Regulation of Th2 Cell Immunity by Dendritic Cells

The Interplay Between Helicobacter pylori and Suppressors of Cytokine Signaling (SOCS) Molecules in the Development of Gastric Cancer and Induction of Immune Response

Helicobacter pylori (H. pylori) colonizes the stomach and leads to the secretion of a vast range of cytokines by infiltrated leukocytes directing immune/inflammatory response against the bacterium. To regulate immune/inflammatory responses, suppressors of cytokine signaling (SOCS) proteins bind to multiple signaling components located downstream of cytokine receptors, such as Janus kinase (JAK), signal transducers and activators of transcription (STAT). Dysfunctional SOCS proteins in immune cells may facilitate the immune evasion of H. pylori, allowing the bacteria to induce chronic inflammation. Dysregulation of SOCS expression and function can contribute to the sustained H. pylori-mediated gastric inflammation which can lead to gastric cancer (GC) development. Among SOCS molecules, dysregulated expression of SOCS1, SOCS2, SOCS3, and SOCS6 were indicated in H. pylori-infected individuals as well as in GC tissues and cells. H. pylori-induced SOCS1, SOCS2, SOCS3, and SOCS6 dysregulation can contribute to the GC development. The expression of SOCS molecules can be influenced by various factors, such as epigenetic DNA methylation, noncoding RNAs, and gene polymorphisms. Modulation of the expression of SOCS molecules in gastric epithelial cells and immune cells can be considered to control gastric carcinogenesis as well as regulate antitumor immune responses, respectively. This review aimed to explain the interplay between H. pylori and SOCS molecules in GC development and immune response induction as well as to provide insights regarding potential therapeutic strategies modulating SOCS molecules.

TXA2 attenuates allergic lung inflammation through regulation of Th2, Th9, and Treg differentiation

In lung, thromboxane A2 (TXA2) activates the TP receptor to induce proinflammatory and bronchoconstrictor effects. Thus, TP receptor antagonists and TXA2 synthase inhibitors have been tested as potential asthma therapeutics in humans. Th9 cells play key roles in asthma and regulate the lung immune response to allergens. Herein, we found that TXA2 reduces Th9 cell differentiation during allergic lung inflammation. Th9 cells were decreased approximately 2-fold and airway hyperresponsiveness was attenuated in lungs of allergic mice treated with TXA2. Naive CD4+ T cell differentiation to Th9 cells and IL-9 production were inhibited dose-dependently by TXA2 in vitro. TP receptor-deficient mice had an approximately 2-fold increase in numbers of Th9 cells in lungs in vivo after OVA exposure compared with wild-type mice. Naive CD4+ T cells from TP-deficient mice exhibited increased Th9 cell differentiation and IL-9 production in vitro compared with CD4+ T cells from wild-type mice. TXA2 also suppressed Th2 and enhanced Treg differentiation both in vitro and in vivo. Thus, in contrast to its acute, proinflammatory effects, TXA2 also has longer-lasting immunosuppressive effects that attenuate the Th9 differentiation that drives asthma progression. These findings may explain the paradoxical failure of anti-thromboxane therapies in the treatment of asthma.

Add-on sirolimus for the treatment of mild or moderate systemic lupus erythematosus via T lymphocyte subsets balance

OBJECTIVE

The efficacy of sirolimus in treating severe or refractory systemic lupus erythematosus (SLE) has been confirmed by small-scale clinical trials. However, few studies focused on mild or moderate SLE. Therefore, in this study we elucidated clinical efficacy of add-on sirolimus in patients with mild or moderate SLE.

METHODS

Data of 17 consecutive patients with SLE were retrospectively collected. SLE Disease Activity Index-2000 (SLEDAI-2K), clinical manifestation, laboratory data and peripheral T lymphocyte subsets with cytokines were collected before and 6 months after sirolimus add-on treatment. T cell subsets were detected by flow cytometry and cytokines were determined by multiplex bead-based flow fluorescent immunoassay simultaneously. Twenty healthy controls matched with age and sex were also included in our study.

RESULTS

(1) The numbers of peripheral blood lymphocytes, T cells, T helper (Th) cells, regulatory T (Treg) cells, Th1 cells, Th2 cells and Treg/Th17 ratios in patients with SLE were significantly lower, while the numbers of Th17 cells were evidently higher than those of healthy control (p<0.05). (2) After 6 months of sirolimus add-on treatment, urinary protein, pancytopenia, immunological indicators and SLEDAI-2K in patients with SLE were distinctively improved compared with those before sirolimus treatment (p<0.05). (3) The numbers of peripheral blood lymphocytes, T cells, Th cells, Treg cells, Th2 cells and the ratios of Treg/Th17 in patients with SLE after treatment were clearly higher than those before (p<0.05). (4) The levels of plasma interleukin (IL)-5, IL-6 and IL-10 in patients with SLE decreased notably, conversely the IL-4 levels increased remarkably compared with pretreatment (p<0.05).

CONCLUSIONS

(1) Patients with SLE presented imbalanced T cell subsets, especially the decreased ratio of Treg/Th17. (2) Sirolimus add-on treatment ameliorated clinical involvement, serological abnormalities and disease activity without adverse reactions in patients with SLE. (3) The multi-target therapy facilitates the enhanced numbers of Treg cells, Treg/Th17 imbalance and anti-inflammatory cytokines, simultaneously, reducing inflammatory cytokines.

Coculture of Human Dendritic and T Cells for the Study of Specific T Cell-Mediated Responses Against Food Allergens

Dendritic cells (DCs) connect innate and adaptive immunity by sampling, capturing, processing, and presenting the allergen to distinct subsets of CD4+ T cells. In food allergy, this process leads to the generation of allergen-specific Th2 responses and the production of type 2 cytokines that ultimately induce the synthesis of IgE by allergen-specific B cells. In this chapter, we have described different protocols for the isolation of circulating DCs as well as the generation of DC-like cells derived from autologous peripheral monocytes and the human monocytic THP-1 cell line. Coculture of isolated/generated DCs with CD4+ T cells obtained from PBMCs of allergic subjects allows the study of antigen-specific T cell immune responses against food allergens. Early responses upon allergen recognition can be determined by the upregulation of activation markers such as CD154 (CD40 ligand) and the detection of type 2 cytokines (IL-4, IL-5, IL-9, and IL-13). Delayed allergen-specific CD4+ T cell responses induce the proliferation of these cells and the accumulation of type 2 cytokines in coculture supernatants that can be quantified by different approaches (ELISA, EllaTM, and multiplex assays). Together, the protocols described in this chapter can be used to investigate the features of food proteins to induce food allergy, the influence of environmental factors to generate Th2-polarization, the function of DCs to generate differential immune responses in allergic versus tolerant individuals, and to assess the immunomodulating properties of potential therapeutic substances.

Straight to the point: targeted mRNA-delivery to immune cells for improved vaccine design

With the deepening of our understanding of adaptive immunity at the cellular and molecular level, targeting antigens directly to immune cells has proven to be a successful strategy to develop innovative and potent vaccines. Indeed, it offers the potential to increase vaccine potency and/or modulate immune response quality while reducing off-target effects. With mRNA-vaccines establishing themselves as a versatile technology for future applications, in the last years several approaches have been explored to target nanoparticles-enabled mRNA-delivery systems to immune cells, with a focus on dendritic cells. Dendritic cells (DCs) are the most potent antigen presenting cells and key mediators of B- and T-cell immunity, and therefore considered as an ideal target for cell-specific antigen delivery. Indeed, improved potency of DC-targeted vaccines has been proved in vitro and in vivo. This review discusses the potential specific targets for immune system-directed mRNA delivery, as well as the different targeting ligand classes and delivery systems used for this purpose.

Sex Differences Define the Vulnerability to Atherosclerosis

For several decades, atherosclerosis has attracted the attention of researchers around the world. Even being a major cause of serious cardiovascular disease and events, atherosclerosis is still not fully understood. Despite the fact that the main players in the pathogenesis of atherosclerosis are well known, many mechanisms of their implementation and interactions remain unknown. The same can be said about the risk factors for atherosclerosis. Many of them are known, but exactly how they work remains to be seen. The main objective of this review is to summarize the latest data on sex as a biological variable in atherosclerosis in humans and animals; to determine what we do not still know about how sex affects the process of growth and complications of atherosclerosis. In this review, we summarized data on sex differences at 3 atherosclerotic aspects: inflammation, vascular remodeling, and plaque morphology. With all overviewed data, we came to the conclusion on the atheroprotective role of female sex.

