From T-cell activation signals to signaling control of anti-cancer immunity

DNA Reaction Circuits to Establish Designated Biological Functions in Multicellular Community

In multicellular organisms, individual cells are coordinated through complex communication networks to accomplish various physiological tasks. Aiming to establish new biological functions in the multicellular community, we used DNA as the building block to develop a cascade of nongenetic reaction circuits to establish a dynamic cell-cell communication network. Utilizing membrane-anchored amphiphilic DNA tetrahedra (TDN) as the nanoscaffold, reaction circuits were incorporated into three unrelated cells in order to uniquely regulate their sense-and-response behaviors. As a proof-of-concept, this step enabled these cells to simulate significant biological events involved in T cell-mediated anticancer immunity. Such events included cancer-associated antigen recognition and the presentation of antigen-presenting cells (APCs), APC-facilitated T cell activation and dissociation, and T cell-mediated cancer targeting and killing. By combining the excellent programmability and molecular recognition ability of DNA, our cell-surface reaction circuits hold promise for mimicking and manipulating many biological processes.

Functional consequence of Iron dyshomeostasis and ferroptosis in systemic lupus erythematosus and lupus nephritis

Systemic lupus erythematosus (SLE) and its renal manifestation Lupus nephritis (LN) are characterized by a dysregulated immune system, autoantibodies, and injury to the renal parenchyma. Iron accumulation and ferroptosis in the immune effectors and renal tubules are recently identified pathological features in SLE and LN. Ferroptosis is an iron dependent non-apoptotic form of regulated cell death and ferroptosis inhibitors have improved disease outcomes in murine models of SLE, identifying it as a novel druggable target. In this review, we discuss novel mechanisms by which iron accumulation and ferroptosis perpetuate immune cell mediated pathology in SLE/LN. We highlight intra-renal dysregulation of iron metabolism and ferroptosis as an underlying pathogenic mechanism of renal tubular injury. The basic concepts of iron biology and ferroptosis are also discussed to expose the links between iron, cell metabolism and ferroptosis, that identify intracellular pro-ferroptotic enzymes and their protein conjugates as potential targets to improve SLE/LN outcomes.

Biopterin metabolism and nitric oxide recoupling in cancer

Tetrahydrobiopterin is a cofactor necessary for the activity of several enzymes, the most studied of which is nitric oxide synthase. The role of this cofactor-enzyme relationship in vascular biology is well established. Recently, tetrahydrobiopterin metabolism has received increasing attention in the field of cancer immunology and immunotherapy due to its involvement in the cytotoxic T cell response. Past research has demonstrated that when the availability of BH4 is low, as it is in chronic inflammatory conditions and tumors, electron transfer in the active site of nitric oxide synthase becomes uncoupled from the oxidation of arginine. This results in the production of radical species that are capable of a direct attack on tetrahydrobiopterin, further depleting its local availability. This feedforward loop may act like a molecular switch, reinforcing low tetrahydrobiopterin levels leading to altered NO signaling, restrained immune effector activity, and perpetual vascular inflammation within the tumor microenvironment. In this review, we discuss the evidence for this underappreciated mechanism in different aspects of tumor progression and therapeutic responses. Furthermore, we discuss the preclinical evidence supporting a clinical role for tetrahydrobiopterin supplementation to enhance immunotherapy and radiotherapy for solid tumors and the potential safety concerns.

Transcriptional Targeting of Dendritic Cells Using an Optimized Human Fascin1 Gene Promoter

Deeper knowledge about the role of the tumor microenvironment (TME) in cancer development and progression has resulted in new strategies such as gene-based cancer immunotherapy. Whereas some approaches focus on the expression of tumoricidal genes within the TME, DNA-based vaccines are intended to be expressed in antigen-presenting cells (e.g., dendritic cells, DCs) in secondary lymphoid organs, which in turn induce anti-tumor T cell responses. Besides effective delivery systems and the requirement of appropriate adjuvants, DNA vaccines themselves need to be optimized regarding efficacy and selectivity. In this work, the concept of DC-focused transcriptional targeting was tested by applying a plasmid encoding for the luciferase reporter gene under the control of a derivative of the human fascin1 gene promoter (pFscnLuc), comprising the proximal core promoter fused to the normally more distantly located DC enhancer region. DC-focused activity of this reporter construct was confirmed in cell culture in comparison to a standard reporter vector encoding for luciferase under the control of the strong ubiquitously active cytomegalovirus promoter and enhancer (pCMVLuc). Both plasmids were also compared upon intravenous administration in mice. The organ- and cell type-specific expression profile of pFscnLuc versus pCMVLuc demonstrated favorable activity especially in the spleen as a central immune organ and within the spleen in DCs.

Crosstalk between trace elements and T-cell immunity during early-life health in pigs

With gradual ban on the use of antibiotics, the deficiency and excessive use of trace elements in intestinal health is gaining attention. In mammals, trace elements are essential for the development of the immune system, specifically T-cell proliferation, and differentiation. However, there remain significant gaps in our understanding of the effects of certain trace elements on T-cell immune phenotypes and functions in pigs. In this review, we summarize the specificity, development, subpopulations, and responses to pathogens of porcine T cells and the effects of functional trace elements (e.g., iron, copper, zinc, and selenium) on intestinal T-cell immunity during early-life health in pigs. Furthermore, we discuss the current trends of research on the crosstalk mechanisms between trace elements and T-cell immunity. The present review expands our knowledge of the association between trace elements and T-cell immunity and provides an opportunity to utilize the metabolism of trace elements as a target to treat various diseases.

The Function of NK Cells in Tumor Metastasis and NK Cell-Based Immunotherapy

Metastatic tumors cause the most deaths in cancer patients. Treating metastasis remains the primary goal of current cancer research. Although the immune system prevents and kills the tumor cells, the function of the immune system in metastatic cancer has been unappreciated for decades because tumors are able to develop complex signaling pathways to suppress immune responses, leading them to escape detection and elimination. Studies showed NK cell-based therapies have many advantages and promise for fighting metastatic cancers. We here review the function of the immune system in tumor progression, specifically focusing on the ability of NK cells in antimetastasis, how metastatic tumors escape the NK cell attack, as well as the recent development of effective antimetastatic immunotherapies.

Immune checkpoints on T and NK cells in the context of HBV infection: Landscape, pathophysiology and therapeutic exploitation

In hepatitis B virus (HBV) infection, the interplay between the virus and the host immune system is crucial in determining the pathogenesis of the disease. Patients who fail to mount a sufficient and sustained anti-viral immune response develop chronic hepatitis B (CHB). T cells and natural killer (NK) cells play decisive role in viral clearance, but they are defective in chronic HBV infection. The activation of immune cells is tightly controlled by a combination of activating and inhibitory receptors, called immune checkpoints (ICs), allowing the maintenance of immune homeostasis. Chronic exposure to viral antigens and the subsequent dysregulation of ICs actively contribute to the exhaustion of effector cells and viral persistence. The present review aims to summarize the function of various ICs and their expression in T lymphocytes and NK cells in the course of HBV infection as well as the use of immunotherapeutic strategies targeting ICs in chronic HBV infection.

