How are T(H)1 and T(H)2 effector cells made?

A tissue-engineered model of T-cell mediated oral mucosal inflammatory disease

T-cell-mediated oral mucocutaneous inflammatory conditions including oral lichen planus (OLP) are common but development of new treatments aimed at relieving symptoms and controlling OLP progression are hampered by the lack of experimental models. Here, we developed a tissue-engineered oral mucosal equivalent (OME) containing polarised T-cells to replicate OLP pathogenesis. Peripheral blood CD4+ and CD8+ T-cells were isolated, activated and polarised into Th1 and cytotoxic T-cells (Tc). OME were constructed by culturing oral keratinocytes on an oral fibroblast-populated hydrogel to produce a stratified squamous epithelium. OME stimulated with IFN-γ and TNF-α or medium from Th1 cells caused increased secretion of inflammatory cytokines/chemokines. A model of T-cell-mediated inflammatory disease was developed by combining OME on top of a Th1/Tc-containing hydrogel, followed by epithelial stimulation with IFN-γ/TNF-α. T-cell recruitment towards the epithelium was associated with increased secretion of T-cell chemoattractants CCL5, CXCL9 and CXCL10. Histological assessment showed tissue damage associated with cleaved-caspase-3 and altered laminin-5 expression. Treatment with inhibitors directed against JAK, KCa3.1 channels or clobetasol in solution and/or via a mucoadhesive patch prevented cytokine/chemokine release and tissue damage. This disease model has potential to probe for mechanisms of pathogenesis or as a test platform for novel therapeutics or treatment modalities.

Construction of a potentially functional lncRNA-miRNA-mRNA network in sepsis by bioinformatics analysis

Objective: Sepsis is a common disease in internal medicine, with a high incidence and dangerous condition. Due to the limited understanding of its pathogenesis, the prognosis is poor. The goal of this project is to screen potential biomarkers for the diagnosis of sepsis and to identify competitive endogenous RNA (ceRNA) networks associated with sepsis.

Methods: The expression profiles of long non-coding RNAs (lncRNAs), microRNAs (miRNAs) and messenger RNAs (mRNAs) were derived from the Gene Expression Omnibus (GEO) dataset. The differentially expressed lncRNAs (DElncRNAs), miRNAs (DEmiRNAs) and mRNAs (DEmRNAs) were screened by bioinformatics analysis. DEmRNAs were analyzed by protein-protein interaction (PPI) network analysis, transcription factor enrichment analysis, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and Gene Set Enrichment Analysis (GSEA). After the prediction of the relevant database, the competitive ceRNA network is built in Cytoscape. The gene-drug interaction was predicted by DGIgb. Finally, quantitative real-time polymerase chain reaction (qRT-PCR) was used to confirm five lncRNAs from the ceRNA network.

Results: Through Venn diagram analysis, we found that 57 DElncRNAs, 6 DEmiRNAs and 317 DEmRNAs expressed abnormally in patients with sepsis. GO analysis and KEGG pathway analysis showed that 789 GO terms and 36 KEGG pathways were enriched. Through intersection analysis and data mining, 5 key KEGG pathways and related core genes were revealed by GSEA. The PPI network consists of 247 nodes and 1,163 edges, and 50 hub genes are screened by the MCODE plug-in. In addition, there are 5 DElncRNAs, 6 DEmiRNAs and 28 DEmRNAs in the ceRNA network. Drug action analysis showed that 7 genes were predicted to be molecular targets of drugs. Five lncRNAs in ceRNA network are verified by qRT-PCR, and the results showed that the relative expression of five lncRNAs was significantly different between sepsis patients and healthy control subjects.

Conclusion: A sepsis-specific ceRNA network has been effectively created, which is helpful to understand the interaction between lncRNAs, miRNAs and mRNAs. We discovered prospective sepsis peripheral blood indicators and proposed potential treatment medicines, providing new insights into the progression and development of sepsis.

The association between diabetes and obesity with Dengue infections

Dengue, an arboviral disease is a global threat to public health as the number of Dengue cases increases through the decades and this trend is predicted to continue. Non-communicable diseases such as diabetes and obesity are also on an upward trend. Moreover, past clinical studies have shown comorbidities worsen the clinical manifestation of especially Severe Dengue. However, discussion regarding the underlying mechanisms regarding the association between these comorbidities and dengue are lacking. The hallmark of Severe Dengue is plasma leakage which is due to several factors including presence of pro-inflammatory cytokines and dysregulation of endothelial barrier protein expression. The key factors of diabetes affecting endothelial functions are Th1 skewed responses and junctional-related proteins expression. Additionally, obesity alters the lipid metabolism and immune response causing increased viral replication and inflammation. The similarity between diabetes and obesity individuals is in having chronic inflammation resulting in endothelial dysfunction. This review outlines the roles of diabetes and obesity in severe dengue and gives some insights into the plausible mechanisms of comorbidities in Severe Dengue.

Multi-Target Effects of ß-Caryophyllene and Carnosic Acid at the Crossroads of Mitochondrial Dysfunction and Neurodegeneration: From Oxidative Stress to Microglia-Mediated Neuroinflammation

Inflammation and oxidative stress are interlinked and interdependent processes involved in many chronic diseases, including neurodegeneration, diabetes, cardiovascular diseases, and cancer. Therefore, targeting inflammatory pathways may represent a potential therapeutic strategy. Emerging evidence indicates that many phytochemicals extracted from edible plants have the potential to ameliorate the disease phenotypes. In this scenario, ß-caryophyllene (BCP), a bicyclic sesquiterpene, and carnosic acid (CA), an ortho-diphenolic diterpene, were demonstrated to exhibit anti-inflammatory, and antioxidant activities, as well as neuroprotective and mitoprotective effects in different in vitro and in vivo models. BCP essentially promotes its effects by acting as a selective agonist and allosteric modulator of cannabinoid type-2 receptor (CB2R). CA is a pro-electrophilic compound that, in response to oxidation, is converted to its electrophilic form. This can interact and activate the Keap1/Nrf2/ARE transcription pathway, triggering the synthesis of endogenous antioxidant “phase 2” enzymes. However, given the nature of its chemical structure, CA also exhibits direct antioxidant effects. BCP and CA can readily cross the BBB and accumulate in brain regions, giving rise to neuroprotective effects by preventing mitochondrial dysfunction and inhibiting activated microglia, substantially through the activation of pro-survival signalling pathways, including regulation of apoptosis and autophagy, and molecular mechanisms related to mitochondrial quality control. Findings from different in vitro/in vivo experimental models of Parkinson’s disease and Alzheimer’s disease reported the beneficial effects of both compounds, suggesting that their use in treatments may be a promising strategy in the management of neurodegenerative diseases aimed at maintaining mitochondrial homeostasis and ameliorating glia-mediated neuroinflammation.

IFNγ suppresses the expression of GFI1 and thereby inhibits Th2 cell proliferation

While IFNγ is a well-known cytokine that actively promotes the type I immune response, it is also known to suppress the type II response by inhibiting the differentiation and proliferation of Th2 cells. However, the mechanism by which IFNγ suppresses Th2 cell proliferation is still not fully understood. We found that IFNγ decreases the expression of growth factor independent-1 transcriptional repressor (GFI1) in Th2 cells, resulting in the inhibition of Th2 cell proliferation. The deletion of the Gfi1 gene in Th2 cells results in the failure of their proliferation, accompanied by an impaired cell cycle progression. In contrast, the enforced expression of GFI1 restores the defective Th2 cell proliferation, even in the presence of IFNγ. These results demonstrate that GFI1 is a key molecule in the IFNγ-mediated inhibition of Th2 cell proliferation.

High Th2 cytokine levels and upper airway inflammation in human inherited T-bet deficiency

We have described a child suffering from Mendelian susceptibility to mycobacterial disease (MSMD) due to autosomal recessive, complete T-bet deficiency, which impairs IFN-γ production by innate and innate-like adaptive, but not mycobacterial-reactive purely adaptive, lymphocytes. Here, we explore the persistent upper airway inflammation (UAI) and blood eosinophilia of this patient. Unlike wild-type (WT) T-bet, the mutant form of T-bet from this patient did not inhibit the production of Th2 cytokines, including IL-4, IL-5, IL-9, and IL-13, when overexpressed in T helper 2 (Th2) cells. Moreover, Herpesvirus saimiri-immortalized T cells from the patient produced abnormally large amounts of Th2 cytokines, and the patient had markedly high plasma IL-5 and IL-13 concentrations. Finally, the patient's CD4+ αβ T cells produced most of the Th2 cytokines in response to chronic stimulation, regardless of their antigen specificities, a phenotype reversed by the expression of WT T-bet. T-bet deficiency thus underlies the excessive production of Th2 cytokines, particularly IL-5 and IL-13, by CD4+ αβ T cells, causing blood eosinophilia and UAI. The MSMD of this patient results from defective IFN-γ production by innate and innate-like adaptive lymphocytes, whereas the UAI and eosinophilia result from excessive Th2 cytokine production by adaptive CD4+ αβ T lymphocytes.

