Interferon receptor signaling in malignancy: a network of cellular pathways defining biological outcomes

Two cytokine receptor family B (CRFB) members in orange-spotted grouper Epinephelus coioides, EcCRFB3 and EcCRFB4, negatively regulate interferon immune responses to assist nervous necrosis virus replication

Receptors of type I interferon (IFNR) play a vital role in the antiviral immune response. However, little is known about the negative regulatory role of the IFNR. Nervous necrosis virus (NNV) is one of the most significant viruses in cultured fish, resulting in great economic losses for the aquaculture industry. In this study, two orange-spotted grouper (Epinephelus coioides) cytokine receptor family B (CRFB) members, EcCRFB3 and EcCRFB4 were cloned and characterized from NNV infected grouper brain (GB) cells. The open reading frame (ORF) of EcCRFB3 consists of 852 bp encoding 283 amino acids, while EcCRFB4 has an ORF of 990 bp encoding 329 amino acids. The mRNA levels of EcCRFB3 or EcCRFB4 were significantly upregulated after NNV infection and the stimulation of poly (I:C) or NNV-encoded Protein A. In addition, EcCRFB3 or EcCRFB4 overexpression facilitated NNV replication, whereas EcCRFB3 or EcCRFB4 silencing resisted NNV replication. Overexpressed EcCRFB3 or EcCRFB4 inhibited the expression of IFN-I-induced ISGs. Taken together, our research provides the first evidence in fish demonstrating the role of IFNRs to regulate the IFN signaling pathway negatively. Our findings enrich the understanding of the functions of IFNRs and reveal a novel escape mechanism of NNV.

Signaling by Type I Interferons in Immune Cells: Disease Consequences

This review addresses interferon (IFN) signaling in immune cells and the tumor microenvironment (TME) and examines how this affects cancer progression. The data reveal that IFNs exert dual roles in cancers, dependent on the TME, exhibiting both anti-tumor activity and promoting cancer progression. We discuss the abnormal IFN signaling induced by cancerous cells that alters immune responses to permit their survival and proliferation.

Understanding immune checkpoints and PD-1/PD-L1-mediated immune resistance towards tumour immunotherapy

Immunotherapy has emerged as a transformative approach in the treatment of various cancers, offering new hope for patients previously faced with limited treatment options. A cornerstone of cancer immunotherapy lies in targeting immune checkpoints, particularly the programmed cell death protein-1 (PD-1) and programmed death-ligand 1 (PD-L1) pathway. Immune checkpoints serve as crucial regulators of the immune response, preventing excessive immune activity and maintaining self-tolerance. PD-1, expressed on the surface of T cells, and its ligand PD-L1, expressed on various cell types, including cancer cells and immune cells, play a central role in this regulatory process. Although the success rate associated with these immunotherapies is very promising, most patients still show intrinsic or acquired resistance. Since the mechanisms related to PD-1/PD-L1 resistance are not well understood, an in-depth analysis is necessary to improve the success rate of anti-PD-1/PD-L1 therapy. Hence, here we provide an overview of PD-1, its ligand PD-L1, and the resistance mechanism towards PD-1/PD-L1. Furthermore, we have discussed the plausible solution to increase efficacy and clinical response. For the following research, joint endeavours of clinicians and basic scientists are essential to address the limitation of resistance towards immunotherapy.

Progress in investigating the relationship between Schlafen5 genes and malignant tumors

The Schlafen5(SLFN5)gene belongs to the third group of the Schlafen protein family. As a tumor suppressor gene, SLFN5 plays a pivotal role in inhibiting tumor growth, orchestrating cell cycle regulation, and modulating the extent of cancer cell infiltration and metastasis in various malignancies. However, the high expression of SLFN 5 in some tumors was positively correlated with lymph node metastasis, tumor stage, and tumor grade. This article endeavors to elucidate the reciprocal relationship between the SLFN5 gene and malignant tumors, thereby enhancing our comprehension of the intricate mechanisms underlying the SLFN5 gene and its implications for the progression, invasive potential, and metastatic behavior of malignant tumors. At the same time, this paper summarizes the basis of SLFN 5 as a new biomarker of tumor diagnosis and prognosis, and provides new ideas for the target treatment of tumor.

Role of Checkpoint Inhibitors in the Management of Gastroesophageal Cancers

PURPOSE

This article reviews the essential clinical trials that have led to these immunotherapy approvals and explores the use of predictive biomarkers, such as PD-L1 expression and MSI status, to identify patients who are most likely to benefit from immunotherapies.

METHODS

This case review series describe findings from different clinical trials and contribute to the evolving understanding of the role of CPIs in managing advanced gastroesophageal cancers and may lead to improved treatment options and patient outcomes. Ongoing clinical trials also hold promise for expanding treatment options and improving patient outcomes in the future.

METHODS

The systematic review followed the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The protocol has not been registered. A systematic literature review was conducted to identify relevant clinical trials and studies that describe the role of immune checkpoint inhibitors in managing advanced gastroesophageal cancers. Electronic database (PubMed, Clinicaltrials.gov, Society of Immunotherapy of Cancer, Aliment Pharmacology & Therapeutics, BMC cancer, Molecular Cancer Research, Nature Reviews Molecular Cell Biology, American Association for Cancer Research, Science, Nature, Cancer Discovery, Journal of the National Cancer Institute, Advanced Immunology, Oncotarget, Nature Medicine, Nature Genetics, Gut, Pathology and Oncology Research, Journal of Clinical Oncology, The New England Journal of Medicine, Gastrointestinal oncology, JAMA Oncology, Journal of Gastrointestinal Oncology, Current Oncology, Annals of Oncology, The Lancet, JCO Oncology Practice, Future Oncology, Gastric Cancer, CA: A Cancer Journal for Clinicians, American Journal of Gastroenterology, Gastroenterology, Journal of the National Cancer Institute, International Journal of Epidemiology, Helicobacter, Gastroenterology Review) were searched using a combination of relevant keywords and MESH terms. The search encompassed articles published up to 5/2023. Additionally, manual searches of reference lists of selected articles and pertinent review papers were conducted to ensure comprehensive coverage of relevant studies. Studies were included if they provided insights into clinical trials evaluating the efficacy and safety of CPIs in treating advanced gastroesophageal cancers. Relevant case reviews and trials exploring combination therapies involving CPIs were also considered. Articles discussed in the utilization of predictive biomarkers were included to assess their impact on treatment outcomes. Data from selected studies were extracted to inform the narrative review. Key findings were summarized, including clinical trial designs, patient populations, treatment regimens, response rates, progression-free survival (PFS), overall survival (OS), and adverse events. The role of predictive biomarkers, particularly PD-L1 expression and MSI status, in identifying patients likely to benefit from CPIs was critically evaluated based on study results. Ongoing clinical trials investigating novel combination strategies and exploring the broader scope of CPIs in gastroesophageal cancers were also highlighted. The collected data were synthesized to provide a comprehensive overview of the crucial clinical trials that have contributed to the approval of CPIs for advanced gastroesophageal cancers. The role of CPIs in different lines of therapy, including first-line regimens, was discussed. Furthermore, the evolving landscape of predictive biomarkers was examined, emphasizing their potential significance in optimizing patient selection for CPI therapy. Ongoing clinical trials were reviewed to underscore the continuous efforts in expanding treatment options and improving patient outcomes in the future.