Taraxasterol prompted the anti-tumor effect in mice burden hepatocellular carcinoma by regulating T lymphocytes

Hepatocellular carcinoma (HCC) is a common digestive malignant tumor with high morbidity and mortality worldwide, however, the treatment of HCC and prognosis of patients are not optimistic, finding more effective treatments are imperative. Taraxacum officinale (L.) Weber ex F.H.Wigg is a perennial herb of compositae, and our study has demonstrated that Taraxacum officinale polysaccharide has certain anti-tumor effect on HCC cells. Taraxasterol (TS) is a natural product extracted from Taraxacum officinale with strong physiological, pharmacological and biological activities, but the effect of TS on HCC is yet to be determined. Therefore, the aim of this study is to explore the effect of dandelion sterol on HCC in vivo and in vitro. The results showed that TS significantly inhibited the proliferation, induced apoptosis and blocked cell cycle in HCC cell lines HepG2 and Huh7 cells in vitro. TS inhibited the tumor growth of H22 bearing mice and the expression of Ki67 in vivo. More importantly, TS regulated the immunity of H22 bearing mice by elevating the ratio of CD4⁺ T cells in spleen, and increasing the number of T cell infiltration in tumor tissue. Except immunomodulation, the mechanism of tumor growth inhibition may be related to the regulation of apoptosis related proteins and IL-6/STAT3 pathway. TS significantly inhibited the growth of HCC cells both in vitro and in vivo. The study would provide a theoretical basis for the new application of TS and the adjuvant treatment of malignant tumor with traditional Chinese medicine.

Nuclear Transporting Factor 2 as a Novel Biomarker of Head and Neck Squamous Cell Carcinoma and Associated with T/B Cell Receptor Signaling Pathway

Objective

This study is aimed at exploring the role of nuclear transporting factor 2 (NUTF2) in head and neck squamous cell carcinoma (HNSCC) based on The Cancer Genome Atlas (TCGA) database.

Methods

We obtained 528 HNSCC patients' clinical data from TCGA and performed expression level analysis of NUTF2. Gene Sets Enrichment Analysis (GSEA) was conducted to identify NUTF2-associated regulatory mechanisms in HNSCC. In addition, several other tools were used to enrich the regulatory network.

Results

We found that NUTF2 was significantly upregulated (P < 0.001) in HNSCC. We then observed that higher NUTF2 is associated with poorer overall survival and disease-free survival. Further, by using Cox analyses, we determined high NUTF2 as an independent risk factor of predicting poorer overall survival. Tumor immune infiltration analysis revealed a significantly negative correlation between NUTF2 expression and the level of tumor infiltrated CD8⁺ T cell and B cell, suggesting that NUTF2 may be involved in the immune regulation of HNSCC. Gene sets related to T/B cell receptor signaling pathways were differentially enriched based on the NUTF2 expression phenotype. KEGG pathways were used to show that NUTF2 may affect proliferation, differentiation, and immune response of T/B cell through regulating PI3K/AKT, NFκB, MAPK, and Calcium signaling pathways.

Conclusion

NUTF2 might be a valuable biomarker for HNSCC and correlated with T/B cell receptor signaling pathway.

A 4 Gene-based Immune Signature Predicts Dedifferentiation and Immune Exhaustion in Thyroid Cancer

CONTEXT

The role of immune-related genes (IRGs) in thyroid cancer dedifferentiation and accompanying immune exhaustion remains largely unexplored.

OBJECTIVE

To construct a significant IRG-based signature indicative of dedifferentiation and immune exhaustion in thyroid cancer.

DESIGN AND SETTINGS

One exploratory cohort and 2 validation cohorts were used to identify stably dysregulated IRGs in dedifferentiated thyroid cancer (DDTC) and to obtain independent risk factors for dedifferentiation. The IRGs formed a gene signature, whose predictive value was tested by the receiver operating characteristic curve. Correlations between the signature and differentiation-related genes, immune checkpoints, and prognosis were analyzed. Gene set enrichment analyses were performed to identify related signaling pathways.

RESULTS

Four IRGs (PRKCQ, PLAUR, PSMD2, and BMP7) were found to be repeatedly dysregulated in DDTC, and they formed an IRG-based signature with a satisfactory predictive value for thyroid cancer dedifferentiation. Correlation analyses revealed that immune checkpoints were closely related to the 4 IRGs and the IRG-based signature, which was significantly associated with the histological subtype (P = 0.026), lymph node metastasis (P = 0.001), and BRAFV600E mutation (P < 0.001). The downregulated expression of PRKCQ shortened the disease-free survival for patients with thyroid cancer. Furthermore, we identified several signaling pathways inherently associated with the IRG-based signature.

CONCLUSIONS

This study suggests that IRGs participate in the dedifferentiation and immune exhaustion process of thyroid cancer and are potential biomarkers for DDTC.

Polymeric nanoparticles containing rapamycin and autoantigen induce antigen-specific immunological tolerance for preventing vitiligo in mice

Vitiligo is an autoimmune disease in which pigment is lost in patches of the skin. CD4⁺ T cells are implicated in vitiligo while regulatory T cells (Tregs) could ameliorate vitiligo. Rapamycin together with autoantigen have been shown to induce immunological tolerance and promote Tregs in multiple autoimmune diseases. In the current study, we synthesized nanoparticles containing rapamycin and autoantigen HEL_46-61 (NP_{HEL46-61/Rapa}) and investigated their effects on vitiligo. We treated bone marrow-derived dendritic cells (BMDCs) from TrpHEL mice with NP_{HEL46-61/Rapa} and monitored the phenotype of BMDCs. We investigated the effects of NP_{HEL46-61/Rapa}-treated BMDCs on CD4⁺ T cell proliferation and differentiation. We administrated NP_{HEL46-61/Rapa} to TCR-TrpHEL mice and investigated the effects on vitiligo. We found that BMDCs can uptake the NP_{HEL46-61/Rapa}, which resulted in decreased expression of costimulation molecules CD80 and CD86 in BMDCs. BMDCs treated with NP_{HEL46-61/Rapa} suppressed antigen-specific CD4⁺ T cell proliferation while promoted the differentiation of these CD4⁺ T cell to Tregs in vitro. Administration of NP_{HEL46-61/Rapa} to TCR-TrpHEL mice ameliorated vitiligo, promoted Treg production, and suppressed IFN-γ and IL-6 production, while induced IL-10 production. Therefore, our study provides experimental evidence that nanoparticles containing rapamycin and autoantigen could induce antigen-specific immunological tolerance and prevent vitiligo.

Identification of lncRNA Signature Associated With Pan-Cancer Prognosis

Long noncoding RNAs (lncRNAs) have emerged as potential prognostic markers in various human cancers as they participate in many malignant behaviors. However, the value of lncRNAs as prognostic markers among diverse human cancers is still under investigation, and a systematic signature based on these transcripts that related to pan-cancer prognosis has yet to be reported. In this study, we proposed a framework to incorporate statistical power, biological rationale, and machine learning models for pan-cancer prognosis analysis. The framework identified a 5-lncRNA signature (ENSG00000206567, PCAT29, ENSG00000257989, LOC388282, and LINC00339) from TCGA training studies (n = 1,878). The identified lncRNAs are significantly associated (all P ≤ 1.48E-11) with overall survival (OS) of the TCGA cohort (n = 4,231). The signature stratified the cohort into low- and high-risk groups with significantly distinct survival outcomes (median OS of 9.84 years versus 4.37 years, log-rank P = 1.48E-38) and achieved a time-dependent ROC/AUC of 0.66 at 5 years. After routine clinical factors involved, the signature demonstrated better performance for long-term prognostic estimation (AUC of 0.72). Moreover, the signature was further evaluated on two independent external cohorts (TARGET, n = 1,122; CPTAC, n = 391; National Cancer Institute) which yielded similar prognostic values (AUC of 0.60 and 0.75; log-rank P = 8.6E-09 and P = 2.7E-06). An indexing system was developed to map the 5-lncRNA signature to prognoses of pan-cancer patients. In silico functional analysis indicated that the lncRNAs are associated with common biological processes driving human cancers. The five lncRNAs, especially ENSG00000206567, ENSG00000257989 and LOC388282 that never reported before, may serve as viable molecular targets common among diverse cancers.

