Molecular mechanisms regulating Th1 immune responses

Notch signalling in T cell homeostasis and differentiation

The evolutionarily conserved Notch signalling pathway regulates the differentiation and function of mature T lymphocytes with major context-dependent consequences in host defence, autoimmunity and alloimmunity. The emerging effects of Notch signalling in T cell responses build upon a more established role for Notch in T cell development. Here, we provide a critical review of this burgeoning literature to make sense of what has been learned so far and highlight the experimental strategies that have been most useful in gleaning physiologically relevant information. We outline the functional consequences of Notch signalling in mature T cells in addition to key specific Notch ligand–receptor interactions and downstream molecular signalling pathways. Our goal is to help clarify future directions for this expanding body of work and the best approaches to answer important open questions.

Alterations in T cell-related transcripts at the feto-maternal interface throughout equine gestation

INTRODUCTION

The tolerance of pregnancy by the maternal immune system is balanced between recognition and protection. In the human this is controlled by balancing helper T cell populations (Th1, Th2) in addition to immune suppression from the regulatory arm (Tregs), but this has not been evaluated in the horse.

METHODS

RNA sequencing was performed on chorioallantois and endometrium of mares at 120, 180, 300 and 330 days of gestation (n = 4/stage), as well as 45-day chorioallantois (n = 4) and diestrus endometrium (n = 3). Transcripts were selected for relativity to Th1, Th2, or Treg-associated. qPCR and immunohistochemistry were used to confirm the results of select differentially expressed genes.

RESULTS

In the endometrium, Th1 transcripts were highest in the diestrus mare and decreased as gestational length progressed. In contrast, Th2 transcripts were upregulated in comparison to the diestrus mare and highest in mid gestation. Treg transcripts were found increased in comparison to the diestrus mare, but decreased prepartum. In the chorioallantois no Th1 transcripts changed. The majority of Th2 transcripts increased from 45 to 300 days gestation, and then decreased prepartum. Treg-related transcripts trended down in the chorioallantois from 45 days to 120 days gestation, followed by an upregulation to 300 days and a secondary decline prepartum.

DISCUSSION

The mare experiences a complex and evolving immune profile within the tissues of the feto-maternal interface. This consists of a balance between the Th1 and Th2 response, and a dynamic Treg response that is hypothesized to regulate overall events within the immune system.

IL-18/IL-18BP and IL-22/IL-22BP: Two interrelated couples with therapeutic potential

Interleukin (IL)-18 and IL-22 are key components of cytokine networks that play a decisive role in (pathological) inflammation, host defense, and tissue regeneration. Tight regulation of cytokine-driven signaling, inflammation, and immunoactivation is supposed to enable nullification of a given deleterious trigger without mediating overwhelming collateral tissue damage or even activating a cancerous face of regeneration. In fact, feedback regulation by specific cytokine opponents is regarded as a major means by which the immune system is kept in balance. Herein, we shine a light on the interplay between IL-18 and IL-22 and their opponents IL-18 binding protein (IL-18BP) and IL-22BP in order to provide integrated information on their biology, pathophysiological significance, and prospect as targets and/or instruments of therapeutic intervention.

Intratumoural-infiltrating CD4 + and FOXP3 + T cells as strong positive predictive markers for the prognosis of resectable colorectal cancer

Background

CD3 +  and CD8 + T-cell infiltration were reported as positive predictive markers of survival in colorectal cancer (CRC) patients. Here, we demonstrate the prognostic significance of CD4 + and FOXP3 + T-cell densities in CRC.

Methods

We quantified the intratumoural densities of CD3 + , CD8 + , CD4 +  and FOXP3 + T cells by immunohistochemistry and digital pathology in 342 CRC patients who underwent curative resection. Microsatellite instability was also assessed in 322 specimens. Patient demographics, clinicopathological features and survival rates were analysed.

Results

High CD3 + , CD4 +  and FOXP3 + T-cell densities were associated with improved relapse-free survival (RFS); high CD8 + , CD4 +  and FOXP3 + T-cell densities were associated with improved disease-specific survival (DSS). Patients with low CD4 + and low FOXP3 + T-cell densities exhibited extremely poor prognoses. T stage, vascular/lymphatic invasion and CD4 + T-cell density were independent prognostic indicators for DSS. The distributions of CD4 + and FOXP3 + T-cell densities were not significantly different between the high microsatellite instability group and other groups, in contrast to those of CD3 + and CD8 + T-cell densities.

Conclusions

Intratumoural CD4 + T-cell density and combined CD4 + and FOXP3 + T-cell densities were stronger prognostic indicators than other clinicopathological features. These results may facilitate the establishment of novel prognostic factors and therapeutic strategies for CRC.

Biology and regulation of IL-2: from molecular mechanisms to human therapy

IL-2 was first identified as a growth factor capable of driving the expansion of activated human T cell populations. In the more than 40 years since its discovery, a tremendous amount has been learned regarding the mechanisms that regulate the expression of both IL-2 and its cell surface receptor, its mechanisms of signalling and its range of biological actions. More recently, the mechanisms by which IL-2 regulates CD4⁺ T cell differentiation and function have been elucidated. IL-2 also regulates the effector and memory responses of CD8⁺ T cells, and the loss of IL-2 or responsiveness to IL-2 at least in part explains the exhausted phenotype that occurs during chronic viral infections and in tumour responses. These basic mechanistic studies have led to the therapeutic ability to manipulate the action of IL-2 on regulatory T (T_reg) cells for the treatment of autoimmune disease and on CD8⁺ T cells for immunotherapy of cancer. IL-2 can have either positive or deleterious effects, and we discuss here recent ideas and approaches for manipulating the actions and overall net effects of IL-2 in disease settings, including cancer.

Cryopreserved Human Natural Killer Cells Exhibit Potent Antitumor Efficacy against Orthotopic Pancreatic Cancer through Efficient Tumor-Homing and Cytolytic Ability (Running Title: Cryopreserved NK Cells Exhibit Antitumor Effect)

Pancreatic cancer is known to be highly aggressive, and desmoplasia-induced accumulation of extracellular matrix (ECM), which is a hallmark of many pancreatic cancers, severely restricts the therapeutic efficacy of both immunotherapeutics and conventional chemotherapeutics due to the ECM functioning as a major physical barrier against permeation and penetration. In the case of cell-based immunotherapeutics, there are several other bottlenecks preventing translation into clinical use due to their biological nature; for example, poor availability of cell therapeutic in a readily usable form due to difficulties in production, handling, shipping, and storage. To address these challenges, we have isolated allogeneic natural killer (NK) cells from healthy donors and expanded them in vitro to generate cryopreserved stocks. These cryopreserved NK cells were thawed to evaluate their therapeutic efficacy against desmoplastic pancreatic tumors, ultimately aiming to develop a readily accessible and mass-producible off-the-shelf cell-based immunotherapeutic. The cultured NK cells post-thawing retained highly pure populations of activated NK cells that expressed various activating receptors and a chemokine receptor. Furthermore, systemic administration of NK cells induced greater in vivo tumor growth suppression when compared with gemcitabine, which is the standard chemotherapeutic used for pancreatic cancer treatment. The potent antitumor effect of NK cells was mediated by efficient tumor-homing ability and infiltration into desmoplastic tumor tissues. Moreover, the infiltration of NK cells led to strong induction of apoptosis, elevated expression of the antitumor cytokine interferon (IFN)-γ, and inhibited expression of the immunosuppressive transforming growth factor (TGF)-β in tumor tissues. Expanded and cryopreserved NK cells are strong candidates for future cell-mediated systemic immunotherapy against pancreatic cancer.