T cell transgressions: Tales of T cell form and function in diverse disease states

Insights into T cell form, function, and dysfunction are rapidly evolving. T cells have remarkably varied effector functions including protecting the host from infection, activating cells of the innate immune system, releasing cytokines and chemokines, and heavily contributing to immunological memory. Under healthy conditions, T cells orchestrate a finely tuned attack on invading pathogens while minimizing damage to the host. The dark side of T cells is that they also exhibit autoreactivity and inflict harm to host cells, creating autoimmunity. The mechanisms of T cell autoreactivity are complex and dynamic. Emerging research is elucidating the mechanisms leading T cells to become autoreactive and how such responses cause or contribute to diverse disease states, both peripherally and within the central nervous system. This review provides foundational information on T cell development, differentiation, and functions. Key T cell subtypes, cytokines that create their effector roles, and sex differences are highlighted. Pathological T cell contributions to diverse peripheral and central disease states, arising from errors in reactivity, are highlighted, with a focus on multiple sclerosis, rheumatoid arthritis, osteoarthritis, neuropathic pain, and type 1 diabetes.

NLRP3 Regulates IL-4 Expression in TOX+ CD4+ T Cells of Cutaneous T Cell Lymphoma to Potentially Promote Disease Progression

In cutaneous T cell lymphoma (CTCL), a dominant Th2 profile associated with disease progression has been proposed. Moreover, although the production and regulation of IL-4 expression during the early stages of the disease may have important implications in later stages, these processes are poorly understood. Here, we demonstrate the presence of TOX+ CD4+ T cells that produce IL-4+ in early-stage skin lesions of CTCL patients and reveal a complex mechanism by which the NLRP3 receptor promotes a Th2 response by controlling IL-4 production. Unassembled NLRP3 is able to translocate to the nucleus of malignant CD4+ T cells, where it binds to the human il-4 promoter. Accordingly, IL-4 expression is decreased by knocking down and increased by promoting the nuclear localization of NLRP3. We describe a positive feedback loop in which IL-4 inhibits NLRP3 inflammasome assembly, thereby further increasing its production. IL-4 induced a potentially malignant phenotype measured based on TOX expression and proliferation. This mechanism of IL-4 regulation mediated by NLRP3 is amplified in late-stage CTCL associated with disease progression. These results indicate that NLRP3 might be a key regulator of IL-4 expression in TOX+ CD4+ T cells of CTCL patients and that this mechanism might have important implications in the progression of the disease.

Potential use of biomarkers for the clinical evaluation of sarcoidosis

Sarcoidosis is a systemic granulomatous disease of unknown etiology and pathogenesis with a heterogeneous clinical presentation. In the appropriate clinical and radiological context and with the exclusion of other diagnoses, the disease is characterized by the pathological presence of non-caseating epithelioid cell granulomas. Sarcoidosis is postulated to be a multifactorial disease caused by chronic antigenic stimulation. The immunopathogenesis of sarcoidosis encompasses a complex interaction between the host, genetic factors and postulated environmental and infectious triggers, which result in granuloma development.The exact pathogenesis of the disease has yet to be elucidated, but some of the inflammatory pathways that play a key role in disease progression and outcomes are becoming apparent, and these may form the logical basis for selecting potential biomarkers.Biomarkers are biological molecules that are altered pathologically. To date, there exists no single reliable biomarker for the evaluation of sarcoidosis, either diagnostically or prognostically but new candidates are emerging. A diagnosis of sarcoidosis ideally requires a biopsy confirming non-caseating granulomas, but the likelihood of progression that requires intervention remains unpredictable. These challenging aspects could be potentially resolved by incorporating biomarkers into clinical practice for both diagnosis and monitoring disease activity.This review outlines the current knowledge on sarcoidosis with an emphasis on pulmonary sarcoidosis, and delineates the understanding surrounding the implication of biomarkers for the clinical evaluation of sarcoidosis.

Tilianin attenuates HDM-induced allergic asthma by suppressing Th2-immune responses via downregulation of IRF4 in dendritic cells

BACKGROUND

Acacetin 7-O-β-D-glucoside (tilianin) is a major constituent of Agastache rugosa, a traditional medicine that has long been used for the treatment of gastrointestinal disorders. Tilianin has a wide variety of pharmacological properties such as cardioprotective, neuroprotective, and anti-atherogenic activities. We recently discovered that tilianin has the ability to suppress MUC5AC expression in vitro. In addition, we have established an in vivo model of allergic asthma using house dust mite (HDM) that can be applied to tilianin.

PURPOSE

We investigated the effects of tilianin on airway inflammation in a HDM-induced asthma mouse model and associated mechanisms.

METHODS

Tilianin was treated in splenocytes cultured in Th0 condition and HDM-stimulated bone marrow-derived dendritic cells (BMDCs), and their mRNA expression and cytokines production were determined by quantitative real-time PCR and ELISA. To evaluate the effects of tilianin in an allergic asthma model, mice were sensitized and challenged with HDM. Tilianin was administered prior to challenge by oral gavage and airway hyper-reactivity (AHR) to methacholine, inflammatory cell infiltration, cytokine levels, and airway remodeling were assessed.

RESULTS

Tilianin inhibited the production of Th2-related cytokines in splenocytes, which play pivotal roles in allergic airway inflammation. When treated in HDM-stimulated BMDCs, tilianin decreased Th2-skewing cytokine IL-33 and transcription factor IRF4. On the contrary, tilianin increased Th1-skewing regulators, IL-12 and IRF1. In an HDM-induced asthmatic mouse model, tilianin attenuated AHR and airway inflammation. Tilianin suppressed the expression of Th2-related cytokines, IL-13 and IL-33 in lung tissues. As seen in HDM-stimulated BMDCs, tilianin also downregulated the expression of the transcription factor IRF4 but not IRF1.

CONCLUSION

Taken together, these results suggest that tilianin attenuates HDM-induced allergic airway inflammation by inhibiting Th2-mediated inflammation through the selective inhibition of the IRF4-IL-33 axis in dendritic cells.

Oral immunotherapy tolerizes mice to enzyme replacement therapy for Morquio A syndrome

Immune response to therapeutic enzymes poses a detriment to patient safety and treatment outcome. Enzyme replacement therapy (ERT) is a standard therapeutic option for some types of mucopolysaccharidoses, including Morquio A syndrome caused by N-acetylgalactosamine-6-sulfate sulfatase (GALNS) deficiency. Current protocols tolerize patients using cytotoxic immunosuppressives, which can cause adverse effects. Here we show development of tolerance in Morquio A mice via oral delivery of peptide or GALNS for 10 days prior to ERT. Our results show that using an immunodominant peptide (I10) or the complete GALNS enzyme to orally induce tolerance to GALNS prior to ERT resulted in several improvements to ERT in mice: (a) decreased splenocyte proliferation after in vitro GALNS stimulation, (b) modulation of the cytokine secretion profile, (c) decrease in GALNS-specific IgG or IgE in plasma, (d) decreased GAG storage in liver, and (e) fewer circulating immune complexes in plasma. This model could be extrapolated to other lysosomal storage disorders in which immune response hinders ERT.

Innate Lymphoid Cells of the Lung

Although, as the major organ of gas exchange, the lung is considered a nonlymphoid organ, an interconnected network of lung-resident innate cells, including epithelial cells, dendritic cells, macrophages, and natural killer cells is crucial for its protection. These cells provide defense against a daily assault by airborne bacteria, viruses, and fungi, as well as prevent the development of cancer, allergy, and the outgrowth of commensals. Our understanding of this innate immune environment has recently changed with the discovery of a family of innate lymphoid cells (ILCs): ILC1s, ILC2s, and ILC3s. All lack adaptive antigen receptors but can provide a substantial and rapid source of IFN-γ, IL-5 and IL-13, and IL-17A or IL-22, respectively. Their ability to afford immediate protection to the lung and to influence subsequent adaptive immune responses highlights the importance of understanding ILC-regulated immunity for the design of future therapeutic interventions.