Comprehensive analysis of ferritin subunits expression and positive correlations with tumor-associated macrophages and T regulatory cells infiltration in most solid tumors

Ferritin is the most important iron storage form and is known to influence tumor immunity. We previously showed that expression of ferritin light chain (FTL) and ferritin heavy chain (FTH1) subunits is increased in head and neck squamous cell carcinoma (HNSC). Here, we analyzed solid tumor datasets from The Cancer Genome Atlas and Genotype-Tissue Expression databases to investigate correlations between FTL and FTH1 expressions and (i) patient survival, using univariate, multivariate, Kaplan-Meier and Receiver Operator Characteristic analysis; and (ii) tumor-infiltrating immune cell subsets, using the bioinformatics tools Estimation of Stomal and Immune cells in Malignant Tumor tissues, Microenvironment Cell Population-counter, Tumor Immune Estimation Resource, and Tumor Immunology Miner. We found that FTL and FTH1 are upregulated and downregulated, respectively, in most of the human cancers analyzed. Tumor FTL levels were associated with prognosis in patients with lower grade glioma (LGG), whereas FTH1 levels were associated with prognosis in patients with liver hepatocellular carcinoma, HNSC, LGG, and kidney renal papillary cell carcinoma. In many cancers, FTL and FTH1 levels was significantly positively correlated with tumor infiltration by tumor-associated macrophages and T regulatory cells. These results suggest an important role for FTL and FTH1 in regulating tumor immunity to solid cancers.

Implications of the microbiome in the development and treatment of pancreatic cancer: Thinking outside of the box by looking inside the gut

Pancreatic ductal adenocarcinoma is the third leading cause of cancer-related death in the United States. As one of the most lethal cancer types, the prognosis for patients diagnosed with pancreatic cancer remains dismal and novel investigations are urgently needed. Evidence for an association of microbes with pancreatic cancer risk, development, treatment response, and post-treatment survivorship is rapidly developing. Herein, we provide an overview on the role of the microbiome as it relates to the natural history of pancreatic cancer, including host immune interactions, alterations in metabolism, direct carcinogenic effect, and its role in treatment response.

Multi-omic analysis reveals HIP-55-dependent regulation of cytokines release

HIP-55 (HPK1 [hematopoietic progenitor kinase 1] -interacting protein of 55 kDa) contains an actin-depolymerizing factor homology (ADF-H) domain at the N-terminus and a src homology 3 (SH3) domain at the C-terminus, which plays an important role in the T cell receptor (TCR) and B-cell receptor (BCR) signaling and immune system. In our previous studies, HIP-55 was found to be highly expressed in several types of tumors and function as a novel oncogenic signaling hub that regulates tumor progression and metastasis through defined functional domains, actin-binding and SH3 modules. However, the wider functions and mechanisms of HIP-55 are still unclear. Here, multi-omic analysis revealed that one of the main biofunctions of HIP-55 is the regulation of cytokines release. Furthermore, to investigate the role of HIP-55 in the cytokine production, a series Cytokine Antibody Arrays were performed to detect differentially expressed cytokines between control and HIP-55 knockdown cells. A total of 97 differentially expressed cytokines were identified from 300 cytokines in A549 cell. Bioinformatics analysis showed these differentially cytokines were mainly enriched in cancer signal pathways and IL-6 is the most critical hub in the integrated network. Analysis of RNAseq data from lung cancer patients showed that there is a strong negative correlation between HIP-55 and interleukin-6 (IL-6) in samples from lung adenocarcinoma patients. Our data indicated that HIP-55 may participate in cancer progression and metastasis via regulating cytokines release.

The Role of Iron Regulation in Immunometabolism and Immune-Related Disease

Immunometabolism explores how the intracellular metabolic pathways in immune cells can regulate their function under different micro-environmental and (patho-)-physiological conditions (Pearce, 2010; Buck et al., 2015; O'Neill and Pearce, 2016). In the last decade great advances have been made in studying and manipulating metabolic programs in immune cells. Immunometabolism has primarily focused on glycolysis, the TCA cycle and oxidative phosphorylation (OXPHOS) as well as free fatty acid synthesis and oxidation. These pathways are important for providing the energy needs of cell growth, membrane rigidity, cytokine production and proliferation. In this review, we will however, highlight the specific role of iron metabolism at the cellular and organismal level, as well as how the bioavailability of this metal orchestrates complex metabolic programs in immune cell homeostasis and inflammation. We will also discuss how dysregulation of iron metabolism contributes to alterations in the immune system and how these novel insights into iron regulation can be targeted to metabolically manipulate immune cell function under pathophysiological conditions, providing new therapeutic opportunities for autoimmunity and cancer.

Type I interferons and endoplasmic reticulum stress in health and disease

Type I interferons (IFNs) comprise of pro-inflammatory cytokines created, as well as sensed, by all nucleated cells with the main objective of blocking pathogens-driven infections. Owing to this broad range of influence, type I IFNs also exhibit critical functions in many sterile inflammatory diseases and immunopathologies, especially those associated with endoplasmic reticulum (ER) stress-driven signaling pathways. Indeed, over the years accumulating evidence has indicated that the presence of ER stress can influence the production, or sensing of, type I IFNs induced by perturbations like pattern recognition receptor (PRR) agonists, infections (bacterial, viral or parasitic) or autoimmunity. In this article we discuss the link between type I IFNs and ER stress in various diseased contexts. We describe how ER stress regulates type I IFNs production or sensing, or how type I IFNs may induce ER stress, in various circumstances like microbial infections, autoimmunity, diabetes, cancer and other ER stress-related contexts.

pathfindR: An R Package for Comprehensive Identification of Enriched Pathways in Omics Data Through Active Subnetworks

Pathway analysis is often the first choice for studying the mechanisms underlying a phenotype. However, conventional methods for pathway analysis do not take into account complex protein-protein interaction information, resulting in incomplete conclusions. Previously, numerous approaches that utilize protein-protein interaction information to enhance pathway analysis yielded superior results compared to conventional methods. Hereby, we present pathfindR, another approach exploiting protein-protein interaction information and the first R package for active-subnetwork-oriented pathway enrichment analyses for class comparison omics experiments. Using the list of genes obtained from an omics experiment comparing two groups of samples, pathfindR identifies active subnetworks in a protein-protein interaction network. It then performs pathway enrichment analyses on these identified subnetworks. To further reduce the complexity, it provides functionality for clustering the resulting pathways. Moreover, through a scoring function, the overall activity of each pathway in each sample can be estimated. We illustrate the capabilities of our pathway analysis method on three gene expression datasets and compare our results with those obtained from three popular pathway analysis tools. The results demonstrate that literature-supported disease-related pathways ranked higher in our approach compared to the others. Moreover, pathfindR identified additional pathways relevant to the conditions that were not identified by other tools, including pathways named after the conditions.

Pathway analysis of expression-related SNPs on genome-wide association study of basal cell carcinoma

Genome-wide association studies (GWASs) have primarily focused on the association between individual genetic markers and risk of disease. We applied a novel approach that integrates skin expression-related single-nucleotide polymorphisms (eSNPs) and pathway analysis for GWAS of basal cell carcinoma (BCC) to identify potential novel biological pathways. We evaluated the associations between 70,932 skin eSNPs and risk of BCC among 2,323 cases and 7,275 controls of European ancestry, and then assigned them to the pathways defined by KEGG, GO, and BioCarta databases. Three KEGG pathways (colorectal cancer, actin cytoskeleton, and BCC), two GO pathways (cellular component disassembly in apoptosis, and nucleus organization), and four BioCarta pathways (Ras signaling, T cell receptor signaling, natural killer cell-mediated cytotoxicity, and links between Pyk2 and Map Kinases) showed significant association with BCC risk with p-value<0.05 and FDR<0.2. These pathways also ranked at top in sensitivity analyses. Two positive controls in KEGG, the hedgehog pathway and the BCC pathway, showed significant association with BCC risk in both main and sensitivity analyses. Our results indicate that SNPs that are undetectable by conventional GWASs are significantly associated with BCC when tested as pathways. Biological studies of these gene groups suggest their potential roles in the etiology of BCC.