Accelerated Atherosclerosis in Rheumatoid Arthritis: Mechanisms and Treatment

Background:

Rheumatoid arthritis (RA) is a chronic systemic autoimmune inflammatory disorder that increases the risk of developing cardiovascular disease. There is accumulating evidence that the RA disease state accelerates the formation of atherosclerotic plaques. Treatments for RA improve joint symptomatology and may reduce inflammation, but consideration of their effects on the cardiovascular system is generally low priority.

Objective:

Since cardiovascular disease is the leading cause of mortality in RA patients, the impact of RA therapies on atherosclerosis is an area in need of attention and the focus of this review.

Results:

The drugs used to treat RA may be analgesics, conventional disease-modifying anti-rheumatic drugs, and/or biologics, including antibodies against the cytokine tumor necrosis factor-α. Pain relievers such as nonselective non-steroidal anti-inflammatory drugs and cyclooxygenase inhibitors may adversely affect lipid metabolism and cyclooxygenase inhibitors have been associated with increased adverse cardiovascular events, such as myocardial infarction and stroke. Methotrexate, the anchor disease-modifying anti-rheumatic drug in RA treatment has multiple atheroprotective advantages and is often combined with other therapies. Biologic inhibitors of tumor necrosis factor-α may be beneficial in preventing cardiovascular disease because tumor necrosis factor-α promotes the initiation and progression of atherosclerosis. However, some studies show a worsening of the lipid profile in RA with blockade of this cytokine, leading to higher total cholesterol and triglycerides.

Conclusion:

Greater understanding of the pharmacologic activity of RA treatments on the atherosclerotic process may lead to improved care, addressing both damages to the joints and heart.

A long-distance relationship: the commensal gut microbiota and systemic viruses

Recent advances defining the role of the commensal gut microbiota in the development, education, induction, function, and maintenance of the mammalian immune system inform our understanding of how immune responses govern the outcome of systemic virus infection. While characterization of the impact of the local oral, respiratory, dermal and genitourinary microbiota on host immune responses and systemic virus infection is in its infancy, the gut microbiota interacts with host immunity systemically and at distal non-gastrointestinal tract sites to modulate the pathogenesis of systemic viruses. Gut microbes, microbe-associated molecular patterns, and microbe-derived metabolites engage receptors expressed on the cell surface, in the endosome, or in the cytoplasm to orchestrate optimal innate and adaptive immune responses important for controlling systemic virus infection.

Investigating immune responses to parasites using transgenesis

Parasites comprise diverse and complex organisms, which substantially impact human and animal health. Most parasites have complex life-cycles, and by virtue of co-evolution have developed multifaceted, often life-cycle stage-specific relationships with the immune system of their hosts. The complexity in the biology of many parasites often limits our knowledge of parasite-specific immune responses, to in vitro studies only. The relatively recent development of methods to stably manipulate the genetic make-up of many parasites has allowed a better understanding of host-parasite interactions, particularly in vivo. In this regard, the use of transgenic parasites can facilitate the study of immunomodulatory mechanisms under in vivo conditions. Therefore, in this review, we specifically highlighted the current developments in the use of transgenic parasites to unravel the host's immune response to different life-cycle stages of some key parasite species such as Leishmania, Schistosoma, Toxoplasma, Plasmodium and Trypanosome and to some degree, the use of transgenic nematode parasites is also briefly discussed.

Lichen Sclerosus: An autoimmunopathogenic and genomic enigma with emerging genetic and immune targets

Lichen sclerosus (LS) is an inflammatory dermatosis with a predilection for anogenital skin. Developing lesions lead to vulvar pain and sexual dysfunction, with a significant loss of structural anatomical architecture, sclerosis, and increased risk of malignancy. Onset may occur at any age in both sexes, but typically affects more females than males, presenting in a bimodal fashion among pre-pubertal children and middle-aged adults. A definitive cure remains elusive as the exact pathogenesis of LS remains unknown. A general review of LS, histologic challenges, along with amounting support for LS as an autoimmune disease with preference for a Th1 immune response against a genetic background is summarized. In addition to the classically referenced ECM1 (extracellular matrix protein 1), a following discussion of other immune and genetic targets more recently implicated as causative or accelerant agents of disease, particularly miR-155, downstream targets of ECM1, galectin-7, p53, and epigenetic modifications to CDKN2A, are addressed from the viewpoint of their involvement in three different, but interconnected aspects of LS pathology. Collectively, these emerging targets serve not only as inherently potential therapeutic targets for treatment, but may also provide further insight into this debilitating and cryptic disease.

Eosinophilic inflammation in lymph nodes of dogs with visceral leishmaniasis

Eosinophils are traditionally associated with the immune response against helminth parasites. However, several studies have demonstrated that these cells have a role regarding protective immunity in leishmaniasis. Here, we examined the relationship between the presence of eosinophils and parasite load in biopsy samples from dogs, obtained through fine needle puncture and aspiration of lymph nodes. Histological slides containing biopsy material from lymph nodes of dogs with canine visceral leishmaniasis and healthy dogs were used to obtain baseline eosinophil counts. Subsequently, scrapings were taken from slides for DNA extraction and determination of parasite load, using real-time PCR (qRT-PCR). Additionally, production of nitric oxide (NO) and reactive oxygen species (ROS) levels by eosinophils in the peripheral blood of dogs with canine visceral leishmaniasis and healthy dogs was measured. The eosinophil percentage were higher in lymph nodes of infected group, and the parasite load showed a significant negative correlation with the eosinophil count. The production of NO and ROS by eosinophils in the peripheral blood was higher in the dogs with canine visceral leishmaniasis. All the results together suggest that eosinophils may participate in antileishmanial immunity in canine visceral leishmaniasis.

Regulation of T cell differentiation and function by ubiquitin-specific proteases

T cells play critical roles in immune responses to pathogens, autoimmunity, and antitumor immunity. During the past few decades, increasing numbers of studies have demonstrated the significance of protein ubiquitination in T cell-mediated immunity. Several E3 ubiquitin ligases and deubiquitinases (DUBs) have been identified as either positive or negative regulators of T cell development and function. In this review, we mainly focus on the roles of DUBs (especially ubiquitin-specific proteases (USPs)) in modulating T cell differentiation and function, as well as the molecular mechanisms. Understanding how T cell development and function is regulated by ubiquitination and deubiquitination will provide novel strategies for treating infection, autoimmune diseases, and cancer.

Defining Barriers that Impede Choices

Committing to a differentiation pathway means leaving alternative pathways behind. Adoue et al. (2019) report that the H3K9-methyltrasferase Setdb1 plays a role in inhibiting the Th1 program in committed Th2 cells, and mechanistically, its role might relate to the selective targeting of endogenous retroviruses adjacent to Th1 enhancers.

Anti-Inflammatory Effects of Cold Thermal Therapy on Allergic Skin Inflammation Induced by Trimellitic Anhydride in BALB/c Mice

Cold and hot thermal therapies are widely used as a traditional therapy in many cultures and are often prescribed in the treatment of various musculoskeletal and neurological conditions which present themselves to primary care physicians. However, there are no reports that investigated either the effects of cold and hot thermal therapies on the skin inflammation of trimellitic anhydride- (TMA-) induced dermatitis-like contact hypersensitivity (CHS) mouse model, or the mechanism of thermal therapy on allergic skin inflammation. Therefore, in this study, to reveal the anti-inflammatory effect of thermal therapy and its mechanism on TMA-induced CHS, we analyzed ear-swelling response (ear edema), vascular permeability, serum IgE levels, histological examination, and histamine and Th2 cytokine levels. Cold thermal therapy reduced the ear-swelling response, the vascular permeability, the serum IgE levels, and the infiltration of eosinophils and mast cells as well as the mast cell degranulation. To determine the mechanism by which cold thermal therapy inhibits allergic skin inflammation, detailed studies were carried out revealing that cold thermal therapy suppressed IL-4 and IL-5 secretion and mast cell activation. These results indicated that cold thermal therapy cures skin inflammation of TMA-induced CHS by decreasing Th2 cytokine release, especially IL-4 and IL-5, and mast cell activation. These data suggest that new insight into the mechanism of robust therapeutic effects of cold thermal therapy against allergic dermatitis, and cold thermal therapy may prove to be a useful therapeutic modality on allergic inflammatory diseases as traditional use as well as Th2- or mast cell-mediated allergic responses.