Association of Interleukin-4 Polymorphisms With Breast Cancer in Taiwan

BACKGROUND/AIM

The present study aimed at evaluating the contribution of IL-4 promoter T-1099G (rs2243248), C-589T (rs2243250), C-33T (rs2070874) genotypes to the risk of breast cancer in Taiwanese.

MATERIALS AND METHODS

A total of 1232 breast cancer patients and 1232 age-matched controls were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology.

RESULTS

Genotypic frequencies of IL-4 rs2243248, rs2243250 and rs2070874 were not differentially distributed between case and control groups. Consistently, there was no difference in the distribution of allelic frequencies among patients and controls.

CONCLUSION

IL-4 rs2243248, rs2243250 and rs2070874 do not confer breast cancer susceptibility in Taiwanese.

Combining Monophosphoryl Lipid A (MPL), CpG Oligodeoxynucleotide (ODN), and QS-21 Adjuvants Induces Strong and Persistent Functional Antibodies and T Cell Responses against Cell-Traversal Protein for Ookinetes and Sporozoites (CelTOS) of Plasmodium falciparum in BALB/c Mice

Plasmodium falciparum cell-traversal protein for ookinetes and sporozoites (PfCelTOS) is an advanced vaccine candidate that has a crucial role in the traversal of the malaria parasite in both mosquito and mammalian hosts. As recombinant purified proteins are normally poor immunogens, they require to be admixed with an adjuvant(s); therefore, the objective of the present study was to evaluate the capacity of different vaccine adjuvants, monophosphoryl lipid A (MPL), CpG, and Quillaja saponaria Molina fraction 21 (QS-21), alone or in combination (MCQ [MPL/CpG/QS-21]), to enhance the immunogenicity of Escherichia coli-expressed PfCelTOS in BALB/c mice. This goal was achieved by the assessment of anti-PfCelTOS IgG antibodies (level, titer, IgG isotype profile, avidity, and persistence) and extracellular Th1 cytokines using an enzyme-linked immunosorbent assay (ELISA) on postimmunized BALB/c mouse sera and PfCelTOS-stimulated splenocytes, respectively. Also, an assessment of the transmission-reducing activity (TRA) of anti-PfCelTOS obtained from different vaccine groups was carried out in female Anopheles stephensi mosquitoes by using a standard membrane feeding assay (SMFA). In comparison to PfCelTOS alone, administration of PfCelTOS with three distinct potent Th1 adjuvants in vaccine mouse groups showed enhancement and improvement of PfCelTOS immunogenicity that generated more bias toward a Th1 response with significantly enhanced titers and avidity of the anti-PfCelTOS responses that could impair ookinete development in A. stephensi However, immunization of mice with PfCelTOS with MCQ mixture adjuvants resulted in the highest levels of induction of antibody titers, avidity, and inhibitory antibodies in oocyst development (88%/26.7% reductions in intensity/prevalence) in A. stephensi It could be suggested that adjuvant combinations with different mechanisms stimulate better functional antibody responses than adjuvants individually against challenging diseases such as malaria.

The impact of environmental pollution on the quality of mother's milk

Breastfeeding is a gold standard of neonate nutrition because human milk contains a lot of essential compounds crucial for proper development of a child. However, milk is also a biofluid which can contain environmental pollution, which can have effects on immune system and consequently on the various body organs. Polychlorinated biphenyls are organic pollutants which have been detected in human milk. They have lipophilic properties, so they can penetrate to fatty milk and ultimately to neonate digestive track. Another problem of interest is the presence in milk of heavy metals-arsenic, lead, cadmium, and mercury-as these compounds can lead to disorders in production of cytokines, which are important immunomodulators. The toxicants cause stimulation or suppression of this compounds. This can lead to health problems in children as allergy, disorders in the endocrine system, end even neurodevelopment delay and disorder. Consequently, correlations between pollutants and bioactive components in milk should be investigated. This article provides an overview of environmental pollutants found in human milk as well as of the consequences of cytokine disorder correlated with presence of heavy metals. Graphical abstract.

Inflammation-Nature's Way to Efficiently Respond to All Types of Challenges: Implications for Understanding and Managing "the Epidemic" of Chronic Diseases

Siloed or singular system approach to disease management is common practice, developing out of traditional medical school education. Textbooks of medicine describe a huge number of discrete diseases, usually in a systematic fashion following headings like etiology, pathology, investigations, differential diagnoses, and management. This approach suggests that the body has a multitude of ways to respond to harmful incidences. However, physiology and systems biology provide evidence that there is a simple mechanism behind this phenotypical variability. Regardless if an injury or change was caused by trauma, infection, non-communicable disease, autoimmune disorders, or stress, the typical physiological response is: an increase in blood supply to the area, an increase in white cells into the affected tissue, an increase in phagocytic activity to remove the offending agent, followed by a down-regulation of these mechanisms resulting in healing. The cascade of inflammation is the body's unique mechanism to maintain its integrity in response to macroscopic as well as microscopic injuries. We hypothesize that chronic disease development and progression are linked to uncontrolled or dysfunctional inflammation to injuries regardless of their nature, physical, environmental, or psychological. Thus, we aim to reframe the prevailing approach of management of individual diseases into a more integrated systemic approach of treating the "person as a whole," enhancing the patient experience, ability to a make necessary changes, and maximize overall health and well-being. The first part of the paper reviews the local immune cascades of pro- and anti-inflammatory regulation and the interconnected feedback loops with neural and psychological pathways. The second part emphasizes one of nature's principles at work-system design and efficiency. Continually overwhelming this finely tuned system will result in systemic inflammation allowing chronic diseases to emerge; the pathways of several common conditions are described in detail. The final part of the paper considers the implications of these understandings for clinical care and explore how this lens could shape the physician-patient encounter and health system redesign. We conclude that healthcare professionals must advocate for an anti-inflammatory lifestyle at the patient level as well as at the local and national levels to enhance population health and well-being.

The Sources of Essential Fatty Acids for Allergic and Cancer Patients; a Connection with Insight into Mammalian Target of Rapamycin: A Narrative Review

Background:

Disturbance in essential fatty acids (EFA) metabolism plays a key role in autoimmune diseases, but EFA supplementation with sources of borage, evening primrose, hemp seed and fish oils was not effective in atopic and cancer diseases, as that seen in the case of multiple sclerosis. It seems that two complexes of the mammalian target of rapamycin (mTOR) signaling, mTORC1 and mTORC2, are congruent with the two bases of the Traditional Iranian Medicine (TIM) therapy, Cold and Hot nature, which are essential for the efficacy of functional oils for controlling immune responses in autoimmune diseases.

Methods:

We searched PubMed database, Web of Science (WOS), Google Scholar, Scopus and selected studies by predefined eligibility criteria. We then assessed their quality and extracted data.

Results:

The oils controlled by Cold or Hot nature may be helpful in maintaining homeostasis and preventing autoimmune diseases. In summary, studies of randomized controlled trials for allergy and cancer patients found no improvement in the signs or response to tests, despite a remarkable change in EFA fractions in the blood by supplementation with sources of borage, evening primrose, hemp seed and fish oils. In contrast, portulaca oleracea oil exhibited protective effects by anti-inflammatory properties via the PI3K/Akt/mTORC2 pathway with a deviation immune response to Th1 to treat atopic diseases and cancer.

Conclusions:

According to the concept of Traditional Iranian Medicine therapy, in contrast to Cold-nature oils, EFA supplementation with the sources of Hot-nature oilsis not suitable for the treatment of atopic and cancerous diseases.

