous Inhibitor of Protein Phosphatase 2A (CIP2A) is an oncogene and a potential cancer therapy target protein. Accordingly, a better understanding of the physiological function of CIP2A, especially in the context of immune cells, is a prerequisite for its exploitation in cancer therapy. Here, we report that CIP2A negatively regulates interleukin (IL)-17 production by Th17 cells in human and mouse. Interestingly, concomitant with increased IL-17 production, CIP2A-deficient Th17 cells had increased strength and duration of STAT3 phosphorylation. We analyzed the interactome of phosphorylated STAT3 in CIP2A-deficient and CIP2A-sufficient Th17 cells and indicated together with genome-wide gene expression profiling, a role of Acylglycerol Kinase (AGK) in the regulation of Th17 differentiation by CIP2A. We demonstrated that CIP2A regulates the strength of the interaction between AGK and STAT3, and thereby modulates STAT3 phosphorylation and expression of IL-17 in Th17 cells.

Increase in IL-17-positive cells in sinonasal inverted papilloma

OBJECTIVE

Neutrophil infiltration in patients with sinonasal inverted papilloma (SNIP) is significantly high. Whether IL-17, which is a potent factor mediating neutrophilic inflammation, is involved in the neutrophilic phenotype of SNIP is investigated in the current study.

STUDY DESIGN

Laboratorial study.

PARTICIPANTS

Nasal papilloma and inferior turbinate were collected from patients with SNIP (n = 50) and control subjects with septal deviation (n = 15).

METHODS

IL-17 + cells were evaluated in tissues obtained from patients with SNIP and control subjects with septal deviation, by immunohistochemistry and flow cytometry.

MAIN OUTCOME MEASURES

The IL-17 + cells were mainly localised in mononuclear cells and neutrophils, and were up-regulated in the SNIP samples compared with those in the controls. The IL-17 + T-cell subsets mainly included CD4+ (Th17, 60.0%) and CD8+ (Tc17, 30.0%), and both subsets were enhanced in the SNIP samples than controls. The total level of IL-17 + cells was significantly correlated with neutrophil infiltration in the SNIP tissues. Furthermore, the SNIP homogenates could significantly promote IL-17 production in peripheral blood mononuclear cells.

CONCLUSIONS

An increase in IL-17 + cells is evident in SNIP and may be involved in neutrophil infiltration in local tissues. IL-17 could be a potential therapeutic target to relieve the neutrophilic pathological change in SNIP.

Asthma biomarkers in the age of biologics

The heterogeneous nature of asthma has been understood for decades, but the precise categorization of asthma has taken on new clinical importance in the era of specific biologic therapy. The simple categories of allergic and non-allergic asthma have given way to more precise phenotypes that hint at underlying biologic mechanisms of variable airflow limitation and airways inflammation. Understanding these mechanisms is of particular importance for the approximately 10% of patients with severe asthma. Biomarkers that aid in phenotyping allow physicians to "personalize" treatment with targeted biologic agents. Unfortunately, testing for these biomarkers is not routine in patients whose asthma is refractory to standard therapy. Scientific advances in the recognition of sensitive and specific biomarkers are steadily outpacing the clinical availability of reliable and non-invasive assessment methods designed for the prompt and specific diagnosis, classification, treatment, and monitoring of severe asthma patients. This article provides a practical overview of current biomarkers and testing methods for prompt, effective management of patients with severe asthma that is refractory to standard therapy.

The Th17 Lineage: From Barrier Surfaces Homeostasis to Autoimmunity, Cancer, and HIV-1 Pathogenesis

The T helper 17 (Th17) cells represent a subset of CD4+ T-cells with unique effector functions, developmental plasticity, and stem-cell features. Th17 cells bridge innate and adaptive immunity against fungal and bacterial infections at skin and mucosal barrier surfaces. Although Th17 cells have been extensively studied in the context of autoimmunity, their role in various other pathologies is underexplored and remains an area of open investigation. This review summarizes the history of Th17 cell discovery and the current knowledge relative to the beneficial role of Th17 cells in maintaining mucosal immunity homeostasis. We further discuss the concept of Th17 pathogenicity in the context of autoimmunity, cancer, and HIV infection, and we review the most recent discoveries on molecular mechanisms regulating HIV replication/persistence in pathogenic Th17 cells. Finally, we stress the need for novel fundamental research discovery-based Th17-specific therapeutic interventions to treat pathogenic conditions associated with Th17 abnormalities, including HIV infection.