Ablation and Inhibition of the Immunoproteasome Catalytic Subunit LMP7 Attenuate Experimental Abdominal Aortic Aneurysm Formation in Mice

Low-molecular mass protein 7 (LMP7) is a proteolytic subunit of the immunoproteasome that is involved in regulating inflammatory responses. However, the role of LMP7 in the pathogenesis of abdominal aortic aneurysm (AAA) remains unknown. In this study, ApoE knockout (KO) or LMP7/ApoE double KO (dKO) mice were infused with angiotensin II (Ang II, 1000 ng/kg per minute) for up to 28 d. We found that LMP7 expression was significantly upregulated in AAA tissues from ApoE KO mice and human patients. Moreover, Ang II infusion markedly increased the incidence and severity of AAA in ApoE KO mice, which was considerably reduced in LMP7/ApoE dKO mice. Histological alterations, including aortic wall thickening, collagen deposition, elastin fragmentation, and vascular smooth muscle cell apoptosis in AAA tissue of ApoE KO mice, were also significantly attenuated in LMP7/ApoE dKO mice. Interestingly, LMP7/ApoE dKO mice showed a marked reduction of infiltration of CD3⁺ T cells, especially CD4⁺ T cells in AAA tissues compared with ApoE KO mice. Moreover, ablation of LMP7 substantially inhibited the differentiation of CD4⁺ T cells into Th1 and Th17 cells by reducing the activation of multiple transcriptional factors. We also investigated the effects of an LMP7-specific inhibitor PR-957 (also known as ONX 0914) on AAA formation in ApoE KO mice. PR-957 treatment could reduce the AAA incidence and severity. In conclusion, our results provide, to our knowledge, novel evidence that ablation or pharmacological inhibition of LMP7 attenuates Ang II-induced AAA formation, and LMP7 might be a novel therapeutic target for treating AAA in humans.

Targeting STATs in neuroinflammation: The road less traveled!

JAK/STAT transduction pathway is a highly conserved pathway implicated in regulating cellular proliferation, differentiation, survival and apoptosis. Dysregulation of this pathway is involved in the onset of autoimmune, haematological, oncological, metabolic and neurological diseases. Over the last few years, the research of anti-neuroinflammatory agents has gained considerable attention. The ability to diminish the STAT-induced transcription of inflammatory genes is documented for both natural compounds (such as polyphenols) and chemical drugs. Among polyphenols, quercetin and curcumin directly inhibit STAT, while Berberis vulgaris L. and Sophora alopecuroides L extracts act indirectly. Also, the Food and Drug Administration has approved several JAK/STAT inhibitors (direct or indirect) for treating inflammatory diseases, indicating STAT can be considered as a therapeutic target for neuroinflammatory pathologies. Considering the encouraging data obtained so far, clinical trials are warranted to demonstrate the effectiveness and potential use in the clinical practice of STAT inhibitors to treat inflammation-associated neurodegenerative pathologies.

Overview of Link Between Inflammatory Bowel Disease and Cardiovascular Disease

Inflammation has been shown to play an increasingly important role in the pathogenesis of atherosclerosis and in precipitating thrombotic events. Inflammatory bowel disease (IBD) is a systemic inflammatory disorder with a wide range of extraintestinal manifestations including a clinically significant increase in the risk of venous thromboembolism compared to matched controls in several studies. The data for the association between IBD and ischemic heart disease are less clear; multiple population-based studies have shown both positive and negative associations between the 2 conditions. While the systemic inflammation should theoretically increase the risk for cardiovascular disease, inflammatory bowel also potentially provides a cardioprotective effect in several ways. Patients with IBD typically enter the healthcare system at an earlier age and experience a lower incidence of obesity, hypercholesterolemia, and hyperlipidemia. Given the complex interplay among the proatherogenic, prothrombogenic, and cardioprotective effects, IBD should be taken into consideration as a nontraditional risk factor for cardiovascular disease in specific subsets of patients.

Molecular cloning and bioactivity of an IL-2 homologue in large yellow croaker (Larimichthys crocea)

Interleukin-2 (IL-2), an important immunomodulatory cytokine, plays a crucial role in promoting the proliferation, activation and differentiation of T cells. Here, the cDNA of an IL-2 homologue (LcIL-2) in large yellow croaker (Larimichthys crocea) was cloned by RACE-PCR techniques. The open reading frame (ORF) of LcIL-2 gene is 426 bp long and encoded a precursor protein of 141 amino acids (aa), with a 20-aa signal peptide and a 121-aa mature peptide containing two putative N-glycosylation sites at Asn⁷⁷ and Asn¹⁰¹. The LcIL-2 is preferentially expressed in lymphocytes-rich tissues, such as spleen and blood, and is increased in head kidney and spleen upon inactivated trivalent bacterial vaccine or poly(I:C) stimulation. LcIL-2 expression could also be detected in primary head kidney leukocytes (PKL), primary head kidney macrophages (PKM) and primary head kidney granulocytes (PKG), with the highest level in PKL. In addition, the expression level of LcIL-2 in PKL was slightly induced by LPS or poly(I:C), while markedly induced by PHA or Con-A. The recombinant LcIL-2 protein produced in Pichia pastoris could increase the expression of genes involved in Th1 (IL-2, IFN-γ and T-bet) and Th2 (IL-4/13A, IL-4/13B and GATA3) development and differentiation, and of the IL-2 downstream transcription factor STAT5B gene, but inhibit the expression of genes related to Th17 (IL-17A/F2 and IL-17A/F3) development and differentiation. Taken together, our results indicated that LcIL-2 possesses similar structural and functional characteristics to other vertebrate IL-2s, and may play a role in T cell development and differentiation.

T Helper Cell Differentiation, Heterogeneity, and Plasticity

Naïve CD4 T cells, on activation, differentiate into distinct T helper (Th) subsets that produce lineage-specific cytokines. By producing unique sets of cytokines, effector Th subsets play critical roles in orchestrating immune responses to a variety of infections and are involved in the pathogenesis of many inflammatory diseases including autoimmunity, allergy, and asthma. The differentiation of Th cells relies on the strength of T-cell receptor (TCR) signaling and signals triggered by polarizing cytokines that activate and/or up-regulate particular transcription factors. Several lineage-specific master transcription factors dictate Th cell fates and functions. Although these master regulators cross-regulate each other, their expression can be dynamic. Sometimes, they are even coexpressed, resulting in massive Th-cell heterogeneity and plasticity. Similar regulation mediated by these master regulators is also found in innate lymphoid cells (ILCs) that are innate counterparts of Th cells.