Osteoimmune Properties of Mesoporous Bioactive Nanospheres: A Study on T Helper Lymphocytes

Bioactive mesoporous glass nanospheres (nanoMBGs) charged with antiosteoporotic drugs have great potential for the treatment of osteoporosis and fracture prevention. In this scenario, cells of the immune system are essential both in the development of disease and in their potential to stimulate therapeutic effects. In the present work, we hypothesize that nanoMBGs loaded with ipriflavone can exert a positive osteoimmune effect. With this objective, we assessed the effects of non-loaded and ipriflavone-loaded nanoparticles (nanoMBGs and nanoMBG-IPs, respectively) on CD4+ Th2 lymphocytes because this kind of cell is implicated in the inhibition of osseous loss by reducing the RANKL/OPG relationship through the secretion of cytokines. The results indicate that nanoMBGs enter efficiently in CD4+ Th2 lymphocytes, mainly through phagocytosis and clathrin-dependent mechanisms, without affecting the function of these T cells or inducing inflammatory mediators or oxidative stress, thus maintaining the reparative Th2 phenotype. Furthermore, the incorporation of the anti-osteoporotic drug ipriflavone reduces the potential unwanted inflammatory response by decreasing the presence of ROS and stimulating intracellular anti-inflammatory cytokine release like IL-4. These results evidenced that nanoMBG loaded with ipriflavone exerts a positive osteoimmune effect.

The Impact of Nigella sativa Essential Oil on T Cells in Women with Hashimoto's Thyroiditis

BACKGROUND

Hashimoto's thyroiditis (HT) is an autoimmune disease mediated by T cells. It is characterized by the presence of thyroid autoantibodies in the serum, such as anti-thyroid peroxidase antibodies (TPO-Ab) and anti-thyroglobulin antibodies (TG-Ab). The essential oil extracted from Nigella sativa seeds is rich in bioactive substances, such as thymoquinone and cymene.

METHODS

Therefore, we examined the effect of essential oil from Nigella sativa (NSEO) on T cells from HT patients, especially their proliferation capacity, ability to produce cytokines, and susceptibility to apoptosis.

RESULTS

The lowest ethanol (EtOH) dilution (1:10) of NSEO significantly inhibited the proliferation of CD4⁺ and CD8⁺ T cells from HT patients and healthy women by affecting the percentage of dividing cells and the number of cell divisions. In addition, 1:10 and 1:50 NSEO dilutions induced cell death. Different dilutions of NSEO also reduced the concentration of IL-17A and IL-10. In healthy women, the level of IL-4 and IL-2 significantly increased in the presence of 1:10 and 1:50 NSEO dilutions. NSEO did not influence the concentration of IL-6 and IFN-γ.

CONCLUSIONS

Our study demonstrates that NSEO has a strong immunomodulatory effect on the lymphocytes of HT patients.

Influence of Humic Acids Isolated from Raised Bog Sphagnum Peat on Development of Th1/Th2 Immune Response

The course administration of humic acids isolated with sodium pyrophosphate from raised bog sphagnum peat reduces the parameters of a Th1-type immune response in C57BL/6 mice, the severity of an anaphylactic shock in outbred CD1 mice, and degranulation of mast cells after their immunization with ovalbumin. The addition of humic acids increases the stimulated production of IL-4, IL-10 and reduces the production of IL-2, IFNγ by peripheral blood mononuclear cells of healthy donors.

Effects of Graphene Oxide and Reduced Graphene Oxide Nanostructures on CD4+ Th2 Lymphocytes

The activation of T helper (Th) lymphocytes is necessary for the adaptive immune response as they contribute to the stimulation of B cells (for the secretion of antibodies) and macrophages (for phagocytosis and destruction of pathogens) and are necessary for cytotoxic T-cell activation to kill infected target cells. For these issues, Th lymphocytes must be converted into Th effector cells after their stimulation through their surface receptors TCR/CD3 (by binding to peptide-major histocompatibility complex localized on antigen-presenting cells) and the CD4 co-receptor. After stimulation, Th cells proliferate and differentiate into subpopulations, like Th1, Th2 or Th17, with different functions during the adaptative immune response. Due to the central role of the activation of Th lymphocytes for an accurate adaptative immune response and considering recent preclinical advances in the use of nanomaterials to enhance T-cell therapy, we evaluated in vitro the effects of graphene oxide (GO) and two types of reduced GO (rGO15 and rGO30) nanostructures on the Th2 lymphocyte cell line SR.D10. This cell line offers the possibility of studying their activation threshold by employing soluble antibodies against TCR/CD3 and against CD4, as well as the simultaneous activation of these two receptors. In the present study, the effects of GO, rGO15 and rGO30 on the activation/proliferation rate of these Th2 lymphocytes have been analyzed by studying cell viability, cell cycle phases, intracellular content of reactive oxygen species (ROS) and cytokine secretion. High lymphocyte viability values were obtained after treatment with these nanostructures, as well as increased proliferation in the presence of rGOs. Moreover, rGO15 treatment decreased the intracellular ROS content of Th2 cells in all stimulated conditions. The analysis of these parameters showed that the presence of these GO and rGO nanostructures did not alter the response of Th2 lymphocytes.

Molecular and Immunomodulatory Actions of New Antiasthmatic Agents: Exploring the Diversity of Biologics in Th2 Endotype Asthma

Asthma is a major respiratory disorder characterised by chronic inflammation and airway remodelling. It affects about 1-8% of the global population and is responsible for over 461,000 deaths annually. Until recently, the pharmacotherapy of severe asthma involved high doses of inhaled corticosteroids in combination with β-agonist for prolonged action, including theophylline, leukotriene antagonist or anticholinergic yielding limited benefit. Although the use of newer agents to target Th2 asthma endotypes has improved therapeutic outcomes in severe asthmatic conditions, there seems to be a paucity of understanding the diverse mechanisms through which these classes of drugs act. This article delineates the molecular and immunomodulatory mechanisms of action of new antiasthmatic agents currently being trialled in preclinical and clinical studies to remit asthmatic conditions. The ultimate goal in developing antiasthmatic agents is based on two types of approaches: either anti-inflammatory or bronchodilators. Biologic and most small molecules have been shown to modulate specific asthma endotypes, targeting thymic stromal lymphopoietin, tryptase, spleen tyrosine kinase (Syk), Janus kinase, PD-L1/PD-L2, GATA-3, and CD38 for the treatment and management of Th2 endotype asthma.

T helper type (Th1/Th2) responses to SARS-CoV-2 and influenza A (H1N1) virus: From cytokines produced to immune responses

Cytokines produced by T helper cells (Th cells) have essential roles in the body's defense against viruses. Type 1 T helper (Th1) cells are essential for the host defense toward intracellular pathogens while T helper type 2 (Th2) cells are considered to be critical for the helminthic parasites' elimination swine-origin influenza A (H1N1) virus, a disease led to an epidemic in 2009 and rapidly spread globally via human-to-human transmission. Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a global pandemic in 2020 and is a serious threat to the public health. Pulmonary immunopathology is the leading cause of death during influenza and SARS-CoV-2 epidemics and pandemics. Influenza and SARS-CoV-2 cause high levels of cytokines in the lung. Both inadequate levels and high levels of specific cytokines can have side effects. In this literature review article, we want to compare the Th1 and Th2 cells responses in SARS-CoV-2 and H1N1.

