A gradient of glucocorticoid sensitivity among helper T cell cytokines

IL-4 regulates neutrophilic pulmonary inflammation in a mouse model of bronchial asthma

Neutrophilic pulmonary inflammation in asthmatics substantially exacerbates the severity of the disease leading to resistance to conventional corticosteroid therapy. Many studies established the involvement of Th1- and Th17-cells and cytokines produced by them (IFNg, IL-17A, IL-17F etc.) in neutrophilic pulmonary inflammation. Recent studies revealed that IL-4 - a Th2-cytokine regulates neutrophil effector functions and migration. It was showed that IL-4 substantially reduces neutrophilic inflammation of the skin in a mouse model of cutaneous bacterial infection and blood neutrophilia in a mouse model systemic bacterial infection. However, there are no data available regarding the influence of IL-4 on non-infectious pulmonary inflammation. In the current study we investigated the effects of IL-4 in a previously developed mouse model of neutrophilic bronchial asthma. We showed that systemic administration of IL-4 significantly restricts neutrophilic inflammation of the respiratory tract probably through the suppression of Th1-/Th17-immune responses and downregulation of CXCR2. Additionally, pulmonary neutrophilic inflammation could be alleviated by IL-4-dependant polarization of N2 neutrophils and M2 macrophages, expressing anti-inflammatory TGFβ. Considering these, IL-4 might be used for reduction of exaggerated pulmonary neutrophilic inflammation and overcoming corticosteroid insensitivity of asthma patients.

A TH17-intrinsic IL-1β-STAT5 axis drives steroid resistance in autoimmune neuroinflammation

Steroid resistance poses a major challenge for the management of autoimmune neuroinflammation. T helper 17 (TH17) cells are widely implicated in the pathology of steroid resistance; however, the underlying mechanisms are unknown. In this study, we identified that interleukin-1 receptor (IL-1R) blockade rendered experimental autoimmune encephalomyelitis (EAE) mice sensitive to dexamethasone (Dex) treatment. Interleukin-1β (IL-1β) induced a signal transducer and activator of transcription 5 (STAT5)-mediated steroid-resistant transcriptional program in TH17 cells, which promoted inflammatory cytokine production and suppressed Dex-induced anti-inflammatory genes. TH17-specific deletion of STAT5 ablated the IL-1β-induced steroid-resistant transcriptional program and rendered EAE mice sensitive to Dex treatment. IL-1β synergized with Dex to promote the STAT5-dependent expression of CD69 and the development of central nervous system (CNS)-resident CD69+ TH17 cells. Combined IL-1R blockade and Dex treatment ablated CNS-resident TH17 cells, reduced EAE severity, and prevented relapse. CD69+ tissue-resident TH17 cells were also detected in brain lesions of patients with multiple sclerosis. These findings (i) demonstrate that IL-1β-STAT5 signaling in TH17 cells mediates steroid resistance and (ii) identify a therapeutic strategy for reversing steroid resistance in TH17-mediated CNS autoimmunity.

All chronic rhinosinusitis endotype clusters demonstrate improvement in patient-reported and clinical outcome measures after endoscopic sinus surgery

BACKGROUND

It is unclear whether chronic rhinosinusitis (CRS) endotypes show a differential response to endoscopic sinus surgery (ESS). We explored patient mucous inflammatory cytokine expression and associations with patient-reported and clinically measured post-operative outcome measures.

METHODS

Patients with CRS were prospectively recruited between 2016 and 2021 into a national multicenter, observational study. Mucus was collected from the olfactory cleft preoperatively and evaluated for 26 biomarkers using cluster analysis. Patient-reported outcome measures included the 22-item Sino-Nasal Outcome Test (SNOT-22) and Questionnaire of Olfactory Dysfunction (QOD). Additional clinical measures of disease severity included threshold, discrimination, and identification (TDI) scores using "Sniffin' Sticks" testing and Lund-Kennedy endoscopic score (LKES).

RESULTS

A total of 115 patients were clustered into type 2 inflammatory, non-type 2 inflammatory, noninflammatory, and two indeterminate clusters based on individual protein levels. Overall, the type 2 inflammatory cluster was found to have the highest mean improvement in both SNOT-22 (-28.3 [standard deviation, ±16.2]) and TDI (6.5 [standard deviation, ±7.9]) scores 6 months after ESS. However, on average, all endotype clusters demonstrated improvement in all outcome measures after ESS without statistically significant between-group differences in SNOT-22 (p = 0.738), QOD (p = 0.306), TDI (p = 0.358), or LKES (p = 0.514) measures.

CONCLUSIONS

All CRS endotype clusters responded favorably to surgery and showed improvements in patient-reported and objective outcome measures. Thus, ESS should be considered a more generalized CRS therapy, and benefits appear to not be limited to specific endotypes.

Immune characteristics and clinical significance of peripheral blood lymphocytes in breast cancer

BACKGROUND

In the context of breast cancer (BC), the correlation between lymphocytes and clinical outcomes, along with treatment response, has garnered attention. Despite this, few investigations have delved into the interplay among distinct peripheral blood lymphocyte (PBL) types, immune attributes, and their clinical implications within the BC landscape.

METHODS

The primary objective of this study was to scrutinize the baseline status of PBL subsets in patients with primary BC, track their dynamic changes throughout treatment, and ascertain their interrelation with prognosis. Flow cytometry was employed to analyse PBLs from a cohort of 74 BC patients.

RESULTS

Our analysis revealed that baseline levels of Treg and PD-L1 + T cells were lower in BC patients compared to the reference values. Notably, a disparity in baseline PD-L1 + T cell levels surfaced between patients who underwent adjuvant therapy and those subjected to neoadjuvant therapy (NAT). Furthermore, a meticulous evaluation of PBL subsets before and after treatment underscored discernible alterations in 324 + T cells and CD19 + CD32 + B cells over the course of therapy. Strikingly, heightened CD4 + T cell levels at baseline were linked to enhanced event-free survival (EFS) (p = 0.02) and a robust response to chemotherapy.

CONCLUSIONS

These results indicate that PBLs may serve as a significant marker to assess the immune status of BC patients, and therapy has the potential to modify patient immune profiles. In addition, peripheral blood CD4 + T cell levels may serve as promising biomarkers for diagnosis and prognosis in future studies of BC.

Impact of endocrine disruptors on peripheral blood mononuclear cells in vitro: role of gender

Humans can be exposed to endocrine disruptors (EDs) in numerous ways. EDs can interfere with endogenous hormones at different levels, resulting in numerous adverse human health outcomes, including immunotoxicity. In this regard, this study aimed to investigate in vitro the possible effects of EDs on immune cells and possible gender differences. Peripheral blood mononuclear cells from healthy humans, both males and females, were exposed to 6 different EDs, namely atrazine (herbicide), cypermethrin (insecticide), diethyl phthalate (plasticizer), 17α-ethynylestradiol (contraceptive drug), perfluorooctanesulfonic acid (persistent organic pollutant), and vinclozolin (fungicide). We evaluated the effect of EDs on RACK1 (receptor for activated C kinase 1) expression, considering it as a bridge between the endocrine and the immune system, and putatively used as screening tool of immunotoxic effects of EDs. The exposure to EDs resulted at different extent in alteration in RACK1 expression, pro-inflammatory activity, natural killer lytic ability, and lymphocyte differentiation, with sex-related differences. In particular, diethyl phthalate and perfluorooctanesulfonic acid resulted the most active EDs tested, with gender differences in terms of effects and magnitude. The results from our study evidenced the ability of EDs to directly affect immune cells.

Research progress of glucocorticoid resistance in chronic rhinosinusitis with nasal polyps: A review

Chronic rhinosinusitis with nasal polyps (CRSwNP) is one of the common chronic inflammatory diseases in otolaryngology. Glucocorticoid (GC) acts as the first-line drug for the treatment of CRSwNP in clinical practice, and they play an irreplaceable role in reducing nasal mucosal inflammation and restoring the normal physiological function of the nasal mucosa. However, many patients are still insensitive to GC treatment, known as GC resistance, which leads to poor control of the disease, and the underlying mechanisms are still not fully elucidated. This article provides a comprehensive overview of the research progress of GC resistance of patients with CRSwNP in recent years.