The relationship between autoimmunity and specific immunotherapy for allergic diseases

The aim of this study was to perform a 20-year post-specific immunotherapy (SIT) observational evaluation for an assessment of any manifestations of autoimmune disease or the appearance of autoantibodies in serum. In total, 1,888 patients (902 women and 986 men) were observed. The mean age of the patients was 34.1 ± 12.4 y at the start of the prospective observation after finishing SIT. New incidences of autoimmune disease and/or the presence of autoantibodies in serum were monitored. The SIT group was compared with control groups consisting of allergic patients who had very received SIT and with non-allergic subjects. There were no significant differences in the autoimmune disease prevalence between the allergic patients with or without SIT. However, significantly higher prevalence of 4 different autoimmune diseases (AID) were observed in the non-allergic patients during the same period. Additionally, the incidence of 8 different autoantibodies was significantly higher in non-allergic patients than in control subjects. Hashimoto disease was the most common autoimmune disease observed. The results of this long-term observational study indicated a lack of a significant prevalence of new instances of autoimmune disease during 20 y of observation post-SIT and at a rate lower than that of non-allergic control subjects, suggesting that SIT is safe in this regard in the long term.

Dose-Dependent Suppression of Cytokine production from T cells by a Novel Phosphoinositide 3-Kinase Delta Inhibitor

There remains a significant need for development of effective small molecules that can inhibit cytokine-mediated inflammation. Phosphoinositide 3 kinase (PI3K) is a direct upstream activator of AKT, and plays a critical role in multiple cell signaling pathways, cell cycle progression, and cell growth, and PI3K inhibitors have been approved or are in clinical development. We examined novel PI3Kdelta inhibitors, which are highly selective for the p110delta isoform of in CD3/CD28 stimulated T-cell cytokine production. In vitro generated CD4+ T effector cells stimulated in the presence of a PI3Kdelta inhibitor demonstrated a dose-dependent suppression of cytokines produced by Th1, Th2, and Th17 cells. This effect was T-cell intrinsic, and we observed similar effects on human PBMCs. Th17 cells expressing a constitutively activated form of AKT were resistant to PI3Kdelta inhibition, suggesting that the inhibitor is acting through AKT signaling pathways. Additionally, PI3Kdelta inhibition decreased IL-17 production in vivo and decreased neutrophil recruitment to the lung in a murine model of acute pulmonary inflammation. These experiments show that targeting PI3Kdelta activity can modulate T-cell cytokine production and reduce inflammation in vivo, suggesting that PI3Kdelta inhibition could have therapeutic potential in treating inflammatory diseases.

Targeting Th17 Effector Cytokines for the Treatment of Autoimmune Diseases

Interleukin (IL)-17-producing T cells, especially T helper (Th)17 cells, play a critical role in the pathogenesis of a variety of autoimmune inflammatory diseases. The pathogenic function of Th17 cells results from their production of Th17 effector cytokines, namely IL-17 (or IL-17A), IL-17F, IL-22 and IL-26. The importance of IL-17 has been demonstrated by antibody neutralization studies in both animal models of autoimmune diseases as well as in human clinical trials. This review highlights the current knowledge of the clinical aspects of the Th17 cytokines as well as therapeutic antibodies against IL-17, IL-17F, IL-17 receptor, IL-22, IL-26 and granulocyte macrophage colony-stimulating factor for the future treatment of autoimmune inflammatory diseases.

Inhibition of phosphoinositide 3-kinase delta attenuates experimental autoimmune encephalomyelitis in mice

The phosphoinositide 3-kinase delta (PI3Kδ) has been implicated in multiple signaling pathways involved in autoimmune diseases. We here aimed to test the hypothesis that selective inhibition of PI3Kδ may promote anti-inflammatory effects by inhibiting Th1 and Th17 cells. We investigated the therapeutic efficacy of a selective PI3Kδ inhibitor IC87114 in experimental autoimmune encephalomyelitis (EAE), a murine model of multiple sclerosis (MS). The efficacy was evaluated based on clinical scores, histopathology, serum cytokines and inflammatory infiltrations in the central nervous system (CNS). Treatment of EAE mice with IC87114 reduced the clinical symptoms, histopathology and cellular infiltration into the CNS. And treatment of EAE with IC87114 suppressed the Th1 and Th17 cell ratios. Consistently, the serum levels of IL-1β, IL-6, IL-17 and INF-γ were markedly reduced by IC87114. Taken together, our studies demonstrate that inhibition of PI3Kδ may serve as novel therapy to suppress neuroinflammation seen during EAE.