Vaccine adjuvants CpG (oligodeoxynucleotides ODNs), MPL (3-O-deacylated monophosphoryl lipid A) and naloxone-enhanced Th1 immune response to the Plasmodium vivax recombinant thrombospondin-related adhesive protein (TRAP) in mice

Despite considerable efforts toward vaccine development over decades, there is no available effective vaccine against Plasmodium vivax. Thrombospondin-related adhesive protein of P. vivax (PvTRAP) is essential for sporozoite motility and invasions into mosquito's salivary gland and vertebrate's hepatocyte; hence, it is a promising target for pre-erythrocytic vaccine. In the current investigation, the role of antibodies and cellular immune responses induced by purified recombinant PvTRAP (rPvTRAP) delivered in three adjuvants, naloxone (NLX), CpG oligodeoxynucleotides ODN1826 (CpG-ODN), and 3-O-deacylated monophosphoryl lipid A (MPL), alone and in combination was evaluated in immunized C57BL/6 mice. The highest level and the avidity of anti-PvTRAP IgG (mean OD_490nm 2.55), IgG2b (mean OD_490nm 1.68), and IgG2c (mean OD_490nm 1.466) were identified in the group received rPvTRA/NLX-MPL-CpG. This group also presented the highest IgG2c/IgG1 (2.58) and IgG2b/IgG1 (2.95) ratio when compared to all other groups, and among the adjuvant groups, the lowest IgG2c/IgG1 (1.86) and IgG2b/IgG1 (2.25) ratio was observed in mice receiving rPvTRAP/NLX. Mice receiving rPvTRAP/adjuvants induced significantly the higher levels of interferon gamma (IFN-γ), low level of detectable IL-10, and no detectable IL-4 production. The present result revealed that PvTRAP is immunogenic and its administration with CPG, MPL, and NLX in C57BL/6 mice induced Th1 immune response. Besides, the rPvTRAP delivery in the mixed formulation of those adjuvants had more potential to increase the level, avidity, and persistence of anti-TRAP antibodies. However, it warrants further assessment to test the blocking activity of the produced antibodies in immunized mice with different adjuvant formulations.

Monocyte chemotactic protein-induced protein 1 controls allergic airway inflammation by suppressing IL-5-producing TH2 cells through the Notch/Gata3 pathway

BACKGROUND

Asthmatic and allergic inflammation is mediated by T_H2 cytokines (IL-4, IL-5, and IL-13). Although we have learned much about how T_H2 cells are differentiated, the T_H2 checkpoint mechanisms remain elusive.

OBJECTIVES

In this study we investigate how monocyte chemotactic protein-induced protein 1 (MCPIP1; encoded by the Zc3h12a gene) regulates IL-5-producing T_H2 cell differentiation and T_H2-mediated inflammation.

METHODS

The functions of Zc3h12a^-/- CD4 T cells were evaluated by checking the expression of T_H2 cytokines and transcription factors in vivo and in vitro. Allergic airway inflammation of Zc3h12a^-/- mice was examined with murine asthma models. In addition, antigen-specific CD4 T cells deficient in MCPIP1 were transferred to wild-type recipient mice, challenged with ovalbumin (OVA) or house dust mite (HDM), and accessed for T_H2 inflammation.

RESULTS

Zc3h12a^-/- mice have spontaneous severe lung inflammation, with an increase in mainly IL-5- and IL-13-producing but not IL-4-producing T_H2 cells in the lung. Mechanistically, differentiation of IL-5-producing Zc3h12a^-/- T_H2 cells is mediated through Notch signaling and Gata3 independent of IL-4. Gata3 mRNA is stabilized in Zc3h12a^-/- T_H2 cells. MCPIP1 promotes Gata3 mRNA decay through the RNase domain. Furthermore, deletion of MCPIP1 in OVA- or HDM-specific T cells leads to significantly increased T_H2-mediated airway inflammation in OVA or HDM murine models of asthma.

CONCLUSIONS

Our study reveals that MCPIP1 regulates the development and function of IL-5-producing T_H2 cells through the Notch/Gata3 pathway. MCPIP1 represents a new and promising target for the treatment of asthma and other T_H2-mediated diseases.

Genetic deletion of the bacterial sensor NOD2 improves murine Crohn's disease-like ileitis independent of functional dysbiosis

Although genetic polymorphisms in NOD2 (nucleotide-binding oligomerization domain-containing 2) have been associated with the pathogenesis of Crohn's disease (CD), little is known regarding the role of wild-type (WT) NOD2 in the gut. To date, most murine studies addressing the role of WT Nod2 have been conducted using healthy (ileitis/colitis-free) mouse strains. Here, we evaluated the effects of Nod2 deletion in a murine model of spontaneous ileitis, i.e., the SAMP1Yit/Fc (SAMP) strain, which closely resembles CD. Remarkably, Nod2 deletion improved both chronic cobblestone ileitis (by 50% assessed, as the % of abnormal mucosa at 24 wks of age), as well as acute dextran sodium sulfate (DSS) colitis. Mechanistically, Th2 cytokine production and Th2-transcription factor activation (i.e., STAT6 phosphorylation) were reduced. Microbiologically, the effects of Nod2 deletion appeared independent of fecal microbiota composition and function, assessed by 16S rRNA and metatranscriptomics. Our findings indicate that pharmacological blockade of NOD2 signaling in humans could improve health in Th2-driven chronic intestinal inflammation.

Immunity and inflammation in diabetic kidney disease: translating mechanisms to biomarkers and treatment targets

Increasing incidences of obesity and diabetes have made diabetic kidney disease (DKD) the leading cause of chronic kidney disease and end-stage renal disease worldwide. Despite current pharmacological treatments, including strategies for optimizing glycemic control and inhibitors of the renin-angiotensin system, DKD still makes up almost one-half of all cases of end-stage renal disease in the United States. Compelling and mounting evidence has clearly demonstrated that immunity and inflammation play a paramount role in the pathogenesis of DKD. This article reviews the involvement of the immune system in DKD and identifies important roles of key immune and inflammatory mediators. One of the most recently identified biomarkers is serum amyloid A, which appears to be relatively specific for DKD. Novel and evolving treatment approaches target protein kinases, transcription factors, chemokines, adhesion molecules, growth factors, advanced glycation end-products, and other inflammatory molecules. This is the beginning of a new era in the understanding and treatment of DKD, and we may have finally reached a tipping point in our fight against the growing burden of DKD.

Effect of fermented soybean products intake on the overall immune safety and function in mice

Various functional activities have been reported for the fermented soybean products doenjang (DJ) and cheonggukjang (CGJ), although no systemic investigations of their immune functions have been conducted to date. We examined the effects of an experimental diet of DJ, CGJ, or a mixture of unfermented raw material for 4 weeks on overall immunity and immune safety in mice. No significant alterations were observed in peripheral or splenic immune cells among groups. Enhanced splenic natural killer cell activity was observed in the DJ and CGJ groups compared with the plain diet group. T helper type-1 (Th1)-mediated immune responses were enhanced in the DJ and CGJ groups with an upregulated production ratio of IFN-γ vs. IL-4 and IgG2a vs. IgG1 in stimulated splenic T and B cells, respectively. Resistance to Listeria monocytogenes infection was observed in the DJ and CGJ groups. Overall, the results of this study suggest that DJ and CGJ intake consolidates humoral and cellular immunity to Th1 responses.

Association of peripheral NK cell counts with Helios+ IFN-γ- Tregs in patients with good long-term renal allograft function

Little is known about a possible interaction of natural killer (NK) cells with regulatory T cells (T_reg ) in long-term stable kidney transplant recipients. Absolute counts of lymphocyte and T_reg subsets were studied in whole blood samples of 136 long-term stable renal transplant recipients and 52 healthy controls using eight-colour fluorescence flow cytometry. Patients were 1946 ± 2201 days (153-10 268 days) post-transplant and showed a serum creatinine of 1·7 ± 0·7 mg/dl. Renal transplant recipients investigated > 1·5 years post-transplant showed higher total NK cell counts than recipients studied < 1·5 years after transplantation (P = 0·006). High NK cells were associated with high glomerular filtration rate (P = 0·002) and low serum creatinine (P = 0·005). Interestingly, high NK cells were associated with high CD4⁺ CD25⁺ CD127^- forkhead box protein 3 (FoxP3⁺ ) T_reg that co-express the phenotype Helios⁺ interferon (IFN)-γ^- and appear to have stable FoxP3 expression and originate from the thymus. Furthermore, high total NK cells were associated with T_reg that co-express the phenotypes interleukin (IL)-10^- transforming growth factor (TGF)-β⁺ (P = 0·013), CD183⁺ CD62L^- (P = 0·003), CD183⁺ CD62⁺ (P = 0·001), CD183^- CD62L⁺ (P = 0·002), CD252^- CD152⁺ (P < 0·001), CD28⁺ human leucocyte antigen D-related (HLA-DR^- ) (P = 0·002), CD28⁺ HLA-DR⁺ (P < 0·001), CD95⁺ CD178^- (P < 0·001) and CD279^- CD152⁺ (P < 0·001), suggesting that these activated T_reg home in peripheral tissues and suppress effector cells via TGF-β and cytotoxic T lymphocyte-associated protein 4 (CTLA-4). The higher numbers of NK and T_reg cell counts in patients with long-term good allograft function and the statistical association of these two lymphocyte subsets with each other suggest a direct or indirect (via DC) interaction of these cell subpopulations that contributes to good long-term allograft acceptance. Moreover, we speculate that regulatory NK cells are formed late post-transplant that are able to inhibit graft-reactive effector cells.

