Targeting T cell activation in immuno-oncology

Development of an immunoinflammatory indicator-related dynamic nomogram based on machine learning for the prediction of intravenous immunoglobulin-resistant Kawasaki disease patients

BACKGROUND

Approximately 10-20% of Kawasaki disease (KD) patients suffer from intravenous immunoglobulin (IVIG) resistance, placing them at higher risk of developing coronary artery aneurysms. Therefore, we aimed to construct an IVIG resistance prediction tool for children with KD in Shanghai, China.

METHODS

Retrospective analysis was conducted on data from 1271 patients diagnosed with KD and the patients were randomly divided into a training set and a validation set in a 2:1 ratio. Machine learning algorithms were employed to identify important predictors associated with IVIG resistance and to build a predictive model. The best-performing model was used to construct a dynamic nomogram. Moreover, receiver operating characteristic curves, calibration plots, and decision-curve analysis were utilized to measure the discriminatory power, accuracy, and clinical utility of the nomogram.

RESULTS

Six variables were identified as important predictors, including C-reactive protein, neutrophil ratio, procalcitonin, CD3 ratio, CD19 count, and IgM level. A dynamic nomogram constructed with these factors was available at https://hktk.shinyapps.io/dynnomapp/. The nomogram demonstrated good diagnostic performance in the training and validation sets (area under the receiver operating characteristic curve = 0.816 and 0.800, respectively). Moreover, the calibration curves and decision curves analysis indicated that the nomogram showed good consistency between predicted and actual outcomes and had good clinical benefits.

CONCLUSION

A web-based dynamic nomogram for IVIG resistance was constructed with good predictive performance, which can be used as a practical approach for early screening to assist physicians in personalizing the treatment of KD patients in Shanghai.

Targeting Neoantigens in Cancer: Possibilities and Opportunities in Breast Cancer

As one of the most prevalent forms of cancer worldwide, breast cancer has garnered significant attention within the clinical research setting. While traditional treatment employs a multidisciplinary approach including a variety of therapies such as chemotherapy, hormone therapy, and even surgery, researchers have since directed their attention to the budding role of neoantigens. Neoantigens are defined as tumor-specific antigens that result from a multitude of genetic alterations, the most prevalent of which is the single nucleotide variant. As a result of their foreign nature, neoantigens elicit immune responses upon presentation by Major Histocompatibility Complexes I and II followed by recognition by T cell receptors. Previously, researchers have been able to utilize these immunogenic properties and manufacture neoantigen-specific T-cells and neoantigen vaccines. Within the context of breast cancer, biomarkers such as tumor protein 53 (TP53), Survivin, Partner and Localizer of BRCA2 (PALB2), and protein tyrosine phosphatase receptor T (PTPRT) display exceeding potential to serve as neoantigens. However, despite their seemingly limitless potential, neoantigens must overcome various obstacles if they are to be fairly distributed to patients. For instance, a prolonged period between the identification of a neoantigen and the dispersal of treatment poses a serious risk within the context of breast cancer. Regardless of these current obstacles, it appears highly promising that future research into neoantigens will make an everlasting impact on the health outcomes within the realm of breast cancer. The purpose of this literature review is to comprehensively discuss the etiology of various forms of breast cancer and current treatment modalities followed by the significance of neoantigens in cancer therapeutics and their application to breast cancer. Further, we have discussed the limitations, future directions, and the role of transcriptomics in neoantigen identification and personalized medicine. The concepts discussed in the original and review articles were included in this review article.

PD-1-mediated inhibition of T cell activation: Mechanisms and strategies for cancer combination immunotherapy

The programmed cell death 1 (PD-1) immune checkpoint of co-inhibitory signaling plays crucial roles in controlling the magnitude and duration of T cell activation to limit tissue damage and maintain self-tolerance. Cancer cells hijack the co-inhibitory pathway and escape immune surveillance by overexpressing the PD-1 ligand PD-L1. Immune checkpoint inhibitors, such as PD-1 blocking antibody have been approved for tumor immunotherapy. However, not all patients can benefit from PD-1 monotherapy. Combination immunotherapy based on PD-1 axis blockade substantially improves clinical anti-tumor efficacy. In this review, we briefly summarize the current progress on the mechanisms of PD-1-mediated inhibition of T cell activation and strategies for cancer combination immunotherapy.