Bacterial respiratory tract inflammation in neonatal rat model is attenuated by benzofuran through inhibition of GATA3

The current study was aimed to investigate the effect of benzofuran on asthma neonatal rat model. Twenty-five neonatal rats were assigned into five groups; Normal control, untreated, 1 mg/kg, 8 mg/kg and 10 mg/kg treatment groups. Methacholine was administered orally to the rats of untreated and treatment groups. Animals in the normal control group were given PBS as a vehicle. FlexiVent system employing a computer-controlled mouse ventilator along with respiratory mechanics was used for the analysis of airway resistance in the rats. Cytokine level and IFN-γ in the rat serum samples was performed by ELISA in accordance with the instructions of manufacturer. Methacholine administration into the rats caused a marked increase in lung airway resistance. However, treatment with 8 and 10 mg/kg doses of benzofuran led to marked decrease in the airway resistance. Benzofuran treatment prevented accumulation of macrophages and inflammatory cells in the lung airways. Inhibition of inflammation in methacholine administered rats by benzofuran was also confirmed by hematoxylin & eosin-staining. Examination of the rat serum showed significantly higher level of Th2 cytokines (IL-4, -5 and -13) in the untreated rats. However, treatment of methacholine administered rats with benzofuran significantly inhibited Th2 cytokine expression. The level of IFN-γ was increased by benzofuran treatment in methacholine administered rats. In methacholine administered rats the level of IgE was markedly higher however treatment of asthma rats with benzofuran inhibited up-regulation of IgE significantly. The expression of T-bet is decreased and that of GATA-3 is increased by methacholine administration in the rat lungs. Benzofuran treatment of methacholine administered rats prevented reduction in T-bet and up-regulation of GATA-3 expression in the rat lungs. The effect of benzofuran was significant at the doses of 8 and 10 mg/kg and non-significant at 1 mg/kg. These finding suggest that benzofuran inhibits expression of dominant T-helper 2 cytokines through targeting GATA-binding protein 3 transcription factor. Thus benzofuran can be of therapeutic importance for the treatment of asthma.

Impaired Autophagy in Intestinal Epithelial Cells Alters Gut Microbiota and Host Immune Responses

Establishing and maintaining beneficial interactions between the host and associated gut microbiota are pivotal requirements for host health. Autophagy is an important catabolic recycling pathway that degrades long-lived proteins and some organelles by lysosome to maintain cellular homeostasis. Although impaired autophagy is thought to be closely correlated with Crohn's disease (CD), the functional role of autophagy in the maintenance of gut microbiota is poorly understood. As autophagy-related 5 (Atg5) is a key gene associated with the extension of the phagophoric membrane in autophagic vesicles, we established a gut-specific Atg5 knockout mouse model, and we found that the disruption of autophagic flux in the intenstinal epithelium cells dramatically altered the composition of the gut microbiota and reduced alpha diversity. Microbial function prediction indicated that the pathway allocated for infectious diseases was enriched in Atg5^-/- mice. "Candidatus Arthromitus" and the Pasteurellaceae family were increased in Atg5^-/- mice, whereas Akkermansia muciniphila and the Lachnospiraceae family were reduced. Transcriptome analysis revealed that two key inflammatory bowel disease (IBD)-related transcription factors, RORC and TBX21, of host cells were upregulated in Atg5^-/- mice, thus elevating the Muc2-related immunological response. The findings suggest that intestinal autophagy plays a vital role in modulating the diversity and composition of gut microbiota.IMPORTANCE The homeostasis of host-microbiota interactions is of great importance to host health. Previous studies demonstrated that disruption of autophagy was linked to inflammatory bowel disease. However, the interaction mechanism of gut microbiota regulated by autophagy was obscure. In an intestinal epithelium-specific autophagy-related 5 (Atg5) knockout mouse model, we observed a significant alteration and decreased diversity in the gut microbiota of Atg5-deficient mice compared with that of wild-type mice. Although the numbers of some organisms (e.g., Akkermansia muciniphila and members of the Lachnospiraceae family) associated with the control of inflammation decreased, those of proinflammationory bacteria (e.g., "Candidatus Arthromitus") and potential pathogens (the Pasteurellaceae family) increased in Atg5^-/- mice. Differential gene expression analysis revealed that two key genes, RORC and TBX21, involved in inflammatory bowel disease were upregulated in Atg5^-/- mice. Our study suggests that Atg5 deficiency results in an imbalance of the host-microbe interaction and deterioration of the gut microenvironment.

Transcriptional regulation of CD4+ TH cells that mediate tissue inflammation

Acquired and genetic immunodeficiencies have revealed an indispensable role for CD4⁺ T cells in the induction of protective host immune responses against a myriad of microbial pathogens. Influenced by the cytokines present in the microenvironment, activated CD4⁺ T cells may differentiate into several highly-specialized helper subsets defined by the production of distinct signature cytokines tailored to combat diverse classes of pathogens. The process of specification and differentiation is controlled by networks of core, master, and accessory transcription factors, which ensure that CD4⁺ T helper (T_H ) cell responses mounted against an invading microbe are of the correct specificity and type. However, aberrant activation or inactivation of transcription factors can result in sustained and elevated expression of immune-related genes, leading to chronic activation of CD4⁺ T_H  cells and organ-specific autoimmunity. In this review, we provide an overview of the molecular basis of CD4⁺ T_H  cell differentiation and examine how combinatorial expression of transcription factors, which promotes genetic plasticity of CD4⁺ T_H  cells, can contribute to immunological dysfunction of CD4⁺ T_H responses. We also discuss recent studies which highlight the potential of exploiting the genetic plasticity of CD4⁺ T_H  cells in the treatment of autoimmune and other immune-mediated disorders.

Induction of adaptive immune response by self-aggregating peptides

INTRODUCTION

Recently, subunit vaccines are replacing some of the traditional vaccines because they offer a higher margin of safety. However, generally subunit vaccines have low antigenicity. Adjuvants are used in vaccine formulations to increase their immunogenicity, but current research suggests that adjuvants could induce serious side effects in susceptible individuals; therefore, the improvement of antigens and adjuvants is important.

AREAS COVERED

Here we reviewed some self-aggregating peptides (SAPs) used as antigen delivery systems. SAPs are based on a short sequence of amino acids, which have self-aggregating properties, inducing self-interaction among peptide molecules by means of non-covalent interactions to generate nanoparticles (NPs).

EXPERT COMMENTARY

SAPs increase the immunogenicity of fused/conjugated antigens because they can interact with antigen-presenting cells and induce adaptive immunity based on both humoral and cellular responses. As an example, we report an antigen delivery system based on SAPs forming NPs. These NPs are synthesized using a recombinant baculovirus. We fused the green fluorescent protein to the first 110 amino acids of polyhedrin protein from Autographa californica nucleopolyhedrovirus, which has self-aggregating properties. We showed that these NPs prompt high antibody levels without inducing inflammation, similarly to some SAPs reported here.

Role of Cytokine Combinations on CD4+ T Cell Differentiation, Partial Polarization, and Plasticity: Continuous Network Modeling Approach

Purpose: We put forward a theoretical and dynamical approach for the semi-quantitative analysis of CD4+ T cell differentiation, the process by which cells with different functions are derived from activated CD4+ T naïve lymphocytes in the presence of particular cytokine microenvironments. We explore the system-level mechanisms that underlie CD4+ T plasticity-the conversion of polarized cells to phenotypes different from those originally induced. Methods: In this paper, we extend a previous study based on a Boolean network to a continuous framework. The network includes transcription factors, signaling pathways, as well as autocrine and exogenous cytokines, with interaction rules derived using fuzzy logic. Results: This approach allows us to assess the effect of relative differences in the concentrations and combinations of exogenous and endogenous cytokines, as well as of the expression levels of diverse transcription factors. We found either abrupt or gradual differentiation patterns between observed phenotypes depending on critical concentrations of single or multiple environmental cytokines. Plastic changes induced by environmental cytokines were observed in conditions of partial phenotype polarization in the T helper 1 to T helper 2 transition. On the other hand, the T helper 17 to induced regulatory T-cells transition was highly dependent on cytokine concentrations, with TGFβ playing a prime role. Conclusion: The present approach is useful to further understand the system-level mechanisms underlying observed patterns of CD4+ T differentiation and response to changing immunological challenges.