A novel intracellular pool of LFA-1 is critical for asymmetric CD8+ T cell activation and differentiation

The integrin lymphocyte function-associated antigen 1 (LFA-1; CD11a/CD18) is a key T cell adhesion receptor that mediates stable interactions with antigen-presenting cell (APC), as well as chemokine-mediated migration. Using our newly generated CD11a-mYFP knock-in mice, we discovered that naive CD8⁺ T cells reserve a significant intracellular pool of LFA-1 in the uropod during migration. Intracellular LFA-1 quickly translocated to the cell surface with antigenic stimulus. Importantly, the redistribution of intracellular LFA-1 at the contact with APC was maintained during cell division and led to an unequal inheritance of LFA-1 in divided T cells. The daughter CD8⁺ T cells with disparate LFA-1 expression showed different patterns of migration on ICAM-1, APC interactions, and tissue retention, as well as altered effector functions. In addition, we identified Rab27 as an important regulator of the intracellular LFA-1 translocation. Collectively, our data demonstrate that an intracellular pool of LFA-1 in naive CD8⁺ T cells plays a key role in T cell activation and differentiation.

T Cell Subset and Stimulation Strength-Dependent Modulation of T Cell Activation by Kv1.3 Blockers

Kv1.3 is a voltage-gated potassium channel expressed on T cells that plays an important role in T cell activation. Previous studies have shown that blocking Kv1.3 channels in human T cells during activation results in reduced calcium entry, cytokine production, and proliferation. The aim of the present study was to further explore the effects of Kv1.3 blockers on the response of different human T cell subsets under various stimulation conditions. Our studies show that, unlike the immune suppressor cyclosporine A, the inhibitory effect of Kv1.3 blockers was partial and stimulation strength dependent, with reduced inhibitory efficacy on T cells under strengthened anti-CD3/CD28 stimulations. T cell responses to allergens including house dust mites and ragweed were partially reduced by Kv1.3 blockers. The effect of Kv1.3 inhibition was dependent on T cell subsets, with stronger effects on CCR7^- effector memory compared to CCR7⁺ central memory CD4 T cells. Calcium entry studies also revealed a population of CD4 T cells resistant to Kv1.3 blockade. Activation of CD4 T cells was accompanied with an increase in Kv1.3 currents but Kv1.3 transcripts were found to be reduced, suggesting a posttranscriptional mechanism in the regulation of Kv1.3 activities. In summary, Kv1.3 blockers inhibit T cell activation in a manner that is highly dependent on the T cell identity and stimulation strength, These findings suggest that Kv1.3 blockers inhibit T cells in a unique, conditional manner, further refining our understanding of the therapeutic potential of Kv1.3 blockers.

The origin of DCs and capacity for immunologic tolerance in central and peripheral tissues

Dendritic cells (DCs) are specialized immune sentinels that play key role in maintaining immune homeostasis by efficiently regulating the delicate balance between protective immunity and tolerance to self. Although DCs respond to maturation signals present in the surrounding milieu, multiple layers of suppression also co-exist that reduce the infringement of tolerance against self-antigens. These tolerance inducing properties of DCs are governed by their origin and a range of other factors including distribution, cytokines, growth factors, and transcriptional programing, that collectively impart suppressive functions to these cells. DCs directing tolerance secrete anti-inflammatory cytokines and induce naïve T cells or B cells to differentiate into regulatory T cells (Tregs) or B cells. In this review, we provide a detailed outlook on the molecular mechanisms that induce functional specialization to govern central or peripheral tolerance. The tolerance-inducing nature of DCs can be exploited to overcome autoimmunity and rejection in graft transplantation.

Expression and methylation patterns partition luminal-A breast tumors into distinct prognostic subgroups

Background

Breast cancer is a heterogeneous disease comprising several biologically different types, exhibiting diverse responses to treatment. In the past years, gene expression profiling has led to definition of several “intrinsic subtypes” of breast cancer (basal-like, HER2-enriched, luminal-A, luminal-B and normal-like), and microarray based predictors such as PAM50 have been developed. Despite their advantage over traditional histopathological classification, precise identification of breast cancer subtypes, especially within the largest and highly variable luminal-A class, remains a challenge. In this study, we revisited the molecular classification of breast tumors using both expression and methylation data obtained from The Cancer Genome Atlas (TCGA).

Methods

Unsupervised clustering was applied on 1148 and 679 breast cancer samples using RNA-Seq and DNA methylation data, respectively. Clusters were evaluated using clinical information and by comparison to PAM50 subtypes. Differentially expressed genes and differentially methylated CpGs were tested for enrichment using various annotation sets. Survival analysis was conducted on the identified clusters using the log-rank test and Cox proportional hazards model.

Results

The clusters in both expression and methylation datasets had only moderate agreement with PAM50 calls, while our partitioning of the luminal samples had better five-year prognostic value than the luminal-A/luminal-B assignment as called by PAM50. Our analysis partitioned the expression profiles of the luminal-A samples into two biologically distinct subgroups exhibiting differential expression of immune-related genes, with one subgroup carrying significantly higher risk for five-year recurrence. Analysis of the luminal-A samples using methylation data identified a cluster of patients with poorer survival, characterized by distinct hyper-methylation of developmental genes. Cox multivariate survival analysis confirmed the prognostic significance of the two partitions after adjustment for commonly used factors such as age and pathological stage.

Conclusions

Modern genomic datasets reveal large heterogeneity among luminal breast tumors. Our analysis of these data provides two prognostic gene sets that dissect and explain tumor variability within the luminal-A subgroup, thus, contributing to the advancement of subtype-specific diagnosis and treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-016-0724-2) contains supplementary material, which is available to authorized users.

Transient exposure to proteins SOX2, Oct-4, and NANOG immortalizes exhausted tumor-infiltrating CTLs

Adoptive cell transfer therapy (ACT) is one of the most promising immunotherapies against cancer, using tumor-infiltrating lymphocytes (TILs) expanded in vitro. Tumor-infiltrating cytotoxic T lymphocytes (TICTLs) play a prominent role in cancer control. TILs terminally differentiate in response to immunosuppressive environments within tumors, and thus are slow to expand and challenging to maintain both in vitro and in patients. To reverse this exhaustion, we utilize a nuclear protein delivery system that exposes TICTLs to the SOX2, Oct-4, and NANOG (SON) proteins. Unlike activated naïve CTLs (effector CTLs), TICTLs respond favorably to SON treatment, exhibiting steady proliferation and extended survivability independent of cytokine and antigen stimulation. Though TICTLs treated with SON (STICTLs) still express T cell receptors as well as other critical downstream components, they are unresponsive to antigen challenge, suggesting that SON treatment regresses TICTLs into a state similar to that of an early double negative T cell. Our findings indicate the TICTL response to SON proteins is unique when compared to effector CTLs, suggesting TICTLs may be sensitive to regulation by other lineage-specific transcription factors and opening a promising new avenue into cancer immunotherapy. To our knowledge, this is the first report on lineage reprogramming of TILs using protein stem cell transcription factors delivered directly to the nucleus.