Type-2 CD8+ T-cell formation relies on interleukin-33 and is linked to asthma exacerbations

CD4+ T helper 2 (Th2) cells and group 2 innate lymphoid cells are considered the main producers of type-2 cytokines that fuel chronic airway inflammation in allergic asthma. However, CD8+ cytotoxic T (Tc) cells - critical for anti-viral defense - can also produce type-2 cytokines (referred to as 'Tc2' cells). The role of Tc cells in asthma and virus-induced disease exacerbations remains poorly understood, including which micro-environmental signals and cell types promote Tc2 cell formation. Here we show increased circulating Tc2 cell abundance in severe asthma patients, reaching peak levels during exacerbations and likely emerging from canonical IFNγ+ Tc cells through plasticity. Tc2 cell abundance is associated with increased disease burden, higher exacerbations rates and steroid insensitivity. Mouse models of asthma recapitulate the human disease by showing extensive type-2 skewing of lung Tc cells, which is controlled by conventional type-1 dendritic cells and IFNγ. Importantly, we demonstrate that the alarmin interleukin-33 (IL-33) critically promotes type-2 cytokine production by lung Tc cells in experimental allergic airway inflammation. Our data identify Tc cells as major producers of type-2 cytokines in severe asthma and during exacerbations that are remarkably sensitive to alterations in their inflammatory tissue micro-environment, with IL-33 emerging as an important regulator of Tc2 formation.

Central and Peripheral Inflammation: A Common Factor Causing Addictive and Neurological Disorders and Aging-Related Pathologies

Many diseases and degenerative processes affecting the nervous system and peripheral organs trigger the activation of inflammatory cascades. Inflammation can be triggered by different environmental conditions or risk factors, including drug and food addiction, stress, and aging, among others. Several pieces of evidence show that the modern lifestyle and, more recently, the confinement associated with the COVID-19 pandemic have contributed to increasing the incidence of addictive and neuropsychiatric disorders, plus cardiometabolic diseases. Here, we gather evidence on how some of these risk factors are implicated in activating central and peripheral inflammation contributing to some neuropathologies and behaviors associated with poor health. We discuss the current understanding of the cellular and molecular mechanisms involved in the generation of inflammation and how these processes occur in different cells and tissues to promote ill health and diseases. Concomitantly, we discuss how some pathology-associated and addictive behaviors contribute to worsening these inflammation mechanisms, leading to a vicious cycle that promotes disease progression. Finally, we list some drugs targeting inflammation-related pathways that may have beneficial effects on the pathological processes associated with addictive, mental, and cardiometabolic illnesses.

Treatment Strategy of Uncontrolled Chronic Rhinosinusitis with Nasal Polyps: A Review of Recent Evidence

Chronic rhinosinusitis (CRS) is recognized as a heterogeneous disease with a wide range of clinical features, resulting in significant morbidity and cost to the healthcare system. While the phenotypic classification is determined by the presence or absence of nasal polyps and comorbidities, the endotype classification has been established based on molecular biomarkers or specific mechanisms. Research on CRS has now developed based on information based on three major endotypes: types 1, 2, and 3. Recently, biological therapies targeting type 2 inflammation have been clinically expanded and may be applied to other inflammatory endotypes in the future. The purpose of this review is to discuss the treatment options according to the type of CRS and summarize recent studies on new therapeutic approaches for patients with uncontrolled CRS with nasal polyps.

Effects of the mTOR Pathway on the Balance of Th2/Treg Cells in Children with Idiopathic Nephrotic Syndrome

Introduction

Immune dysfunction contributes to the progression of idiopathic nephrotic syndrome (INS), but the details of the pathogenesis of progression remain unknown. This study of children with INS investigated the relationship of activation of the mechanistic target of rapamycin (mTOR) pathway (PI3K/AKT/mTOR/p70S6K) with the levels of T helper 2/regulatory T (Th2/Treg) cells.

Materials and Methods

Twenty children with active INS (before steroid treatment), 20 children with remitting INS (INS-R, after steroid treatment), and 20 healthy control children (Ctrl) were enrolled. The levels of Th2/Treg cells in their peripheral circulatory systems were measured using flow cytometry, and the concentration of interleukin (IL)-4 was determined using a cytometric bead array (CBA). The levels of PI3K, AKT, mTOR, p70S6K, and transcription factors associated with Th2/Treg cells were measured using real-time polymerase chain reaction.

Results

The INS group had a greater proportion of circulating Th2 cells; level of IL-4 protein; and levels of GATA, PI3K, AKT, mTOR, and p70S6K mRNAs than the Ctrl group (all P < 0.05), but a lower proportion of circulating Tregs and expression of Foxp3 (both P < 0.05). Patients in the INS-R group had normalization of these markers (all P < 0.05). Patients in the INS group had negative correlation in the percentage of Treg cells with Th2 cells and with IL-4 level and a negative correlation in the levels of GATA3 and Foxp3 mRNAs.

Conclusions

Patients with active INS had an imbalance of Th2/Treg cells, which might result from the aberrant signaling of the mTOR pathway (PI3K/AKT/mTOR/p70S6K).

Steroid treatment suppresses the CD4+ T-cell response to the third dose of mRNA COVID-19 vaccine in systemic autoimmune rheumatic disease patients

Prolonged steroid treatment has a suppressive effect on the immune system, however, its effect on the cellular response to mRNA vaccine is unknown. Here we assessed the impact of prolonged steroid treatment on the T-cell and humoral response to the SARS-CoV-2 spike (S) peptide following the third dose of the BNT162b2 vaccine in systemic autoimmune rheumatic disease patients. We found that CD4 T-cell response to the S peptide in patients on high-dose long-term steroid treatment showed significantly less S-peptide specific response, compare to low-dose or untreated patients. Remarkably, these results were not reflected in their humoral response, since almost all patients in the cohort had sufficient antibody levels. Moreover, S-peptide activation failed to induce significant mRNA levels of IFNγ and TNFα in patients receiving high-dose steroids. RNA-sequencing datasets analysis implies that steroid treatments' inhibitory effect of nuclear factor kappa-B signaling may interfere with the activation of S-specific CD4 T-cells. This reveals that high-dose steroid treatment inhibits T-cell response to the mRNA vaccine, despite having sufficient antibody levels. Since T-cell immunity is a crucial factor in the immune response to viruses, our findings highlight the need for enhancing the efficiency of vaccines in immune-suppressive patients, by modulation of the T-cell response.

T-cell responses in asthma exacerbations

OBJECTIVE

Asthma is a chronic lung disease comprising multiple endotypes and characterized by periodic exacerbations. A diverse array of T cells has been found to contribute to all endotypes of asthma in pathogenic and regulatory roles. Here, we review the contributions of CD4+, CD8+, and unconventional T cells in allergic and nonallergic asthma.

DATA SOURCES

Review of published literature pertaining to conventional and unconventional T-cell types in asthma.

STUDY SELECTIONS

Recent peer-reviewed articles pertaining to T cells in asthma, with additional peer-reviewed studies for context.

RESULTS

Much research in asthma has focused on the roles of CD4+ TH cells. Roles for TH2 cells in promoting allergic asthma pathogenesis have been well-described, and the recent description of pathogenic TH2A cells provides additional insight into these responses. Other TH types, notably TH1 and TH17, have been linked to neutrophilic and steroid-resistant asthma phenotypes. Beyond CD4+ T cells, CD8+ Tc2 cells are also strongly associated with allergic asthma. An emerging area for study is unconventional T-cell types, including γδT, invariant natural killer T, and mucosal-associated invariant T cells. Although data in asthma remain limited for these cells, their ability to bridge innate and adaptive responses likely makes them key players in asthma. A number of asthma therapies target T-cell responses, and, although data are limited, they seem to modulate T-cell populations.

CONCLUSION

Given the diversity and heterogeneity of asthma and T-cell responses, there remain many rich avenues for research to better understand the pathogenesis of asthma. Despite the breadth of T cells in asthma, approved therapeutics remain limited to TH2 networks.

Recombinant multimeric dog allergen prevents airway hyperresponsiveness in a model of asthma marked by vigorous TH 2 and TH 17 cell responses

BACKGROUND

Allergy to dogs affects around 10% of the population in developed countries. Immune therapy of allergic patients with dog allergen extracts has shown limited therapeutic benefit.