Caspase-11 regulates lung inflammation in response to house dust mites

Asthma is an inflammatory lung disorder characterized by mucus hypersecretion, cellular infiltration, and bronchial hyper-responsiveness. House dust mites (HDM) are the most prevalent cause of allergic sensitization. Canonical and noncanonical inflammasomes are multiprotein complexes that assemble in response to pathogen or danger-associated molecular patterns (PAMPs or DAMPs). Murine caspase-11 engages the noncanonical inflammasome. We addressed the role of caspase-11 in mediating host responses to HDM and subsequent allergic inflammation using caspase-11-/- mice, which lack caspase-11 while express caspase-1. We found that HDM induce caspase-11 expression in vitro. The presence of IL-4 and IL-13 promote caspase-11 expression. Additionally, caspase-11-/- macrophages show reduced release of IL-6, IL-12, and KC, and express lower levels of costimulatory molecules (e.g., CD40, CD86 and MHCII) in response to HDM stimulation. Notably, HDM sensitization of caspase-11-/- mice resulted in similar levels of IgE responses and hypothermia in response to nasal HDM challenge compared to WT. However, analysis of cell numbers and cytokines in bronchiolar alveolar lavage fluid (BALF) and histopathology of representative lung segments demonstrate altered inflammatory responses and reduced neutrophilia in the airways of the caspase-11-/- mice. These findings indicate that caspase-11 regulates airway inflammation in response to HDM exposure.

Enhancing Cancer Immunotherapeutic Efficacy with Sonotheranostic Strategies

Immunotherapy has revolutionized the modality for establishing a firm immune response and immunological memory. However, intrinsic limitations of conventional low responsive poor T cell infiltration and immune related adverse effects urge the coupling of cancer nanomedicines with immunotherapy for boosting antitumor response under ultrasound (US) sensitization to mimic dose-limiting toxicities for safe and effective therapy against advanced cancer. US is composed of high-frequency sound waves that mediate targeted spatiotemporal control over release and internalization of the drug. The unconventional US triggered immunogenic nanoengineered arena assists the limited immunogenic dose, limiting toxicities and efficacies. In this Review, we discuss current prospects of enhanced immunotherapy using nanomedicine under US. We highlight how nanotechnology designs and incorporates nanomedicines for the reprogramming of systematic immunity in the tumor microenvironment. We also emphasize the mechanical and biological potential of US, encompassing sonosensitizer activation for enhanced immunotherapeutic efficacies. Finally, the smartly converging combinational platform of US stimulated cancer nanomedicines for amending immunotherapy is summarized. This Review will widen scientists' ability to explore and understand the limiting factors for combating cancer in a precisely customized way.

Rapamycin alleviates renal damage in mice with systemic lupus erythematosus through improving immune response and function

This study aimed to explore the therapeutic effect and mechanism of rapamycin (RAPA) on systemic lupus erythematosus (SLE) in BALB/C mice induced by pristane. The mice were randomly divided into 5 groups (n = 6): control, model, saline, RAPA (1 mg/kg) and RAPA (2 mg/kg). All groups were injected with pristane except control. HE staining revealed 1 mg/kg and 2 mg/kg RAPA treatments obviously alleviated pathological changes in the kidney of SLE mice such as glomeruli enlargement, hyperplasia of mesangial cells, epithelial and endothelial cells, infiltration of inflammatory cells, and edema-like degeneration of renal tubules. Compared with control group, body weights and anti-ribosomal P-protein antibody (ARPA) level of the mice in model group and saline group decreased (P < 0.05), while immune complex deposition and levels of anti-dsDNA antibody, anti-smRNP antibody and urine protein in model group and saline group increased (P < 0.05). However, compared with model group and saline group, body weights of the mice in RAPA (1 mg/kg) group and RAPA (2 mg/kg) group increased (P < 0.05), while immune complex deposition and levels of anti-dsDNA antibody, anti-smRNP antibody, ARPA, and urine protein in RAPA (1 mg/kg) group and RAPA (2 mg/kg) group decreased (P < 0.05). Compared with control group, the proportion of dentritic cells (DC) in the kidney and peripheral blood decreased while the proportion of Th1, Th2 and Th17 cells in the spleen, kidney and peripheral blood increased in model group and saline group (P < 0.05). Compared with model group and saline group, 1 mg/kg and 2 mg/kg RAPA treatments boosted the proportion of DC in the kidney and peripheral blood, reduced the proportion of Th1 and Th17 cells in the spleen, kidney and peripheral blood, and lessened the proportion of Th2 cells in the kidney and peripheral blood (P < 0.05). In conclusion, RAPA alleviated renal damage in SLE mice through improving immune response and function.

Decrease of IL-5 Production by Naive T Cells Cocultured with IL-18-Producing BCG-Pulsed Dendritic Cells from Patients Allergic to House Dust Mite

The only currently available anti-tuberculosis vaccine, Bacillus Calmette–Guérin (BCG), has been reported to also protect against unrelated diseases, including inflammatory diseases such as allergic asthma. Recombinant BCG strains that produce IL-18 have been shown to enhance Th1 responses over non-recombinant BCG and to reduce IL-5 production and bronchoalveolar eosinophilia in mice. However, their ability to decrease the immune polarization of human Th2 cells is not known. Here, we show that BCG and recombinant BCG producing human IL-18 (rBCG-hIL-18) induced the maturation of Der p 1-stimulated monocyte-derived dendritic cells (MD-DCs) from healthy controls and from patients allergic to house dust mites. After incubation with mycobacteria and Der p 1, MD-DCs produced significantly more IL-23 and IP-10 but had no effect on IL-12p70 or IL-10 production compared to Der p 1-pulsed MD-DCs in the absence of mycobacteria. In the presence of Der p 1, BCG- and rBCG-hIL-18-pulsed MD-DCs cocultured with naive, but not with memory T cells from allergic patients, resulted in a decrease in IL-5 production compared to non-pulsed MD-DCs cultured in the presence of Der p 1. BCG, and especially rBCG-hIL-18, may thus be potential therapeutic tools to reduce exacerbated Th2 responses in patients with allergic asthma.

On the surface: Skin microbial exposure contributes to allergic disease

OBJECTIVE

To discuss the skin microbiome modulates immunity by interactions between skin immunology with keratinocytes to combat pathogens. Allergic disorders are classified by immunoglobulin E sensitivity and aberrant TH2 cell responses, and an increasing number of studies have described the associations with skin microbiome fluctuations. In this review, we discuss commensal-epidermal homeostasis and its influence on allergic disease.

DATA SOURCES

All included references were obtained from the PubMed database.

STUDY SELECTIONS

Studies addressing relevant aspects of commensal-epidermal homeostasis, skin microbiome dysbiosis, microbiome-targeted therapeutics, and prevention in allergy were included.

RESULTS

Homeostasis between the commensal microbiome and the epidermis is important in protecting against allergic disease. Commensals promote antiallergic TH1 and TH17 immunophenotypes within the skin and induce keratinocytes to secrete antimicrobial peptides and alarmins that enhance barrier function and antagonize proallergic organisms. Perturbations in this homeostasis, however, is associated with allergic disease development. Atopic dermatitis is associated with decreases in skin commensals and increases in the pathogen, Staphylococcus aureus. Fluctuations in the skin microbiome contributes to decreased barrier dysfunction, allergic sensitization, and TH2 cytokine secretion. Little is known about how the skin microbiome affects food allergy, allergic rhinitis, and asthma, and it is poorly understood how cutaneous inflammation influences systemic allergic responses. Therapies are targeted toward maintenance of the skin barrier, replacement of healthy commensals, and anti-TH2 biologic therapy.

CONCLUSION

Although the effects of commensal-epidermal homeostasis on allergy within the skin are becoming increasingly clear, future studies are necessary to assess its effects on extracutaneous allergic disorders and explore potential therapeutics targeting the skin microbiome.

Whole Transcriptome Analysis of Myeloid Dendritic Cells Reveals Distinct Genetic Regulation in Patients with Allergies

Dendritic cells (DCs) play critical roles in atopic diseases, orchestrating both innate and adaptive immune systems. Nevertheless, limited information is available regarding the mechanism through which DCs induce hyperresponsiveness in patients with allergies. This study aims to reveal novel genetic alterations and future therapeutic target molecules in the DCs from patients with allergies using whole transcriptome sequencing. Transcriptome sequencing of human BDCA-3+/CD11c+ DCs sorted from peripheral blood monocytes obtained from six patients with allergies and four healthy controls was conducted. Gene expression profile data were analyzed, and an ingenuity pathway analysis was performed. A total of 1638 differentially expressed genes were identified at p-values < 0.05, with 11 genes showing a log2-fold change ≥1.5. The top gene network was associated with cell death/survival and organismal injury/abnormality. In validation experiments, amphiregulin (AREG) showed consistent results with transcriptome sequencing data, with increased mRNA expression in THP-1-derived DCs after Der p 1 stimulation and higher protein expression in myeloid DCs obtained from patients with allergies. This study suggests an alteration in the expression of DCs in patients with allergies, proposing related altered functions and intracellular mechanisms. Notably, AREG might play a crucial role in DCs by inducing the Th2 immune response.