Cellular state landscape and herpes simplex virus type 1 infection progression are connected

Prediction, prevention and treatment of virus infections require understanding of cell-to-cell variability that leads to heterogenous disease outcomes, but the source of this heterogeneity has yet to be clarified. To study the multimodal response of single human cells to herpes simplex virus type 1 (HSV-1) infection, we mapped high-dimensional viral and cellular state spaces throughout the infection using multiplexed imaging and quantitative single-cell measurements of viral and cellular mRNAs and proteins. Here we show that the high-dimensional cellular state scape can predict heterogenous infections, and cells move through the cellular state landscape according to infection progression. Spatial information reveals that infection changes the cellular state of both infected cells and of their neighbors. The multiplexed imaging of HSV-1-induced cellular modifications links infection progression to changes in signaling responses, transcriptional activity, and processing bodies. Our data show that multiplexed quantification of responses at the single-cell level, across thousands of cells helps predict infections and identify new targets for antivirals.

IFN-Inducible SerpinA5 Triggers Antiviral Immunity by Regulating STAT1 Phosphorylation and Nuclear Translocation

Deeply understanding virus-host interactions is a prerequisite for developing effective strategies to control frequently emerging infectious diseases, which have become a serious challenge for global public health. The type I interferon (IFN)-mediated JAK/STAT pathway is well known for playing an essential role in host antiviral immunity, but the exact regulatory mechanisms of various IFN-stimulated genes (ISGs) are not yet fully understood. We herein reported that SerpinA5, as a novel ISG, played a previously unrecognized role in antiviral activity. Mechanistically, SerpinA5 can upregulate the phosphorylation of STAT1 and promote its nuclear translocation, thus effectively activating the transcription of IFN-related signaling pathways to impair viral infections. Our data provide insights into SerpinA5-mediated innate immune signaling during virus-host interactions.

Type I and II interferon signaling in colorectal cancer liver metastasis

Metastatic colorectal cancer is one of the leading causes of cancer-related deaths worldwide. Traditional chemotherapy extended the lifespan of cancer patients by only a few months, but targeted therapies and immunotherapy prolonged survival and led to long-term remissions in some cases. Type I and II interferons have direct pro-apoptotic and anti-proliferative effects on cancer cells and stimulate anti-cancer immunity. As a result, interferon production by cells in the tumor microenvironment is in the spotlight of immunotherapies as it affects the responses of anti-cancer immune cells. However, promoting effects of interferons on colorectal cancer metastasis have also been reported. Here we summarize our knowledge about pro- and anti-metastatic effects of type I and II interferons in colorectal cancer liver metastasis and discuss possible therapeutic implications.

Proteomics and Phospho-Proteomics Profiling of the Co-Formulation of Type I and II Interferons, HeberFERON, in the Glioblastoma-Derived Cell Line U-87 MG

HeberFERON, a co-formulation of Interferon (IFN)-α2b and IFN-γ, has effects on skin cancer and other solid tumors. It has antiproliferative effects over glioblastoma multiform (GBM) clones and cultured cell lines, including U-87 MG. Here, we report the first label-free quantitative proteomic and phospho-proteomic analyses to evaluate changes induced by HeberFERON after 72 h incubation of U-87 MG that can explain the effect on cellular proliferation. LC-MS/MS, functional enrichment and networking analysis were performed. We identified 7627 proteins; 122 and 211 were down- and up-regulated by HeberFERON (fold change > 2; p < 0.05), respectively. We identified 23,549 peptides (5692 proteins) and 8900 phospho-peptides; 523 of these phospho-peptides (359 proteins) were differentially modified. Proteomic enrichment showed IFN signaling and its control, direct and indirect antiviral mechanisms were the main modulated processes. Phospho-proteome enrichment displayed the cell cycle as one of the most commonly targeted events together with cytoskeleton organization; translation/RNA splicing, autophagy and DNA repair, as represented biological processes. There is a high interconnection of phosphoproteins in a molecular network; mTOR occupies a centric hub with interactions with translation machinery, cytoskeleton and autophagy components. Novel phosphosites and others with unknown biological functionality in key players in the aforementioned processes were regulated by HeberFERON and involved CDK and ERK kinases. These findings open new experimental hypotheses regarding HeberFERON action. The results obtained contribute to a better understanding of HeberFERON effector mechanisms in the context of GBM treatment.

Enhanced IFN Sensing by Aggressive Chronic Lymphocytic Leukemia Cells

Type I IFN is made by cells in response to stress. Cancer cells exist in a state of stress, but their IFN response is complex and not completely understood. This study investigated the role of autocrine IFN in human chronic lymphocytic leukemia (CLL) cells. CLL cells were found to make low amounts of IFN via TANK-binding kinase 1 pathways, but p-STAT1 and -STAT2 proteins along with IFN-stimulated genes that reflect IFN activation were variably downregulated in cultured CLL cells by the neutralizing IFNAR1 Ab anifrolumab. Patients with CLL were segregated into two groups based on the response of their leukemia cells to anifrolumab. Samples associated with more aggressive clinical behavior indicated by unmutated IGHV genes along with high CD38 and p-Bruton’s tyrosine kinase expression exhibited responses to low amounts of IFN that were blocked by anifrolumab. Samples with more indolent behavior were unaffected by anifrolumab. Hypersensitivity to IFN was associated with higher expression of IFNAR1, MX1, STAT1, and STAT2 proteins and lower activity of negative regulatory tyrosine phosphatases. Autocrine IFN protected responsive CLL cells from stressful tissue culture environments and therapeutic drugs such as ibrutinib and venetoclax in vitro, in part by upregulating Mcl-1 expression. These findings suggest hypersensitivity to IFN may promote aggressive clinical behavior. Specific blockade of IFN signaling may improve outcomes for patients with CLL with higher-risk disease.