Gαq Regulates the Development of Rheumatoid Arthritis by Modulating Th1 Differentiation

The Gαq-containing G protein, an important member of G_q/11 class, is ubiquitously expressed in mammalian cells. Gαq has been found to play an important role in immune regulation and development of autoimmune disease such as rheumatoid arthritis (RA). However, how Gαq participates in the pathogenesis of RA is still not fully understood. In the present study, we aimed to find out whether Gαq controls RA via regulation of Th1 differentiation. We observed that the expression of Gαq was negatively correlated with the expression of signature Th1 cytokine (IFN-γ) in RA patients, which suggests a negative role of Gαq in differentiation of Th1 cells. By using Gαq knockout (Gnaq-/-) mice, we demonstrated that loss of Gαq led to enhanced Th1 cell differentiation. Gαq negative regulated the differentiation of Th1 cell by modulating the expression of T-bet and the activity of STAT4. Furthermore, we detected the increased ratio of Th1 cells in Gnaq-/- bone marrow (BM) chimeras spontaneously developing inflammatory arthritis. In conclusion, results presented in the study demonstrate that loss of Gαq promotes the differentiation of Th1 cells and contributes to the pathogenesis of RA.

Intratumoral Th2 predisposition combines with an increased Th1 functional phenotype in clinical response to intravesical BCG in bladder cancer

Th1-type immunity is considered to be required for efficient response to BCG in bladder cancer, although Th2 predisposition of BCG responders has recently been reported. The aim was to evaluate the relationship of Th1 and Th2 components in 23 patients undergoing BCG treatment. Peripheral blood, serum and urine samples were prospectively collected at baseline, during and after BCG. Th1 (neopterin, tryptophan, kynurenine, kynurenine-to-tryptophan ratio (KTR), IL-12, IFN-γ, soluble TNF-R75 and IL-2Rα) and Th2 (IL-4, IL-10) biomarkers as well as CD4 expression in T helper (Th), effector and regulatory T cells were determined. Local immune cell subsets were measured on formalin-fixed, paraffin-embedded cancer tissue by immunohistochemistry to examine expression of transcription factors that control Th1 (T-bet) and Th2-type (GATA3) immunity. We confirmed a Th2 predisposition with a mean GATA3/T-bet ratio of 5.51. BCG responders showed significantly higher levels of urinary (p = 0.003) and serum neopterin (p = 0.012), kynurenine (p = 0.015), KTR (p = 0.005), IFN-γ (p = 0.005) and IL-12 (p = 0.003) during therapy, whereas levels of IL-10 decreased significantly (p < 0.001) compared to non-responders. GATA3/T-bet ratio correlated positively with serum neopterin (p = 0.008), IFN-γ (p = 0.013) and KTR (p = 0.018) after the first BCG instillation. We observed a significant increase in CD4 expression in the Th cell population (p < 0.05), with only a modest tendency toward higher frequency in responders compared to non-responders (p = 0.303). The combined assessment of GATA3/T-bet ratio, neopterin and KTR may be a useful biomarker in predicting BCG response. Th2-promoting factors such as GATA3 may trigger Th1-type immune responses and thus contribute to the BCG success.

Pro-Tumor and Anti-Tumor Functions of IL-17 and of TH17 Cells in Tumor Microenvironment

The current review reveals the seven subclasses of CD4+ T helper cells, i.e. Th1, Th2, Th9, Th17, Th22, regulatory T cells and Tfh, the cytokines produced by them and their role in tumor microenvironment. Main attention was paid to IL-17 and Th17 cells. IL-17-producing cells were described, among which were Treg17 cells and Tc17 cells. The transcription factors, engaged in the activation of Th17 cell differentiation were reviewed. It was shown that Th17 cells might possess regulatory functions in tumor microenvironments that directs toward immunosuppression. The reciprocity between Treg and Th17 cells is realized when the production of a large amount of TGF-β in tumors causes Treg cell differentiation, and the addition of IL-6 shifts the differentiation of naïve T cells to Th17 cells. The main pro-tumor role of IL-17 is the promotion of tumor angiogenesis through stimulation of fibroblasts and endothelial cells. The antitumor functions of IL-17 are associated with enhancement of cytotoxic activity of tumor specific CTL cells and with angiogenesis that provide channels through which immune cells might invade tumor and promote antitumor immunity.

Molecular Pathogenesis of Peripheral T Cell Lymphoma

Understanding the molecular pathogenesis of peripheral T cell lymphomas (PTCLs) has lagged behind that of B cell lymphomas due to disease rarity. However, novel approaches are gradually clarifying these mechanisms, and gene profiling has identified specific signaling pathways governing PTCL cell survival and growth. For example, genetic alterations have been discovered, including signal transducer and activator of transcription (STAT)3 and STAT5b mutations in several PTCLs, disease-specific ras homolog family member A (RHOA) mutations in angioimmunoblastic T cell lymphoma (AITL), and recurrent translocations at the dual specificity phosphatase 22 (DUSP22) locus in anaplastic lymphoma receptor tyrosine kinase (ALK)-negative anaplastic large cell lymphomas (ALCLs). Intriguingly, some PTCL-relevant mutations are seen in apparently normal blood cells as well as tumor cells, while others are confined to tumor cells. These data have dramatically changed our understanding of PTCL origins: once considered to originate from mature T lymphocytes, some PTCLs are now believed to emerge from immature hematopoietic progenitor cells.

Xianfanghuomingyin, a Chinese Compound Medicine, Modulates the Proliferation and Differentiation of T Lymphocyte in a Collagen-Induced Arthritis Mouse Model

In traditional Chinese medicine (TCM), xianfanghuomingyin (XFHM) is used to treat autoimmune diseases, including rheumatoid arthritis (RA). Here, we studied the mechanisms underlying its treatment effects, especially its anti-inflammatory effects in a collagen-induced arthritis (CIA) mouse model. We found that cartilage destruction and pannus formation were alleviated by treatment with XFHM. The abnormal differentiation of Th1 and Th17 cells was downregulated significantly by XFHM, and Th2 and Treg cells were upregulated. Moreover, the expression levels of specific cytokines and transcription factors related to Th1 cells (interferon γ [IFNγ], T-bet) and Th17 cells (interleukin- [IL-] 17) and the nuclear receptor retinoic acid receptor-related orphan receptor-gamma (RORγ) were downregulated. Serum IL-4 and GATA-3, which contribute to Th2 cells differentiation, increased significantly after XFHM administration. These results indicate that XFHM can restore the balance of T lymphocytes and reestablish the immunological tolerance to inhibit autoinflammatory disorder of RA. Taken together, XFHM can be used as a complementary or alternative traditional medicine to treat RA.

Lack of galectin-3 increases Jagged1/Notch activation in bone marrow-derived dendritic cells and promotes dysregulation of T helper cell polarization

Galectin-3, an endogenous glycan-binding protein, is abundantly expressed at sites of inflammation and immune cell activation. Although this lectin has been implicated in the control of T helper (Th) polarization, the mechanisms underlying this effect are not well understood. Here, we investigated the role of endogenous galectin-3 during the course of experimental Leishmania major infection using galectin-3-deficient (Lgals3(-/-)) mice in a BALB/c background and the involvement of Notch signaling pathway in this process. Lgals3(-/-) mice displayed an augmented, although mixed Th1/Th2 responses compared with wild-type (WT) mice. Concomitantly, lymph node and footpad lesion cells from infected Lgals3(-/-) mice showed enhanced levels of Notch signaling components (Notch-1, Jagged1, Jagged2 and Notch target gene Hes-1). Bone marrow-derived dendritic cells (BMDCs) from uninfected Lgals3(-/-) mice also displayed increased expression of the Notch ligands Delta-like-4 and Jagged1 and pro-inflammatory cytokines. In addition, activation of Notch signaling in BMDCs upon stimulation with Jagged1 was more pronounced in Lgals3(-/-) BMDCs compared to WT BMDCs; this condition resulted in increased production of IL-6 by Lgals3(-/-) BMDCs. Finally, addition of exogenous galectin-3 to Lgals3(-/-) BMDCs partially reverted the increased sensitivity to Jagged1 stimulation. Our results suggest that endogenous galectin-3 regulates Notch signaling activation in BMDCs and influences polarization of T helper responses, thus increasing susceptibility to L. major infection.