Pan-cancer analysis of RNA 5-methylcytosine reader (ALYREF)

The increasing interest in RNA modifications has significantly advanced epigenomic and epitranscriptomic technologies. This study focuses on the immuno-oncological impact of ALYREF in human cancer through a pan-cancer analysis, enhancing understanding of this gene's role in cancer. We observed differential ALYREF expression between tumor and normal samples, correlating strongly with prognosis in various cancers, particularly kidney renal papillary cell carcinoma (KIRP) and liver hepatocellular carcinoma (LIHC). ALYREF showed a negative correlation with most tumor-infiltrating cells in lung squamous cell carcinoma (LUSC) and lymphoid neoplasm diffuse large B-cell lymphoma (DLBC), while positive correlations were noted in LIHC, kidney chromophobe (KICH), mesothelioma (MESO), KIRP, pheochromocytoma and paraganglioma (PARD), and glioma (GBMLGG). Additionally, ALYREF expression was closely associated with tumor heterogeneity, stemness indices, and a high mutation rate in TP53 across these cancers. In conclusion, ALYREF may serve as an oncogenic biomarker in numerous cancers, meriting further research attention.

Metabolism-related gene vaccines and immune infiltration in ovarian cancer: A novel risk score model of machine learning

BACKGROUND

The present study aims to develop a metabolic gene signature to evaluate the survival rate of ovarian cancer (OC) patients and analyze the potential mechanisms of metabolic genes in OC because the difficulty in early detection of OC often leads to poor treatment outcomes.

METHODS

A non-negative matrix factorization algorithm was applied to determine molecular subtypes according to metabolism genes. To build a risk prognosis model, least absolute shrinkage and selection operator multivariate Cox analysis was carried out with weighted correlation network analysis (WCGNA). Glycolytic flux and mitochondrial function were evaluated by conducting seahorse analysis.

RESULTS

On the basis of metabolism-related genes, the two subtypes of OC samples present in The Cancer Genome Atlas database were distinguished. An analysis of WGCNA identified 1056 genes. Lastly, a 10-gene signature (CMAS, ADH1B, PLA2G2D, BHMT, CACNA1C, AADAC, ALOX12, CYP2R1, SCN1B and ME1) was constructed that demonstrated promising performance in predicting outcome in patients with OC. The RiskScore of the gene signature was linked to microenvironment cell infiltration and immune checkpoint. Higher RiskScores were associated with poorer results for OC patients. Seahorse analysis shows the influence of CMAS in cell energy metabolism.

CONCLUSIONS

In the present study, a novel marker for evaluating the survival of OC patients was developed through the creation of a gene signature incorporating metabolism-related genes. Our knowledge of immunotherapy and microenvironment cell infiltration may be enriched by evaluating metabolism-related gene modification patterns.

Targeting innate immune pathways for cancer immunotherapy

The innate immune system is critical for inducing durable and protective T cell responses to infection and has been increasingly recognized as a target for cancer immunotherapy. In this review, we present a framework wherein distinct innate immune signaling pathways activate five key dendritic cell activities that are important for T cell-mediated immunity. We discuss molecular pathways that can agonize these activities and highlight that no single pathway can agonize all activities needed for durable immunity. The immunological distinctions between innate immunotherapy administration to the tumor microenvironment versus administration via vaccination are examined, with particular focus on the strategies that enhance dendritic cell migration, interferon expression, and interleukin-1 family cytokine production. In this context, we argue for the importance of appreciating necessity vs. sufficiency when considering the impact of innate immune signaling in inflammation and protective immunity and offer a conceptual guideline for the development of efficacious cancer immunotherapies.