METHODS

We established a mouse model of dog allergy by repeatedly administering dog dander and epithelium extracts via the intranasal route. We also assessed the efficacy of a recombinant multimeric protein containing Can f 1, f 2, f 4 and f 6 in preventing inflammatory responses to dog extracts.

RESULTS

Repeated inhalation of dog extracts induced infiltration of the airways by T_H 2 cells, eosinophils and goblet cells, reminiscent of the house dust mite (HDM) model of asthma. Dog extracts also induced robust airway hyperresponsiveness and promoted T_H 17 cell responses, which was associated with a high neutrophilic infiltration of the airways. scRNA-Seq analysis of T helper cells in the airways pinpointed a unique gene signature for T_H 17 cells. Analysis of T-cell receptors depicted a high frequency of clones that were shared between T_H 17, T_H 2 and suppressive Treg cells, indicative of a common differentiation trajectory for these subsets. Importantly, sublingual administration of multimeric Can f 1-2-4-6 protein prior to sensitization reduced airway hyperresponsiveness and type 2-mediated inflammation in this model.

CONCLUSION

Dog allergen extracts induce robust T_H 2 and T_H 17 cell-mediated responses in mice. Recombinant Can f 1-2-4-6 can induce tolerance to complex dog allergen extracts.

The protective capability of Hedyotis diffusa Willd on lupus nephritis by attenuating the IL-17 expression in MRL/lpr mice

Lupus nephritis (LN), the most severe organ manifestation of systemic lupus erythematosus (SLE), is generally treated with glucocorticoids (GC) in clinical practice, leading to drug resistance and adverse effects in the long term. Fortunately, the combination of GC and traditional Chinese medical prescriptions can attenuate the adverse effects and improve therapeutic efficiency. Hedyotis diffusa Willd (HDW) is one of the most commonly used herbal compounds for LN treatment, which exhibits “heat-clearing” and “detoxification” effects. However, the underlying pharmacological mechanism remains unclear. The present study identified the chemical compounds in HDW extract with UPLC-Q-TOF-MS/MS. A total of 49 components were identified in the HDW extract, and the IL-17 signaling pathway was highly enriched by network pharmacological analysis. MRL/lpr model mice, reflecting the spontaneous development of LN, were used to evaluate the protective activity and investigate the underlying mechanism of the combination treatment. The white blood cell content (WBC), including lymphocytes and neutrophils, cytokines (IL-6, MCP-1, TNF-a), and various autoantibodies (ANA, ab-dsDNA, ab-snRNP/sm) in the blood of MRL/lpr mice were significantly improved by the intragastric administration of HDW. Additionally, the expression of STAT3, IL-17, Ly6G, and MPO in the kidney and neutrophil NETosis were ameliorated with HDW treatment. The pathological and morphological analysis suggested that HDW application could reduce urinary protein levels and inflammatory cell infiltration and inhibit glomerular interstitial cell proliferation. Hence, HDW might ameliorate lupus nephritis by inhibiting IL-6 secretion and STAT3-induced IL-17 expression. The active compounds in HDW were predictively selected with computational methods. The docking affinity of asiatic acid, neoandrographolide to IL-6, glycyrrhetinic acid, oleanolic acid, ursolic acid, and wilforlide A to STAT3 are extremely high. In conclusion, the IL-6 and STAT3/IL-17signaling pathways could be critical regulative targets of HDW on LN.

New insights on Effects of Glucocorticoids in SARS-CoV-2 infection

Objective

Since January 2020, the highly contagious novel coronavirus SARS-CoV-2 has caused a global pandemic. Severe COVID-19 leads to a massive release of proinflammatory mediators, leading to diffuse damage to the lung parenchyma, and the development of acute respiratory distress syndrome. Treatment with the highly potent glucocorticoid (GC) dexamethasone was found to be effective in reducing mortality in severely affected patients.

Methods

To review the effects of glucocorticoids in the context of COVID-19 we performed a literature search in the PubMed database using the terms COVID-19 and glucocorticoid treatment. We identified 1429 article publications related to COVID-19 and glucocorticoid published from 1.1.2020 to the present including 238 review articles and 36 Randomized Controlled Trials. From these studies, we retrieved 13 Randomized Controlled Trials and 86 review articles that were relevant to our review topics. We focused on the recent literature dealing with glucocorticoid metabolism in critically ill patients and investigating the effects of glucocorticoid therapy on the immune system in COVID-19 patients with severe lung injury.

Results

In our review, we have discussed the regulation of the hypothalamic-pituitary-adrenal axis in patients with critical illness, selection of a specific GC for critical illness-related GC insufficiency, and recent studies that investigated hypothalamic-pituitary-adrenal dysfunction in patients with COVID-19. We have also addressed the specific activation of the immune system with chronic endogenous glucocorticoid excess, as seen in patients with Cushing syndrome, and, finally, we have discussed immune activation due to coronavirus infection and the possible mechanisms leading to improved outcomes in patients with COVID-19 treated with GCs.

Conclusion

For clinical endocrinologists prescribing GCs for their patients, a precise understanding of both the molecular- and cellular-level mechanisms of endogenous and exogenous GCs is imperative, including timing of administration, dosage, duration of treatment, and specific formulations of GCs.

Preliminary Study on the Imbalance Between Th17 and Regulatory T Cells in Antiphospholipid Syndrome

Objective

Patients with antiphospholipid syndrome (APS) have immune cell abnormalities that remain poorly understood. This study compared primary APS (PAPS) and secondary APS (SAPS) patients with healthy controls with respect to peripheral blood lymphocytes, CD4+T cell subsets, and cytokine levels. The correlation between antiphospholipid antibody titres and T helper 17 (Th17) and T regulatory (Treg) cell subsets was also analyzed, together with the correlations between cytokine profiles and the clinical characteristics of APS patients.

Methods

The retrospective study population consisted of 67 APS patients (12 with PAPS, 55 with SAPS) and 40 healthy controls. Absolute numbers of peripheral blood lymphocyte subsets and CD4+ T cell subsets were detected by flow cytometry, and serum cytokine levels by flow cytometry bead array.

Results

Patients with SAPS had lower absolute values of T, B and CD4+T cells than the healthy control group, while only natural killer (NK) cell levels were decreased in patients with PAPS. Absolute numbers of T, B, NK, and CD4+T cells were significantly higher in the PAPS than SAPS group. The trends in CD4+T cell subsets were the same in PAPS and SAPS patients as in healthy controls, with increased Th1, decreased Th2, and decreased Treg levels, and thus an increased Th17/Treg ratio. Th2, Th17, and Treg cell counts were higher in the PAPS than SAPS group. Cytokine analysis showed that only IL-10 levels differed between the two APS groups. However, the levels of all of the studied cytokines were higher in APS patients than healthy controls, and correlated with the clinical characteristics of the patients. In the PAPS group, the titres of two autoantibodies correlated positively with the Th17/Treg ratio and negatively with the levels of D-dimer and Treg subsets.

Conclusions

Our study clearly showed that APS patients have immune disturbances, the most prominent of which is an increase in the Th17/Treg ratio, due to a decrease in the number of Treg cells. These abnormalities may be involved in the occurrence and progression of APS. An additional finding was a higher level of peripheral blood lymphocytes in PAPS than SAPS patients, which may be related to the immunosuppressive treatment of SAPS patients.

Biomaterials to enhance stem cell transplantation

The successful transplantation of stem cells has the potential to transform regenerative medicine approaches and open promising avenues to repair, replace, and regenerate diseased, damaged, or aged tissues. However, pre-/post-transplantation issues of poor cell survival, retention, cell fate regulation, and insufficient integration with host tissues constitute significant challenges. The success of stem cell transplantation depends upon the coordinated sequence of stem cell renewal, specific lineage differentiation, assembly, and maintenance of long-term function. Advances in biomaterials can improve pre-/post-transplantation outcomes by integrating biophysiochemical cues and emulating tissue microenvironments. This review highlights leading biomaterials-based approaches for enhancing stem cell transplantation.