Systems biology approach to studying proliferation-dependent prognostic subnetworks in breast cancer

Tumor proliferative capacity is a major biological correlate of breast tumor metastatic potential. In this paper, we developed a systems approach to investigate associations among gene expression patterns, representative protein-protein interactions, and the potential for clinical metastases, to uncover novel survival-related subnetwork signatures as a function of tumor proliferative potential. Based on the statistical associations between gene expression patterns and patient outcomes, we identified three groups of survival prognostic subnetwork signatures (SPNs) corresponding to three proliferation levels. We discovered 8 SPNs in the high proliferation group, 8 SPNs in the intermediate proliferation group, and 6 SPNs in the low proliferation group. We observed little overlap of SPNs between the three proliferation groups. The enrichment analysis revealed that most SPNs were enriched in distinct signaling pathways and biological processes. The SPNs were validated on other cohorts of patients, and delivered high accuracy in the classification of metastatic vs non-metastatic breast tumors. Our findings indicate that certain biological networks underlying breast cancer metastasis differ in a proliferation-dependent manner. These networks, in combination, may form the basis of highly accurate prognostic classification models and may have clinical utility in guiding therapeutic options for patients.

Regulation of the development of asthmatic inflammation by in situ CD4(+)Foxp3 (+) T cells in a mouse model of late allergic asthma

CD4(+)Foxp3(+)T cells (Tregs) mediate homeostatic peripheral tolerance by suppressing helper T2 cells in allergy. However, the regulation of asthmatic inflammation by local (in situ) Tregs in asthma remains unclear. BALB/c mice sensitized and challenged with ovalbumin (OVA) (asthma group) developed asthmatic inflammation with eosinophils and lymphocytes, but not mast cells. The number of Tregs in the circulation, pulmonary lymph nodes (pLNs), and thymi significantly decreased in the asthma group compared to the control group without OVA sensitization and challenge in the effector phase. The development of asthmatic inflammation is inversely related to decreased Tregs with reduced mRNA expression such as interleukin (IL)-4, transforming growth factor-β1, and IL-10, but not interferon-γ, in pLNs. Moreover, M2 macrophages increased in the local site. The present study suggests that Tregs, at least in part, may regulate the development of asthmatic inflammation by cell-cell contact and regional cytokine productions.

The catalytic activity of the kinase ZAP-70 mediates basal signaling and negative feedback of the T cell receptor pathway

T cell activation by antigens binding to the T cell receptor (TCR) must be properly regulated to ensure normal T cell development and effective immune responses to pathogens and transformed cells while avoiding autoimmunity. The Src family kinase Lck and the Syk family kinase ZAP-70 (ζ chain-associated protein kinase of 70 kD) are sequentially activated in response to TCR engagement and serve as critical components of the TCR signaling machinery that leads to T cell activation. We performed a mass spectrometry-based phosphoproteomic study comparing the quantitative differences in the temporal dynamics of phosphorylation in stimulated and unstimulated T cells with or without inhibition of ZAP-70 catalytic activity. The data indicated that the kinase activity of ZAP-70 stimulates negative feedback pathways that target Lck and thereby modulate the phosphorylation patterns of the immunoreceptor tyrosine-based activation motifs (ITAMs) of the CD3 and ζ chain components of the TCR and of signaling molecules downstream of Lck, including ZAP-70. We developed a computational model that provides a mechanistic explanation for the experimental findings on ITAM phosphorylation in wild-type cells, ZAP-70-deficient cells, and cells with inhibited ZAP-70 catalytic activity. This model incorporated negative feedback regulation of Lck activity by the kinase activity of ZAP-70 and predicted the order in which tyrosines in the ITAMs of TCR ζ chains must be phosphorylated to be consistent with the experimental data.

Membrane-mediated regulation of the intrinsically disordered CD3ϵ cytoplasmic tail of the TCR

The regulation of T-cell-mediated immune responses depends on the phosphorylation of immunoreceptor tyrosine-based activation motifs (ITAMs) on T-cell receptors. Although many details of the signaling cascades are well understood, the initial mechanism and regulation of ITAM phosphorylation remains unknown. We used molecular dynamics simulations to study the influence of different compositions of lipid bilayers on the membrane association of the CD3ϵ cytoplasmic tails of the T-cell receptors. Our results show that binding of CD3ϵ to membranes is modulated by both the presence of negatively charged lipids and the lipid order of the membrane. Free-energy calculations reveal that the protein-membrane interaction is favored by the presence of nearby basic residues and the ITAM tyrosines. Phosphorylation minimizes membrane association, rendering the ITAM motif more accessible to binding partners. In systems mimicking biological membranes, the CD3ϵ chain localization is modulated by different facilitator lipids (e.g., gangliosides or phosphoinositols), revealing a plausible regulatory effect on activation through the regulation of lipid composition in cell membranes.

T-cell activation and early gene response in dogs

T-cells play a crucial role in canine immunoregulation and defence against invading pathogens. Proliferation is fundamental to T-cell differentiation, homeostasis and immune response. Initiation of proliferation following receptor mediated stimuli requires a temporally programmed gene response that can be identified as immediate-early, mid- and late phases. The immediate-early response genes in T-cell activation engage the cell cycle machinery and promote subsequent gene activation events. Genes involved in this immediate-early response in dogs are yet to be identified. The present study was undertaken to characterise the early T-cell gene response in dogs to improve understanding of the genetic mechanisms regulating immune function. Gene expression profiles were characterised using canine gene expression microarrays and quantitative reverse transcription PCR (qRT-PCR), and paired samples from eleven dogs. Significant functional annotation clusters were identified following stimulation with phytohemagluttinin (PHA) (5μg/ml), including the Toll-like receptor signaling pathway and phosphorylation pathways. Using strict statistical criteria, 13 individual genes were found to be differentially expressed, nine of which have ontologies that relate to proliferation and cell cycle control. These included, prostaglandin-endoperoxide synthase 2 (PTGS2/COX2), early growth response 1 (EGR1), growth arrest and DNA damage-inducible gene (GADD45B), phorbol-12-myristate-13-acetate-induced protein 1 (PMAIP1), V-FOS FBJ murine osteosarcoma viral oncogene homolog (FOS), early growth response 2 (EGR2), hemogen (HEMGN), polo-like kinase 2 (PLK2) and polo-like kinase 3 (PLK3). Differential gene expression was re-examined using qRT-PCR, which confirmed that EGR1, EGR2, PMAIP1, PTGS2, FOS and GADD45B were significantly upregulated in stimulated cells and ALAS2 downregulated. PTGS2 and EGR1 showed the highest levels of response in these dogs. Both of these genes are involved in cell cycle regulation. This study provides a comprehensive analysis of the early T-cell gene response to activation in dogs.

A logical model of HIV-1 interactions with the T-cell activation signalling pathway

MOTIVATION

Human immunodeficiency virus type 1 (HIV-1) hijacks host cellular processes to replicate within its host. Through interactions with host proteins, it perturbs and interrupts signaling pathways that alter key cellular functions. Although networks of viral-host interactions have been relatively well characterized, the dynamics of the perturbation process is poorly understood. Dynamic models of infection have the potential to provide insights into the HIV-1 host interaction.