First-in-human phase I/Ib study of NIZ985, a recombinant heterodimer of IL-15 and IL-15Rα, as a single agent and in combination with spartalizumab in patients with advanced and metastatic solid tumors

BACKGROUND

Preclinically, interleukin-15 (IL-15) monotherapy promotes antitumor immune responses, which are enhanced when IL-15 is used in combination with immune checkpoint inhibitors (ICIs). This first-in-human study investigated NIZ985, a recombinant heterodimer comprising physiologically active IL-15 and IL-15 receptor α, as monotherapy and in combination with spartalizumab, an anti-programmed cell death protein-1 (anti-PD-1) monoclonal antibody, in patients with advanced solid tumors.

METHODS

This phase I/Ib study had two dose-escalation arms: single-agent NIZ985 administered subcutaneously thrice weekly (TIW, 2 weeks on/2 weeks off) or once weekly (QW, 3 weeks on/1 week off), and NIZ985 TIW or QW administered subcutaneously plus spartalizumab (400 mg intravenously every 4 weeks (Q4W)). The dose-expansion phase investigated NIZ985 1 µg/kg TIW/spartalizumab 400 mg Q4W in patients with anti-PD-1-sensitive or anti-PD-1-resistant tumor types stratified according to approved indications. The primary objectives were the safety, tolerability, and the maximum tolerated doses (MTDs) and/or recommended dose for expansion (RDE) of NIZ985 for the dose-expansion phase.

RESULTS

As of February 17, 2020, 83 patients (median age: 63 years; range: 28-85) were treated in dose escalation (N=47; single-agent NIZ985: n=27; NIZ985/spartalizumab n=20) and dose expansion (N=36). No dose-limiting toxicities occurred nor was the MTD identified. The most common treatment-related adverse event (TRAE) was injection site reaction (primarily grades 1-2; single-agent NIZ985: 85% (23/27)); NIZ985/spartalizumab: 89% [50/56]). The most common grade 3-4 TRAE was decreased lymphocyte count (single-agent NIZ985: 7% [2/27]; NIZ985/spartalizumab: 5% [3/56]). The best overall response was stable disease in the single-agent arm (30% (8/27)) and partial response in the NIZ985/spartalizumab arm (5% [3/56]; melanoma, pancreatic cancer, gastric cancer). In dose expansion, the disease control rate was 45% (5/11) in the anti-PD-1-sensitive and 20% (5/25) in the anti-PD-1-resistant tumor type cohorts. Pharmacokinetic parameters were similar across arms. The transient increase in CD8+ T cell and natural killer cell proliferation and induction of several cytokines occurred in response to the single-agent and combination treatments.

CONCLUSIONS

NIZ985 was well tolerated in the single-agent and NIZ985/spartalizumab regimens. The RDE was established at 1 µg/kg TIW. Antitumor activity of the combination was observed against tumor types known to have a poor response to ICIs.

TRIAL REGISTRATION NUMBER

NCT02452268.

Immune cell status, cardiorespiratory fitness and body composition among breast cancer survivors and healthy women: a cross sectional study