Chronic Allergen Challenge Induces Corticosteroid Insensitivity With Persistent Airway Remodeling and Type 2 Inflammation

Type 2-high severe asthma is described as a distinct endotype with Th2 inflammation, high eosinophil lung infiltration, impaired lung function, and reduced corticosteroid sensitivity. While the inflammatory milieu is similar to mild asthma, patients with type 2-high severe asthma likely have underlying mechanisms that sustain asthma pathophysiology despite corticosteroid treatments. Acute and chronic allergen models induce robust type 2 inflammatory responses, however differences in corticosteroid sensitivity remains poorly understood. In the present study, we sensitized and challenged mice with ovalbumin (OVA; acute model) or mixed allergens (MA; chronic model). Corticosteroid sensitivity was assessed by administering vehicle, 1, or 3 mg/kg fluticasone propionate (FP) and examining key asthmatic features such as airway inflammation, remodeling, hyperresponsiveness, and antioxidant capacity. Both acute and chronic allergen exposure exhibited enhanced AHR, immune cell infiltration, airway inflammation, and remodeling, but corticosteroids were unable to fully alleviate inflammation, AHR, and airway smooth muscle mass in MA-challenged mice. While there were no differences in antioxidant capacity, persistent IL-4+ Th2 cell population suggests the MA model induces type 2 inflammation that is insensitive to corticosteroids. Our data indicate that chronic allergen exposure is associated with more persistent type 2 immune responses and corticosteroid insensitivity. Understanding differences between acute and chronic allergen models could unlock underlying mechanisms related to type 2-high severe asthma.

Endotypes of chronic rhinosinusitis: Relationships to disease phenotypes, pathogenesis, clinical findings, and treatment approaches

Chronic rhinosinusitis (CRS) is a common clinical syndrome that produces significant morbidity and costs to our health system. The study of CRS has progressed from an era focused on phenotype to include endotype-based information. Phenotypic classification has identified clinical heterogeneity in CRS based on endoscopically observed features such as presence of nasal polyps, presence of comorbid or systemic diseases, and timing of disease onset. More recently, laboratory-based findings have established CRS endotype based upon specific mechanisms or molecular biomarkers. Understanding the basis of widespread heterogeneity in the manifestations of CRS is advanced by findings that the three main endotypes, Type 1, 2, and 3, orchestrate the expression of three distinct large sets of genes. The development and use of improved methods of endotyping disease in the clinic are ushering in an expansion of the use of biological therapies targeting Type 2 inflammation now and perhaps other inflammatory endotypes in the near future. The purpose of this review is to discuss the phenotypic and endotypic heterogeneity of CRS from the perspective of advancing the understanding of the pathogenesis and improvement of treatment approaches and outcomes.

Steroid-Refractory Gut Graft-Versus-Host Disease: What We Have Learned From Basic Immunology and Experimental Mouse Model

Intestinal graft-versus-host disease (Gut-GVHD) is one of the major causes of mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). While systemic glucocorticoids (GCs) comprise the first-line treatment option, the response rate for GCs varies from 30% to 50%. The prognosis for patients with steroid-refractory acute Gut-GVHD (SR-Gut-aGVHD) remains dismal. The mechanisms underlying steroid resistance are unclear, and apart from ruxolitinib, there are no approved treatments for SR-Gut-aGVHD. In this review, we provide an overview of the current biological understanding of experimental SR-Gut-aGVHD pathogenesis, the advanced technology that can be applied to the human SR-Gut-aGVHD studies, and the potential novel therapeutic options for patients with SR-Gut-aGVHD.

Socioeconomic status, financial stress, and glucocorticoid resistance among youth with asthma: Testing the moderation effects of maternal involvement and warmth

OBJECTIVES

Children who grow up in more socioeconomically disadvantaged homes experience greater levels of inflammation and worse asthma symptoms than children from more advantaged families. However, recent evidence suggests that certain family-level factors can mitigate health disparities associated with socioeconomic status (SES). In a sample of youth with asthma, we investigated the potential buffering effects of maternal involvement and warmth on SES disparities in asthma-related immune responses, assessed via glucocorticoid resistance (GR) of immune cells.

METHODS

One hundred and forty-three youth (10-16 years of age) with asthma completed measures of maternal involvement and warmth, and their primary caregivers reported their levels of education, income, and financial stress. Peripheral blood mononuclear cells from youth's blood were isolated, cultured, and assayed to determine mitogen-stimulated (PMA/INO + Etho) and mitogen/hydrocortisone-stimulated (PMA/INO + Cort) levels of two Th-2 cytokines (i.e., interleukin-5, interleukin-13) and one Th-1 cytokine (i.e., interferon-γ). GR was calculated by subtracting log-transformed cytokine concentration in the PMA/INO + Etho samples from log-transformed cytokine concentration in the PMA/INO + Cort samples.

RESULTS

Both maternal involvement and warmth moderated the indirect pathway from family SES to GR of Th-2 cytokines via financial stress. Specifically, we found that low family SES was associated with elevated GR of Th-2 cytokines via increased financial stress among youth reporting low levels of maternal involvement and warmth, but not among those reporting high levels of maternal involvement or warmth.

CONCLUSIONS

These results highlight the protective role of maternal involvement and warmth in health-related biological processes modulated by family SES among youth with asthma.

Glucocorticoids: Dr. Jekyll and Mr. Hyde of Hippocampal Neuroinflammation

Glucocorticoids (GCs) are an important component of adaptive response of an organism to stressogenic stimuli, a typical stress response being accompanied by elevation of GC levels in blood. Anti-inflammatory effects of GCs are widely used in clinical practice, while pro-inflammatory effects of GCs are believed to underlie neurodegeneration. This is particularly critical for the hippocampus, brain region controlling both cognitive function and emotions/affective behavior, and selectively vulnerable to neuroinflammation and neurodegeneration. The hippocampus is believed to be the main target of GCs since it has the highest density of GC receptors potentially underlying high sensitivity of hippocampal cells to severe stress. In this review, we analyzed the results of studies on pro- and anti-inflammatory effects of GCs in the hippocampus in different models of stress and stress-related pathologies. The available data form a sophisticated, though often quite phenomenological, picture of a modulatory role of GCs in hippocampal neuroinflammation. Understanding the dual nature of GC-mediated effects as well as causes and mechanisms of switching can provide us with effective approaches and tools to avert hippocampal neuroinflammatory events and as a result to prevent and treat brain diseases, both neurological and psychiatric. In the framework of a mechanistic view, we propose a new hypothesis describing how the anti-inflammatory effects of GCs may transform into the pro-inflammatory ones. According to it, long-term elevation of GC level or preliminary treatment with GC triggers accumulation of FKBP51 protein that suppresses activity of GC receptors and activates pro-inflammatory cascades, which, finally, leads to enhanced neuroinflammation.

Systems pharmacology dissection of action mechanisms for herbs in osteoporosis treatment

Objective

Osteoporosis has become the biggest cause of non-fatal health issue. Currently, the limitations of traditional anti-osteoporosis drugs such as long-term ill-effects and drug resistance, have raised concerns toward complementary and alternative therapies, particularly herbal medicines and their natural active compounds. Thus, this study aimed to provide an integrative analysis of active chemicals, drug targets and interacting pathways of the herbs for osteoporosis treatment.

Methods

Here, we introduced a systematic pharmacology model, combining the absorption, distribution, metabolism, and excretion (ADME) screening model, drug targeting and network pharmacology, to probe into the therapeutic mechanisms of herbs in osteoporosis.

Results

We obtained 86 natural compounds with favorable pharmacokinetic profiles and their 58 targets from seven osteoporosis-related herbs. Network analysis revealed that they probably synergistically work through multiple mechanisms, such as suppressing inflammatory response, maintaining bone metabolism or improving organism immunity, to benefit patients with osteoporosis. Furthermore, experimental results showed that all the five compounds (calycosin, asperosaponin VI, hederagenin, betulinic acid and luteolin) enhanced osteoblast proliferation and differentiation in vitro, which corroborated the validity of this system pharmacology approach. Notably, gentisin and aureusidin among the identified compounds were first predicted to be associated with osteoporosis.

Conclusion

Herbs and their natural compounds, being characterized as the classical combination therapies, might be engaged in multiple mechanisms to coordinately improve the osteoporosis symptoms. This work may contribute to offer novel strategies and clues for the therapy and drug discovery of osteoporosis and other complex diseases.