An Immunological Approach to the Biocompatibility of Mesoporous SiO2-CaO Nanospheres

Mesoporous bioactive glass nanospheres (NanoMBGs) have high potential for clinical applications. However, the impact of these nanoparticles on the immune system needs to be addressed. In this study, the biocompatibility of SiO₂-CaO NanoMBGs was evaluated on different mouse immune cells, including spleen cells subsets, bone marrow-derived dendritic cells (BMDCs), or cell lines like SR.D10 Th2 CD4⁺ lymphocytes and DC2.4 dendritic cells. Flow cytometry and confocal microscopy show that the nanoparticles were rapidly and efficiently taken up in vitro by T and B lymphocytes or by specialized antigen-presenting cells (APCs) like dendritic cells (DCs). Nanoparticles were not cytotoxic and had no effect on cell viability or proliferation under T-cell (anti-CD3) or B cell (LPS) stimuli. Besides, NanoMBGs did not affect the balance of spleen cell subsets, or the production of intracellular or secreted pro- and anti-inflammatory cytokines (TNF-α, IFN-γ, IL-2, IL-6, IL-10) by activated T, B, and dendritic cells (DC), as determined by flow cytometry and ELISA. T cell activation surface markers (CD25, CD69 and Induced Costimulator, ICOS) were not altered by NanoMBGs. Maturation of BMDCs or DC2.4 cells in vitro was not altered by NanoMBGs, as shown by expression of Major Histocompatibility Complex (MHC) and costimulatory molecules (CD40, CD80, CD86), or IL-6 secretion. The effect of wortmannin and chlorpromazine indicate a role for phosphoinositide 3-kinase (PI3K), actin and clathrin-dependent pathways in NanoMBG internalization. We thus demonstrate that these NanoMBGs are both non-toxic and non-inflammagenic for murine lymphoid cells and myeloid DCs despite their efficient intake by the cells.

Specific Polyunsaturated Fatty Acids Can Modulate in vitro Human moDC2s and Subsequent Th2 Cytokine Release

Allergy is becoming a rapidly increasing problem worldwide, and in vitro models are frequently used to study the mechanisms behind the different types of allergic response. The dendritic cell (DC)–T-cell model can be used to study sensitization. However, lipopolysaccharide (LPS) is often used to maturate the DCs, but it gives rise to a DC1 phenotype, whereas Th2-driven inflammatory diseases such as allergy are characterized by the involvement of the DC2 phenotype. Our aim was to create a DC2–T-cell human model (human moDC2s) to study in vitro sensitization and validate the model using polyunsaturated fatty acids (PUFAs) that were previously shown to have immunomodulatory properties. We found that the generated DC2s expressed OX40L and drove naive T-cells into IL-13 production of CD4⁺ effector T-cells. In line with in vivo findings, n−3 long-chain (LC)PUFA docosahexaenoic acid (DHA) effectively decreased the DC2's surface expression of OX40L, as well as the IL-12p40 and IL-23 cytokine production by DC2s and subsequently lowered IL-13 production by DC2-induced effector T-cells. Similar cytokine production effects were found with eicosapentaenoic acid (EPA) and arachidonic acid (AA), whereas linoleic acid (LA) increased OX40L surface expression and subsequent T-cell-derived IL-13/IFNγ ratios, suggesting an increased risk of allergy development. Altogether, these data show that human moDC2s are able to induce Th2-type IL-13 secretion by T-cell differentiated in the presence of these DC2s and that this model can be differentially modulated by PUFAs. These results are in line with previous in vivo studies using PUFAs, indicating that this model may be of use to predict in vivo outcomes.

Ultrasound in tumor immunotherapy: Current status and future developments

Immunotherapy has considerable potential in eliminating cancers by activating the host's own immune system, while the thermal and mechanical effects of ultrasound have various applications in tumor therapy. Hyperthermia, ablation, histotripsy, and microbubble stable/inertial cavitation can alter the tumor microenvironment to enhance immunoactivation to inhibit tumor growth. Microbubble cavitation can increase vessel permeability and thereby improve the delivery of immune cells, cytokines, antigens, and antibodies to tumors. Violent microbubble cavitation can disrupt tumor cells and efficiently expose them to numerous antigens so as to promote the maturity of antigen-presenting cells and subsequent adaptive immune-cell activation. This review provides an overview and compares the mechanisms of ultrasound-induced immune modulation for peripheral and brain tumor therapy, even degenerative brain diseases therapy. The possibility of reversing tumors to an immunoactive microenvironment by utilizing the cavitation of microbubbles loaded with therapeutic gases is also proposed as another potential pathway for immunotherapy. Finally, we disuss the challenges and opportunities of ultrasound in immunotherapy for future development.

Mycobacterium avium subsp. paratuberculosis MAP1889c Protein Induces Maturation of Dendritic Cells and Drives Th2-biased Immune Responses

Mycobacterium avium subsp. paratuberculosis (MAP) is a causative agent of chronic granulomatous bowel disease in animals and is associated with various autoimmune diseases in humans including Crohn’s disease. A good understanding of the host-protective immune response and antibacterial immunity controlled by MAP and its components may contribute to the development of effective control strategies. MAP1889c was identified as a seroreactive antigen in Crohn’s disease patients. In this study, we investigated the immunological function of MAP1889c in dendritic cells (DCs). MAP1889c stimulated DCs to increase expression of co-stimulatory molecules (CD80 and CD86) and major histocompatibility complex (MHC) class molecules and to secret higher interleukin (IL)-10 and moderate IL-6, tumor necrosis factor (TNF)-α, and IL-12p70 levels through the Toll-like receptor (TLR) 4 pathway. MAP1889c-induced DC activation was mediated by mitogen-activated protein kinases (MAPKs), cAMPp-response element binding protein (CREB), and nuclear factor kappa B (NF-κB). In particular, the CREB signal was essential for MAP1889c-mediated IL-10 production but not TNF-α and IL-12p70. In addition, MAP1889c-matured DCs induced T cell proliferation and drove the Th2 response. Production of lipopolysaccharide (LPS)-mediated pro-inflammatory cytokines and anti-inflammatory cytokines was suppressed and enhanced respectively by MAP1889c pretreatment in DCs and T cells. Furthermore, treatment of MAP1889c in M. avium-infected macrophages promoted intracellular bacterial growth and IL-10 production. These findings suggest that MAP1889c modulates the host antimycobacterial response and may be a potential virulence factor during MAP infection.

New insights into roles of basophils in initiating T helper type 2 immunity

Allergic diseases, mainly mediated by T helper type 2 (Th2) immunity, have become a worldwide public health problem. Traditional Chinese medicine (TCM) has long been used in treating and preventing allergic symptoms. As the new target of anti-allergy TCM, basophils, after approximately 140 years since their discovery, are just now gaining respect as important contributors in the pathogenesis underlying allergic inflammation and disease. In addition to their role as effector cells, basophils can release early IL-4, migrate from circulatory system into draining lymph nodes, present antigen to naive CD4⁺T cells, and promote the differentiation of Th2 cells. Herein, we briefly summarized the recent research advances of the essential contributions of basophils in the initiation of Th2 immune responses.