Methods: We examined whether immune cell profiles differ between healthy women (n = 38) and breast cancer survivors (n = 27) within 2 years of treatment, and whether any group-differences were influenced by age, cytomegalovirus infection, cardiorespiratory fitness and body composition. Using flow cytometry, CD4+ and CD8+ T cell subsets, including naïve (NA), central memory (CM) and effector cells (EM and EMRA) were identified using CD27/CD45RA. Activation was measured by HLA-DR expression. Stem cell-like memory T cells (TSCMs) were identified using CD95/CD127. B cells, including plasmablasts, memory, immature and naïve cells were identified using CD19/CD27/CD38/CD10. Effector and regulatory Natural Killer cells were identified using CD56/CD16. Results: Compared to healthy women, CD4+ CM were +Δ21% higher among survivors (p = 0.028) and CD8+ NA were -Δ25% lower (p = 0.034). Across CD4+ and CD8+ subsets, the proportion of activated (HLA-DR+) cells was +Δ31% higher among survivors: CD4+ CM (+Δ25%), CD4+ EM (+Δ32%) and CD4+ EMRA (+Δ43%), total CD8⁺ (+Δ30%), CD8+ EM (+Δ30%) and CD8+ EMRA (+Δ25%) (p < 0.046). The counts of immature B cells, NK cells and CD16+ NK effector cells were higher among survivors (+Δ100%, +Δ108% and +Δ143% respectively, p < 0.04). Subsequent analyses examined whether statistically significant differences in participant characteristics, influenced immunological differences between groups. Compared to healthy women, survivors were older (56 ± 6 y vs. 45 ± 11 y), had lower cardiorespiratory fitness (V˙O2max mL kg^-1 min^-1: 28.8 ± 5.0 vs. 36.2 ± 8.5), lower lean mass (42.3 ± 5.0 kg vs. 48.4 ± 15.8 kg), higher body fat (36.3% ± 5.3% vs. 32.7% ± 6.4%) and higher fat mass index (FMI kg/m²: 9.5 ± 2.2 vs. 8.1 ± 2.7) (all p < 0.033). Analysis of covariance revealed divergent moderating effects of age, CMV serostatus, cardiorespiratory fitness and body composition on the differences in immune cell profiles between groups, depending on the cell type examined. Moreover, across all participants, fat mass index was positively associated with the proportion of HLA-DR+ CD4+ EMRA and CD8+ EM/EMRA T cells (Pearson correlation: r > 0.305, p < 0.019). The association between fat mass index and HLA-DR+ CD8+ EMRA T cells withstood statistical adjustment for all variables, including age, CMV serostatus, lean mass and cardiorespiratory fitness, potentially implicating these cells as contributors to inflammatory/immune-dysfunction in overweight/obesity.

The Effect of the Histone Chaperones HSPA8 and DEK on Tumor Immunity in Hepatocellular Carcinoma

Complex immune contexture leads to resistance to immunotherapy in hepatocellular carcinoma (HCC), and the need for new potential biomarkers of immunotherapy in HCC is urgent. Histone chaperones are vital determinants of gene expression and genome stability that regulate tumor development. This study aimed to investigate the effect of histone chaperones on tumor immunity in HCC. Bioinformatics analyses were initially performed using The Cancer Genome Atlas (TCGA) database, and were validated using the Gene Expression Omnibus (GEO) database and the International Cancer Genome Consortium (ICGC) database. Immune-related histone chaperones were screened with the Spearman rank coefficient. Consensus clustering was utilized to divide the HCC samples into two clusters. ESTIMATE, CIBERSORT and ssGSEA analyses were performed to assess immune infiltration. The expression of immunomodulatory genes, chemokines and chemokine receptors was analyzed to evaluate sensitivity to immunotherapy. The differentially expressed genes (DEGs) were included in weighted gene coexpression network analysis (WGCNA) to identify the hub genes. Enrichment analyses were used to investigate the functions of the hub genes. The Kaplan-Meier method and log-rank test were conducted to draw survival curves. A Cox regression analysis was utilized to identify independent risk factors affecting prognosis. HSPA8 and DEK were screened out from 36 known histone chaperones based on their strongest correlation with the ESTIMATE score. Cluster 2, with high HSPA8 expression and low DEK expression, tended to have stronger immune infiltration and better sensitivity to immunotherapy than Cluster 1, with low HSPA8 expression and high DEK expression. Furthermore, WGCNA identified 12 hub genes closely correlated with immune infiltration from the DEGs of the two clusters, of which FBLN2 was proven to be an independent protective factor of HCC patients. HSPA8 and DEK are expected to be biomarkers for precisely predicting the effect of immunotherapy, and FBLN2 is expected to be a therapeutic target of HCC.