Protection of Antigen-Primed Effector T Cells From Glucocorticoid-Induced Apoptosis in Cell Culture and in a Mouse Model of Multiple Sclerosis

Induction of T cell apoptosis constitutes a major mechanism by which therapeutically administered glucocorticoids (GCs) suppress inflammation and associated clinical symptoms, for instance in multiple sclerosis (MS) patients suffering from an acute relapse. The sensitivity of T cells to GC action depends on their maturation and activation status, but the precise effect of antigen-priming in a pathological setting has not been explored. Here we used transgenic and congenic mouse models to compare GC-induced apoptosis between naïve and antigen-specific effector T cells from mice immunized with a myelin peptide. Antigen-primed effector T cells were protected from the pro-apoptotic activity of the synthetic GC dexamethasone in a dose-dependent manner, which resulted in their accumulation relative to naïve T cells in vitro and in vivo. Notably, the differential sensitivity of T cells to GC-induced apoptosis correlated with their expression level of the anti-apoptotic proteins Bcl-2 and Bcl-X_L and a loss of the mitochondrial membrane potential. Moreover, accumulation of antigen-primed effector T cells following GC treatment in vitro resulted in an aggravated disease course in an adoptive transfer mouse model of MS in vivo, highlighting the clinical relevance of the observed phenomenon. Collectively, our data indicate that antigen-priming influences the T cells’ sensitivity to therapeutically applied GCs in the context of inflammatory diseases.

IL-22-dependent dysbiosis and mononuclear phagocyte depletion contribute to steroid-resistant gut graft-versus-host disease in mice

Efforts to improve the prognosis of steroid-resistant gut acute graft-versus-host-disease (SR-Gut-aGVHD) have suffered from poor understanding of its pathogenesis. Here we show that the pathogenesis of SR-Gut-aGVHD is associated with reduction of IFN-γ+ Th/Tc1 cells and preferential expansion of IL-17-IL-22+ Th/Tc22 cells. The IL-22 from Th/Tc22 cells causes dysbiosis in a Reg3γ-dependent manner. Transplantation of IFN-γ-deficient donor CD8+ T cells in the absence of CD4+ T cells produces a phenocopy of SR-Gut-aGVHD. IFN-γ deficiency in donor CD8+ T cells also leads to a PD-1-dependent depletion of intestinal protective CX3CR1hi mononuclear phagocytes (MNP), which also augments expansion of Tc22 cells. Supporting the dual regulation, simultaneous dysbiosis induction and depletion of CX3CR1hi MNP results in full-blown Gut-aGVHD. Our results thus provide insights into SR-Gut-aGVHD pathogenesis and suggest the potential efficacy of IL-22 antagonists and IFN-γ agonists in SR-Gut-aGVHD therapy.

Steroid-resistant human inflammatory ILC2s are marked by CD45RO and elevated in type 2 respiratory diseases

Group 2 innate lymphoid cells (ILC2s) orchestrate protective type 2 immunity and have been implicated in various immune disorders. In the mouse, circulatory inflammatory ILC2s (iILC2s) were identified as a major source of type 2 cytokines. The human equivalent of the iILC2 subset remains unknown. Here, we identify a human inflammatory ILC2 population that resides in inflamed mucosal tissue and is specifically marked by surface CD45RO expression. CD45RO⁺ ILC2s are derived from resting CD45RA⁺ ILC2s upon activation by epithelial alarmins such as IL-33 and TSLP, which is tightly linked to STAT5 activation and up-regulation of the IRF4/BATF transcription factors. Transcriptome analysis reveals marked similarities between human CD45RO⁺ ILC2s and mouse iILC2s. Frequencies of CD45RO⁺ inflammatory ILC2 are increased in inflamed mucosal tissue and in the circulation of patients with chronic rhinosinusitis or asthma, correlating with disease severity and resistance to corticosteroid therapy. CD45RA-to-CD45RO ILC2 conversion is suppressed by corticosteroids via induction of differentiation toward an immunomodulatory ILC2 phenotype characterized by low type 2 cytokine and high amphiregulin expression. Once converted, however, CD45RO⁺ ILC2s are resistant to corticosteroids, which is associated with metabolic reprogramming resulting in the activation of detoxification pathways. Our combined data identify CD45RO⁺ inflammatory ILC2s as a human analog of mouse iILC2s linked to severe type 2 inflammatory disease and therapy resistance.

Cytokines in CAR T Cell-Associated Neurotoxicity

Chimeric antigen receptor (CAR) T cells provide new therapeutic options for patients with relapsed/refractory hematologic malignancies. However, neurotoxicity is a frequent, and potentially fatal, complication. The spectrum of manifestations ranges from delirium and language dysfunction to seizures, coma, and fatal cerebral edema. This novel syndrome has been designated immune effector cell-associated neurotoxicity syndrome (ICANS). In this review, we draw an arc from our current understanding of how systemic and potentially local cytokine release act on the CNS, toward possible preventive and therapeutic approaches. We systematically review reported correlations of secreted inflammatory mediators in the serum/plasma and cerebrospinal fluid with the risk of ICANS in patients receiving CAR T cell therapy. Possible pathophysiologic impacts on the CNS are covered in detail for the most promising candidate cytokines, including IL-1, IL-6, IL-15, and GM-CSF. To provide insight into possible final common pathways of CNS inflammation, we place ICANS into the context of other systemic inflammatory conditions that are associated with neurologic dysfunction, including sepsis-associated encephalopathy, cerebral malaria, thrombotic microangiopathy, CNS infections, and hepatic encephalopathy. We then review in detail what is known about systemic cytokine interaction with components of the neurovascular unit, including endothelial cells, pericytes, and astrocytes, and how microglia and neurons respond to systemic inflammatory challenges. Current therapeutic approaches, including corticosteroids and blockade of IL-1 and IL-6 signaling, are reviewed in the context of what is known about the role of cytokines in ICANS. Throughout, we point out gaps in knowledge and possible new approaches for the investigation of the mechanism, prevention, and treatment of ICANS.

Osteoimmunology: The Regulatory Roles of T Lymphocytes in Osteoporosis

Immune imbalance caused bone loss. Osteoimmunology is emerging as a new interdisciplinary field to explore the shared molecules and interactions between the skeletal and immune systems. In particular, T lymphocytes (T cells) play pivotal roles in the regulation of bone health. However, the roles and mechanisms of T cells in the treatment of osteoporosis are not fully understood. The present review aims to summarize the essential regulatory roles of T cells in the pathophysiology of various cases of osteoporosis and the development of T cell therapy for osteoporosis from osteoimmunology perspective. As T cell-mediated immunomodulation inhibition reduced bone loss, there is an increasing interest in T cell therapy in an attempt to treat osteoporosis. In summary, the T cell therapy may be further pursued as an immunomodulatory strategy for the treatment of osteoporosis, which can provide a novel perspective for drug development in the future.

How I treat steroid-refractory acute graft-versus-host disease

Steroid-resistant or steroid-refractory acute graft-versus-host disease (SR-aGVHD) poses one of the most vexing challenges faced by providers who care for patients after allogeneic hematopoietic cell transplantation. For the past 4 decades, research in the field has been driven by the premise that persistent graft-versus-host disease (GVHD) results from inadequate immunosuppression. Accordingly, most efforts to solve this problem have relied on retrospective or prospective studies testing agents that have direct or indirect immunosuppressive effects. Retrospective studies far outnumber prospective studies, and no controlled prospective trial has shown superior results for any agent over others. Truth be told, I do not know how to treat SR-aGVHD. Preclinical work during the past decade has provided fresh insights into the pathogenesis of acute GVHD, and translation of these insights toward development of more effective treatments for patients with SR-aGVHD has at last begun. Given the limited state of current knowledge, this "How I Treat" review highlights the overriding imperative to avoid harm in caring for patients with SR-aGVHD. Prospective trials that are widely available are urgently needed to advance the field.