Transcription Factor KLF2 in Dendritic Cells Downregulates Th2 Programming via the HIF-1α/Jagged2/Notch Axis

The adaptive immune response is tightly regulated by complex signals in dendritic cells (DCs). Although Th2 polarization is dictated by defined functional DC subsets, the molecular factors that govern the amplitude of these responses are not well understood. Krüppel-like factor 2 (KLF2) is a transcription factor that negatively regulates the activation of numerous immune cells in response to stimuli. Here, we demonstrate that suppression of KLF2 in conditioned DCs preferentially amplifies Th2 responses in two model systems, one of which is a prototypical intracellular pathogen and the other an allergen. This elevation in Th2 responses was dependent on contact-mediated Notch signaling in vitro and in vivo. A deficiency of KLF2 increased the expression of Notch ligand Jagged2 via hypoxia-inducible factor 1α (HIF-1α), which led to Th2 amplification. Our results revealed a novel circuit in DCs for Th2 polarization that is governed by KLF2.

Dendritic cells are the key element that bridges innate and adaptive immunity. A complex and not-well-understood area in dendritic cell biology is the regulatory network that predetermines or moderates their function to shape the adaptive immune response. Our study for the first time demonstrates that KLF2, a transcription factor, conditions dendritic cells to regulate Th2 responses via a Jagged2/Notch axis. Downregulation of KLF2 expression in dendritic cells may provide a beneficial effect for treatment of diseases such as obesity or parasitic infections but may be deleterious in the case of invasion by intracellular pathogens. Strategies to tune KLF2 may be useful for future therapeutic approaches to particular diseases of mankind.

Electronic Sorting of Immune Cell Subpopulations Based on Highly Plastic Genes

Immune cells are highly heterogeneous and plastic with regard to gene expression and cell phenotype. In this study, we categorized genes into those with low and high gene plasticity, and those categories revealed different functions and applications. We proposed that highly plastic genes could be suited for the labeling of immune cell subpopulations; thus, novel immune cell subpopulations could be identified by gene plasticity analysis. For this purpose, we systematically analyzed highly plastic genes in human and mouse immune cells. In total, 1,379 human and 883 mouse genes were identified as being extremely plastic. We also expanded our previous immunoinformatic method, electronic sorting, which surveys big data to perform virtual analysis. This approach used correlation analysis and took dosage changes into account, which allowed us to identify the differentially expressed genes. A test with human CD4(+) T cells supported the method's feasibility, effectiveness, and predictability. For example, with the use of human nonregulatory T cells, we found that FOXP3(hi)CD4(+) T cells were highly expressive of certain known molecules, such as CD25 and CTLA4, and that this process of investigation did not require isolating or inducing these immune cells in vitro. Therefore, the sorting process helped us to discover the potential signature genes or marker molecules and to conduct functional evaluations for immune cell subpopulations. Finally, in human CD4(+) T cells, 747 potential immune cell subpopulations and their candidate signature genes were identified, which provides a useful resource for big data-driven knowledge discoveries.

Arnica montana effects on gene expression in a human macrophage cell line. Evaluation by quantitative Real-Time PCR

BACKGROUND

Arnica montana is a popular traditional remedy widely used in complementary medicine, also for its wound healing properties. Despite its acknowledged action in clinical settings at various doses, the molecular aspects relating to how A. montana promotes wound healing remain to be elucidated. To fill this gap, we evaluated the whole plant extract, in a wide range of dilutions, in THP-1 human cells, differentiated into mature macrophages and into an alternative IL-4-activated phenotype involved in tissue remodelling and healing.

METHODS

Real-time quantitative Reverse Transcription Polymerase Chain Reaction (PCR) analysis was used to study the changes in the expression of a customized panel of key genes, mainly cytokines, receptors and transcription factors.

RESULTS

On macrophages differentiated towards the wound healing phenotype, A. montana affected the expression of several genes. In particular CXC chemokine ligand 1 (CXCL1), coding for an chief chemokine, exhibited the most consistent increase of expression, while also CXC chemokine ligand 2 (CXCL2), Interleukin8 (IL8) and bone morphogenetic protein (BMP2) were slightly up-regulated, suggesting a positive influence of A. montana on neutrophil recruitment and on angiogenesis. MMP1, coding for a metalloproteinase capable of cleaving extracellular matrix substrates, was down-regulated. Most results showed non-linearity of the dose-effect relationship.

CONCLUSIONS

This exploratory study provides new insights into the cellular and molecular mechanisms of action of A. montana as a promoter of healing, since some of the genes it modifies are key regulators of tissue remodelling, inflammation and chemotaxis.

Gfi1, a transcriptional repressor, inhibits the induction of the T helper type 1 programme in activated CD4 T cells

A transcriptional repressor Gfi1 promotes T helper type 2 (Th2) cell development and inhibits Th17 and inducible regulatory T-cell differentiation. However, the role of Gfi1 in regulating Th1 cell differentiation and the Th1-type immune response remains to be investigated. We herein demonstrate that Gfi1 inhibits the induction of the Th1 programme in activated CD4 T cells. The activated Gfi1-deficient CD4 T cells spontaneously develop into Th1 cells in an interleukin-12- and interferon-γ-independent manner. The increase of Th1-type immune responses was confirmed in vivo in Gfi1-deficient mice using a murine model of nickel allergy and delayed-type hypersensitivity (DTH). The expression levels of Th1-related transcription factors were found to increase in Gfi1-deficient activated CD4 T cells. Tbx21, Eomes and Runx2 were identified as possible direct targets of Gfi1. Gfi1 binds to the Tbx21, Eomes and Runx2 gene loci and reduces the histone H3K4 methylation levels in part by modulating Lsd1 recruitment. Together, these findings demonstrate a novel regulatory role of Gfi1 in the regulation of the Th1-type immune response.

LZTFL1 Upregulated by All-Trans Retinoic Acid during CD4+ T Cell Activation Enhances IL-5 Production

Retinoic acids, which are metabolites of vitamin A, have been shown to be involved in multiple T cell effector responses through their binding to the retinoic acid receptor, a ligand-activated transcription factor. Because the molecular mechanism of regulation by retinoic acid is still not fully uncovered, we investigated the gene expression profile of all-trans retinoic acid (ATRA)-treated human CD4(+) T cells. Leucine zipper transcription factor-like 1 (LZTFL1) was upregulated by ATRA in a dose- and time-dependent manner. The expression of LZTFL1 depended on both ATRA and TCR signaling. LZTFL1 accumulated in the plasma membrane compartment of human CD4(+) T cells, and, during immunological synapse formation, it transiently redistributed to the T cell and APC contact zone, indicating its role in T cell activation. Live-cell imaging demonstrates that at the initial stage of immunological synapse formation, LZTFL1 is concentrated at the APC contact site, and, during later stages, it relocates to the distal pole. Knockdown of LZTFL1 reduced the basal- and ATRA-induced levels of IL-5 in CD4(+) T cells, and overexpression of LZTFL1 enhanced the TCR-mediated NFAT signaling, suggesting that LZTFL1 is an important regulator of ATRA-induced T cell response. Together, these data indicate that LZTFL1 modulates T cell activation and IL-5 levels.

Immunomodulator plasmid projected by systems biology as a candidate for the development of adjunctive therapy for respiratory syncytial virus infection

An imbalance in Th1/Th2 cytokine immune response has been described to influence the pathogenesis of respiratory syncytial virus (RSV) acute bronchiolitis and the severity of infection. Th2-driven response has been well described under first RSV vaccine (formalin-inactivated RSV vaccine antigens) and replicated in some conditions for RSV-infected mice, in which a Th2-dependent lung eosinophilia increases illness severity, accompanied of tissue damage. Currently, several prototypes of RSV vaccine are being tested, but there is no vaccine available so far. The advance of bioinformatics can help to solve this issue. Systems biology approaches based on network topological analysis may help to identify new genes in order to direct Th1 immune response during RSV challenge. For this purpose, network centrality analyses from high-throughput experiments were performed in order to select major genes enrolled in each T-helper immune response. Thus, genes termed Hub (B) and bottlenecks (H), which control the flow of biological information (Th1 or Th2 immune response, in this case) within the network, would be identified. As these genes possess high potential to promote Th1 immune response, they could be cloned under regulation of specific promoters in a plasmid, which will be available as a gene-transfer adjunctive to vaccines. Th1 immune response potentiated by our strategy may contribute to accelerate Th1/Th2 shift from neonatal immune system, which might favor protective immunity against RSV infection and reduce lung damage.