Combined Vaccination with B Cell Peptides Targeting Her-2/neu and Immune Checkpoints as Emerging Treatment Option in Cancer

The application of monoclonal antibodies (mAbs), targeting tumor-associated (TAAs) or tumor-specific antigens or immune checkpoints (ICs), has shown tremendous success in cancer therapy. However, the application of mAbs suffers from a series of limitations, including the necessity of frequent administration, the limited duration of clinical response and the emergence of frequently pronounced immune-related adverse events. However, the introduction of mAbs has also resulted in a multitude of novel developments for the treatment of cancers, including vaccinations against various tumor cell-associated epitopes. Here, we reviewed recent clinical trials involving combination therapies with mAbs targeting the PD-1/PD-L1 axis and Her-2/neu, which was chosen as a paradigm for a clinically highly relevant TAA. Our recent findings from murine immunizations against the PD-1 pathway and Her-2/neu with peptides representing the mimotopes/B cell peptides of therapeutic antibodies targeting these molecules are an important focus of the present review. Moreover, concerns regarding the safety of vaccination approaches targeting PD-1, in the context of the continuing immune response, as a result of induced immunological memory, are also addressed. Hence, we describe a new frontier of cancer treatment by active immunization using combined mimotopes/B cell peptides aimed at various targets relevant to cancer biology.

The role of the natural killer (NK) cell modulation in breast cancer incidence and progress

The importance of the immune system on tumor surveillance has been investigated for many years, and its impact on controlling tumor progression has been verified. An important subgroup of the innate immune system is natural killer (NK) cells, whose essential function in modulating tumor behavior and suppressing metastasis and tumor growth has been demonstrated. The first idea of NK cells' crucial biological processes was demonstrated through their potent ability to conduct direct cellular cytotoxicity, even without former sensitization. These properties of NK cells allow them to recognize transformed cells that have attenuated self-ligand and express stress-induced ligands. Furthermore, secretion of various cytokines and chemokines after their activation leads to tumor elimination via either direct cytotoxic effect on malignant cells or activation of the adaptive immune system. In addition, novel immunotherapeutic approaches tend to take advantage of NK cells' ability, leading to antibody-based approaches, the formation of engineered CAR-NK cells, and adoptive cell transfer. However, the restricted functionality of NK cells and the inability to infiltrate tumors are its blind spots in breast cancer patients. In this review, we gathered newly acquired data on the biology and functions of NK cells in breast cancer and proposed ways to employ this knowledge for novel therapeutic approaches in cancers, particularly breast cancer.

Characteristics of Prognostic Programmed Cell Death-Related Long Noncoding RNAs Associated With Immune Infiltration and Therapeutic Responses to Colon Cancer

Programmed cell death (PCD) plays an important role in the onset and progression of various cancers. The molecular events surrounding the occurrence of abnormally expressed long noncoding RNAs (lncRNAs) leading to colon cancer (CC) have become a focus. We comprehensively evaluated the roles of PCD-related lncRNAs in the clinical management of CC and their immune responses. Therefore, we screened 41 prognostic PCD-related lncRNAs in The Cancer Genome Atlas database using co-expression analysis and assigned patients to groups according to the results of cluster analysis. The immune response and functions of cluster 2 were substantially suppressed, which might explain the poor prognosis in this group. A prognostic model comprising eight PCD-related lncRNAs was developed, and its effectiveness was verified using an external database. High-and low-risk groups had different epigenetic modifications and changes in immune cell infiltration. Patients in the high-risk group were resistant to immunotherapy and various chemotherapeutic drugs. Studies in vitro and in vivo further confirmed a carcinogenic role of the lncRNA U62317.4. Our findings of the prognostic value of PCD-related lncRNAs revealed their important roles in immune response disorders, thus providing valuable insights into the clinical management and molecular mechanisms of CC.

Cancer immunotherapy in adult patients with HIV

The availability of antiretroviral therapy (ART) has increased the life expectancy of people with HIV (PWH) and reduced the incidence of AIDS-associated malignancies, yet PWH have a significantly increased incidence of malignancy and less favorable outcomes of cancer treatment compared with the general population.Immunotherapy has revolutionized cancer therapy, becoming the standard of care for various malignancy treatments. However, PWH are an underserved population with limited access to clinical trials and cancer treatment.This review of the available evidence on different classes of cancer immunotherapy in PWH is mostly based on case reports, case series, but few prospective studies and clinical trials due to the exclusion of PWH from most oncologic clinical trials. The results of the available evidence support the safety of immunotherapy in PWH. Immunotherapy has similar effectiveness in PWH, an acceptable toxicity profile, and has no clinically significant impact on HIV viral load and CD4-T cell count. In addition, there is no reported change in the incidence of opportunistic infections and other complications for PWH with well-controlled viremia.This review aims to briefly summarize the current state of immunotherapy in cancer, guide clinicians in the management of immunotherapy in cancer PWH, and encourage the inclusion of PWH in clinical trials of cancer immunotherapy.