Divergent immune responses in behaviorally-inhibited vs. non-inhibited male rats

Stable behavioral traits (temperament, personality) often predict health outcomes. Temperament-specific differences in immune function could explain temperament-specific health outcomes, however, we have limited information on whether immune function varies by personality. In the present study, we examined the relationship between a basic behavioral trait (behavioral-inhibition vs. non-inhibition) and two immune responses (innate inflammation and delayed-type hypersensitivity, DTH) in a rodent model. In humans, behavioral inhibition (fearful temperament) is associated with altered stress physiology and allergies. In laboratory rats, the trait is associated with elevated glucocorticoid production. We hypothesized that behavioral inhibition is associated with glucocorticoid resistance and dampened T-helper 1 cell responses often associated with chronic stress and allergies. Further, this immune profile would predict poorly-regulated innate inflammation and dampened DTH. In male Sprague-Dawley rats, we quantified consistent behavioral phenotypes by measuring latency to contact two kinds of novelty (object vs. social), then measured lipopolysaccharide(LPS)-induced innate inflammation or keyhole limpet hemocyanin(KLH)-induced DTH. Behaviorally-inhibited rats had heightened glucocorticoid and interleukin-6 responses to a low/moderate dose of LPS and reduced DTH swelling to KLH re-exposure compared to non-inhibited rats. These results suggest that behavioral inhibition is associated with a glucocorticoid resistant state with poorly regulated innate inflammation and dampened cell-mediated immune responses. This immune profile may be associated with exaggerated T-helper 2 responses, which could set the stage for an allergic/asthmatic/atopic predisposition in inhibited individuals. Human and animal models of temperament-specific immune responses represent an area for further exploration of mechanisms involved in individual differences in health.

Glucocorticoids-All-Rounders Tackling the Versatile Players of the Immune System

Glucocorticoids regulate fundamental processes of the human body and control cellular functions such as cell metabolism, growth, differentiation, and apoptosis. Moreover, endogenous glucocorticoids link the endocrine and immune system and ensure the correct function of inflammatory events during tissue repair, regeneration, and pathogen elimination via genomic and rapid non-genomic pathways. Due to their strong immunosuppressive, anti-inflammatory and anti-allergic effects on immune cells, tissues and organs, glucocorticoids significantly improve the quality of life of many patients suffering from diseases caused by a dysregulated immune system. Despite the multitude and seriousness of glucocorticoid-related adverse events including diabetes mellitus, osteoporosis and infections, these agents remain indispensable, representing the most powerful, and cost-effective drugs in the treatment of a wide range of rheumatic diseases. These include rheumatoid arthritis, vasculitis, and connective tissue diseases, as well as many other pathological conditions of the immune system. Depending on the therapeutically affected cell type, glucocorticoid actions strongly vary among different diseases. While immune responses always represent complex reactions involving different cells and cellular processes, specific immune cell populations with key responsibilities driving the pathological mechanisms can be identified for certain autoimmune diseases. In this review, we will focus on the mechanisms of action of glucocorticoids on various leukocyte populations, exemplarily portraying different autoimmune diseases as heterogeneous targets of glucocorticoid actions: (i) Abnormalities in the innate immune response play a crucial role in the initiation and perpetuation of giant cell arteritis (GCA). (ii) Specific types of CD4+ T helper (Th) lymphocytes, namely Th1 and Th17 cells, represent important players in the establishment and course of rheumatoid arthritis (RA), whereas (iii) B cells have emerged as central players in systemic lupus erythematosus (SLE). (iv) Allergic reactions are mainly triggered by several different cytokines released by activated Th2 lymphocytes. Using these examples, we aim to illustrate the versatile modulating effects of glucocorticoids on the immune system. In contrast, in the treatment of lymphoproliferative disorders the pro-apoptotic action of glucocorticoids prevails, but their mechanisms differ depending on the type of cancer. Therefore, we will also give a brief insight into the current knowledge of the mode of glucocorticoid action in oncological treatment focusing on leukemia.

Genetic Identification of Two Novel Loci Associated with Steroid-Sensitive Nephrotic Syndrome

BACKGROUND

Steroid-sensitive nephrotic syndrome (SSNS), the most common form of nephrotic syndrome in childhood, is considered an autoimmune disease with an established classic HLA association. However, the precise etiology of the disease is unclear. In other autoimmune diseases, the identification of loci outside the classic HLA region by genome-wide association studies (GWAS) has provided critical insights into disease pathogenesis. Previously conducted GWAS of SSNS have not identified non-HLA loci achieving genome-wide significance.

METHODS

In an attempt to identify additional loci associated with SSNS, we conducted a GWAS of a large cohort of European ancestry comprising 422 ethnically homogeneous pediatric patients and 5642 ethnically matched controls.

RESULTS

The GWAS found three loci that achieved genome-wide significance, which explain approximately 14% of the genetic risk for SSNS. It confirmed the previously reported association with the HLA-DR/DQ region (lead single-nucleotide polymorphism [SNP] rs9273542, P=1.59×10^-43; odds ratio [OR], 3.39; 95% confidence interval [95% CI], 2.86 to 4.03) and identified two additional loci outside the HLA region on chromosomes 4q13.3 and 6q22.1. The latter contains the calcium homeostasis modulator family member 6 gene CALHM6 (previously called FAM26F). CALHM6 is implicated in immune response modulation; the lead SNP (rs2637678, P=1.27×10^-17; OR, 0.51; 95% CI, 0.44 to 0.60) exhibits strong expression quantitative trait loci effects, the risk allele being associated with lower lymphocytic expression of CALHM6.

CONCLUSIONS

Because CALHM6 is implicated in regulating the immune response to infection, this may provide an explanation for the typical triggering of SSNS onset by infections. Our results suggest that a genetically conferred risk of immune dysregulation may be a key component in the pathogenesis of SSNS.

Prednisone may rebuild the immunologic homeostasis: Alteration of Th17 and Treg cells in the lymphocytes from rats' spleens after treated with prednisone-containing serum

Background

This study aimed to investigate alterations of T helper 17 (Th17), regulatory T (Treg) cells and relative cytokines after treating with prednisone‐contained serum. Lymphocytes were isolated from female rats' spleens.

Methods

The splenic lymphocytes were divided into four groups: which were treated with normal rats' serum (control); prednisone‐containing rats' serum (PDN); normal rats' serum and cytokines (CTK); cytokines and prednisone‐containing rats' serum (PDN + CTK). The mRNA expression level of RORC, Foxp3 and interleukin‐17 (IL‐17) was examined by reverse transcription‐polymerase chain reaction. The quantities of Th17 and Treg cells were tested by flow cytometry, and the concentrations of IL‐17 and IL‐10 were detected by enzyme‐linked immunosorbent assay.

Results

Higher mRNA expression level of Foxp3, percentages of Treg/CD4⁺, and concentrations of IL‐10, lower mRNA expressions of RORC and IL‐17, concentrations of IL‐17 and percentages of Th17/CD4⁺ in PDN group were detected, compared with control group (all p < 0.01). Similar trend was detected in PDN + CTK group, compared with CTK group (all p < 0.01).

Conclusion

Our results suggest that prednisone may rebuild the immunologic homeostasis and may be used in human diseases with changes in the imbalance immune system such as unexplained recurrent spontaneous abortion (URSA), hepatitis B infection, or other autoimmune diseases.

Altered Th17/Treg Ratio in Peripheral Blood of Systemic Lupus Erythematosus but Not Primary Antiphospholipid Syndrome

Introduction: The role of the immune response in the pathogenesis of antiphospholipid syndrome (APS) remains elusive. It is possible that differences in the frequencies of Th17 cells and/or defects in the immunoregulatory mechanisms are involved in the pathogenesis of APS. Our aim was to determine the peripheral blood Th cells phenotype and the circulating cytokine profile in patients with primary APS (pAPS) and compare it with systemic lupus erythemathosus (SLE) as disease control group.

Methods: The frequencies of circulating regulatory T cells (Tregs) were determined in PBMCs from 36 patients with pAPS by flow cytometry. As control groups we included 21 age- and gender-matched healthy controls (HC) and 11 patients with SLE. The suppressive capacity of Tregs was evaluated in vitro by coculture assay. On the other hand, intracellular cytokine production was assessed in Th1, Th2, and Th17 cells and circulating IL-6, IL-10, and IL-35 were measured by Cytometric Bead Array and ELISA. The quantification of Th master gene expression levels was performed by real time quantitative PCR.