Primary cilia contribute to the aggressiveness of atypical teratoid/rhabdoid tumors

Atypical teratoid/rhabdoid tumor (AT/RT) is a highly malignant brain tumor in infants that is characterized by loss of nuclear expression of SMARCB1 or SMARCA4 proteins. Recent studies show that AT/RTs comprise three molecular subgroups, namely AT/RT-TYR, AT/RT-MYC and AT/RT-SHH. The subgroups show distinct expression patterns of genes involved in ciliogenesis, however, little is known about the functional roles of primary cilia in the biology of AT/RT. Here, we show that primary cilia are present across all AT/RT subgroups with specific enrichment in AT/RT-TYR patient samples. Furthermore, we demonstrate that primary ciliogenesis contributes to AT/RT biology in vitro and in vivo. Specifically, we observed a significant decrease in proliferation and clonogenicity following disruption of primary ciliogenesis in AT/RT cell line models. Additionally, apoptosis was significantly increased via the induction of STAT1 and DR5 signaling, as detected by proteogenomic profiling. In a Drosophila model of SMARCB1 deficiency, concomitant knockdown of several cilia-associated genes resulted in a substantial shift of the lethal phenotype with more than 20% of flies reaching adulthood. We also found significantly extended survival in an orthotopic xenograft mouse model of AT/RT upon disruption of primary ciliogenesis. Taken together, our findings indicate that primary ciliogenesis or its downstream signaling contributes to the aggressiveness of AT/RT and, therefore, may constitute a novel therapeutic target.

NAD/NAMPT and mTOR Pathways in Melanoma: Drivers of Drug Resistance and Prospective Therapeutic Targets

Malignant melanoma represents the most fatal skin cancer due to its aggressive behavior and high metastatic potential. The introduction of BRAF/MEK inhibitors and immune-checkpoint inhibitors (ICIs) in the clinic has dramatically improved patient survival over the last decade. However, many patients either display primary (i.e., innate) or develop secondary (i.e., acquired) resistance to systemic treatments. Therapeutic resistance relies on the rewiring of multiple processes, including cancer metabolism, epigenetics, gene expression, and interactions with the tumor microenvironment that are only partially understood. Therefore, reliable biomarkers of resistance or response, capable of facilitating the choice of the best treatment option for each patient, are currently missing. Recently, activation of nicotinamide adenine dinucleotide (NAD) metabolism and, in particular, of its rate-limiting enzyme nicotinamide phosphoribosyltransferase (NAMPT) have been identified as key drivers of targeted therapy resistance and melanoma progression. Another major player in this context is the mammalian target of rapamycin (mTOR) pathway, which plays key roles in the regulation of melanoma cell anabolic functions and energy metabolism at the switch between sensitivity and resistance to targeted therapy. In this review, we summarize known resistance mechanisms to ICIs and targeted therapy, focusing on metabolic adaptation as one main mechanism of drug resistance. In particular, we highlight the roles of NAD/NAMPT and mTOR signaling axes in this context and overview data in support of their inhibition as a promising strategy to overcome treatment resistance.

Transcriptome and metabolome analyses of the immune response to light stress in the hybrid grouper (Epinephelus lanceolatus ♂ × Epinephelus fuscoguttatus ♀)

Light intensity is an important environmental factor that affects fish growth and health through multiple physiological activities and metabolism and eventually impacts aquaculture harvest. There is a need to evaluate the fish stress response to light intensities, which will benefit aquaculture. Here, hybrid grouper (Epinephelus lanceolatus ♂ × Epinephelus fuscoguttatus ♀) was treated with three light intensities for evaluation of the light stress response, including high light intensity (1 250 lx), low light intensity (10 lx) and moderate light intensity (250 lx). Transcriptome analysis showed that a total of 71 318 unigene sequences were obtained with an N50 of 2 589 bp. Compared to the control group (250 lx), 1 697 differentially expressed genes (DEGs), a considerable quantity, were detected in the 1 250 lx group. Among those genes, 548 were upregulated, and the remaining 149 genes showed decreased expression. Comparatively small numbers of DEGs were detected in the 10 lx group; 54 out of 103 genes exhibited upregulated expression, and 49 genes showed downregulation. For further KEGG analysis, 82 DEGs were enriched in nine common signalling pathways in immunity, of which 73 DEGs were significantly inhibited in the 1 250 lx group. In contrast, only 11 DEGs were enriched in three immunity pathways, with nine DEGs showing a significant increase in the 10 lx group. The metabolome analysis revealed 59 and 44 differential metabolites (DMs) from the 1 250 lx and 10 lx groups, respectively. Of note, those DMs from the 1 250 lx-treated group were tendentiously involved in amino acid metabolism and lipid metabolism pathways, while the purine metabolism, amino acid metabolism and lipid metabolism pathways were mostly found in the 10 lx treatment group. In summary, our data indicated that high light intensity significantly inhibited the immune response in hybrid grouper, while low light intensity presented low stimulation of immune activity. In addition, both high and low light intensity could inhibit protein synthesis and amino acid metabolism. Taken together, hybrid grouper exhibited a much milder stress response to low light intensity than to high light intensity.

What Happens to the Immune Microenvironment After PD-1 Inhibitor Therapy?

The fruitful results of tumor immunotherapy establish its indispensable status in the regulation of the tumorous immune context. It seems that the treatment of programmed cell death receptor 1 (PD-1) blockade is one of the most promising approaches for cancer control. The significant efficacy of PD-1 inhibitor therapy has been made in several cancer types, such as breast cancer, lung cancer, and multiple myeloma. Even so, the mechanisms of how anti-PD-1 therapy takes effect by impacting the immune microenvironment and how partial patients acquire the resistance to PD-1 blockade have yet to be studied. In this review, we discuss the cross talk between immune cells and how they promote PD-1 blockade efficacy. In addition, we also depict factors that may underlie tumor resistance to PD-1 blockade and feasible solutions in combination with it.

Comparison of expression profiles between undifferentiated and differentiated porcine IPEC-J2 cells

BACKGROUND

The intestinal porcine enterocyte cell line (IPEC-J2) is a well-established model to study porcine intestinal physiology. IPEC-J2 cells undergo spontaneous differentiation during culture while changes in expression patterns of differentiated IPEC-J2 remain unclear. Therefore, this study was aimed to investigate the expression profiles of IPEC-J2 cells at the transcriptional level. Differentially expressed genes (DEGs), enriched pathways and potential key genes were identified. Alkaline phosphatase (AKP) and percentages of apoptotic cells were also measured.