Transthyretin-mediated protein and peptide oligomerization for enhanced target clustering

Advances in cancer research have led to the development of new therapeutics with significant and durable responses such as immune checkpoint inhibitors. More recent therapies aim to stimulate anti-tumor immune responses by targeting the tumor necrosis factor (TNF) receptors, however this approach has been shown to require clustering of receptors in order to achieve a significant response. Here we present a perspective on using transthyretin, a naturally occurring serum protein, as a drug delivery platform to enable cross-linking independent clustering of targets. TTR forms a stable homo-tetramer with exposed termini that make TTR a highly versatile platform for generating multimeric antibody fusions to enable enhanced target clustering. Fusions with antibodies or Fabs targeting TRAILR2 were shown to have robust cytotoxic activity in vitro and in vivo in colorectal xenograft models demonstrating that TTR is a highly versatile, stable, therapeutic fusion platform that can be used with antibodies, Fabs and other bioactive fusion partners and has broad applications in oncology and infectious disease research.

N6-Methylandenosine-Related lncRNA Signature Is a Novel Biomarkers of Prognosis and Immune Response in Colon Adenocarcinoma Patients

Background

Colon adenocarcinoma (COAD) is the most common type of colon cancer. To date, however, the prognostic values of m6A RNA methylation-related long non-coding RNAs (lncRNAs) in COAD are largely unknown.

Materials and Methods

The m6A-related lncRNAs were identified from The Cancer Genome Atlas (TCGA) data set. Univariate and multivariate Cox regression analyses were performed to explore the prognostic m6A-related lncRNAs. Consistent clustering analysis was performed to classify the COAD patients into different subgroups based on the expression of m6A-related lncRNAs. The potential biological functions as well as differences in the stemness index and tumor immune microenvironment between different subgroups were analyzed. The prognostic m6A-related lncRNAs were used to establish an m6A-related lncRNA risk model to predict prognosis and survival status.

Results

We identified 31 m6A-associated lncRNAs with prognostic values from the TCGA data set. Based on the expression of prognostic m6A-associated lncRNAs, TCGA-COAD patients were classified into three clusters using consistent clustering analysis. There was a low correlation of tumor stemness between the three clusters but a significant correlation with the tumor immune microenvironment as well as the tumor mutational load. Thirty-one prognostic-related m6A-associated lncRNAs were used to construct a risk model, which was further determined by survival analysis, receiver operating characteristic (ROC) curve, and univariate and multifactor Cox analysis. The m6A-related risk model demonstrates good performance in predicting prognosis and survival status. The model-based high-risk group exhibited poorer overall survival (OS) compared with the low-risk group.

Conclusion

In this study, we construct a risk model that consists of 31 m6A-related lncRNAs with independent prognostic values in COAD. Our study shows the critical roles of these 31 m6A-related lncRNAs in the tumor immune microenvironment, indicating the prospect of informing prognostic stratification and the development of immunotherapeutic strategies for COAD patients.

Engineered immune cells with nanomaterials to improve adoptive cell therapy

Cell-based cancer immunotherapy is mainly performed to re-stimulate or boost the anti-tumor immunity by leveraging the anti-tumoral functions of infused cells. Although conventional adoptive cell therapy with T cells and DC vaccines had potentiated the use of ex vivo engineered cells for cancer immunotherapy, these approaches had a low success rate and some off-target side effects. Recent developments on this intervention are adopting nanoengineering to overcome limitations imposed by the environment the therapeutic cells would be in and the natural characteristics of the cells; thus, enhancing the efficacy of therapies. For this purpose, T cells, NK cells, DCs, and macrophages are engineered to either maintain anti-tumoral phenotypes, target tumor efficiently, or improve the innate functionalities and viability.