Atopy in children with the enthesitis-related arthritis (ERA) subtype of juvenile idiopathic arthritis is associated with a worse outcome

We aimed to assess the influence of co-existing atopy on the prognosis of enthesitis-related arthritis (ERA). Patients diagnosed with ERA between March 2006 and August 2012 were enrolled in a prospective cohort study and followed for 2 years. Management of patients was evaluated using the American College of Rheumatology (ACR) pediatric (Pedi) 30/50/70 criteria and laboratory variables. A total of 151 ERA patients were enrolled at diagnosis and were divided into those with atopy (n = 62) and those without (n = 89). When compared with the non-atopic group, atopic patients had significantly more active joints at disease onset (4.72 vs. 3.75), more joints with limitation of motion (LOM) (1.45 vs. 0.87), more painful joints (3.61 vs. 2.80), and more swollen joints (1.02 vs. 0.69) (p < 0.05 for all comparisons). At 3, 6, 12, 18, and 24 months, fewer ERA patients with atopy reached the ACR Pedi 50 and 70 criteria (at 3 months, 25.8 vs. 60.7 % and 11.3 vs. 34.8 %, respectively; at 6 months, 50 vs. 77.5 % and 22.6 vs. 58.4 %, respectively; at 12 months, 53.2 vs. 70.8 % and 33.9 vs. 55.1 %, respectively; at 18 months, 62.9 vs. 86.5 % and 56.5 vs. 78.7 %, respectively; at 24 months, 66.1 vs. 89.9 % and 61.3 vs. 78.7 %, respectively; all p < 0.05). During the 2 years of follow-up, the number of flares was significantly higher in ERA patients with co-existing atopy (1.48 vs. 0.70, p < 0.05).

CONCLUSION

Co-existing atopy in children with ERA may exert an adverse influence on ERA, with atopic patients manifesting more active disease at diagnosis and poorer outcome. \

Immunobiology of the critical asthma syndrome

It is now recognized that asthma incorporates a broad spectrum of syndromes with varying clinical manifestations. Future improvements in asthma treatment will require a clear characterization of these asthma phenotypes and the cellular mechanisms underlying these clinical manifestations. Herein, we will describe the current knowledge of asthma biology. This will include a review of the early pioneers in asthma and allergy, how this work led to our understanding of TH1 and TH2 cytokines, and the development of the "hygiene hypothesis." We will discuss the utility and limitations of the TH1-TH2 model of asthma in animal and human studies, and how this knowledge addresses controversies surrounding the hygiene hypothesis and other competing models. We will discuss novel therapies that have been developed based on mechanistic understanding of asthma pathobiology, including successes and shortcomings of these therapies. We will review the early work that led to the recognition of "asthma phenotypes." This will include the early discovery of various inflammatory subtypes in asthma and how these inflammatory subtypes correlate with response to therapy. Finally, we will describe recent discoveries in asthma biology that will include the role of the airway epithelium in asthma pathogenesis, novel cytokines important in asthma that may serve as novel therapeutic targets, and the identification of newly described innate immune cells and their role in asthma. Improved understanding of the complex biology underpinning the various asthma phenotypes is critical for our ability to optimize treatment for all patients that suffer from asthma and critical asthma syndromes.

Differential induction of total IgE by two Salmonella enterica serotypes

The main goal of this study was to establish how the inflammation caused by infection with two different Salmonella enterica serotypes, S. Typhimurium and S. Enteritidis, may lead to the predisposition to allergy as measured by total IgE level in the blood. Infection by S. Typhimurium did not affect the systemic IgE concentration while in S. Enteritidis-infected patients there was a significant 3.5-fold increase. This effect was especially profound in patients >4 years old, with up to the 8-fold increase above the norm. The degree of dysbiosis in these two infections measured with the comparative counts of cultivated bacteria showed an inverse relationship with the IgE concentration. Earlier we reported the elevated level of IL-17 in patients infected by S. Enteritidis. In the current study a significant correlation was found between the concentrations of IL-17 and IgE suggesting a possible role played by this cytokine in triggering the production of IgE in response to S. Enteritidis infection.

Allergen immunotherapy, routes of administration and cytokine networks: an update

Allergen immunotherapy is a disease-modifying therapy, effective for the treatment of allergic rhinitis, allergic asthma, conjunctivitis or stinging insect allergy. Allergen immunotherapy involves the administration of increasing doses of allergens with the aim of ameliorating the allergic response. Although precise underlying mechanisms of the induction of immune tolerance remain unclear, immunotherapy has been associated with the induction of distinct subsets of Tregs that eventually lead to peripheral tolerance by inducing a deviation from Th2 to Th1 immune responses. This review focuses on the current knowledge of the mechanisms of immunotherapy in relationship to different routes of administration and also provides a unifying view.