RESULTS

Overall, a total of 988 DEGs were identified, including 704 up-regulated and 284 down-regulated genes. GO analysis revealed that epithelial cell differentiation, apoptotic signaling pathway, regulation of cytokine production and immune system process, regulation of cell death and proliferation, cell junction complexes, and kinase binding were enriched significantly. Consistently, KEGG, REACTOME, and CORUM analysis indicated that cytokine responses modulation may be involved in IPEC-J2 differentiation. Moreover, AKP activity, a recognized marker of enterocyte differentiation, was significantly increased in IPEC-J2 after 14 days of culture. Meanwhile, annexin V-FITC/PI assay demonstrated a remarkable increase in apoptotic cells after 14 days of culture. Additionally, 10 hub genes were extracted, and STAT1, AKT3, and VEGFA were speculated to play roles in IPEC-J2 differentiation.

CONCLUSIONS

These findings may contribute to the molecular characterization of IPEC-J2, and may progress the understanding of cellular differentiation of swine intestinal epithelium.

Igniting Hope for Tumor Immunotherapy: Promoting the “Hot and Cold” Tumor Transition

The discovery of immune checkpoint inhibitors (ICIs) has ushered a new era for immunotherapy against malignant tumors through the killing effects of cytotoxic T lymphocytes in the tumor microenvironment (TME), resulting in long-lasting tumor suppression and regression. Nevertheless, given that ICIs are highly dependent on T cells in the TME and that most tumors lack T-cell infiltration, promoting the conversion of such immunosuppressive “cold” tumors to “hot” tumors is currently a key challenge in tumor immunotherapy. Herein, we systematically outlined the mechanisms underlying the formation of the immunosuppressive TME in cold tumors, including the role of immunosuppressive cells, impaired antigen presentation, transforming growth factor-β, STAT3 signaling, adenosine, and interferon-γ signaling. Moreover, therapeutic strategies for promoting cold tumors to hot tumors with adequate T-cell infiltration were also discussed. Finally, the prospects of therapeutic tools such as oncolytic viruses, nanoparticles, and photothermal therapy in restoring immune activity in cold tumors were thoroughly reviewed.

Determinants of Ligand Specificity and Functional Plasticity in Type I Interferon Signaling

The Type I Interferon family of cytokines all act through the same cell surface receptor and induce phosphorylation of the same subset of response regulators of the STAT family. Despite their shared receptor, different Type I Interferons have different functions during immune response to infection. In particular, they differ in the potency of their induced anti-viral and anti-proliferative responses in target cells. It remains not fully understood how these functional differences can arise in a ligand-specific manner both at the level of STAT phosphorylation and the downstream function. We use a minimal computational model of Type I Interferon signaling, focusing on Interferon-α and Interferon-β. We validate the model with quantitative experimental data to identify the key determinants of specificity and functional plasticity in Type I Interferon signaling. We investigate different mechanisms of signal discrimination, and how multiple system components such as binding affinity, receptor expression levels and their variability, receptor internalization, short-term negative feedback by SOCS1 protein, and differential receptor expression play together to ensure ligand specificity on the level of STAT phosphorylation. Based on these results, we propose phenomenological functional mappings from STAT activation to downstream anti-viral and anti-proliferative activity to investigate differential signal processing steps downstream of STAT phosphorylation. We find that the negative feedback by the protein USP18, which enhances differences in signaling between Interferons via ligand-dependent refractoriness, can give rise to functional plasticity in Interferon-α and Interferon-β signaling, and explore other factors that control functional plasticity. Beyond Type I Interferon signaling, our results have a broad applicability to questions of signaling specificity and functional plasticity in signaling systems with multiple ligands acting through a bottleneck of a small number of shared receptors.

Intratumor heterogeneity: the hidden barrier to immunotherapy against MSI tumors from the perspective of IFN-γ signaling and tumor-infiltrating lymphocytes

In this era of precision medicine, with the help of biomarkers, immunotherapy has significantly improved prognosis of many patients with malignant tumor. Deficient mismatch repair (dMMR)/microsatellite instability (MSI) status is used as a biomarker in clinical practice to predict favorable response to immunotherapy and prognosis. MSI is an important characteristic which facilitates mutation and improves the likelihood of a favorable response to immunotherapy. However, many patients with dMMR/MSI still respond poorly to immunotherapies, which partly results from intratumor heterogeneity propelled by dMMR/MSI. In this review, we discuss how dMMR/MSI facilitates mutations in tumor cells and generates intratumor heterogeneity, especially through type II interferon (IFN-γ) signaling and tumor-infiltrating lymphocytes (TILs). We discuss the mechanism of immunotherapy from the perspective of dMMR/MSI, molecular pathways and TILs, and we discuss how intratumor heterogeneity hinders the therapeutic effect of immunotherapy. Finally, we summarize present techniques and strategies to look at the tumor as a whole to design personalized regimes and achieve favorable prognosis.

L-Leucine Promotes STAT1 and ISGs Expression in TGEV-Infected IPEC-J2 Cells via mTOR Activation

L-leucine (Leu), as one of the effective amino acids to activate the mTOR signaling pathway, can alleviate transmissible gastroenteritis virus (TGEV) infection. However, the underlying mechanism by which Leu alleviates the virus infection has not been fully characterized. In particular, how Leu impacts TGEV replication through mTOR signaling has yet to be elucidated. In the present study, we found that TGEV proliferated efficiently in intestinal porcine epithelial cells (IPEC-J2 cells) as evidenced by the increase in viral contents by flow cytometry, the inhibition of cell proliferation by CCK-8 assay as well as the reduction of PCNA level by western blot. Besides, western blot analysis showed that STAT1 expression was markedly reduced in TGEV-infected cells. The results of ELISA revealed the inhibition of ISGs (ISG56, MxA, and PKR) expressions by TGEV infection. TGEV-induced mTOR and its downstream p70 S6K and 4E-BP1, STAT1 and ISGs downregulation were blocked by an mTOR activator-MHY1485 but not by an mTOR inhibitor-RAPA. Concurrently, mTOR activation by MHY1485 reduced the contents of TGEV and vice versa. Furthermore, Leu reversed the inhibition of STAT1 and ISGs by activating mTOR and its downstream p70 S6K and 4E-BP1 in TEGV-infected cells. Our findings demonstrated that Leu promoted the expressions of STAT1 and ISGs via activating mTOR signaling in IPEC-J2 cells, aiming to prevent TGEV infection.