Oncolytic virotherapy induced CSDE1 neo-antigenesis restricts VSV replication but can be targeted by immunotherapy

In our clinical trials of oncolytic vesicular stomatitis virus expressing interferon beta (VSV-IFNβ), several patients achieved initial responses followed by aggressive relapse. We show here that VSV-IFNβ-escape tumors predictably express a point-mutated CSDE1P5S form of the RNA-binding Cold Shock Domain-containing E1 protein, which promotes escape as an inhibitor of VSV replication by disrupting viral transcription. Given time, VSV-IFNβ evolves a compensatory mutation in the P/M Inter-Genic Region which rescues replication in CSDE1P5S cells. These data show that CSDE1 is a major cellular co-factor for VSV replication. However, CSDE1P5S also generates a neo-epitope recognized by non-tolerized T cells. We exploit this predictable neo-antigenesis to drive, and trap, tumors into an escape phenotype, which can be ambushed by vaccination against CSDE1P5S, preventing tumor escape. Combining frontline therapy with escape-targeting immunotherapy will be applicable across multiple therapies which drive tumor mutation/evolution and simultaneously generate novel, targetable immunopeptidomes associated with acquired treatment resistance.

Tropomodulin1 Expression Increases Upon Maturation in Dendritic Cells and Promotes Their Maturation and Immune Functions

Dendritic cells (DCs) are the most potent antigen-presenting cells. Upon maturation, DCs express costimulatory molecules and migrate to the lymph nodes to present antigens to T cells. The actin cytoskeleton plays key roles in multiple aspects of DC functions. However, little is known about the mechanisms and identities of actin-binding proteins that control DC maturation and maturation-associated functional changes. Tropomodulin1 (Tmod1), an actin-capping protein, controls actin depolymerization and nucleation. We found that Tmod1 was expressed in bone marrow-derived immature DCs and was significantly upregulated upon lipopolysaccharide (LPS)-induced DC maturation. By characterizing LPS-induced mature DCs (mDCs) from Tmod1 knockout mice, we found that compared with Tmod1+/+ mDCs, Tmod1-deficient mDCs exhibited lower surface expression of costimulatory molecules and chemokine receptors and reduced secretion of inflammatory cytokines, suggesting that Tmod1 deficiency retarded DC maturation. Tmod1-deficient mDCs also showed impaired random and chemotactic migration, deteriorated T-cell stimulatory ability, and reduced F-actin content and cell stiffness. Furthermore, Tmod1-deficient mDCs secreted high levels of IFN-β and IL-10 and induced immune tolerance in an experimental autoimmune encephalomyelitis (EAE) mouse model. Mechanistically, Tmod1 deficiency affected TLR4 signaling transduction, resulting in the decreased activity of MyD88-dependent NFκB and MAPK pathways but the increased activity of the TRIF/IRF3 pathway. Rescue with exogenous Tmod1 reversed the effect of Tmod1 deficiency on TLR4 signaling. Therefore, Tmod1 is critical in regulating DC maturation and immune functions by regulating TLR4 signaling and the actin cytoskeleton. Tmod1 may be a potential target for modulating DC functions, a strategy that would be beneficial for immunotherapy for several diseases.

Repositioning of Immunomodulators: A Ray of Hope for Alzheimer's Disease?

Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder characterized by cognitive decline and by the presence of amyloid β plaques and neurofibrillary tangles in the brain. Despite recent advances in understanding its pathophysiological mechanisms, to date, there are no disease-modifying therapeutic options, to slow or halt the evolution of neurodegenerative processes in AD. Current pharmacological treatments only transiently mitigate the severity of symptoms, with modest or null overall improvement. Emerging evidence supports the concept that AD is affected by the impaired ability of the immune system to restrain the brain's pathology. Deep understanding of the relationship between the nervous and the immune system may provide a novel arena to develop effective and safe drugs for AD treatment. Considering the crucial role of inflammatory/immune pathways in AD, here we discuss the current status of the immuno-oncological, immunomodulatory and anti-TNF-α drugs which are being used in preclinical studies or in ongoing clinical trials by means of the drug-repositioning approach.