Functional and Phenotypic Plasticity of CD4(+) T Cell Subsets

The remarkable plasticity of CD4(+) T cells allows individuals to respond to environmental stimuli in a context-dependent manner. A balance of CD4(+) T cell subsets is critical to mount responses against pathogen challenges to prevent inappropriate activation, to maintain tolerance, and to participate in antitumor immune responses. Specification of subsets is a process beginning in intrathymic development and continuing within the circulation. It is highly flexible to adapt to differences in nutrient availability and the tissue microenvironment. CD4(+) T cell subsets have significant cross talk, with the ability to "dedifferentiate" given appropriate environmental signals. This ability is dependent on the metabolic status of the cell, with mTOR acting as the rheostat. Autoimmune and antitumor immune responses are regulated by the balance between regulatory T cells and Th17 cells. When a homeostatic balance of subsets is not maintained, immunopathology can result. CD4(+) T cells carry complex roles within tumor microenvironments, with context-dependent immune responses influenced by oncogenic drivers and the presence of inflammation. Here, we examine the signals involved in CD4(+) T cell specification towards each subset, interconnectedness of cytokine networks, impact of mTOR signaling, and cellular metabolism in lineage specification and provide a supplement describing techniques to study these processes.

Administration of naloxone in combination with recombinant Plasmodium vivax AMA-1 in BALB/c mice induces mixed Th1/Th2 immune responses

Naloxone (NLX) has the ability to shift the immune response to a Th1 profile. Therefore, the adjuvant efficacy of NLX with recombinant P. vivax apical membrane antigen-1(rPvAMA-1) in BALB/c mice was evaluated. Mice were immunized subcutaneously with purified rPvAMA-1 formulated with NLX (doses of 5 mg/kg body weight) alone or in combination with IFA. A significant increase in anti-PvAMA-1 IgG antibody after the second boost (mean OD₄₉₀  = 2·08 and 2·17, in groups received, rPvAMA-1/NLX and rPvAMA-1/NLX/IFA, respectively) was detected. IgG1 and IgG2b were the predominant isotypes in all immunized mouse groups. In immunized mice with rPvAMA-1/NLX (mean: 1036 pg/mL) and with rPvAMA-1/NLX/IFA (mean: 1024 pg/mL), IFN-γ was elicited in response to rPvAMA-1 after the second boost. No detectable IL-4 secretion was determined in all tested groups. In conclusion, the administration of NLX alone or NLX/IFA with rPvAMA-1 in BALB/c mice, which induced mixed Th1/Th2 immune responses, was comparable with that of the same recombinant antigen with CFA/IFA adjuvant. The results indicate that NLX alone may possibly not be considered as a potent Th1 adjuvant in PvAMA-1-based vaccine. However, in order to modulate immune responses from mixed Th1/Th2 to strong and protective Th1 response, further study is warranted on combination of NLX with other adjuvants such as CpG motifs or MPL in proper vaccine formulation. Additionally, dose-response study is necessary to determine the effect of different doses of antigen combined with NLX (at various doses) in Balb/c mice.

Hyperoxia promotes polarization of the immune response in ovalbumin-induced airway inflammation, leading to a TH17 cell phenotype

Previous studies have demonstrated that hyperoxia-induced stress and oxidative damage to the lungs of mice lead to an increase in IL-6, TNF-α, and TGF-β expression. Together, IL-6 and TGF-β have been known to direct T cell differentiation toward the TH17 phenotype. In the current study, we tested the hypothesis that hyperoxia promotes the polarization of T cells to the TH17 cell phenotype in response to ovalbumin-induced acute airway inflammation. Airway inflammation was induced in female BALB/c mice by intraperitoneal sensitization and intranasal introduction of ovalbumin, followed by challenge methacholine. After the methacholine challenge, animals were exposed to hyperoxic conditions in an inhalation chamber for 24 h. The controls were subjected to normoxia or aluminum hydroxide dissolved in phosphate buffered saline. After 24 h of hyperoxia, the number of macrophages and lymphocytes decreased in animals with ovalbumin-induced airway inflammation, whereas the number of neutrophils increased after ovalbumin-induced airway inflammation. The results showed that expression of Nrf2, iNOS, T-bet and IL-17 increased after 24 of hyperoxia in both alveolar macrophages and in lung epithelial cells, compared with both animals that remained in room air, and animals with ovalbumin-induced airway inflammation. Hyperoxia alone without the induction of airway inflammation lead to increased levels of TNF-α and CCL5, whereas hyperoxia after inflammation lead to decreased CCL2 levels. Histological evidence of extravasation of inflammatory cells into the perivascular and peribronchial regions of the lungs was observed after pulmonary inflammation and hyperoxia. Hyperoxia promotes polarization of the immune response toward the TH17 phenotype, resulting in tissue damage associated with oxidative stress, and the migration of neutrophils to the lung and airways. Elucidating the effect of hyperoxia on ovalbumin-induced acute airway inflammation is relevant to preventing or treating asthmatic patients that require oxygen supplementation to reverse the hypoxemia.

IFNγ+ Treg in-vivo and in-vitro represent both activated nTreg and peripherally induced aTreg and remain phenotypically stable in-vitro after removal of the stimulus

Background

IFNγ-producing CD4+CD25+Foxp3+CD127- Treg represent the first line of Treg during an immune response. In the present study we determined whether IFNγ+ Treg in-vivo and in-vitro are Helios-positive representing activated natural (nTreg) or Helios-negative representing adaptive Treg (aTreg) and whether they originate from CD4+CD25+ and/or CD4+CD25- PBL. Furtheron, we investigated whether they are inducible by recombinant IFNγ (rIFNγ) as a single stimulus, decrease in-vitro after elimination of the stimulus, and have a demethylated Foxp3 Treg-specific demethylated region (TSDR) which is associated with stable Foxp3 expression.

Method

Subsets of IFNγ+ Treg were determined in peripheral blood of healthy controls using eight-color flow cytometry and were further investigated in-vitro. Foxp3 TSDR methylation status was determined using bisulphite polymerase chain reaction (PCR) and high resolution melt (HRM) analysis.

Results

Nearly all Treg in the peripheral blood were Helios+IFNγ- (1.9 ± 1.1/μl) and only few were Helios+IFNγ+ or Helios-IFNγ+ Treg (both 0.1 ± 0.1/μl). Enriched IFNγ+ Treg subsets showed in part strong Foxp3 TSDR demethylation. In-vitro, rIFNγ was unable to induce Treg. CD4+CD25+ enriched PBL stimulated with PMA/Ionomycin in the presence of rIFNγ were rather resistant to the effect of rIFNγ, in contrast to CD4+CD25- enriched PBL which showed increasing total Treg with Helios+ Treg switching from IFNγ- to IFNγ+ and increasing Helios-IFNγ+ Treg. The data indicate that rIFNγ, in combination with a polyclonal stimulus, activates nTreg and induces aTreg. When phorbol 12-myristate 13-acetate (PMA)/Ionomycin was washed out from the cell culture after 6 h stimulation, Treg induction continued for at least 96 h of cell culture, contradicting the hypothesis that removal of the stimulus results in significant decrease of IFNγ- and IFNγ+ CD4+CD25+Foxp3+CD127- Treg due to loss of Foxp3 expression.

Conclusions

IFNγ+Helios- aTreg as well as IFNγ+Helios+ nTreg are detectable in the blood of healthy individuals, show in part strong Foxp3 TSDR demethylation and are inducible in-vitro. The present data provide further insight concerning the in-vivo and in-vitro characteristics of IFNγ+ Treg and help to understand their role in immunoregulation. Alloantigen-specific demethylated IFNγ+Helios+ nTreg might represent a suitable marker for monitoring graft-specific immunosuppression in renal transplant recipients.

Expression levels of Notch1 and Delta-like 4 in peripheral lymphocytes and their relationship with T helper 17 (Th17) cells in renal transplant recipients

OBJECTIVE

This study aimed to investigate the role of the Notch1/Delta-like 4 signaling pathway and its relationship with T helper 17 (Th17) cells in the peripheral transplantation immune of renal transplant recipients.