Analysis of lncRNA, miRNA, and mRNA Expression Profiling in Type I IFN and Type II IFN Overexpressed in Porcine Alveolar Macrophages

Current data is scarce regarding the function of noncoding RNAs (ncRNAs) such as microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) in the interferon- (IFN-) mediated immune response. This is a comprehensive study that analyzes the lncRNA and miRNA expression profiles of the type I IFN and type II IFN in porcine alveolar macrophages using RNA sequencing. There was a total of 152 overexpressed differentially expressed (DE) lncRNAs and 21 DE miRNAs across type I IFN and type II IFN in porcine alveolar macrophages. Subsequent lncRNA-miRNA-mRNA network construction revealed the involvement of 36 DE lncRNAs and 12 DE miRNAs. LncRNAs such as the XLOC_211306, XLOC_100516, XLOC_00695, XLOC_149196, and XLOC_014459 were expressed at a higher degree in the type I IFN group, while XLOC_222640, XLOC_047290, XLOC_147777, XLOC_162298, XLOC_220210, and XLOC_165237 were expressed at a higher degree in the type II IFN group. These lncRNAs were found to act as "sponges" for miRNAs such as miR-34a, miR-328, miR-885-3p, miR-149, miR-30c-3p, miR-30b-5p, miR-708-5p, miR-193a-5p, miR-365-5p, and miR-7. Their target genes FADS2, RPS6KA1, PIM1, and NOD1 were found to be associated with several immune-related signaling pathways including the NOD-like receptor, Jak-STAT, mTOR, and PPAR signaling pathways. These experiments provide a comprehensive profile of overexpressed noncoding RNAs in porcine alveolar macrophages, providing new insights regarding the IFN-mediated immune response.

Potential role of IFN-α in COVID-19 patients and its underlying treatment options

The coronavirus disease (COVID-19) caused by a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread rapidly worldwide. Given that this contagious viral outbreak is still unfolding, it is urgent to understand the pathogenesis of SARS-CoV-2 infection and explore effective treatments to protect patients from developing a severe illness related to COVID-19. Recently, IFN-α has been considered a potential therapeutic strategy to treat COVID-19 disease, mainly because the innate immune system rapidly produces IFN-α as the first line of defense to combat viral infections. However, IFN-α can also play a role in immunoregulatory effects, causing pathogenic damage and uncontrolled inflammatory responses. There are 13 human IFN-α subtypes that bind to the same receptor and induce different interferon-stimulated gene (ISG) expression, regulating various antiviral and immunoregulatory effects. The varying degrees of inflammatory regulations may raise concerns about the possible side effects to enlarge the inflammatory responses, exacerbating the severity of infection. Thus, the analysis of various IFN-α subtype induction during SARS-CoV-2 infection is necessary in exploring the mechanism of COVID-19 pathogenesis. This review summarizes the current understanding of IFN-α in the pathogenesis of respiratory virus diseases and IFN-α based clinical intervention used in SARS-CoV-2 infection and other respiratory virus diseases. Besides, new ideas in selecting suitable IFN-α subtypes or combinations as drug candidates for viral infection treatment will also be discussed.Key Points• IFN-α plays an important role in anti-viral and immunoregulatory effects in COVID-19 patients caused by SARS-CoV-2.• The uncontrolled inflammation and disease severity correlated to the diversity of IFN-α subtype induction.• Selecting suitable IFN-α subtypes or combinations as drug candidates will be beneficial for the treatment of patients with COVID-19.

Type I and II Interferons in the Anti-Tumor Immune Response

The interferons (IFNs) are essential components of the immune response against infections and malignancies. IFNs are potent promoters of the anti-tumor response, but there is also evidence that feedback mechanisms regulated by IFNs negatively control immune responses to avoid hyper-activation and limit inflammation. This balance of responses plays an important role in cancer surveillance, immunoediting and response to anticancer therapeutic approaches. Here we review the roles of both type I and type II IFNs on the control of the immune response against malignancies in the context of effects on both malignant cells and cells of the immune system in the tumor microenvironment.

Interferon Receptor Trafficking and Signaling: Journey to the Cross Roads

Like most plasma membrane proteins, type I interferon (IFN) receptor (IFNAR) traffics from the outer surface to the inner compartments of the cell. Long considered as a passive means to simply control subunits availability at the plasma membrane, an array of new evidence establishes IFNAR endocytosis as an active contributor to the regulation of signal transduction triggered by IFN binding to IFNAR. During its complex journey initiated at the plasma membrane, the internalized IFNAR complex, i.e. IFNAR1 and IFNAR2 subunits, will experience post-translational modifications and recruit specific effectors. These finely tuned interactions will determine not only IFNAR subunits destiny (lysosomal degradation vs. plasma membrane recycling) but also the control of IFN-induced signal transduction. Finally, the IFNAR system perfectly illustrates the paradigm of the crosstalk between membrane trafficking and intracellular signaling. Investigating the complexity of IFN receptor intracellular routes is therefore necessary to reveal new insight into the role of IFNAR membrane dynamics in type I IFNs signaling selectivity and biological activity.

Cancer-associated fibroblasts downregulate type I interferon receptor to stimulate intratumoral stromagenesis

Activation of cancer-associated fibroblasts (CAFs) and ensuing desmoplasia play an important role in the growth and progression of solid tumors. Here we demonstrate that, within colon and pancreatic ductal adenocarcinoma tumors, efficient stromagenesis relies on downregulation of the IFNAR1 chain of the type I interferon (IFN1) receptor. Expression of the fibroblast activation protein (FAP) and accumulation of the extracellular matrix (ECM) was notably impaired in tumors grown in the Ifnar1S526A (SA) knock-in mice, which are deficient in IFNAR1 downregulation. Primary fibroblasts from these mice exhibited elevated levels of Smad7, a negative regulator of the transforming growth factor-β (TGFβ) pathway. Knockdown of Smad7 alleviated deficient ECM production in SA fibroblasts in response to TGFβ. Analysis of human colorectal cancers revealed an inverse correlation between IFNAR1 and FAP levels. Whereas growth of tumors in SA mice was stimulated by co-injection of wild type but not SA fibroblasts, genetic ablation of IFNAR1 in fibroblasts also accelerated tumor growth. We discuss how inactivation of IFNAR1 in CAFs acts to stimulate stromagenesis and tumor growth.