Body fluid from the parasitic worm Ascaris suum inhibits broad-acting pro-inflammatory programs in dendritic cells

Dendritic cells (DCs) are essential for generating T-cell-based immune responses through sensing of potential inflammatory and metabolic cues in the local environment. However, there is still limited insight into the processes defining the resultant DC phenotype, including the type of early transcriptional changes in pro-inflammatory cues towards regulatory or type 2 immune-based cues induced by a variety of exogenous and endogenous molecules. Here we compared the ability of a selected number of molecules to modulate the pro-inflammatory phenotype of lipopolysaccharide (LPS) and interferon-γ (IFN-γ)-stimulated human monocyte-derived DCs towards an anti-inflammatory or regulatory phenotype, including Ascaris suum body fluid [helminth pseudocoelomic fluid (PCF)], the metabolites succinate and butyrate, and the type 2 cytokines thymic stromal lymphopoietin and interleukin-25. Our data show that helminth PCF and butyrate treatment suppress the T helper type 1 (Th1)-inducing pro-inflammatory DC phenotype through induction of different transcriptional programs in DCs. RNA sequencing indicated that helminth PCF treatment strongly inhibited the Th1 and Th17 polarizing ability of LPS + IFN-γ-matured DCs by down-regulating myeloid differentiation primary response gene 88 (MyD88)-dependent and MyD88-independent pathways in Toll-like receptor 4 signaling. By contrast, butyrate treatment had a strong Th1-inhibiting action, and transcripts encoding important gut barrier defending factors such as IL18, IL1B and CXCL8 were up-regulated. Collectively, our results further understanding of how compounds from parasites and gut microbiota-derived butyrate may exert immunomodulatory effects on the host immune system.

Transcriptional control of dendritic cell development and functions

Dendritic cells (DCs) are major regulators of adaptive immunity, as they are not only capable to induce efficient immune responses, but are also crucial to maintain peripheral tolerance and thereby inhibit autoimmune reactions. DCs bridge the innate and the adaptive immune system by presenting peptides of self and foreign antigens as peptide MHC complexes to T cells. These properties render DCs as interesting target cells for immunomodulatory therapies in cancer, but also autoimmune diseases. Several subsets of DCs with special properties and functions have been described. Recent achievements in understanding transcriptional programs on single cell level, together with the generation of new murine models targeting specific DC subsets, advanced our current understanding of DC development and function. Thus, DCs arise from precursor cells in the bone marrow with distinct progenitor cell populations splitting the monocyte populations and macrophage populations from the DC lineage, which upon lineage commitment can be separated into conventional cDC1, cDC2, and plasmacytoid DCs (pDCs). The DC populations harbor intrinsic programs enabling them to react for specific pathogens in dependency on the DC subset, and thereby orchestrate T cell immune responses. Similarities, but also varieties, between human and murine DC subpopulations are challenging, and will require further investigation of human specimens under consideration of the influence of the tissue micromilieu and DC subset localization in the future.

Myeloid and Plasmacytoid Dendritic Cells and Cancer - New Insights

Dendritic cells (DCs) use effective mechanisms to combat antigens and to bring about adaptive immune responses through their ability to stimulate näive T cells. At present, four major cell types are categorised as DCs: Classical or conventional (cDCs), Plasmacytoid (pDCs), Langerhans cells (LCs), and monocyte-derived DCs (Mo-DCs). It was suggested that pDCs, CD1c+ DCs and CD141+ DCs in humans are equivalent to mouse pDCs, CD11b+ DCs and CD8α+ DCs, respectively. Human CD141+ DCs compared to mouse CD8α+ DCs have remarkable functional and transcriptomic similarities. Characteristic markers, transcription factors, toll-like receptors, T helpers (Th) polarisation, cytokines, etc. of DCs are discussed in this review. Major histocompatibility complex (MHC) I and II antigen presentation, cross-presentation and Th polarisation are defined, and the dual role of DCs in the tumour is discussed. Human DCs are the main immune cells that orchestrate the immune response in the tumour microenvironment.

Induction of humoral and cellular immune response to HBV vaccine can be up-regulated by STING ligand

A persistent hepatitis B virus (HBV) infection is characterized by a lack of or a weak immune response to HBV. Efficient induction of the HBV-specific immune response leads to the clearance of HBV. Stimulator of interferon (IFN) genes (STING) is a cytoplasmic sensor of intracellular DNA from microbes and host cells. In the present study, we examined the efficacy of cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) that is a ligand of the STING pathway as an HBV vaccine adjuvant. Wild-type (WT) mice and HBV-transgenic (HBV-Tg) mice were immunized with hepatitis B surface antigen (HBsAg) and cGAMP. The vaccination with HBsAg and cGAMP significantly enhanced the humoral and cellular immune response to HBsAg in WT and HBV-Tg mice. Cytokine production related to Th1 and Th2 responses and the activation of antigen-presenting cells in lymphoid tissues were induced by cGAMP. Vaccination using cGAMP may overcome tolerance in patients with chronic HBV infection.

Salivary gland immunization via Wharton's duct activates differential T-cell responses within the salivary gland immune system

Salivary glands are a major component of the mucosal immune system that confer adaptive immunity to mucosal pathogens. As previously demonstrated, immunization of the submandibular gland with tissue culture-derived murine cytomegalovirus (tcMCMV) or replication-deficient adenoviruses expressing individual murine cytomegalovirus (MCMV) genes protected mice against a lethal MCMV challenge. Here, we report that salivary gland inoculation of BALB/cByJ mice with tcMCMV or recombinant adenoviruses differentially activates T helper (T_h)1, -2, and -17 cells in the salivary glands vs. the associated lymph nodes. After inoculation with tcMCMV, lymphocytes from the submandibular gland preferentially express the transcription factor T-cell-specific T-box transcription factor (T-bet), which controls the expression of the hallmark T_h1 cytokine, IFN-γ. Lymphocytes from the periglandular lymph nodes (PGLNs) express both T-bet and GATA-binding protein 3 (GATA3), which promotes the secretion of IL-4, -5, and -10 from T_h2 cells. In contrast, after inoculation with replication-deficient adenoviruses, lymphocytes from the submandibular gland express T-bet, GATA3, and RAR-related orphan receptor γ, thymus-specific isoform (RORγt) (required for differentiation of T_h17 cells) and forkhead box P3 (Foxp3) (required for the differentiation of regulatory T cells). Lymphocytes from the PGLNs were not activated. The differential induction of T_h responses in the salivary gland vs. the PGLNs after inoculation with attenuated virus vs. a nominal protein antigen supports the use of the salivary as an alternative mucosal route for administering vaccines.-Liu, G., Zhang, F., Wang, R., London, S. D., London, L. Salivary gland immunization via Wharton's duct activates differential T-cell responses within the salivary gland immune system.

Dendritic Cell-Mediated Th2 Immunity and Immune Disorders

Dendritic cells (DCs) are the professional antigen-presenting cells that recognize and present antigens to naïve T cells to induce antigen-specific adaptive immunity. Among the T-cell subsets, T helper type 2 (Th2) cells produce the humoral immune responses required for protection against helminthic disease by activating B cells. DCs induce a Th2 immune response at a certain immune environment. Basophil, eosinophil, mast cells, and type 2 innate lymphoid cells also induce Th2 immunity. However, in the case of DCs, controversy remains regarding which subsets of DCs induce Th2 immunity, which genes in DCs are directly or indirectly involved in inducing Th2 immunity, and the detailed mechanisms underlying induction, regulation, or maintenance of the DC-mediated Th2 immunity against allergic environments and parasite infection. A recent study has shown that a genetic defect in DCs causes an enhanced Th2 immunity leading to severe atopic dermatitis. We summarize the Th2 immune-inducing DC subsets, the genetic and environmental factors involved in DC-mediated Th2 immunity, and current therapeutic approaches for Th2-mediated immune disorders. This review is to provide an improved understanding of DC-mediated Th2 immunity and Th1/Th2 immune balancing, leading to control over their adverse consequences.

Human Dendritic Cells: Their Heterogeneity and Clinical Application Potential in Cancer Immunotherapy

Dendritic cells (DC) are professional antigen presenting cells, uniquely able to induce naïve T cell activation and effector differentiation. They are, likewise, involved in the induction and maintenance of immune tolerance in homeostatic conditions. Their phenotypic and functional heterogeneity points to their great plasticity and ability to modulate, according to their microenvironment, the acquired immune response and, at the same time, makes their precise classification complex and frequently subject to reviews and improvement. This review will present general aspects of the DC physiology and classification and will address their potential and actual uses in the management of human disease, more specifically cancer, as therapeutic and monitoring tools. New combination treatments with the participation of DC will be also discussed.