Altered distribution and function of splenic innate lymphoid cells in adult chronic immune thrombocytopenia

Innate lymphoid cells (ILCs) have been characterized as innate immune cells capable to modulate the immune response in the mucosae. Human ILCs have been rarely described in secondary lymphoid organs except in tonsils. Moreover, their function and phenotype in human secondary lymphoid organs during autoimmune diseases have never been studied. We took advantage of splenectomy as a treatment of immune thrombocytopenia (ITP) to describe and compare splenic ILC from 18 ITP patients to 11 controls. We first confirmed that ILC3 represented the most abundant ILC subset in human non-inflamed spleens, accounting for 90% of total ILC, and that they were mostly constituted of NKp44^- cells. On the contrary, proportions of ILC1 and ILC2 in spleens were lower than in blood. Splenic IL-2- and IFN-γ-producing ILC1 were increased in ITP. While the frequencies of total splenic ILC3 were similar in the two groups, splenic GM-CSF-producing ILC3 were increased in ITP. This is the first description of human ILC in a major secondary lymphoid organ during an autoimmune disease, ITP. We observed an expansion of splenic ILC1 that could participate to the Th1 skewing, while the increased production of GM-CSF by splenic ILC3 could stimulate splenic macrophages which play a key role in ITP pathophysiology.

Epstein-Barr virus-encoded microRNAs as regulators in host immune responses

Epstein-Barr virus (EBV) is an oncogenic virus that infects over 90% of the world's adult population. EBV can establish life-long latent infection in host due to the balance between EBV and host immune system. EBV latency is associated with various malignancies such as nasopharyngeal carcinoma, gastric carcinoma and Burkitt's lymphoma. EBV is the first human virus that has the capability to encode microRNAs (miRNAs). Remarkably, EBV-encoded miRNAs are abundantly expressed in latently-infected cells and serve important function in viral infection and pathogenesis. Increasing evidence indicates that EBV miRNAs target the host mRNAs involved in cell proliferation, apoptosis and transformation. EBV miRNAs also inhibit the expression of viral antigens, thereby enabling infected cells to escape immune recognition. Intriguingly, EBV miRNAs directly suppress host antiviral immunity by interfering with antigen presentation and immune cell activation. This review will update the current knowledge about EBV miRNAs implicated in host immune responses. An in-depth understanding of the functions of EBV miRNAs in host antiviral immunity will shed light on the EBV-host interactions and provide potential therapeutic targets for the treatment of EBV-associated malignancies.

Transcription regulatory factor expression in T-helper cell differentiation pathway in eutopic endometrial tissue samples of women with endometriosis associated with infertility

Endometriosis is a disease of epidemiological gravity of unknown primary reason. A complex of constitutional factors including the immune system has been considered as its background. The aim of the study was to identify Th1 and Th2 cells as well as the T-regulatory subset in the endometrium of women with endometriosis associated with infertility upon transcription factors expression. Expression of T-bet, GATA3, and Foxp3 genes was examined using a method of polymerase chain reaction (PCR) in the eutopic endometrial samples of 20 women with endometriosis associated with infertility and 20 women with infertility of tubal origin. An increase in mRNA expression for T-bet and GATA3 with prevailing mRNA level for T-bet and a decrease in Foxp3 expression were observed. In conclusion, the revealed changes in expression of transcription factors may indicate the imbalance between T-helper cells of the Th1 and Th2 type and elimination of regulatory function of T-cells, which can be one of the causes of endometriosis predisposing to the development of infertility associated with this disease.

CANTOS: A breakthrough that proves the inflammatory hypothesis of atherosclerosis

Atherosclerosis is no longer considered solely a disorder of subintimal deposition of modified low-density lipoprotein particles in the arterial wall. Rather, it is known to be a chronic inflammatory disorder. No evidence has shown that reducing vascular inflammation in the absence of concomitant lowering of lipoproteins levels reduces the rates of adverse cardiovascular (CV) events. Canakinumab, a fully human monoclonal antibody that neutralizes interleukin (IL)-1β, significantly reduced the rate of recurrent CV events in patients with prior myocardial infarction in the Canakinumab Anti-inflammatory Thrombosis Outcome Study (CANTOS). Canakinumab has no effect on CV or all-cause mortality, however it was associated with high incidence of fatal infections. Thus, the net benefit needs to be properly addressed in future studies that evaluate the potential benefit of the anti-inflammatory therapies and whether it can change clinical practice in the near future.

T-bet promotes potent antitumor activity of CD4+ CAR T cells

Chimeric antigen receptor (CAR) therapy has shown promise against B cell malignancies in the clinic. However, limited success in patients with solid tumors has prompted the development of new CAR strategies. In this study, a B7H6-specific CAR was combined with different variants of T-bet, a transcription factor that acts as the master regulator to induce a Th1 phenotype in CD4⁺ T cells, to create more effective CAR T cells. Skewing CD4⁺ CAR T cells into a Th1 improved CAR T cell functional activity while promoting a robust proinflammatory response against B7H6-expressing tumors. The expression of T-bet with the B7H6-specific CAR in CD4⁺ T cells conferred higher expression of the CAR, elevated secretion of Th1 and proinflammatory cytokines, and improved cellular cytotoxicity against B7H6-expressing tumor cells. In vivo, CD4⁺ T cells co-expressing a B7H6-specific CAR and T-bet improved the survival of RMA-B7H6 lymphoma-bearing mice. Thus, CD4⁺ CAR T cells with increased T-bet expression have the potential to modify the tumor microenvironment and the immune response to better treat solid and hematologic cancers.

In vitro intracellular IFNγ, IL-17 and IL-10 producing T cells correlates with the occurrence of post-transplant opportunistic infection in liver and kidney recipients

AIM

To validate intracellular cytokine production functional assay as means of cell-mediated immunity monitoring of post-transplant patients with opportunistic infection (OI).

METHODS

Intracellular cytokine-producing CD4⁺ and CD8⁺ T-cell monitoring was carried out in 30 liver transplant (LTr) and 31 kidney transplant (KTr) recipients from 2010 to 2012. Patients were assessed in our Department of Immunology at the Clinical University ‘Hospital Virgen de la Arrixaca-IMIB’ in Murcia, Spain for one year following transplantation. FACS Canto II flow cytometer was employed to quantify the intracellular production of IL-17, IFNγ and IL-10 cytokines on stimulated CD4⁺CD69⁺ and CD8⁺CD69⁺ T cells and BD FACS DIVA v.6 software was used to analysed the data. Statistical analysis was carried out using SPSS 22.0.

RESULTS

LTr with OI had significantly lower % of CD8⁺CD69⁺IFNγ⁺ T cells at 60 (7.95 ± 0.77 vs 26.25 ± 2.09, P < 0.001), 90 (7.47 ± 1.05 vs 30.34 ± 3.52, P < 0.001) and 180 (15.31 ± 3.24 vs 24.59 ± 3.28, P = 0.01) d post-transplantation. Higher % of CD4⁺CD69⁺IL-10⁺ as well as CD4⁺CD69⁺IL-17⁺ T cells were yet reported at 30 (14.06 ± 1.65 vs 6.09 ± 0.53, P = 0.0007 and 4.23 ± 0.56 vs 0.81 ± 0.14, P = 0.005; respectively), 60 (11.46 ± 1.42 vs 4.54 ± 0.91, P = 0.001 and 4.21 ± 0.59 vs 1.43 ± 0.42, P = 0.03; respectively) and 90 d (16.85 ± 1.60 vs 4.07 ± 0.63, P < 0.001 and 3.97 ± 0.43 vs 0.96 ± 0.17, P = 0.001). Yet, KTr with OI had significantly lower percentage of CD4⁺CD69⁺IFNγ⁺ at 30 (11.80 ± 1.59 vs 20.64 ± 3.26, P = 0.035), 60 (11.19 ± 1.35 vs 15.85 ± 1.58, P = 0.02), 90 (11.37 ± 1.42 vs 22.99 ± 4.12, P = 0.028) and 180 (13.63 ± 2.21 vs 21.93 ± 3.88, P = 0.008) d post-transplantation as opposed to CD4⁺CD69⁺IL-10⁺ and CD8⁺CD69⁺IL-10⁺ T cells which percentages were higher at 30 (25.21 ± 2.74 vs 8.54 ± 1.64, P < 0.001 and 22.37 ± 1.35 vs 17.18 ± 3.54, P = 0.032; respectively), 90 (16.85 ± 1.60 vs 4.07 ± 0.63, P < 0.001 and 23.06 ± 2.89 vs 10.19 ± 1.98, P = 0.002) and 180 (21.81 ± 1.72 vs 6.07 ± 0.98, P < 0.001 and 19.68 ± 2.27 vs 10.59 ± 3.17, P = 0.016) d post-transplantation. The auROC curve model determined the most accurate cut-off values to stratify LTr and KTr at high risk of OI and Cox Regression model confirmed these biomarkers as the most significant risk factors to opportunistic infection.