Participation of interleukin 17A in neuroimmune interactions

Inflammation involving the helper T cell 17 (Th17) subset of lymphocytes has been implicated in a number of diseases that affect the nervous system. As the canonical cytokine of Th17 cells, interleukin 17A (IL-17A) is thought to contribute to these neuroimmune interactions. The main receptor for IL-17A is expressed in many neural tissues. IL-17A has direct effects on neurons but can also impact neural function via signaling to satellite cells and immune cells. In the central nervous system, IL-17A has been associated with neuropathology in multiple sclerosis, epilepsy syndromes and ischemic brain injury. Effects of IL-17A at the level of dorsal root ganglia and the spinal cord may contribute to enhanced nociception during neuropathic and inflammatory pain. Finally, IL-17A plays a role in sympathetic axon growth and regeneration of damaged axons that innervate the cornea. Given the widespread effects of IL-17A on neural tissues, it will be important to determine whether selectively mitigating the damaging effects of this cytokine while augmenting its beneficial effects is a possible strategy to treat inflammatory damage to the nervous system.

Piperlongumine alleviates lupus nephritis in MRL-Fas(lpr) mice by regulating the frequency of Th17 and regulatory T cells

Recent data have shown that piperlongumine (PL), an important component of Piper longum fruits, is known to possess anti-inflammatory and vascular-protective activities. This study aimed to examine the therapeutic effects and underlying mechanisms of PL on lupus-prone MRL-Fas(lpr) mice. Female MRL-Fas(lpr) mice were intraperitoneally treated with PL (2.4 mg kg(-1) d(-1)) for 10 weeks, and the proteinuria level was biweekly monitored. After the mice were euthanized, serum biochemical parameters and renal damage were determined. Splenocytes of MRL-Fas(lpr) mice were isolated for in vitro study. Treatment of the mice with PL significantly attenuated the progression of proteinuria and glomerulonephritis. The improvement was accompanied by decreased serum levels of nephritogenic anti-dsDNA antibodies, IL-6, IL-17, IL-23 and TNF-α. Treatment of the mice with PL suppressed the frequency of Th17 cells and increased the regulatory T cells (Tregs). In vitro, the levels of IL-6, IL-17, IL-23 and TNF-α were significantly decreased in the cultures of splenocytes from PL-treated mice compared with those from vehicle-treated mice. In addition, PL treatment impeded activation of the JAK/STAT3 signaling in splenocytes. Of great important, the survival of MRL-Fas(lpr) mice were improved by PL treatment. In summary, PL effectively ameliorates lupus syndrome in MRL-Fas(lpr) mice by suppressing the pathogenic Th17 cells and increasing the Tregs as well as inhibiting activation of the JAK/STAT3 signaling pathway. This study sheds new light on the immune-modulatory role of PL.

Refractory asthma: mechanisms, targets, and therapy

Asthma is a common medical condition affecting 300 million people worldwide. Airway inflammation, smooth muscle bronchoconstriction leading to airflow obstruction, and mucous hypersecretion are clinical hallmarks of asthma. The NHLBI Expert Panel Report 3 recommends inhaled corticosteroids (ICS) for patients with moderate to severe persistent asthma. Inhaled corticosteroids (ICS) target gene transcription through their interactions with the glucocorticoid (GC) receptor (GR) at the glucocorticoid response element (GRE). The GC/GR complex enhances anti-inflammatory but inhibits pro-inflammatory mediator production. Classically, asthma has been described as a Th2-associated eosinophil-predominant disease, but recently alternative models have been described including a Th17-mediated neutrophil-predominant phenotype resulting in patients with more severe disease who may be less responsive to steroids. Additional mechanisms of steroid resistance include increased activity of GR phosphorylating kinases which modify the interactions of GR with transcription factors to inhibit the ability of GR to bind with GRE, leading to an increase in pro-inflammatory gene transcription. Oxidative stress also affects the balance between pro-inflammatory and anti-inflammatory gene transcription through the modification of transcription factors and cofactors (such as PI3K) leading to the inhibition of histone deacetylase 2. Continued investigations into the mechanisms behind glucocorticoid resistance will lead to novel treatments that improve control of severe refractory asthma.

A tale of two cytokines: IL-17 and IL-22 in asthma and infection

The Th17 pathway has recently been shown to play a critical role in host defense, allergic responses and autoimmune inflammation. Th17 cells predominantly produce IL-17 and IL-22, which are two cytokines with broad effects in the lung and other tissues. This review summarizes not only what is currently known about the molecular regulation of this pathway and Th17-related cytokine signaling, but also the roles of these cytokines in pathogen immunity and asthma. In the last 5 years, the Th17 field has rapidly grown and research has revealed that the Th17 pathway is essential in lung pathogenesis in response to exogenous stimuli. As work in the field continues, it is expected that many exciting therapeutic advances will be made for a broad range of diseases.