Overcoming Genetically Based Resistance Mechanisms to PD-1 Blockade

Mechanism-based strategies to overcome resistance to PD-1 blockade therapy are urgently needed. We developed genetic acquired resistant models of JAK1, JAK2, and B2M loss-of-function mutations by gene knockout in human and murine cell lines. Human melanoma cell lines with JAK1/2 knockout became insensitive to IFN-induced antitumor effects, while B2M knockout was no longer recognized by antigen-specific T cells and hence was resistant to cytotoxicity. All of these mutations led to resistance to anti-PD-1 therapy in vivo. JAK1/2-knockout resistance could be overcome with the activation of innate and adaptive immunity by intratumoral Toll-like receptor 9 agonist administration together with anti-PD-1, mediated by natural killer (NK) and CD8 T cells. B2M-knockout resistance could be overcome by NK-cell and CD4 T-cell activation using the CD122 preferential IL2 agonist bempegaldesleukin. Therefore, mechanistically designed combination therapies can overcome genetic resistance to PD-1 blockade therapy. SIGNIFICANCE: The activation of IFN signaling through pattern recognition receptors and the stimulation of NK cells overcome genetic mechanisms of resistance to PD-1 blockade therapy mediated through deficient IFN receptor and antigen presentation pathways. These approaches are being tested in the clinic to improve the antitumor activity of PD-1 blockade therapy.This article is highlighted in the In This Issue feature, p. 1079.

Interferon signaling in cancer. Non-canonical pathways and control of intracellular immune checkpoints

The interferons (IFNs) are cytokines with important antineoplastic and immune modulatory effects. These cytokines have been conserved through evolution as important elements of the immune surveillance against cancer. Despite this, defining their precise and specific roles in the generation of antitumor responses remains challenging. Emerging evidence suggests the existence of previously unknown roles for IFNs in the control of the immune response against cancer that may redefine our understanding on how these cytokines function. Beyond the engagement of classical JAK-STAT signaling pathways that promote transcription and expression of gene products, the IFNs engage multiple other signaling cascades to generate products that mediate biological responses and outcomes. There is recent emerging evidence indicating that IFNs control the expression of both traditional immune checkpoints like the PD-L1/PD1 axis, but also less well understood "intracellular" immune checkpoints whose targeting may define new approaches for the treatment of malignancies.

Resistance to Checkpoint Inhibition in Cancer Immunotherapy

The interaction of the host immune system with tumor cells in the tissue microenvironment is essential in understanding tumor immunity and development of successful cancer immunotherapy. The presence of lymphocytes in tumors is highly correlated with an improved outcome. T cells have a set of cell surface receptors termed immune checkpoints that when activated suppress T cell function. Upregulation of immune checkpoint receptors such as programmed cell death 1 (PD-1) and cytotoxic T lymphocyte associated protein 4 (CTLA-4) occurs during T cell activation in an effort to prevent damage from an excessive immune response. Immune checkpoint inhibitors allow the adaptive immune system to respond to tumors more effectively. There has been clinical success in different types of cancer blocking immune checkpoint receptors such as PD-1 and CTLA. However, relapse has occurred. The innate and acquired/therapy induced resistance to treatment has been encountered. Aberrant cellular signal transduction is a major contributing factor to resistance to immunotherapy. Combination therapies with other co-inhibitory immune checkpoints such as TIM-3, LAG3 and VISTA are currently being tested to overcome resistance to cancer immunotherapy. Expression of TIM-3 has been associated with resistance to PD-1 blockade and combined blockade of TIM-3 and PD-1 has demonstrated improved responses in preclinical models. LAG3 blockade has the potential to increase the responsiveness of cytotoxic T-cells to tumors. Furthermore, tumors that were found to express VISTA had an increased rate of growth due to the T cell suppression. The growing understanding of the inhibitory immune checkpoints’ ligand biology, signaling mechanisms, and T-cell suppression in the tumor microenvironment continues to fuel preclinical and clinical advancements in design, testing, and approval of agents that block checkpoint molecules. Our review seeks to bridge fundamental regulatory mechanisms across inhibitory immune checkpoint receptors that are of great importance in resistance to cancer immunotherapy. We will summarize the biology of different checkpoint molecules, highlight the effect of individual checkpoint inhibition as anti-tumor therapies, and outline the literatures that explore mechanisms of resistance to individual checkpoint inhibition pathways.

COPZ1 depletion in thyroid tumor cells triggers type I IFN response and immunogenic cell death

The coatomer protein complex zeta 1 (COPZ1) represents a non-oncogene addiction for thyroid cancer (TC); its depletion impairs the viability of thyroid tumor cells, leads to abortive autophagy, ER stress, UPR and apoptosis, and reduces tumor growth of TC xenograft models. In this study we investigated the molecular pathways activated by COPZ1 depletion and the paracrine effects on cellular microenvironment and immune response. By comprehensive and target approaches we demonstrated that COPZ1 depletion in TPC-1 and 8505C thyroid tumor cell lines activates type I IFN pathway and viral mimicry responses. The secretome from COPZ1-depleted cells was enriched for several inflammatory molecules and damage-associated molecular patterns (DAMPs). Moreover, we found that dendritic cells, exposed to these secretomes, expressed high levels of differentiation and maturation markers, and stimulated the proliferation of naïve T cells. Interestingly, T cells stimulated with COPZ1-depleted cells showed increased cytotoxic activity against parental tumor cells. Collectively, our findings support the notion that targeting COPZ1 may represent a promising therapeutic approach for TC, considering its specificity for cancer cells, the lack of effect on normal cells, and the capacity to prompt an anti-tumor immune response.

Predictive biomarkers and mechanisms underlying resistance to PD1/PD-L1 blockade cancer immunotherapy

Immune checkpoint blockade targeting PD-1/PD-L1 has promising therapeutic efficacy in a variety of tumors, but resistance during treatment is a major issue. In this review, we describe the utility of PD-L1 expression levels, mutation burden, immune cell infiltration, and immune cell function for predicting the efficacy of PD-1/PD-L1 blockade therapy. Furthermore, we explore the mechanisms underlying immunotherapy resistance caused by PD-L1 expression on tumor cells, T cell dysfunction, and T cell exhaustion. Based on these mechanisms, we propose combination therapeutic strategies. We emphasize the importance of patient-specific treatment plans to reduce the economic burden and prolong the life of patients. The predictive indicators, resistance mechanisms, and combination therapies described in this review provide a basis for improved precision medicine.