Results: pAPS patients and SLE patients did not show differences in the percentage or number of Tregs compared to HC. The suppressive capacity of Tregs was also similar in the three study group. Instead, we found higher FoxP3·mRNA expression levels in pAPS patients and HC than SLE patients. Regarding the Th17 response, patients with pAPS and HC showed a significantly lower frequency of circulating Th17 cells than SLE. However, no differences were observed in the Th1 response between patients and controls. Thus, increased Th17/Th1 and Th17/Treg ratios were found in SLE patients but not in pAPS patients. pAPS and SLE patients had higher serum IL-6 levels than HC but there was not difference between both disease groups. Besides, a significant increase in the immunosuppressive cytokine levels was observed only in pAPS as compared to HC.

Conclusions: Our data demonstrate an increased inflammatory profile of peripheral blood CD4⁺ T cells from SLE as compared with pAPS mostly due to an increased Th17 response. In conclusion, there seems not to be a direct pathogenic role for Th cells in pAPS but in SLE.

Residual Activatability of Circulating Tfh17 Predicts Humoral Response to Thymodependent Antigens in Patients on Therapeutic Immunosuppression

The generation of antibodies against protein antigens (such as donor-specific HLA molecules) requires that T follicular helper cells (Tfh) provide help to B cells. Immunosuppressive (IS) armamentarium prevents T cell activation, yet a significant proportion of renal transplant patients develop donor-specific antibodies (DSA), which suggests that IS drugs do not efficiently block T follicular helper cells. To test this hypothesis, the number of circulating Tfh, their polarization profile, and ability to up-regulate (i) the co-stimulatory molecules CD40L and ICOS, and (ii) the activation marker CD25, following in vitro stimulation in presence of IS drugs, were compared between 36 renal transplant patients (6–72 months post transplantation) and nine healthy controls. IS drugs reduced the number of Tfh1 and 2 but had little impact on Tfh17, which was the dominant subset in transplant patients. Although, IS drugs decreased activation-induced expression of co-stimulatory molecules by Tfh, the impact was highly variable between individuals. Furthermore, 20% of transplant patients displayed normal expression of CD25 on Tfh following in vitro stimulation (i.e., “residual activatability”). To test whether residual activatability of Tfh correlates with antibody response against thymo-dependent antigens we took advantage of the 2015 influenza vaccination campaign, which provided a normalized setting for antigenic stimulation. In line with our hypothesis, responders to influenza vaccine exhibited significantly higher percentage of CD25-expressing Tfh17 after in vitro stimulation. A results that was confirmed retrospectively in nine transplanted patients at the time of first DSA detection. We concluded that “residual activatability” of Tfh17 might be used as a non-invasive biomarker to identify transplant patients at higher risk to develop DSA under immunosuppression. If validated in larger studies, this assay might help optimizing the prevention of DSA through personalized adaptation of immunosuppressive regimen.

Enriched environment regulates thymocyte development and alleviates experimental autoimmune encephalomyelitis in mice

Environmental and social factors have profound impacts on immune homeostasis. Our work on environmental enrichment (EE) has revealed a novel anti-obesity and anticancer phenotype associated with enhanced activity of CD8+ cytotoxic T lymphocytes in secondary lymphoid tissues. Here we investigated how an EE modulated thymus and thymocyte development. EE decreased thymus mass and cellularity, decreased the double positive thymocyte population, increased the proportion of CD8+ T cells, reduced the CD4:CD8 ratio, and downregulated CD69 expression in T cells. In a model of multiple sclerosis: experimental autoimmune encephalomyelitis (EAE), EE alleviated symptoms, inhibited spinal cord inflammation through regulation of type 1 T-helper cells mediated by glucocorticoid receptor signaling, and prevented EAE-induced thymic disturbance. Our mechanistic studies demonstrated that hypothalamic BDNF activated a hypothalamic-pituitary-adrenal axis mediating the EE's thymic effects. Our results indicate that a lifestyle intervention links the nervous, endocrine, and adaptive immune system, allowing the body to adapt to internal and external environments.

Immunology of idiopathic nephrotic syndrome

The pathogenesis of idiopathic nephrotic syndrome (INS) is as yet unknown, but several lines of evidence indicate that the immune system may play a crucial pathogenic role in non-genetic INS. The most important of these are, first, the effectiveness of therapy based on immunosuppression and, second, a vast body of data derived both from experimental models and from patient studies that implicate T cells and more recently B cells as major players in INS pathogenesis. However, recent findings also suggest a direct role of podocytes as drivers of the disease process, and the interplay between the glomerulus and the immune system is still being elucidated. In this review we provide an overview of current knowledge on the role of different components of the immune system in determining disease. Advances in our understanding of the pathogenesis of INS may help drive new, more tailored therapeutic approaches.

Regulatory effects of dexamethasone on NK and T cell immunity

Glucocorticoids (GCs) act via the intracellular glucocorticoid receptor (GR), which can regulate the expression of target genes. With regard to the immune system, GCs may affect both innate and adaptive immunity. Our study analyzed the immunoregulatory effects of dexamethasone (Dex) treatment on splenic T, Treg, NK and NKT cells by treating C57Bl6 mice with various doses of Dex. We observed that treatment with Dex decreased the number of NK cells in the spleen and suppressed their activity. In particular, the expression of both Ly49G and NKG2D receptors was decreased by Dex. However, Dex did not affect the population of NKT cells. With regard to splenic T cells, our results show a dose-dependent reduction in CD3⁺, CD4⁺, CD8⁺, CD44⁺ and CD8⁺CD122⁺ T cells, but a stimulatory effect on CD4⁺CD25⁺ regulatory T cells by Dex treatment. In addition, treatment with Dex suppressed anti-tumor immune response in a mouse EG7 tumor model. We conclude that Dex may suppress both T- and NK-mediated immunity.

Prednisone may induce immunologic tolerance by activating the functions of decidual immune cells in early pregnancy

The objective of this study was to investigate alterations in human first-trimester decidual immune cells (DICs) and relevant cytokines after treatment with prednisone. Decidual lymphocytes were treated with prednisone alone, cytokines alone or the combination of prednisone and cytokines. Levels of STAT3, STAT5, RORC and FOXP3 mRNA were assayed using quantitative real-time PCR, proportions of CD4⁺ T helper 17 (Th17) and CD4⁺ T regulatory (Treg) cells were measured using flow cytometry, and concentrations of interleukin (IL)-17A and IL-10 were determined using enzyme-linked immunosorbent assay. After treatment with prednisone alone, levels of STAT5 and FOXP3 mRNA were significantly higher than in untreated control cells (both P < 0.01), while levels of RORC mRNA were significantly lower than in controls (P < 0.05). Levels of STAT3 mRNA did not vary significantly with treatment. After treatment with prednisone alone, proportions of Th17/CD4⁺ cells and levels of IL-17A were significantly lower than in control cells, and proportions of Treg/CD4⁺ cells and levels of IL-10 significantly higher than in controls (all P < 0.01). Our results suggest that prednisone may improve pregnancy outcomes by restoring immunological homeostasis through up-regulation of STAT5 and FOXP3, induction of DIC differentiation into Treg cells, inhibition of DIC differentiation into Th17 cells, reduction of IL-17A secretion and induction of IL-10 secretion.

Dexamethasone and sex regulate placental glucocorticoid receptor isoforms in mice

Maternal dexamethasone exposure in the mouse impairs placental development and programs adult disease in a sexually dimorphic manner. Glucocorticoids bind to different glucocorticoid receptor (GR) isoforms to regulate gene transcription and cellular signaling. We hypothesized that sexually dimorphic placental responses to glucocorticoids are due to differences in GR isoforms present in the placenta. Pregnant C57Bl6 mice were exposed to saline or dexamethasone from E12.5 until E14.5 (1 µg/kg/h) before the collection of placentae. Cytoplasmic and nuclear protein fractions were extracted from placentae of male and female fetuses for Western blot analysis of GR isoforms. Eight known isoforms of the GR were detected in the mouse placenta including the translational isoforms GRα-A, B, C and D1-3 and the splice variants GRA and GRP. The expression of GRA, GRP and each of the GRα isoforms were altered by dexamethasone in relation to fetal sex and cellular location. Placentae of female fetuses had higher GRα-A and GRP expression in the cytoplasm than males, and GRα-C was more highly expressed in the nucleus of females than that in males. Dexamethasone significantly increased the cytoplasmic expression of GRα-A, but reduced the expression of GRα-C in placentae of males. Dexamethasone increased the expression of the GRα-C-regulated genes Sgk1 and Bcl2l11, particularly in females. The cleaved caspase-3 staining in placental sections indicated GRα-C may mediate sex differences in dexamethasone-induced apoptosis. These findings may underlie the sex-specific placental adaptations that regulate different growth profiles in males and females and different risks for programmed disease outcomes in offspring.