RESULTS

We employed a logical signal flow network to model the dynamic interactions between HIV-1 proteins and key human signal transduction pathways necessary for activation of CD4+ T lymphocytes. We integrated viral-host interaction and host signal transduction data into a dynamic logical model comprised of 137 nodes (16 HIV-1 and 121 human proteins) and 336 interactions collected from the HIV-1 Human Interaction Database. The model reproduced expected patterns of T-cell activation, co-stimulation and co-inhibition. After simulations, we identified 26 host cell factors, including MAPK1&3, Ikkb-Ikky-Ikka and PKA, which contribute to the net activation or inhibition of viral proteins. Through in silico knockouts, the model identified a further nine host cell factors, including members of the PI3K signalling pathway that are essential to viral replication. Simulation results intersected with the findings of three siRNA gene knockout studies and identified potential drug targets. Our results demonstrate how viral infection causes the cell to lose control of its signalling system. Logical Boolean modelling therefore provides a useful approach for analysing the dynamics of host-viral interactions with potential applications for drug discovery.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Core and specific network markers of carcinogenesis from multiple cancer samples

Cancer is the leading cause of death worldwide and is generally caused by mutations in multiple proteins or the dysregulation of pathways. Understanding the causes and the underlying carcinogenic mechanisms can help fight this disease. In this study, a systems biology approach was used to construct the protein-protein interaction (PPI) networks of four cancers and the non-cancers by their corresponding microarray data, PPI modeling and database-mining. By comparing PPI networks between cancer and non-cancer samples to find significant proteins with large PPI changes during carcinogenesis process, core and specific network markers were identified by the intersection and difference of significant proteins, respectively, with carcinogenesis relevance values (CRVs) for each cancer. A total of 28 significant proteins were identified as core network markers in the carcinogenesis of four types of cancer, two of which are novel cancer-related proteins (e.g., UBC and PSMA3). Moreover, seven crucial common pathways were found among these cancers based on their core network markers, and some specific pathways were particularly prominent based on the specific network markers of different cancers (e.g., the RIG-I-like receptor pathway in bladder cancer, the proteasome pathway and TCR pathway in liver cancer, and the HR pathway in lung cancer). Additional validation of these network markers using the literature and new tested datasets could strengthen our findings and confirm the proposed method. From these core and specific network markers, we could not only gain an insight into crucial common and specific pathways in the carcinogenesis, but also obtain a high promising PPI target for cancer therapy.

Identification of thyroid carcinoma related genes with mRMR and shortest path approaches

Thyroid cancer is a malignant neoplasm originated from thyroid cells. It can be classified into papillary carcinomas (PTCs) and anaplastic carcinomas (ATCs). Although ATCs are in an very aggressive status and cause more death than PTCs, their difference is poorly understood at molecular level. In this study, we focus on the transcriptome difference among PTCs, ATCs and normal tissue from a published dataset including 45 normal tissues, 49 PTCs and 11 ATCs, by applying a machine learning method, maximum relevance minimum redundancy, and identified 9 genes (BCL2, MRPS31, ID4, RASAL2, DLG2, MY01B, ZBTB5, PRKCQ and PPP6C) and 1 miscRNA (miscellaneous RNA, LOC646736) as important candidates involved in the progression of thyroid cancer. We further identified the protein-protein interaction (PPI) sub network from the shortest paths among the 9 genes in a PPI network constructed based on STRING database. Our results may provide insights to the molecular mechanism of the progression of thyroid cancer.

Genome-wide association study combining pathway analysis for typical sporadic amyotrophic lateral sclerosis in Chinese Han populations

Sporadic amyotrophic lateral sclerosis (sALS) is a severe neurodegenerative disease that causes progressive motor neuron death. Although the etiology of sALS remains unknown, genetic variants are thought to predispose individuals to the disease. Several recent genome-wide association studies have identified a number of loci that increase sALS susceptibility, but these only explain a small proportion of the disease. To extend the current genetic evidence and to identify novel candidates of sALS, we performed a pooling genome-wide association study by 859,311 autosomal single-nucleotide polymorphisms of IlluminaHumanOmniZhongHua-8 combining pathway analysis in 250 typical sALS cases precluding age, clinical course, and phenotype interference and 250 control subjects from Chinese Han populations (CHP). The results revealed that 8 novel loci of 1p34.3, 3p21.1, 3p22.2, 10p15.2, 22q12.1, 3q13.11, 11q25, 12q24.33, and 5 previously reported loci of CNTN4 (kgp11325216), ATXN1 (kgp8327591), C9orf72 (kgp6016770), ITPR2 (kgp3041552), and SOD1 (kgp10760302) were associated with sALS from CHP. Furthermore, the pathway analysis based on the Gene Set Analysis Toolkit V2 showed that 10 top pathways were strongly associated with sALS from CHP, and among them, the 7 most potentially candidate pathways were phosphatidylinositol signaling system, Wnt signaling pathway, axon guidance, MAPK signaling pathway, neurotrophin signaling pathway, arachidonic acid metabolism, and T-cell receptor signaling pathway, a total of 39 significantly associate genes in 7 candidate pathways was suggested to involve in the pathogenesis of sALS from CHP. In conclusion, our results revealed several new loci and pathways related to sALS from CHP and extend the association evidence for partial loci, genes, and pathways, which were previously identified in other populations. Thus, our data provided new clues for exploring the pathogenesis of sALS.

Reovirus type-2-triggered autoimmune cholangitis in extrahepatic bile ducts of weanling DBA/1J mice

BACKGROUND

Reovirus is a proposed cause of infantile biliary atresia. However, mechanistic insight regarding Reo-2 as a potential cholangiotropic virus is lacking. Furthermore, it is unknown whether Reo-2 infection can induce autoimmune-mediated bile duct injury.

METHODS

Lesions of bile ducts in newborn DBA/1J mice infected with Reo-2 were analyzed immunopathologically.

RESULTS

Damage to biliary epithelia occurs after Reo-2 infection. In addition, nonsuppurative cholangitis with fibrosis in extrahepatic (especially septal) bile ducts developed following complete viral clearance from the liver. At the inflamed ducts, major histocompatibility complex class I expressing((+)) and FAS(+) cholangiocytes were associated with FAS ligand(+) lymphocytes and tumor necrosis factor-α(+) mononuclear cells (macrophages and lymphocytes). These cholangiocytes were apoptotic and necrotic. Moreover, affected ducts were infiltrated by CD3(+), CD4(+), CD8(+), IFN-γ(+), and FAS(+) lymphocytes. Analysis of blood from Reo-2-infected mice revealed that they developed anticholangiocyte cytoplasm antibodies and had high serum IFN-γ concentration. Notably, there was no increase in Foxp3(+) lymphocytes at inflamed ducts, lymph nodes, and thymi.

CONCLUSION

Reo-2 infection induced T-helper cell type 1-dependent injury to bile ducts in weanling mice. The lesions observed in mice may be analogous to those associated with human infantile biliary atresia, which are caused by an autoimmune-mediated process.

IL-12 and type I interferon prolong the division of activated CD8 T cells by maintaining high-affinity IL-2 signaling in vivo

The signal 3 cytokines interleukin-12 and type I interferon sustain CD8 T cell division by prolonging expression of CD25 in vivo.

TCR ligation and co-stimulation induce cellular division; however, optimal accumulation of effector CD8 T cells requires direct inflammatory signaling by signal 3 cytokines, such as IL-12 or type I IFNs. Although in vitro studies suggest that IL-12/type I IFN may enhance T cell survival or early proliferation, the mechanisms underlying optimal accumulation of CD8 T cells in vivo are unknown. In particular, it is unclear if disparate signal 3 cytokines optimize effector CD8 T cell accumulation by the same mechanism and how these inflammatory cytokines, which are transiently produced early after infection, affect T cell accumulation many days later at the peak of the immune response. Here, we show that transient exposure of CD8 T cells to IL-12 or type I IFN does not promote survival or confer an early proliferative advantage in vivo, but rather sustains surface expression of CD25, the high-affinity IL-2 receptor. This prolongs division of CD8 T cells in response to basal IL-2, through activation of the PI3K pathway and expression of FoxM1, a positive regulator of cell cycle progression genes. Thus, signal 3 cytokines use a common pathway to optimize effector CD8 T cell accumulation through a temporally orchestrated sequence of cytokine signals that sustain division rather than survival.

Dendritic cell-based approaches for therapeutic immune regulation in solid-organ transplantation

To avoid immune rejection, allograft recipients require drug-based immunosuppression, which has significant toxicity. An emerging approach is adoptive transfer of immunoregulatory cells. While mature dendritic cells (DCs) present donor antigen to the immune system, triggering rejection, regulatory DCs interact with regulatory T cells to promote immune tolerance. Intravenous injection of immature DCs of either donor or host origin at the time of transplantation have prolonged allograft survival in solid-organ transplant models. DCs can be treated with pharmacological agents before injection, which may attenuate their maturation in vivo. Recent data suggest that injected immunosuppressive DCs may inhibit allograft rejection, not by themselves, but through conventional DCs of the host. Genetically engineered DCs have also been tested. Two clinical trials in type-1 diabetes and rheumatoid arthritis have been carried out, and other trials, including one trial in kidney transplantation, are in progress or are imminent.