Fas Signaling in Dendritic Cells Mediates Th2 Polarization in HDM-Induced Allergic Pulmonary Inflammation

Fas-Fas ligand (FasL) signaling plays an important role in the development of allergic inflammation, but the cellular and molecular mechanisms are still not well known. By using the bone marrow-derived dendritic cell (BMDC) transfer-induced pulmonary inflammation model, we found that house dust mite (HDM)-stimulated FAS-deficient BMDCs induced higher Th2-mediated allergic inflammation, associated with increased mucus production and eosinophilic inflammation. Moreover, FAS-deficient BMDCs promoted Th2 cell differentiation upon HDM stimulation in vitro. Compared to wild-type BMDCs, the Fas-deficient BMDCs had increased ERK activity and decreased IL-12 production upon HDM stimulation. Inhibition of ERK activity could largely increase IL-12 production, consequently restored the increased Th2 cytokine expression of OT-II CD4⁺ T cells activated by Fas-deficient BMDCs. Thus, our results uncover an important role of DC-specific Fas signaling in Th2 differentiation and allergic inflammation, and modulation of Fas signaling in DCs may offer a useful strategy for the treatment of allergic inflammatory diseases.

The Phosphoinositide Kinase PIKfyve Promotes Cathepsin-S-Mediated Major Histocompatibility Complex Class II Antigen Presentation

Antigen presentation to T cells in major histocompatibility complex class II (MHC class II) requires the conversion of early endo/phagosomes into lysosomes by a process called maturation. Maturation is driven by the phosphoinositide kinase PIKfyve. Blocking PIKfyve activity by small molecule inhibitors caused a delay in the conversion of phagosomes into lysosomes and in phagosomal acidification, whereas production of reactive oxygen species (ROS) increased. Elevated ROS resulted in reduced activity of cathepsin S and B, but not X, causing a proteolytic defect of MHC class II chaperone invariant chain Ii processing. We developed a novel universal MHC class II presentation assay based on a bio-orthogonal "clickable" antigen and showed that MHC class II presentation was disrupted by the inhibition of PIKfyve, which in turn resulted in reduced activation of CD4⁺ T cells. Our results demonstrate a key role of PIKfyve in the processing and presentation of antigens, which should be taken into consideration when targeting PIKfyve in autoimmune disease and cancer.

Therapeutic potentials of ginger for treatment of Multiple sclerosis: A review with emphasis on its immunomodulatory, anti-inflammatory and anti-oxidative properties

Multiple sclerosis (MS) is characterized by chronic inflammatory response-induced demyelination of the neurons and degeneration of the axons within the central nervous system (CNS). A complex network of immunopathological-, inflammatory- and oxidative parameters involve in the development and advancement of MS. The anti-inflammatory, immunomodulatory and anti-oxidative characteristics of the ginger and several of its components have been indicated in some of experimental and clinical investigations. The possible therapeutic potentials of ginger and its ingredients in the treatment of MS may exert mainly through the regulation of the Th1-, Th2-, Th9-, Th17-, Th22- and Treg cell-related immune responses, down-regulation of the B cell-related immune responses, modulation of the macrophages-related responses, modulation of the production of pro- and anti-inflammatory cytokines, down-regulation of the arachidonic acid-derived mediators, interfering with the toll like receptor-related signaling pathways, suppression of the inflammasomes, down-regulation of the oxidative stress, reduction of the adhesion molecules expression, and down-regulation of the expression of the chemokines and chemokine receptors. This review aimed to provide a comprehensive knowledge regarding the immunomodulatory-, anti-inflammatory and anti-oxidative properties of ginger and its components, and highlight novel insights into the possible therapeutic potentials of this plant for treatment of MS. The review encourages more investigations to consider the therapeutic potentials of ginger and its effective components for managing of MS.

Importance of EMT Factor ZEB1 in cDC1 "MutuDC Line" Mediated Induction of Th1 Immune Response

The role of Epithelial to Mesenchymal Transition (EMT) factor Zeb1 is well defined in metastasis and cancer progression but it's importance in dendritic cells (DCs) is unexplored until now. For the first time we report here that Zeb1 controls immunogenic responses of CD8α⁺ conventional Type-I (cDC1) DCs. We found that ZEB1 expression increases significantly after TLR9 stimulation and its depletion impairs activation, co-stimulation and secretion of important cytokines like IL-6, IL-10 and IL-12 in cDC1 MutuDC line. We further confirmed our findings in primary cDC1 DCs derived from bone marrow. Co-culture of these Zeb1 knock down (KD) DCs with OT-II CD4⁺ T helper cells skewed their differentiation toward Th2 subtype. Moreover, adoptive transfer of activated Zeb1 KD DCs cleared intestinal worms in helminth infected mice by increasing Th2 responses in vivo. Integrative genomic analysis showed Zeb1 as an activator of immune response genes in cDC1 MutuDCs as compared to other pathway genes. In addition, differentially regulated genes in Zeb1 KD RNA-seq showed significant enrichment of Th2 activation pathways supporting our in vitro findings. Mechanistically, we showed that decreased IL-12 secreted by Zeb1 KD DCs is the plausible mechanism for increased Th2 differentiation. Collectively our data demonstrate that Zeb1 could be targeted in DCs to modulate T-cell mediated adaptive immune responses.

The Key Role of TNF-TNFR2 Interactions in the Modulation of Allergic Inflammation: A Review

Tumor necrosis factor-alpha (TNF) is a pleiotropic cytokine, which is thought to play a major role in the pathogenesis of inflammatory diseases, including allergy. TNF is produced at the early stage of allergen sensitization, and then continues to promote the inflammation cascade in the effector phase of allergic reactions. Consequently, anti-TNF treatment has been proposed as a potential therapeutic option. However, recent studies reveal anti-intuitive effects of TNF in the activation and proliferative expansion of immunosuppressive Tregs, tolerogenic DCs and MDSCs. This immunosuppressive effect of TNF is mediated by TNFR2, which is preferentially expressed by immunosuppressive cells. These findings redefine the role of TNF in allergic reaction, and suggest that targeting TNF-TNFR2 interaction itself may represent a novel strategy in the treatment of allergy.

Different Expressions of Specific Transcription Factors of Th1 (T-bet) and Th2 cells (GATA-3) by Peripheral Blood Mononuclear Cells From Patients With Multiple Sclerosis

Introduction:

Multiple Sclerosis (MS) is an inflammatory disorder caused by self-reactive Th1 lymphocytes, while Th2 cells may confer protection. The Th1 and Th2 cell differentiation are regulated by specific transcription factors, especially T-bet and GATA-3, respectively. This investigation aimed to measure the T-bet and GATA-3 expression by Peripheral Blood Mononuclear Cells (PBMCs) obtained from MS patients after specific and non-specific in vitro stimulation.

Methods:

The PBMCs were separated from 22 patients with MS and 20 healthy individuals. They were cultured at 37°C for 24 h in the absence of a stimulator or in the presence of Myelin oligodendrocyte Glycoprotein (MOG) or Phytohemagglutinin (PHA) at a concentration of 10 μg/mL. Then the T-bet and GATA-3 expression was measured by real time-PCR.

Results:

The T-bet expression was enhanced, while the GATA-3 expression diminished. Therefore the expression of T-bet/GATA-3 ratio diminished in not-stimulated, MOG-stimulated and PHA-stimulated PBMCs from MS patients compared with equal cultures from the healthy individuals (P<0.01, P<0.01 and P<0.01, for T-bet; P<0.03, P<0.01 and P<0.02, for GATA-3; P<0.01, P<0.001 and P<0.01 for T-bet/GATA-3 ratio, respectively). The not-stimulated, MOG-stimulated, and PHA-stimulated PBMCs from men with MS expressed higher amounts of GATA-3 than equal cells from MS women (P<0.05, P<0.05 and P<0.01, respectively).

Conclusion:

These results probably indicate an imbalance in Th1/Th2 cells in the level of transcription factors with a tendency toward Th1 cells in MS. The clinical utilization of the transcription factors as novel biomarkers of MS should be evaluated in further studies.