METHODS

Fifty-two kidney transplant recipients in our hospital were selected and divided into the acute rejection group (AR), renal tubular necrosis (ATN) group, and stable renal function group, according to their postoperative recovery. Flow cytometry was used to detect the expression of Notch1 and Delta-like 4 in peripheral lymphocytes and the presence of Th17 cells in the kidney of transplant recipients.

RESULTS

The expression levels of Notch1 and Delta-like 4 and level of Th17 cells among the three groups before surgery and at postoperative day 1 showed no significant differences (P>0.05). At 3, 7, and 14d after surgery, these three factors in the AR group were significantly higher than in the stable renal function group (P<0.01) and ATN group (P<0.01), where the levels in the latter two groups were similar. Upon the occurrence of acute rejection, the Notch1 and Delta-like 4 expression and Th17 cell ratio were significantly increased (P<0.01) but gradually decreased after anti-rejection therapy. Notch1 and Delta-like 4 were significantly positively correlated with Th17 cells (r=0.893, P<0.01 and r=0.893, P<0.01, respectively).

CONCLUSION

The detection of Notch1 and Delta-like 4 expression in peripheral blood lymphocytes of renal transplant recipients can serve as a positive indicator for evaluating the diagnosis and treatment efficacy of the AR reaction.

Vehicular exhaust particles promote allergic airway inflammation through an aryl hydrocarbon receptor-notch signaling cascade

BACKGROUND

Traffic-related particulate matter (PM) has been linked to a heightened incidence of asthma and allergic diseases. However, the molecular mechanisms by which PM exposure promotes allergic diseases remain elusive.

OBJECTIVE

We sought to determine the expression, function, and regulation of pathways involved in promotion of allergic airway inflammation by PM.

METHODS

We used gene expression transcriptional profiling, in vitro culture assays, and in vivo murine models of allergic airway inflammation.

RESULTS

We identified components of the Notch pathway, most notably Jagged 1 (Jag1), as targets of PM induction in human monocytes and murine dendritic cells. PM, especially ultrafine particles, upregulated TH cytokine levels, IgE production, and allergic airway inflammation in mice in a Jag1- and Notch-dependent manner, especially in the context of the proasthmatic IL-4 receptor allele Il4raR576. PM-induced Jag1 expression was mediated by the aryl hydrocarbon receptor (AhR), which bound to and activated AhR response elements in the Jag1 promoter. Pharmacologic antagonism of AhR or its lineage-specific deletion in CD11c(+) cells abrogated the augmentation of airway inflammation by PM.

CONCLUSION

PM activates an AhR-Jag1-Notch cascade to promote allergic airway inflammation in concert with proasthmatic alleles.

Development of a unique epigenetic signature during in vivo Th17 differentiation

Activated naive CD4⁺ T cells are highly plastic cells that can differentiate into various T helper (Th) cell fates characterized by the expression of effector cytokines like IFN-γ (Th1), IL-4 (Th2) or IL-17A (Th17). Although previous studies have demonstrated that epigenetic mechanisms including DNA demethylation can stabilize effector cytokine expression, a comprehensive analysis of the changes in the DNA methylation pattern during differentiation of naive T cells into Th cell subsets is lacking. Hence, we here performed a genome-wide methylome analysis of ex vivo isolated naive CD4⁺ T cells, Th1 and Th17 cells. We could demonstrate that naive CD4⁺ T cells share more demethylated regions with Th17 cells when compared to Th1 cells, and that overall Th17 cells display the highest number of demethylated regions, findings which are in line with the previously reported plasticity of Th17 cells. We could identify seven regions located in Il17a, Zfp362, Ccr6, Acsbg1, Dpp4, Rora and Dclk1 showing pronounced demethylation selectively in ex vivo isolated Th17 cells when compared to other ex vivo isolated Th cell subsets and in vitro generated Th17 cells, suggesting that this unique epigenetic signature allows identifying and functionally characterizing in vivo generated Th17 cells.

The First Line of Defense: The Effects of Alcohol on Post-Burn Intestinal Barrier, Immune Cells, and Microbiome

Alcohol (ethanol) is one of the most globally abused substances, and is one of the leading causes of premature death in the world. As a result of its complexity and direct contact with ingested alcohol, the intestine represents the primary source from which alcohol-associated pathologies stem. The gut is the largest reservoir of bacteria in the body, and under healthy conditions, it maintains a barrier preventing bacteria from translocating out of the intestinal lumen. The intestinal barrier is compromised following alcohol exposure, which can lead to life-threatening systemic complications including sepsis and multiple organ failure. Furthermore, alcohol is a major confounding factor in pathology associated with trauma. Experimental data from both human and animal studies suggest that alcohol perturbs the intestinal barrier and its function, which is exacerbated by a "second hit" from traumatic injury. This article highlights the role of alcohol-mediated alterations of the intestinal epithelia and its defense against bacteria within the gut, and the impact of alcohol on intestinal immunity, specifically on T cells and neutrophils. Finally, it discusses how the gut microbiome both contributes to and protects the intestines from dysbiosis after alcohol exposure and trauma.

Insufficient interleukin-12 signalling favours differentiation of human CD4(+) and CD8(+) T cells into GATA-3(+) and GATA-3(+) T-bet(+) subsets in humanized mice

Differentiation of CD4(+) T cells into type 1 or type 2 subsets is mediated by the expression of the opposing lineage defining transcription factors T-bet and GATA-3. However, the existence of GATA-3(+) T-bet(+) CD4(+) T cells in mice suggests functional plasticity of these subsets. Little is known about type 1 and type 2 plasticity of human T-cell subsets in vivo. Here, we show that in the xenogeneic environment of humanized mice, which lacks a functional immune-regulatory network, human CD4(+) and, notably, CD8(+) T cells preferentially differentiate into interleukin (IL)-4(+) GATA-3(+) and IL-4(+) interferon-γ(+) GATA-3(+) T-bet(+) subsets. Treatment with recombinant human IL-12 or expansion of IL-12-producing human dendritic cells in vivo reverted this phenotype and led to the down-regulation of GATA-3 expression. These changes also correlated with improved antiviral immune responses in humanized mice. In conclusion, our study shows the capacity of human CD4(+) and CD8(+) T cells for stable co-expression of GATA-3 and T-bet in humanized mice and reveals a critical role for IL-12 in regulating this phenotype.

The mucosal immune system in the oral cavity-an orchestra of T cell diversity

The mucosal immune system defends against a vast array of pathogens, yet it exhibits limited responses to commensal microorganisms under healthy conditions. The oral-pharyngeal cavity, the gateway for both the gastrointestinal and respiratory tracts, is composed of complex anatomical structures and is constantly challenged by antigens from air and food. The mucosal immune system of the oral-pharyngeal cavity must prevent pathogen entry while maintaining immune homeostasis, which is achieved via a range of mechanisms that are similar or different to those utilized by the gastrointestinal immune system. In this review, we summarize the features of the mucosal immune system, focusing on T cell subsets and their functions. We also discuss our current understanding of the oral-pharyngeal mucosal immune system.

Cleavage of the terminal N-acetylglucosamine of egg-white ovalbumin N-glycans significantly reduces IgE production and Th2 cytokine secretion

Ovalbumin (OA) is one of the most abundant of the glycoprotein allergens, and induces a T-helper type 2 immune response that results in an IgE-mediated hypersensitivity. In this study, the terminal carbohydrates of N-glycans from intact OA were cleaved with the exoglycosidases galactosidase, mannosidase, and N-acetylglucosaminidase to generate degalactosylated-OA, demannosylated-OA, and de-N-acetylglucosaminylated-OA, respectively, in order to evaluate their role in allergenicity. The exoglycosidase digestion procedure did not result in either degradation or contamination of the three deglycosylated sample, and the digestion efficiency was confirmed by comparing the results of glycan analysis of the three exoglycosidase-treated OAs with that of glycans of intact OA. Mice were immunized with either intact or exoglycosidase-treated OAs, and their respective allergic reactions were compared. IgE production in the de-N-acetylglucosaminylated-OA group was reduced to 58.8% of that in the intact OA group. In addition, the production levels of the cytokines interleukin-4 and interleukin-5 were significantly reduced in the de-N-acetylglucosaminylated-OA group to 53.4% and 45.8% of the levels in the intact OA group, respectively. However, there were almost no changes (or only slight reductions) in the degalactosylated-OA and demannosylated-OA groups, respectively. These results indicate that cleavage of the terminal carbohydrate, and particularly N-acetylglucosamine, reduces the allergenicity of OA. This is the first report of the effect of cleavage of the terminal carbohydrate on glycoprotein allergenicity.