Association of changes in the gene expression profile of blood cells with the local tumor inflammatory response in a murine tumor model

Cancer tissue is frequently associated with the host inflammatory response, which involves blood cells. Using DNA microarrays, we examined the gene expression profiles of blood and tumors in a murine subcutaneous hepatocellular carcinoma model, in which tumors develop during the initial 10 days and then diminish and disappear by day 25 after implantation. Immunohistochemical and gene expression analysis indicated that tumor tissues were associated with an active immune response, particularly the CD4+ T cell-mediated immune response, on day 10. The genes commonly up-regulated in blood and the fraction enriched with tumor-associated inflammatory cells on day 10 also suggested the involvement of CD4+ T cells. Unsupervised hierarchical clustering analysis of gene expression of peripheral blood cells on days 0, 10, 15, 20, and 25 indicated two major clusters: the tumor-existence cluster on days 10, 15, and 20, and the tumor-free cluster on days 0 and 25. Additionally, sub-clusters were detected on each day. These results suggest that the gene expression profile of whole blood cells is affected by the local tumor condition, and is associated with the local host immune response. Its analysis will facilitate exploration of the underlying important features of the host immune response to tumors.

The effect of photodynamic therapy on tumor cell expression of major histocompatibility complex (MHC) class I and MHC class I-related molecules

BACKGROUND AND OBJECTIVE

Photodynamic therapy (PDT) is FDA-approved anti-cancer modality for elimination of early disease and palliation in advanced disease. PDT efficacy depends in part on elicitation of a tumor-specific immune response that is dependent on cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. The cytolytic potential of CTLs and NK cells is mediated by the ability of these cells to recognize major histocompatibility complex (MHC) class I and MHC class I-related molecules. The MHC class I-related molecules MICA and MICB are induced by oxidative stress and have been reported to activate NK cells and co-stimulate CD8(+) T cells. The purpose of this study was to examine the effect of PDT on tumor cell expression of MHC classes I and II-related molecules in vivo and in vitro.

STUDY DESIGN/MATERIALS AND METHODS

Human colon carcinoma Colo205 cells and murine CT26 tumors were treated with 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH)-PDT at various doses. MHC classes I and I-related molecule expression following treatment of Colo205 cells was temporally examined by flow cytometry using antibodies specific for components of MHC class I molecules and by quantitative PCR using specific primers. Expression of MHC class I-related molecules following HPPH-based PDT (HPPH-PDT) of murine tumors was monitored using a chimeric NKG2D receptor.

RESULTS

In vitro HPPH-PDT significantly induces MICA in Colo205 cells, but had no effect on MHC class I molecule expression. PDT also induced expression of NKG2D ligands (NKG2DL) following in vivo HPPH-PDT of a murine tumor. Induction of MICA corresponded to increased NK killing of PDT-treated tumor cells.

CONCLUSIONS

PDT induction of MICA on human tumor cells and increased expression of NKG2DL by murine tumors following PDT may play a role in PDT induction of anti-tumor immunity. This conclusion is supported by our results demonstrating that tumor cells have increased sensitivity to NK cell lysis following PDT.

Cestode antigens induce a tolerogenic-like phenotype and inhibit LPS inflammatory responses in human dendritic cells

Pathogens have developed strategies to modify Dendritic Cells (DCs) phenotypes and impair their functions in order to create a safer environment for their survival. DCs responses to helminths and their derivatives vary among different studies. Here we show that excretory/secretory products of the cestode Taenia crassiceps (TcES) do not induce the maturation of human DCs judged by a lack of increment in the expression of CD83, HLA-DR, CD80 and CD86 molecules but enhanced the production of IL-10 and positively modulated the expression of the C-type lectin receptor MGL and negatively modulated the expression of DC-SIGN. Additionally, these antigens were capable of down-modulating the inflammatory response induced by LPS in these cells by reducing the expression of the maturation markers and the production of the inflammatory cytokines IL-1β, TNF, IL-12 and IL-6. The effects of TcES upon the DCs responses to LPS were stronger if cells were exposed during their differentiation to the helminth antigens. All together, these findings suggest the ability of TcES to induce the differentiation of human DCs into a tolerogenic-like phenotype and to inhibit the effects of inflammatory stimuli.

The SCHOOL of nature: III. From mechanistic understanding to novel therapies

Protein-protein interactions play a central role in biological processes and thus represent an appealing target for innovative drug design and development. They can be targeted by small molecule inhibitors, modulatory peptides and peptidomimetics, which represent a superior alternative to protein therapeutics that carry many disadvantages. Considering that transmembrane signal transduction is an attractive process to therapeutically control multiple diseases, it is fundamentally and clinically important to mechanistically understand how signal transduction occurs. Uncovering specific protein-protein interactions critical for signal transduction, a general platform for receptor-mediated signaling, the signaling chain homooligomerization (SCHOOL) platform, suggests these interactions as universal therapeutic targets. Within the platform, the general principles of signaling are similar for a variety of functionally unrelated receptors. This suggests that global therapeutic strategies targeting key protein-protein interactions involved in receptor triggering and transmembrane signal transduction may be used to treat a diverse set of diseases. This also assumes that clinical knowledge and therapeutic strategies can be transferred between seemingly disparate disorders, such as T cell-mediated skin diseases and platelet disorders or combined to develop novel pharmacological approaches. Intriguingly, human viruses use the SCHOOL-like strategies to modulate and/or escape the host immune response. These viral mechanisms are highly optimized over the millennia, and the lessons learned from viral pathogenesis can be used practically for rational drug design. Proof of the SCHOOL concept in the development of novel therapies for atopic dermatitis, rheumatoid arthritis, cancer, platelet disorders and other multiple indications with unmet needs opens new horizons in therapeutics.

The paradoxical immuno-response of adenosine triphosphate effects

The actual research on the paradoxical effects of ATP to obtain to optimal conditions of the immune response against certain pathologies. The ATP Paradox, after its interaction with iron or aluminum, which have shown important effects on carcinogenesis, suggests its implication in pathological systems in which overcalcification may play a role.

New therapeutic strategies targeting transmembrane signal transduction in the immune system

Single-chain receptors and multi-chain immune recognition receptors (SRs and MIRRs, respectively) represent families of structurally related but functionally different surface receptors expressed on different cells. In contrast to SRs, a distinctive and common structural characteristic of MIRR family members is that the extracellular recognition domains and intracellular signaling domains are located on separate subunits. How extracellular ligand binding triggers MIRRs and initiates intracellular signal transduction processes is not clear. A novel model of immune signaling, the Signaling Chain HOmoOLigomerization (SCHOOL) model, suggests that the homooligomerization of receptor intracellular signaling domains represents a necessary and sufficient condition for receptor triggering. In this review, I demonstrate striking similarities between a consensus model of SR signaling and the SCHOOL model of MIRR signaling and show how these models, together with the lessons learned from viral pathogenesis, provide a molecular basis for novel pharmacological approaches targeting inter- and intrareceptor transmembrane interactions as universal therapeutic targets for a diverse variety of immune and other disorders.