Emodin alleviates alternatively activated macrophage and asthmatic airway inflammation in a murine asthma model

Alternatively activated macrophages (AAMs) are not only associated with asthma but also lead to asthmatic airway inflammation and remodeling. Inhibition of AAMs is an alternative therapeutic strategy for treating asthma. In this study we investigated whether emodin (1,3,8-trihydroxy-6-methylanthraquinone), isolated from the rhizome of Rheum palmatum, alleviated asthmatic airway inflammation and reduced AAM polarization in a murine asthma model. Mice were sensitized with a triple allergen mix containing dust mite, ragweed and aspergillus (DRA). In mice with DRA-induced asthma, asthmatic inflammation was significantly enhanced. Intraperitoneal injection of emodin (20 mg·kg^-1·d^-1, ip) 1 h prior to DRA challenge on days 12-14 significantly decreased pulmonary eosinophil and lymphocyte infiltration, mucus secretion and serum IgE production, as well as IL-4 and IL-5 production in bronchoalveolar lavage fluid. In response to emodin treatment, activated markers of AAM Ym-1, Fizz-1 and arginase-1 in the lung tissues were remarkably decreased. In mouse bone marrow-derived macrophages (BMDMs) in vitro, emodin (2-50 μmol/L) dose-dependently inhibited IL-4-induced AAM polarization and STAT6 phosphorylation. Collectively, our results suggest that emodin effectively ameliorates asthmatic airway inflammation and AAM polarization, and it may therefore become a potential agent for the treatment of asthma.

The opposite roles of PAS-5 and Galectin-1 in immune response during the early infection of Angiostrongylus cantonensis

BACKGROUND

Angiostrongylus cantonensis is a human zoonotic nematode parasite. Our previous studies found that PAS-5 and Galectin-1 (Gal-1) proteins of A. cantonensis could be strongly recognized by sera from mice infected with A. cantonensis. In this study, we further evaluated the potential roles of these two proteins in the induction of immune response in mice.

METHODS

Mice were immunized with recombinant PAS-5 or Gal-1 and then challenged with 30 infective A. cantonensis larvae following the last immunization. We then examined the infected mice for changes in serum antibodies and cytokines by ELISA, CD4+ T cells and CD4+CD25+FoxP3+ regulatory T cells (Tregs) by flow cytometry, and tissue damage severity by hematoxylin-eosin (H&E) staining.

RESULTS

Compared with control mice, the PAS-5-immunized mice exhibited increased levels of serum antibodies and cytokines (except for IL-10) at different time points post-infection. PAS-5 immunization promoted significant proliferation of CD4+ T cells, and caused more damage in the brain tissue. Vaccination with Gal-1 inhibited the production of antibodies (except for IgG1) and IFN-γ, but promoted the expression of IL-4 and IL-10. Gal-1 immunization results in significant increases in the levels of CD4+CD25+FoxP3+ Tregs, and mild inflammatory changes.

CONCLUSIONS

Taken together, our findings show that PAS-5 enhances, but Gal-1 inhibits the immune response in the early stage of A. cantonensis infections.

Mast Cell Interactions and Crosstalk in Regulating Allergic Inflammation

PURPOSE OF REVIEW

This review summarizes recent findings on mast cell biology with a focus on IgE-independent roles of mast cells in regulating allergic responses.

RECENT FINDINGS

Recent studies have described novel mast cell-derived molecules, both secreted and membrane-bound, that facilitate cross-talk with a variety of immune effector cells to mediate type 2 inflammatory responses. Mast cells are complex and dynamic cells that are persistent in allergy and are capable of providing signals that lead to the initiation and persistence of allergic mechanisms.

T cell subsets play an important role in the determination of the clinical outcome of Helicobacter pylori infection

Helicobacter pylori (H. pylori) is one of the most prevalent human pathogen and a persistent infection with this bacterium causes common pathologies, such as gastritis or peptic ulcers, and also less common but more serious pathologies, such as gastric cancer or gastric mucosa-associated lymphoid tissue (MALT) lymphoma. The clinical outcome of gastrointestinal infection sustained by H. pylori is determined by the reciprocal interactions between virulence factors of the bacterium and host factors, including immune response genes. Although H. pylori induces a strong immune response, the bacterium is not eliminated. The eradication failure could be attributed to the bacterial capability to regulate helper T (Th) cell-related responses. H. pylori specific CD4⁺ T cells play a fundamental role in regulating host immunity and immunopathologic events. It has been documented that Th1, Th2, Th9, Th17, Th22 and T regulatory (Treg) cells, separately or in coordination with each other, can affect the outcome of the infection sustained by of H. pylori. Some studies indicated that both Th1 and Th17 cells may be protective or pathogenic, whereas Treg and Th2 cells perform anti-inflammatory impacts during H. pylori infection. This review gathers recent information regarding the association of the CD4⁺ T cells-mediated immunological responses and the clinical consequence of H. pylori infection.

Humoral and T cell-mediated immune response against trichomoniasis

Trichomonas vaginalis (T. vaginalis) infection leads to the synthesis of specific antibodies in the serum and local secretions. The profile of T. vaginalis-specific antibodies and T cell-mediated immune responses may influence the outcome of infection, towards parasite elimination, persistence or pathological reactions. Studies have indicated that Th1-, Th17- and Th22 cell-related cytokines may be protective or pathogenic, whereas Th2- and Treg cell-related cytokines can exert anti-inflammatory effects during T. vaginalis infection. A number of T. vaginalis-related components such as lipophosphoglycan (TvLPG), α-actinin, migration inhibitory factor (TvMIF), pyruvate:ferredoxin oxidoreductase (PFO), legumain-1 (TvLEGU-1), adhesins and cysteine proteases lead to the induction of specific antibodies. T. vaginalis has acquired several strategies to evade the humoral immune responses such as degradation of immunoglobulins by cysteine proteases, antigenic variation and killing of antibody-producing B cells. The characterization of the T. vaginalis-specific antibodies to significant immunogenic molecules and formulation of strategies to promote their induction in vaginal mucosa may reveal their potential protective effects against trichomoniasis. In this review, we discuss the current understanding of antibody and T cell-mediated immune responses to T. vaginalis and highlight novel insights into the possible role of immune responses in protection against parasite.

Shuang-Huang-Lian prevents basophilic granulocyte activation to suppress Th2 immunity

BACKGROUND

Basophilic granulocytes (BGs) not only initiate the induction of Th2 cell differentiation, but also amplify the ongoing Th2 response. Shuang-Huang-Lian (SHL) is clinically used for relieving type I hypersensitivity by continuous treatment for several weeks.

METHODS

ELISA, flow cytometry, magnetic activated cell sorting, isoelectric precipitation, hybridoma technique, transfection and luciferase reporter assay were used in this study. The statistical analysis was performed using a one-way ANOVA.

RESULTS

Our recently published study demonstrated that SHL exerted a remarkable effect on mast cell stabilization. Herein, we sought to elucidate the effect of SHL on shrimp tropomyosin (ST)-induced Th2 immunity and its underlying mechanisms. The obtained data showed that continuous treatment with SHL significantly suppressed ST-stimulated Th2-cytokines release and IgE synthesis. A mechanistic study indicated that SHL not only reduced BG early IL-4 release before ST-specific IgE (sIgE) production, but also inhibited BG activation in the presence of sIgE, including suppressing CD200R surface expression and decreasing IL-4 production. Moreover, SHL markedly decreased the cytosolic Ca²⁺ (Ca²⁺_[c]) level and inhibited the nuclear factor of activated T cells (NFAT) activation in RBL-2H3 cells.

CONCLUSIONS

Collectively, SHL potently reduces ST-induced Th2 immunity by inhibiting the BG Ca²⁺-NFAT pathway and, thus, suppressing the early IL-4 release before sIgE synthesis and inhibiting BG activation in the presence of sIgE. This study provides the pharmacological basis for the clinical use of SHL to relieve type I hypersensitivity by a successive dose regimen.