Sleep deprivation predisposes allergic mice to neutrophilic lung inflammation

BACKGROUND

Although different studies associated sleep deprivation (SD) with systemic inflammatory changes, the effect of sleep duration on the pathology of allergic chronic diseases is poorly understood.

OBJECTIVE

We sought to evaluate the influence of SD on allergen-induced pulmonary inflammation.

METHODS

Ovalbumin (OVA)-sensitized C57BL/6 mice were exposed to a first set of intranasal OVA challenge under SD or healthy sleep (HS) conditions, followed by a second OVA challenge, 1 week apart. Some groups were subjected to corticosteroid treatment with dexamethasone.

RESULTS

OVA-sensitized mice with SD had more severe airway inflammation than the allergic group with HS. Analysis of lung parenchyma revealed that the inflammation in allergic mice with SD was marked by an influx of neutrophils (mainly) and eosinophils and secretion of IL-6, TNF-α, and IL-17 in contrast to the eosinophilic inflammation and IL-4 production observed in allergic mice with HS. The same cytokine profile was observed in ex vivo culture of cervical lymph node cells and splenocytes, indicating that in allergic mice SD favors immune responses toward a proinflammatory T_H17 profile. This idea is supported by the fact that disruption of IL-17 signaling (IL-17 receptor A^-/-) prevented airway neutrophilia in allergic mice with SD. Furthermore, allergic mice with SD became refractory to corticosteroid treatment in contrast to the allergic group with HS.

CONCLUSION

Collectively, our data show that sleep quality participates in the progression of allergen-induced eosinophilic lung inflammation to corticosteroid-refractory neutrophilic manifestation.

Effects of peritoneal macrophage autophagy on the immune function of sepsis mice

OBJECTIVE

To investigate the effect of peritoneal macrophage autophagy on immune function in sepsis mice.

METHODS

Seventy-two male BALB/C mice were intraperitoneally injected with LPS to induce sepsis. The mice were randomly divided into six groups: LPS+2 h, LPS+6 h, LPS+12 h, LPS+24 h and LPS+36 h. LPS with a dose of 10 mg/kg was intraperitoneally injected into the abdominal cavity of the sepsis mice, and the control group was injected with the same dose of saline. ELISA was used to detect the concentrations of inflammatory factors IL-2, IL-10 and TNF-α in the peripheral blood, and the CD4+T/CD8+T ratio in the peripheral blood was detected by flow cytometry. The expression levels of LC3II and Beclin-1/beta-action in the mouse macrophages were measured using Western blot to determine the level of autophagy.

RESULTS

The expression levels of LC3II and Beclin-1 were significantly higher in the peritoneal macrophages of the mice from the LPS+2 h group than in those of the mice from the normal group (P<0.05). Meanwhile, these levels continuously declined in the LPS+6 h, LPS+12 h, LPS+24 h and LPS+36 h groups (P<0.05). The peripheral blood CD4+T/CD8+T cell ratio was significantly higher in the LPS+2 h and LPS+6 h groups than in the normal group (P<0.05). The ratio peaked at 6 h and then continuously declined (P<0.05). Furthermore, the concentrations of IL-2 and Tnf-α were significantly higher in the peripheral blood serum of the LPS+2 h, LPS+6 h and LPS+12 h groups than in those of the normal group (P<0.05). The peak was observed at 12 h followed by a continuous decline in the LPS+24 h and 3 LPS+6 h groups (P<0.05). The peripheral serum IL-10 concentration was significantly higher in the LPS+2 h, LPS+6 h, LPS+12 h, LPS+24 h and LPS+36 h groups than in the normal group (P<0.05). In the LPS+6 h, LPS+12 h, LPS+24 h and LPS+36 h groups, the peritoneal macrophages LC3II, Beclin-1 and peripheral serum CD+4T/CD+8T ratio correlation index R²=0.716 (P=0.043), R²=0.954 (P=0.023).

CONCLUSION

Autophagy in peritoneal macrophages plays an important role in the immune function of sepsis mice. In addition, the autophagy of peritoneal macrophages and the immune function of sepsis mice are strongly correlated. Furthermore, macrophage autophagy plays an important role in the immune function changes in sepsis mice, and the underlying mechanism may be involved in inflammation and macrophage antigen presentation by regulating the secretion of inflammatory cytokines and lymphocyte apoptosis antagonism.

Associations between polymorphisms in the IL-4 gene and renal cell carcinoma in Chinese Han population

Renal cell carcinoma (RCC) is considered to be a kind of cytokine reactive tumor. The research has been suggested that the host immune system can regulate the clinical course of RCC. Therefore, cytokine gene polymorphisms in RCC patients were analyzed was necessary. Our study is purpose to analyzing the interleukin-4(IL-4) polymorphisms associated with RCC risk from Han Chinese population. IL-4 genetic polymorphisms were genotyped using Massarray technology from a total of 291RCC and 463 controls. Unconditional logistic regression analysis was performed to analyze their relationship with risk of RCC. A significant association was found between the rs2243250 “C” allel and decreased risk of RCC (OR=0.75, 95%CI=0.59-0.96, P=0.02). Stratified analysis based on the age, gender, smoking status, drinking status revealed no significant association with RCC in age>55, female, smoking and nodrinking. However, for age<55 group (rs2243250, rs2243267, rs2243270), male group (rs2243250), nonsmoking group (rs2227284), and drinking group (rs2243250, rs2227284, rs2243267, rs2243270) polymorphisms were found obviously associated with RCC. The haplotype analyses showed that the haplotype have a significant decreased risk of RCC in the rs2243250/rs2227284/rs2243267/rs2243270/rs2243283/rs2243289 (CGGACA) (Total, OR=0.73, 95%CI=0.54-0.98, P=0.034; Male, OR=0.59, 95%CI=0.39-0.90, P=0.014). Therefore, the present study suggests that IL-4 may be a candidate gene for assessing the risk of RCC.

Granulocyte colony-stimulating factor blockade enables dexamethasone to inhibit lipopolysaccharide-induced murine lung neutrophils

Glucocorticoids promote neutrophilic inflammation, the mechanisms of which are poorly characterized. Using a lipopolysaccharide (LPS)-induced acute murine lung injury model, we determined the role of granulocyte colony-stimulating factor (G-CSF) in mouse lung neutrophil numbers in the absence and presence of dexamethasone, a potent glucocorticoid. G-CSF was blocked using a neutralizing antibody. Airway neutrophil numbers, cytokine levels, and lung injury parameters were measured. Glucocorticoid treatment maintained LPS-induced airway G-CSF while suppressing TNF and IL-6. The addition of anti-G-CSF antibodies enabled dexamethasone to decrease airway G-CSF, neutrophils, and lung injury scores. In LPS-challenged murine lungs, structural cells and infiltrating leukocytes produced G-CSF. In vitro using BEAS 2B bronchial epithelial cells, A549 lung epithelial cells, human monocyte-derived macrophages, and human neutrophils, we found that dexamethasone and proinflammatory cytokines synergistically induced G-CSF. Blocking G-CSF production in BEAS 2B cells using shRNAs diminished the ability of BEAS 2B cells to protect neutrophils from undergoing spontaneous apoptosis. These data support that G-CSF plays a role in upregulation of airway neutrophil numbers by dexamethasone in the LPS-induced acute lung injury model.

Immunopathology alters Th17 cell glucocorticoid sensitivity

Th17 cells contribute to several inflammatory conditions and increasing evidence supports that Th17 cells are glucocorticoid resistant. However, Th17 cells in psoriasis and related diseases are glucocorticoid sensitive. We compare glucocorticoid sensitive and resistant immunological diseases and suggest that several aspects in Th17-related diseases alter glucocorticoid sensitivity of Th17 cells. We identify molecular pathways that are implicated in glucocorticoid sensitivity of Th17 cells in the literature, as this information is useful for developing approaches to overcome glucocorticoid-resistant immunopathology.