CONCLUSION

Post-transplant percentages of T-cell subsets differed significantly amongst infected- and non-infected-LTr and -KTr and yet this imbalance was found to contribute towards a worst clinical outcome.

Oncolytic adenovirus coexpressing interleukin-12 and shVEGF restores antitumor immune function and enhances antitumor efficacy

Tumor microenvironment is extremely immunosuppressive, preventing efficient induction of antitumor immunity. To overcome tumor-mediated immunosuppression and enhance the potency of immunogene therapy, oncolytic adenovirus (Ad) co-expressing interleukin (IL)-12 and vascular endothelial growth factor (VEGF)-specific short hairpin ribonucleic acid (shVEGF; RdB/IL12/shVEGF) was generated. Intratumoral injection of RdB/IL12/shVEGF induced a strong antitumor effect in an immune competent B16-F10 melanoma model. RdB/IL12/shVEGF restored immune surveillance function in tumor tissues and actively recruited immune cells by elevating the expression levels of IL-12 and interferon-γ. RdB/IL12/shVEGF efficiently suppressed expression of immunosuppressive VEGF, resulting in restoration of the antitumor immune response and prevention of thymic atrophy. In situ delivery of RdB/IL12/shVEGF to tumor tissues resulted in massive infiltration of differentiated CD4⁺ T cells, CD8⁺ T cells, natural killer cells, and dendritic cells to tissues surrounding the necrotic region of tumor. Furthermore, RdB/IL12/shVEGF induced a potent tumor-specific T helper type 1 immune response, implying that attenuation of the immunosuppressive environment mediated by downregulation of VEGF can significantly enhance immune stimulatory functions in the tumor milieu. Collectively, these findings indicate the potential of inducing and restoring potent antitumor immunity using intratumorally administered oncolytic Ad co-expressing IL-12 and shVEGF.

Variations in the leukocyte and cytokine profiles between placental and maternal circulation in pregnancy-associated malaria

BACKGROUND

Activation of immune cells by malaria infection induces the secretion of cytokines and the synthesis of other inflammatory mediators. This study compared the cytokine levels and leukocyte count between malaria-infected peripheral and placental blood of pregnant women before delivery and postpartum. The cytokines assessed include interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin-4 (IL-4), interleukin-6 (IL-6) and interleukin-10 (IL-10).

MATERIALS AND METHODS

The subjects comprised 144 malaria-infected pregnant women and 60 malaria-infected women at post-partum stage (for placental blood collection). Others were 60 malaria-uninfected pregnant women and 40 malaria-uninfected women at postpartum stage (for placental blood collection). Forty malaria-infected and 40 malaria-uninfected nonpregnant women served as control subjects. The test groups were asymptomatic, and the control groups were apparently healthy subjects. All were aged between 17 and 44 years. Ethical approval for the study was obtained at Abia State University Teaching Hospital and Living Word Mission Hospital, Aba. Informed consent was obtained from the participants. Blood samples were aseptically collected initially from the maternal peripheral circulation and from the placenta on delivery, and tested for HIV and malaria using standard methods. IFN-γ, TNF-α, IL-4, IL-6 and IL-10 were measured by enzyme-linked immunosorbent assay technique. Kruskal-Wallis test was used for comparison of the groups.

RESULTS

IFN-γ was significantly higher in the peripheral than in placental blood (P=0.001). IL-4 and IL-10 were significantly lower in the peripheral than in placental blood (P=0.001 and P=0.004, respectively). The total leukocytes, neutrophils and lymphocyte counts were significantly higher in the placenta than in peripheral blood (P=0.001), and the mixed differential count was significantly higher in the placenta than in peripheral blood (P=0.012).

CONCLUSION

This study has shown that the cytokine levels and leukocyte counts may differ between the peripheral and placental blood of the same women. Therefore, measurement of parameters in the peripheral circulation may not always reflect the levels in the placental blood for the assessment of immune cellular response at the materno-fetal interface.

A cellular and molecular view of T helper 17 cell plasticity in autoimmunity

Since the original identification of the T helper 17 (Th17) subset in 2005, it has become evident that these cells do not only contribute to host defence against pathogens, such as bacteria and fungi, but that they are also critically involved in the pathogenesis of many autoimmune diseases. In contrast to the classic Th1 and Th2 cells, which represent rather stably polarized subsets, Th17 cells display remarkable heterogeneity and plasticity. This has been attributed to the characteristics of the key transcription factor that guides Th17 differentiation, retinoic acid receptor-related orphan nuclear receptor gamma (RORγ). Unlike the 'master regulators' T-bet and GATA3 that orchestrate Th1 and Th2 differentiation, respectively, RORγ controls transcription at relatively few loci in Th17 cells. Moreover, its expression is not stabilized by positive feedback loops but rather influenced by environmental cues, allowing for substantial functional plasticity. Importantly, a subset of IL-17/IFNγ double-producing Th17 cells was identified in both human and mouse models. Evidence is accumulating that these IL-17/IFNγ double-producing cells are pathogenic drivers in autoimmune diseases, including rheumatoid arthritis, multiple sclerosis and inflammatory bowel disease. In addition, IL-17/IFNγ double-producing cells have been identified in disorders in which the role of autoimmunity remains unclear, such as sarcoidosis. The observed plasticity of Th17 cells towards the Th1 phenotype can be explained by extensive epigenetic priming of the IFNG locus in Th17 cells. In fact, Th17 cells display an IFNG chromatin landscape that is remarkably similar to that of Th1 cells. On the other hand, pathogenic capabilities of Th17 cells can be restrained by stimulating IL-10 production and transdifferentiation into IL-10 producing T regulatory type 1 (Tr1) cells. In this review, we discuss recent advances in our knowledge on the cellular and molecular mechanisms involved in Th17 differentiation, heterogeneity and plasticity. We focus on transcriptional regulation of the Th17 expression program, the epigenetic dynamics involved, and how genetic variants associated with autoimmunity may affect immune responses through distal gene regulatory elements. Finally, the implications of Th17 cell plasticity for the pathogenesis and treatment of human autoimmune diseases will be discussed.