Interferons α and β in cancer: therapeutic opportunities from new insights

Over the past decade, preclinical and clinical research have confirmed the essential role of interferons for effective host immunological responses to malignant cells. Type I interferons (IFNα and IFNβ) directly regulate transcription of >100 downstream genes, which results in a myriad of direct (on cancer cells) and indirect (through immune effector cells and vasculature) effects on the tumour. New insights into endogenous and exogenous activation of type I interferons in the tumour and its microenvironment have given impetus to drug discovery and patient evaluation of interferon-directed strategies. When combined with prior observations or with other effective modalities for cancer treatment, modulation of the interferon system could contribute to further reductions in cancer morbidity and mortality. This Review discusses new interferon-directed therapeutic opportunities, ranging from cyclic dinucleotides to genome methylation inhibitors, angiogenesis inhibitors, chemoradiation, complexes with neoantigen-targeted monoclonal antibodies, combinations with other emerging therapeutic interventions and associations of interferon-stimulated gene expression with patient prognosis - all of which are strategies that have or will soon enter translational clinical evaluation.

Manipulation of Intestinal Antiviral Innate Immunity and Immune Evasion Strategies of Porcine Epidemic Diarrhea Virus

Porcine epidemic diarrhea virus (PEDV) infection causes watery diarrhea, dehydration, and high mortality in neonatal pigs, due to its clinical pathogenesis of the intestinal mucosal barrier dysfunction. The host's innate immune system is the first line of defence upon virus invasion of the small intestinal epithelial cells. In turn, the virus has evolved to modulate the host's innate immunity during infection, resulting in pathogen virulence, survival, and the establishment of successful infection. In this review, we gather current knowledge concerning the interplay between PEDV and components of host innate immunity, focusing on the role of cytokines and interferons in intestinal antiviral innate immunity, and the mechanisms underlying the immune evasion strategies of PEDV invasion. Finally, we provide some perspectives on the potential prevention and treatment for PEDV infection.

Global virus outbreaks: Interferons as 1st responders

Outbreaks of severe virus infections with the potential to cause global pandemics are increasing. In many instances these outbreaks have been newly emerging (SARS coronavirus), re-emerging (Ebola virus, Zika virus) or zoonotic (avian influenza H5N1) virus infections. In the absence of a targeted vaccine or a pathogen-specific antiviral, broad-spectrum antivirals would function to limit virus spread. Given the direct antiviral effects of type I interferons (IFNs) in inhibiting the replication of both DNA and RNA viruses at different stages of their replicative cycles, and the effects of type I IFNs on activating immune cell populations to clear virus infections, IFNs-α/β present as ideal candidate broad-spectrum antivirals.

Functional analysis and clinical significance of sodium iodide symporter expression in gastric cancer

BACKGROUND

Recent studies have described important roles for the sodium iodide symporter (NIS) in tumor behavior. The objectives of the present study were to investigate the role of NIS in the regulation of genes involved in tumor progression and the clinicopathological significance of its expression in gastric cancer (GC).

METHODS

In human GC cell lines, knockdown experiments were conducted using NIS siRNA, and the effects on proliferation, survival, and cellular movement were analyzed. The gene expression profiles of cells were examined using a microarray analysis. An immunohistochemical analysis was performed on 145 primary tumor samples obtained from GC patients.

RESULTS

NIS was strongly expressed in MKN45 and MKN74 cells. The depletion of NIS inhibited cell proliferation, migration, and invasion and induced apoptosis. The results of the microarray analysis revealed that various interferon (IFN) signaling-related genes, such as STAT1, STAT2, IRF1, and IFIT1, were up-regulated in NIS-depleted MKN45 cells. Furthermore, the down-regulation of NIS affected the phosphorylation of MAPKs and NF-kB. Immunohistochemical staining showed that NIS was primarily located in the cytoplasm or cell membranes of carcinoma cells, and its expression was related to the histological type or venous invasion. Prognostic analyses revealed that the strong expression of NIS was associated with shorter postoperative survival.

CONCLUSIONS

These results suggest that NIS regulates tumor progression by affecting IFN signaling, and that its strong expression is related to a worse prognosis in patients with GC. These results provide an insight into the role of NIS as a mediator and/or a biomarker for GC.

Innate immunity and interferons in the pathogenesis of Sjögren's syndrome

Primary SS (pSS) is a rheumatic disease characterized by an immune-mediated exocrinopathy, resulting in severe dryness of eyes and mouth. Systemic symptoms include fatigue and joint pain and a subset of patients develop more severe disease with multi-organ involvement. Accumulating evidence points to involvement of innate immunity and aberrant activity of the type I IFN system in both the initiation and propagation of this disease. Analysis of the activity of IFN-inducible genes has evidenced that more than half of pSS patients present with a so-called 'type I IFN signature'. In this review, we examine activation of the IFN system in pSS patients and how this may drive autoimmunity through various immune cells. We further discuss the clinical value of assessing IFN activity as a biomarker in pSS patients and review novel therapies targeting IFN signalling and their potential use in pSS.

Sirtuin 2-mediated deacetylation of cyclin-dependent kinase 9 promotes STAT1 signaling in type I interferon responses

Type I interferons (IFNs) induce expression of multiple genes that control innate immune responses to invoke both antiviral and antineoplastic activities. Transcription of these interferon-stimulated genes (ISGs) occurs upon activation of the canonical Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling pathways. Phosphorylation and acetylation are both events crucial to tightly regulate expression of ISGs. Here, using mouse embryonic fibroblasts and an array of biochemical methods including immunoblotting and kinase assays, we show that sirtuin 2 (SIRT2), a member of the NAD-dependent protein deacetylase family, is involved in type I IFN signaling. We found that SIRT2 deacetylates cyclin-dependent kinase 9 (CDK9) in a type I IFN-dependent manner and that the CDK9 deacetylation is essential for STAT1 phosphorylation at Ser-727. We also found that SIRT2 is subsequently required for the transcription of ISGs and for IFN-driven antiproliferative responses in both normal and malignant cells. These findings establish the existence of a previously unreported signaling pathway whose function is essential for the control of JAK-STAT signaling and the regulation of IFN responses. Our findings suggest that targeting sirtuin activities may offer an avenue in the development of therapies for managing immune-related diseases and cancer.