Cbl-b in T-cell activation

Peripheral activation of antigen-specific T cells is stringently controlled to prevent immune responses against self-antigens. Only after a T cell is presented with two signals, an antigen and a co-stimulatory signal, can they be fully activated. In case antigen presentation occurs without co-stimulation, T-cell receptor (TCR) signaling pathways are regulated to prevent T-cell activation and induce T-cell tolerance. Thus, for a productive T-cell response to occur, co-stimulatory receptors need to serve the dual role of amplifying the TCR signaling while concomitantly releasing T cells from suppression. Biochemical and genetic studies during the last 10 years have documented the critical role of the E3 ubiquitin-ligase Cbl-b in this fundamental two-signal modulation of T-cell responses. In this review, we will discuss our current understanding on how Cbl-b controls T-cell activation and tolerance, its in vivo implications, as well as mechanisms for tuning T-cell-mediated immune responses by this essential E3 ligase.

How tolerogenic dendritic cells induce regulatory T cells

Since their discovery by Steinman and Cohn in 1973, dendritic cells (DCs) have become increasingly recognized for their crucial role as regulators of innate and adaptive immunity. DCs are exquisitely adept at acquiring, processing, and presenting antigens to T cells. They also adjust the context (and hence the outcome) of antigen presentation in response to a plethora of environmental inputs that signal the occurrence of pathogens or tissue damage. Such signals generally boost DC maturation, which promotes their migration from peripheral tissues into and within secondary lymphoid organs and their capacity to induce and regulate effector T cell responses. Conversely, more recent observations indicate that DCs are also crucial to ensure immunological peace. Indeed, DCs constantly present innocuous self- and nonself-antigens in a fashion that promotes tolerance, at least in part, through the control of regulatory T cells (Tregs). Tregs are specialized T cells that exert their immunosuppressive function through a variety of mechanisms affecting both DCs and effector cells. Here, we review recent advances in our understanding of the relationship between tolerogenic DCs and Tregs.

Density of tumour stroma is correlated to outcome after adoptive transfer of CD4+ and CD8+ T cells in a murine mammary carcinoma model

Adoptive immunotherapy shows promise for the treatment of cancer; however, partial or mixed responses remain common outcomes due to the heterogeneity of tumours. We studied three murine mammary tumour lines that express an ovalbumin-tagged version of HER-2/neu and reproducibly undergo complete regression (CR), partial regression (PR), or progressive disease (PD) after adoptive transfer of ovalbumin-specific CD8(+) (OT-I) and CD4(+) (OT-II) T cells. The three tumour lines were implanted in immunocompetent C57Bl/6 host mice, and established tumours were treated by adoptive transfer of naive OT-I and OT-II T cells. Tumours of the CR and PR classes triggered almost indistinguishable T cell responses in terms of activation, proliferation, trafficking to the tumour site, infiltration of tumour stroma, and intratumoural T cell proliferation; however, tumours of the PR class showed reduced infiltration of tumour epithelium by donor T cells. PD responses were associated with early impairment of T cell activation and proliferation in draining lymph node, followed by negligible infiltration of tumour tissue by donor T cells. Histopathological determinants of outcome were investigated through an unsupervised analysis of 64 untreated tumours representing the three response classes. Tumours of the CR class had proportionately more stroma, which had a looser, more collagen-rich histological appearance. Thus, the amount and composition of tumour stroma distinguished successfully (CR) from unsuccessful (PR or PD) outcomes after adoptive T cell transfer, a finding that might facilitate the design of immunotherapy trials for human breast cancer.

A comparative approach to the principal mechanisms of different memory systems

The term "memory" applies not only to the preservation of information in neuronal and immune systems but also to phenomena observed for example in plants, single cells, and RNA viruses. We here compare the different forms of information storage with respect to possible common features. The latter may be characterized by (1) selection of pre-existing information, (2) activation of memory systems often including transcriptional, and translational, as well as epigenetic and genetic mechanisms, (3) subsequent consolidation of the activated state in a latent form (standby mode), and (4) reactivation of the latent state of memory systems when the organism is exposed to the same (or conditioned) signal or to previous selective constraints. These features apparently also exist in the "evolutionary memory," i.e., in evolving populations which have highly variable mutant spectra.

Cbl- and Nedd4-family ubiquitin ligases: balancing tolerance and immunity

Engagement of the T cell receptor (TCR) with its cognate peptide/MHC initiates a cascade of signaling events that results in T cell activation. Limiting the extent and duration of TCR signaling ensures a tightly constrained response, protecting cells from the deleterious impact of chronic activation. In order to limit the duration of activation, T cells must adjust levels of key signaling proteins. This can be accomplished by altering protein synthesis or by changing the rate of protein degradation. Ubiquitination is a process of 'tagging' a protein with ubiquitin and is one means of initiating protein degradation. This process is activated when an E3 ubiquitin ligase mediates the transfer of ubiquitin to a target protein. Accordingly, E3 ubiquitin ligases have recently emerged as key regulators of immune cell function. This review will explore how a small group of E3 ubiquitin ligases regulate T cell responses and thus direct adaptive immunity.

Dendritic cells in Barrett's esophagus and esophageal adenocarcinoma

BACKGROUND

Like other premalignant conditions that develop in the presence of chronic inflammation, the development and progression of Barrett's esophagus is associated with the development of an immune response, but how this immune response is regulated is poorly understood. A comprehensive literature search failed to find any report of the presence of dendritic cells in Barrett's intestinal metaplasia and esophageal adenocarcinoma and this prompted our study.

MATERIAL AND METHODS

We used immunohistochemical staining and electron microscopy to examine whether dendritic cells are present in Barrett's esophagus and esophageal adenocarcinoma. Immunohistochemical staining with CD83, a specific marker for dendritic cells, was performed on paraffin-embedded sections of Barrett's intestinal metaplasia (IM, n = 12), dysplasia (n = 11) and adenocarcinoma (n = 14).

RESULTS

CD83+ cells were identified in the lamina propria surrounding intestinal type glands in Barrett's IM, dysplasia, and cancer tissues. Computerized quantitative analysis showed that the numbers of dendritic cells were significantly higher in cancer tissues. Double immunostaining with CD83, CD20, and CD3, and electron microscopy demonstrated that dendritic cells are present in Barrett's esophagus and form clusters with T cells and B cells directly within the lamina propria.

CONCLUSIONS

These findings demonstrate that dendritic cells are present in Barrett's tissues, with a significant increase in density in adenocarcinoma compared to benign Barrett's esophagus. Dendritic cells may have a role in the pathogenesis and immunotherapy treatment of Barrett's esophagus and adenocarcinoma.

Galectin-9 increases Tim-3+ dendritic cells and CD8+ T cells and enhances antitumor immunity via galectin-9-Tim-3 interactions

A Tim-3 ligand, galectin-9 (Gal-9), modulates various functions of innate and adaptive immune responses. In this study, we demonstrate that Gal-9 prolongs the survival of Meth-A tumor-bearing mice in a dose- and time-dependent manner. Although Gal-9 did not prolong the survival of tumor-bearing nude mice, transfer of naive spleen cells restored a prolonged Gal-9-induced survival in nude mice, indicating possible involvement of T cell-mediated immune responses in Gal-9-mediated antitumor activity. Gal-9 administration increased the number of IFN-gamma-producing Tim-3(+) CD8(+) T cells with enhanced granzyme B and perforin expression, although it induced CD4(+) T cell apoptosis. It simultaneously increased the number of Tim-3(+)CD86(+) mature dendritic cells (DCs) in vivo and in vitro. Coculture of CD8(+) T cells with DCs from Gal-9-treated mice increased the number of IFN-gamma producing cells and IFN-gamma production. Depletion of Tim-3(+) DCs from DCs of Gal-9-treated tumor-bearing mice decreased the number of IFN-gamma-producing CD8(+) T cells. Such DC activity was significantly abrogated by Tim-3-Ig, suggesting that Gal-9 potentiates CD8(+) T cell-mediated antitumor immunity via Gal-9-Tim-3 interactions between DCs and CD8(+) T cells.