Enhanced CD25+Foxp3+ regulatory T cell development by amodiaquine through activation of nuclear receptor 4A

CD4+ T cells play key roles in the regulation of immune responses against pathogenic infectious antigens via development into effector T helper and induced regulatory T (iTreg) cells. Particularly, CD4+CD25+Foxp3+ iTreg cells are crucial for maintaining immune homeostasis and controlling inflammatory diseases. Anti-inflammatory drugs that enhance iTreg cell generation would be effective at preventing and treating inflammatory and autoimmune diseases. In this study, we examined whether anti-malarial and anti-arthritic amodiaquine (AQ) could affect iTreg cell development. Despite the anti-proliferative activity of AQ, AQ only moderately decreased iTreg cell proliferation but substantially increased IL-2 production by iTreg cells. Furthermore, AQ dose-dependently increased iTreg cell development and significantly upregulated iTreg cell markers including CD25. Interestingly, CD25 expression was decreased at later stages of iTreg cell development but was sustained in the presence of AQ, which was independent of IL-2 signaling pathway. AQ directly increased CD25 gene transcription by enhancing the DNA-binding and transcriptional activity of nuclear receptor 4 A. Most importantly, in vivo administration of AQ attenuated inflammatory colitis, resulted in the increased iTreg cells and decreased inflammatory cytokines. The ability of anti-malarial AQ to potentiate iTreg cell development makes it a promising drug for preventing and treating inflammatory and autoimmune diseases.

Live Attenuated Leishmania donovani Centrin Gene-Deleted Parasites Induce IL-23-Dependent IL-17-Protective Immune Response against Visceral Leishmaniasis in a Murine Model

No vaccine exists against visceral leishmaniasis. To develop effective vaccines, we have previously reported protective role of live attenuated centrin gene-deleted Leishmania donovani (LdCen^-/- ) parasites through induction of Th1 type immune response in mice, hamsters, and dogs. In this study, we specifically explored the role of Th17 cells in LdCen^-/- -induced host protection in mice. Our results showed that compared with wild-type L. donovani infection, LdCen^-/- parasites induce significantly higher expression of Th17 differentiation cytokines in splenic dendritic cells. There was also induction of IL-17 and its promoting cytokines in total splenocytes and in both CD4 and CD8 T cells following immunization with LdCen^-/- Upon challenge with wild-type parasites, IL-17 and its differentiating cytokines were significantly higher in LdCen^-/- -immunized mice compared with nonimmunized mice that resulted in parasite control. Alongside IL-17 induction, we observed induction of IFN-γ-producing Th1 cells as reported earlier. However, Th17 cells are generated before Th1 cells. Neutralization of either IL-17 or IFN-γ abrogated LdCen^-/- -induced host protection further confirming the essential role of Th17 along with Th1 cytokines in host protection. Treatment with recombinant IL-23, which is required for stabilization and maintenance of IL-17, heightened Th17, and Tc17 responses in immunized mice splenocytes. In contrast, Th17 response was absent in immunized IL-23R^-/- mice that failed to induce protection upon virulent Leishmania challenge suggesting that IL-23 plays an essential role in IL-17-mediated protection by LdCen^-/- parasites. This study unveiled the role of IL-23-dependent IL-17 induction in LdCen^-/- parasite-induced immunity and subsequent protection against visceral leishmaniasis.

Increased expression of Th17 cytokines and interleukin-22 correlates with disease activity in pristane-induced arthritis in rats

The objective of this study was to identify the key changed subtype of T helper cells (Th cells) and their cytokines in pristane-induced arthritis (PIA) in rats. The severity of arthritis was evaluated by body weight, clinical score, the perimeter of ankle and mid-paw and histological assessment of ankle joints. Cytokines of Th1, Th2 and Th17 were determined in the spleen and inguinal lymph nodes at 28 days after pristane injection by real-time qPCR. The mRNA levels of IL-22 receptors, IL-22R1 and IL-22BP, in the spleen were quantified by real-time qPCR. Additionally, IL-22 expression in synovial membrane was detected by Western blotting, and serum IL-22 concentration was determined by ELISA. Correlation between IL-22 concentration and clinical score was analyzed. By screening the cytokines of Th1, Th2 and Th17 expression profile, we found that the mRNA levels of Th17 cytokines were significantly increased in PIA rats. Particularly, a significant increase in the protein expression of IL-22 was determined in synovial membrane and serum from PIA rats, and correlated with clinical score. We conclude that IL-22 expression level was increased and correlated with disease severity, which indicated that IL-22 may play an important role in development of PIA, and was helpful to explorer the pathogenesis of rheumatoid arthritis.

Adaptive Immunity to Cryptococcus neoformans Infections

The Cryptococcus neoformans/Cryptococcus gattii species complex is a group of fungal pathogens with different phenotypic and genotypic diversity that cause disease in immunocompromised patients as well as in healthy individuals. The immune response resulting from the interaction between Cryptococcus and the host immune system is a key determinant of the disease outcome. The species C. neoformans causes the majority of human infections, and therefore almost all immunological studies focused on C. neoformans infections. Thus, this review presents current understanding on the role of adaptive immunity during C. neoformans infections both in humans and in animal models of disease.

Inhibition of Phosphorylated c-Jun NH(2)-terminal Kinase by 2',4'-dihydroxy-6-methoxy-3,5-dimethylchalcone Isolated from Eugenia aquea Burm f. Leaves in Jurkat T-cells

Background:

Indonesian medicinal plants have been used for their anticancer activity for decades. However, the therapeutic effects of medicinal plants have not been fully examined scientifically. As cancer is a major health problem worldwide, searching for a new anticancer compound has attracted considerable attention. Our previous study found that 2’,4’-dihydroxy-6-methoxy-3,5-dimethylchalcone, an active compound isolated from leaves of Indonesian medicinal plants Eugenia aquea Burm f. (Myrtaceae), had anticancer activity in MCF-7 human breast cancer cells through induction of apoptosis.

Objective:

To investigate the molecular mechanism of 2’,4’-dihydroxy-6-methoxy-3,5-dimethylchalcone antiproliferative activity.

Materials and Methods:

Leaves of E. aquea were extracted by ethanol, fractionated by ethyl acetate, n-hexane, or water, and isolated for its active compound. Jurkat T-cells were treated with 2’,4’-dihydroxy-6-methoxy-3,5-dimethylchalcone for 12 and 24 h, and a cell viability assay and real-time-reverse transcriptase polymerase chain reaction for interleukin-2 (IL-2) mRNA measurement were performed. The effects of active compound to mitogen-activated protein kinases were also examined to investigate the mechanism of its antiproliferative activity.

Results:

2’,4’-dihydroxy-6-methoxy-3,5-dimethylchalcone inhibited Jurkat T-cell proliferation with a half maximal inhibitory concentration of 59.5 mM. Although IL-2 mRNA expression was slightly increased after treatment, it inhibited c-Jun N-terminal kinase expression but not p38 and extracellular signal-regulated kinase expression.

Conclusions:

Our study indicated that the molecular mechanism mediating the antiproliferative activity of 2’,4’-dihydroxy-6-methoxy-3,5-dimethylchalcone may be attributed to the stimulation of an immunological microenvironment in the cells.

SUMMARY

2’,4’-dihydroxy-6-methoxy-3,5-dimethylchalcone was isolated from Eugenia aquea. The antiproliferative activity of 2’,4’-dihydroxy-6- methoxy-3,5-dimethylchalcone significantly showed in Jurkat T-cells with a half maximal inhibitory concentration of 59.5 mM through inhibition of c-Jun N-terminal kinase phosphorylation. Interleukin-2 mRNA expression was also slightly increased after treatment with the compound, and this result may be indicated to the stimulation of the immunological microenvironment in T-cells.

Abbreviations used:E. aquea: Eugenia aquea, IL-2: Interleukin-2, MAPK: Mitogen-activated protein kinase, ERKs: Extracellular signal-regulated kinases, JNKs: c-Jun N-terminal kinases, p38: p38 MAPK, PI3K: Phosphatidylinositol-3 kinase, IC₅₀: Half maximal inhibitory concentration.