Unbiased Quantitative Proteomics Reveals a Crucial Role of the Allergen Context for the Activation of Human Dendritic Cells

Worldwide, more than 1 billion people suffer from allergic diseases. However, until now it is not fully understood how certain proteins can induce allergic immune responses, while others cannot. Studies suggest that allergenicity is a process not only determined by properties of the allergen itself but also by costimulatory factors, that are not classically associated with allergic reactions. To investigate the allergenicity of the major birch pollen allergen Bet v 1 and the impact of adjuvants associated with pollen, e.g. lipopolysaccharide (LPS), we performed quantitative proteome analysis to study the activation of monocyte-derived dendritic cells (moDCs). Thus, we treated cells with birch pollen extract (BPE), recombinant Bet v 1, and LPS followed by proteomic profiling via high-performance liquid chromatography and tandem mass spectrometry (HPLC-MS/MS) using isobaric labelling. Enrichment and pathway analysis revealed the influence of regulated proteins especially in cytokine signalling and dendritic cell activation. We found highly regulated, but differentially expressed proteins after treatment with BPE and LPS, whereas the cellular response to Bet v 1 was limited. Our findings lead to the conclusion that Bet v 1 needs a specific “allergen context” involving cofactors apart from LPS to induce an immune response in human moDCs.

Type 2 cytokine responses: regulating immunity to helminth parasites and allergic inflammation

Purpose of Review

It is well established that T helper type 2 (T_H2) immune responses are necessary to provide protection against helminth parasites but also to promote the detrimental inflammation associated with allergies and asthma. Given the importance of type 2 immunity and inflammation, many studies have focused on better understanding the factors that regulate T_H2 cell development and activation. As a result, significant progress has been made in understanding the signaling pathways and molecular events necessary to promote T_H2 cell polarization. In addition to the adaptive compartment, emerging studies are better defining the innate immune pathways needed to promote T_H2 cell responses. Given the recent and substantial growth of this field, the purpose of this review is to highlight recent studies defining the innate immune events that promote immunity to helminth parasites and allergic inflammation.

Recent Findings

Emerging studies have begun to elucidate the importance of cytokine alarmins such as thymic stromal lymphopoietin (TSLP), IL-25 (IL-17E) and IL-33 in promoting type 2 immunity and inflammation following helminth challenge or exposure to allergens. Specifically, recent reports have begun to define the complex cellular networks these alarmins activate and their contribution to type 2 immunity and inflammation.

Summary

Our increased understanding of the pathways that regulate type 2 cytokine-mediated immunity and inflammation have revealed novel therapeutic targets to treat both helminth infections and allergic disease states.

Fibrinogen cleavage products and Toll-like receptor 4 promote the generation of programmed cell death 1 ligand 2-positive dendritic cells in allergic asthma

BACKGROUND

Inhaled protease allergens preferentially trigger T_H2-mediated inflammation in allergic asthma. The role of dendritic cells (DCs) on induction of T_H2 cell responses in allergic asthma has been well documented; however, the mechanism by which protease allergens induce T_H2-favorable DCs in the airway remains unclear.

OBJECTIVE

We sought to determine a subset of DCs responsible for T_H2 cell responses in allergic asthma and the mechanism by which protease allergens induce the DC subset in the airway.

METHODS

Mice were challenged intranasally with protease allergens or fibrinogen cleavage products (FCPs) to induce allergic airway inflammation. DCs isolated from mediastinal lymph nodes were analyzed for surface phenotype and T-cell stimulatory function. Anti-Thy1.2 and Mas-TRECK mice were used to deplete innate lymphoid cells and mast cells, respectively. Adoptive cell transfer, bone marrow DC culture, anti-IL-13, and Toll-like receptor (TLR) 4-deficient mice were used for further mechanistic studies.

RESULTS

Protease allergens induced a remarkable accumulation of T_H2-favorable programmed cell death 1 ligand 2 (PD-L2)⁺ DCs in mediastinal lymph nodes, which was significantly abolished in mice depleted of mast cells and, to a lesser extent, innate lymphoid cells. Mechanistically, FCPs generated by protease allergens triggered IL-13 production from wild-type mast cells but not from TLR4-deficient mast cells, which resulted in an increase in the number of PD-L2⁺ DCs. Intranasal administration of FCPs induced an increase in numbers of PD-L2⁺ DCs in the airway, which was significantly abolished in TLR4- and mast cell-deficient mice. Injection of IL-13 restored the PD-L2⁺ DC population in mice lacking mast cells.

CONCLUSION

Our findings unveil the "protease-FCP-TLR4-mast cell-IL-13" axis as a molecular mechanism for generation of T_H2-favorable PD-L2⁺ DCs in allergic asthma and suggest that targeting the PD-L2⁺ DC pathway might be effective in suppressing allergic T-cell responses in the airway.

The function of dendritic cells in modulating the host response

Dendritic cells (DCs) are antigen-presenting cells that capture, process, and present antigens to lymphocytes to initiate and regulate the adaptive immune response. DCs detect bacteria in skin and mucosa and migrate into regional lymph nodes, where they stimulate antigen-specific T and B lymphocyte activation and proliferation. DCs direct CD4 T cells to differentiate to T-cell subsets such as T helper cells types 1, 2, and 17, and regulatory T cells. The periodontium is chronically exposed to oral bacteria that stimulate an inflammatory response to induce gingivitis or periodontitis. DCs play both protective and destructive roles through activation of the acquired immune response and are also reported to be a source of osteoclast precursors that promote bone resorption. FOXO1, a member of the forkhead box O family of transcription factors, plays a significant role in the activation of DCs. The function of DCs in periodontal inflammation has been investigated in a mouse model by lineage-specific deletion of FOXO1 in these cells. Deletion of FOXO1 reduces DC protective function and enhances susceptibility to periodontitis. The kinase Akt, phosphorylates FOXO1 to inhibit FOXO activity. Hence the Akt-FOXO1 axis may play a key role in regulating DCs to have a significant impact on periodontal disease.

Co-delivery of tumor-derived exosomes with alpha-galactosylceramide on dendritic cell-based immunotherapy for glioblastoma

Dendritic cell (DC) vaccine-based immunotherapy for glioblastoma multiforme (GBM) has shown apparent benefit in animal experiments and early-phase clinical trials, but the survival benefit is variable. In this work, we analyzed the mechanism of the potent antitumor immune response induced in vivo by tumor-associated antigen (TAA)-specific DCs with an invariant natural killer T (iNKT) cell adjuvant in orthotopic glioblastoma-bearing rats vaccinated with tumor-derived exosomes and α-galactosylceramide (α-GalCer) -pulsed DCs. Compared with traditional tumor lysate, exosomes were utilized as a more potent antigen to load DCs. iNKT cells, as an effective cellular adjuvant activated by α-GalCer, strengthened TAA presentation through their interaction with DCs. Co-delivery of tumor-derived exosomes with α-GalCer on a DC-based vaccine showed powerful effects in glioblastoma immunotherapy. This vaccine induced strong activation and proliferation of tumor-specific cytotoxic T lymphocytes, synergistically breaking the immune tolerance and improving the immunosuppressive environment.

IL-7 plays a critical role for the homeostasis of allergen-specific memory CD4 T cells in the lung and airways

Memory T cells respond rapidly to repeated antigen exposure and can maintain their population for extended periods through self-renewal. These characteristics of memory T cells have mainly been studied during viral infections, whereas their existence and functions in allergic diseases have been studied incompletely. Since allergic patients can suffer repeated relapses caused by intermittent allergen exposure, we hypothesized that allergen- specific memory Th2 cells are present and the factors necessary for the maintenance of these cells are provided by the lung and airways. Using a murine model of airway inflammation, we found that allergen-specific CD4 T cells survived longer than 70 days in the lung and airways in an IL-7 dependent fashion. These T cells showing homeostatic proliferation were largely found in the mediastinal lymph node (mLN), rather than the airways; however, cells residing in the lung and airways developed recall responses successfully. We also found that CD4 T cells exhibited differential phenotypes in the mLN and in the lung. Altogether, we believe that allergen-specific memory T cells reside and function in the lung and airways, while their numbers are replenished through homeostatic turnover in the mLNs. Furthermore, we determined that IL-7 signaling is important for the homeostasis of these cells.