Sense and Immunity: Context-Dependent Neuro-Immune Interplay

The sensory nervous and immune systems, historically considered autonomous, actually work in concert to promote host defense and tissue homeostasis. These systems interact with each other through a common language of cell surface G protein-coupled receptors and receptor tyrosine kinases as well as cytokines, growth factors, and neuropeptides. While this bidirectional communication is adaptive in many settings, helping protect from danger, it can also become maladaptive and contribute to disease pathophysiology. The fundamental logic of how, where, and when sensory neurons and immune cells contribute to either health or disease remains, however, unclear. Our lab and others’ have begun to explore how this neuro-immune reciprocal dialog contributes to physiological and pathological immune responses and sensory disorders. The cumulative results collected so far indicate that there is an important role for nociceptors (noxious stimulus detecting sensory neurons) in driving immune responses, but that this is highly context dependent. To illustrate this concept, we present our findings in a model of airway inflammation, in which nociceptors seem to have major involvement in type 2 but not type 1 adaptive immunity.

Role of Th17 and Treg cells in septic arthritis and the impact of the Th17/Treg -derived cytokines in the pathogenesis of S. aureus induced septic arthritis in mice

Intravenous inoculation of Swiss mice with S. aureus leads to severe synovial joint tissue swelling along with prominent T lymphocyte infiltrate with associated inflammation in synovial tissue. Cytokines released from macrophages such as TNF-α, IL-1β and IL-6 the main players that precede cartilage and bone destruction during septic arthritis (SA) followed by osteoclast differentiation and bone resorption. CD4⁺ naïve T cells upon cytokine driven activation, differentiate into lineages of helper (Th) and regulatory T cells (Treg) including inflammatory Th17 cell lineage. Acting as counterbalance, Tregs protect the host by releasing anti-inflammatory IL-10. A disturbed balance between Th17 and Treg cell development skews the pathways towards Th17 lineage, but how it actually induces SA is still unexplored. Therefore, this study has been attempted to demonstrate the Th17/Treg ratio in synovial tissue, spleen and peripheral blood by FACS and their derived cytokines from serum of arthritic mice. Here, we reported that the ratios of Th17/Treg as well as their related cytokine levels were increased at 3 days post-infection which was decreased during 9 DPI but heightened again at 15DPI resulting in persistence of the disease, though decreased again at 30 DPI even in animals with increased dose of infection. Bacterial colonies were present in synovial joints at 15 DPI in animals with increased infection but found to be absent at 30 DPI. Maintaining Th17/Treg balance by neutralizing functionally active Th17 and their related cytokines or adoptive transfer of fully active Tregs and/or their related cytokines may lead to a novel therapeutic strategy for combating Staphylococcal arthritis.

Small Nuclear Ribonucleoprotein Polypeptide A-Mediated Alternative Polyadenylation of STAT5B during Th1 Cell Differentiation

T cells are activated and differentiated into Th cells depending on the rapid and accurate changes in the cell transcriptome. In addition to changes in mRNA expression, the sequences of many transcripts are altered by alternative splicing and alternative polyadenylation (APA). We profiled the APA sites of human CD4⁺ T cell subsets with high-throughput sequencing and found that Th1 cells harbored more genes with shorter tandem 3' untranslated regions (UTRs) than did naive T cells. We observed that STAT5B, a key regulator of Th1 differentiation, possessed three major APA sites and preferred shorter 3' UTRs in Th1 cells. In addition, small nuclear ribonucleoprotein polypeptide A (SNRPA) was found to bind directly to STAT5B 3' UTR and facilitate its APA switching. We also found that p65 activation triggered by TCR signaling could promote SNRPA transcription and 3' UTR shortening of STAT5B. Thus we propose that the APA switching of STAT5B induced by TCR activation is mediated by SNRPA.

New Insights into the Role of Inflammation in the Pathogenesis of Atherosclerosis

Atherosclerosis is a chronic inflammatory disease characterized by the accumulation of lipids, smooth muscle cell proliferation, cell apoptosis, necrosis, fibrosis, and local inflammation. Immune and inflammatory responses have significant effects on every phase of atherosclerosis, and increasing evidence shows that immunity plays a more important role in atherosclerosis by tightly regulating its progression. Therefore, understanding the relationship between immune responses and the atherosclerotic microenvironment is extremely important. This article reviews existing knowledge regarding the pathogenesis of immune responses in the atherosclerotic microenvironment, and the immune mechanisms involved in atherosclerosis formation and activation.

Enhanced Acid Sphingomyelinase Activity Drives Immune Evasion and Tumor Growth in Non-Small Cell Lung Carcinoma

The lipid hydrolase enzyme acid sphingomyelinase (ASM) is required for the conversion of the lipid cell membrane component sphingomyelin into ceramide. In cancer cells, ASM-mediated ceramide production is important for apoptosis, cell proliferation, and immune modulation, highlighting ASM as a potential multimodal therapeutic target. In this study, we demonstrate elevated ASM activity in the lung tumor environment and blood serum of patients with non-small cell lung cancer (NSCLC). RNAi-mediated attenuation of SMPD1 in human NSCLC cells rendered them resistant to serum starvation-induced apoptosis. In a murine model of lung adenocarcinoma, ASM deficiency reduced tumor development in a manner associated with significant enhancement of Th1-mediated and cytotoxic T-cell-mediated antitumor immunity. Our findings indicate that targeting ASM in NSCLC can act by tumor cell-intrinsic and -extrinsic mechanisms to suppress tumor cell growth, most notably by enabling an effective antitumor immune response by the host. Cancer Res; 77(21); 5963-76. ©2017 AACR.

Targeting methionine cycle as a potential therapeutic strategy for immune disorders

INTRODUCTION

Methionine cycle plays an essential role in regulating many cellular events, especially transmethylation reactions, incorporating the methyl donor S-adenosylmethionine (SAM). The transmethylations and substances involved in the cycle have shown complicated effects and mechanisms on immunocytes developments and activations, and exert crucial impacts on the pathological processes in immune disorders. Areas covered: Methionine cycle has been considered as an effective means of drug developments. This review discussed the role of methionine cycle in immune responses and summarized the potential therapeutic strategies based on the cycle, including SAM analogs, methyltransferase inhibitors, S-adenosylhomocysteine hydrolase (SAHH) inhibitors, adenosine receptors specific agonists or antagonists and homocysteine (Hcy)-lowering reagents, in treating human immunodeficiency virus (HIV) infections, systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), multiple sclerosis (MS), systemic sclerosis (SSc) and other immune disorders. Expert opinion: New targets and biomarkers grown out of methionine cycle have developed rapidly in the past decades. However, impacts of epigenetic regulations on immune disorders are unclear and whether the substances in methionine cycle can be clarified as biomarkers remains controversial. Therefore, further elucidation on the role of epigenetic regulations and substances in methionine cycle may contribute to exploring the cycle-derived biomarkers and drugs in immune disorders.

Optimized T-cell receptor-mimic chimeric antigen receptor T cells directed toward the intracellular Wilms Tumor 1 antigen

CD19-directed chimeric antigen receptor (CAR) T cells are clinically effective in a limited set of leukemia patients. However, CAR T-cell therapy thus far has been largely restricted to targeting extracellular tumor-associated antigens (TAA). Herein, we report a T-cell receptor-mimic (TCRm) CAR, termed WT1-28z, that is reactive to a peptide portion of the intracellular onco-protein Wilms Tumor 1(WT1), as it is expressed on the surface of the tumor cell in the context of HLA-A*02:01. T cells modified to express WT1-28z specifically targeted and lysed HLA-A*02:01+ WT1+ tumors and enhanced survival of mice engrafted with HLA-A*02:01+, WT1+ leukemia or ovarian tumors. This in vivo functional validation of TCRm CAR T cells provides the proof-of-concept necessary to expand the range of TAA that can be effectively targeted for immunotherapy to include attractive intracellular targets, and may hold great potential to expand on the success of CAR T-cell therapy.