IFN-γ-inducible antiviral responses require ULK1-mediated activation of MLK3 and ERK5

It is well established that activation of the transcription factor signal transducer and activator of transcription 1 (STAT1) is required for the interferon-γ (IFN-γ)-mediated antiviral response. Here, we found that IFN-γ receptor stimulation also activated Unc-51-like kinase 1 (ULK1), an initiator of Beclin-1-mediated autophagy. Furthermore, the interaction between ULK1 and the mitogen-activated protein kinase kinase kinase MLK3 (mixed lineage kinase 3) was necessary for MLK3 phosphorylation and downstream activation of the kinase ERK5. This autophagy-independent activity of ULK1 promoted the transcription of key antiviral IFN-stimulated genes (ISGs) and was essential for IFN-γ-dependent antiviral effects. These findings define a previously unknown IFN-γ pathway that appears to be a key element of the antiviral response.

Plant-Derived Products for Treatment of Vascular Intima Hyperplasia Selectively Inhibit Vascular Smooth Muscle Cell Functions

Natural products are used widely for preventing intimal hyperplasia (IH), a common cardiovascular disease. Four different cells initiate and progress IH, namely, vascular smooth muscle, adventitial and endothelial cells, and circulation or bone marrow-derived cells. Vascular smooth muscle cells (VSMCs) play a critical role in initiation and development of intimal thickening and formation of neointimal hyperplasia. In this review, we describe the different originating cells involved in vascular IH and emphasize the effect of different natural products on inhibiting abnormal cellular functions, such as VSMC proliferation and migration. We further present a classification for the different natural products like phenols, flavonoids, terpenes, and alkaloids that suppress VSMC growth. Abnormal VSMC physiology involves disturbance in MAPKs, PI3K/AKT, JAK-STAT, FAK, and NF-κB signal pathways. Most of the natural isolate studies have revealed G1/S phase of cell cycle arrest, decreased ROS production, induced cell apoptosis, restrained migration, and downregulated collagen deposition. It is necessary to screen optimal drugs from natural sources that preferentially inhibit VSMC rather than vascular endothelial cell growth to prevent early IH, restenosis following graft implantation, and atherosclerotic diseases.

Strategies for Predicting Response to Checkpoint Inhibitors

PURPOSE OF REVIEW

Despite the clinical successes of immune checkpoint blockade across multiple tumor types, many patients do not respond to these therapies or become resistant after an initial response. This underscores the need to improve our understanding of the molecular determinants of response to guide more personalized and rational utilization of these therapies. Here, we describe available biomarkers of checkpoint blockade activity by classifying them into four major categories: tumor-intrinsic, immune microenvironmental, host-related, and dynamic factors.

RECENT FINDINGS

The clinical experience accumulated thus far with checkpoint blockade now offers the opportunity to comprehensively study the molecular and immune features associated with response. This is yielding a growing set of biomarkers whose integration will be key to more accurately predict clinical outcome. We propose a model for systematic assessment of available baseline and dynamic biomarkers in relationship with patients' outcomes. This will improve our understanding of the tumor-immune interactions and dynamics that predict a clinical response and will provide key information to develop more personalized and effective treatment strategies.

Slfn2 Regulates Type I Interferon Responses by Modulating the NF-κB Pathway

Although members of the Slfn family have been implicated in the regulation of type I interferon (IFN) responses, the mechanisms by which they mediate their effects remain unknown. In the present study, we provide evidence that targeted disruption of the Slfn2 gene leads to increased transcription of IFN-stimulated genes (ISGs) and enhanced type I IFN-mediated antiviral responses. We demonstrate that Slfn2 interacts with protein phosphatase 6 regulatory subunit 1 (PPP6R1), leading to reduced type I IFN-induced activation of nuclear factor kappa B (NF-κB) signaling, resulting in reduced expression of ISGs. Altogether, these data suggest a novel mechanism by which Slfn2 controls ISG expression and provide evidence for a critical role for Slfn2 in the regulation of IFN-mediated biological responses.

Acquired resistance to cancer immunotherapy

In recent times, advances in cancer immunotherapy have yielded impressive, durable clinical responses in patients with varied subtypes of cancer. However, a significant proportion of patients who initially demonstrate encouraging tumor regression develop resistance and progress over time. The identification of novel therapeutic approaches to overcome resistance may result in significantly improved clinical outcomes and remains an area of high scientific priority. This review aims to summarize the current knowledge regarding the role of both tumor-intrinsic and tumor-extrinsic factors in the development of resistance to cancer immunotherapy and to discuss current and possible future therapeutic strategies targeting these mechanisms.

HeberFERON, a new formulation of IFNs with improved pharmacodynamics: Perspective for cancer treatment

The rational combination of recombinant IFN-α2b and IFN-γ resulted in a new formulation of interferons (HeberFERON) with improved pharmacodynamics. In basal cell carcinomas HeberFERON produces a more rapid antitumor effect and results in a larger number of complete responses. In patients with glioblastoma multiforme, the administration of HeberFERON after surgery and radiotherapy results in an estimated overall survival of 19 months. Patients with stage III or IV renal cell carcinoma also appear to benefit from the intravenous administration of HeberFERON, with prolongation of survival and good quality of live. HeberFERON offers a promising alternative formulation of interferons for the treatment of cancer with a very favorable safety profile.

Endothelial cell functions impaired by interferon in vitro: Insights into the molecular mechanism of thrombotic microangiopathy associated with interferon therapy

INTRODUCTION

Interferon (IFN)-α and IFN-β approved for treatment of chronic hepatitis C viral infection and multiple sclerosis respectively have been linked to thrombotic microangiopathy (TMA) affecting renal function. Since the molecular mechanisms underlying this severe complication remain largely unclear, we aimed to investigate whether IFN affects directly in vitro endothelial cell functions associated with angiogenesis and blood haemostasis, as well as endothelial cell-derived vasodilators of nitric oxide (NO) and prostacyclin.

METHODS

Proliferation and survival of human umbilical vein endothelial cells (HUVECs) were measured by BrdU incorporation and alamarBlue assays. Angiogenesis was evaluated in co-cultures of HUVECs and human dermal fibroblasts. Fibrinolysis molecules were measured with ELISA. NO and prostacyclin were measured using a fluorescent NO-specific probe and a competitive enzyme immunoassay, respectively.

RESULTS

HUVEC proliferation was dose-dependently inhibited by IFN-β1a and IFN-β1b, but not by IFN-α2a and IFN-α2b. Consistently, IFN-β1a and IFN-β1b also reduced survival of HUVECs, but this again was not observed with IFN-α. However, both IFN subtypes inhibited VEGF-induced development of capillary-like structures, but the effect of IFN-α was less potent than IFN-β. In addition, both IFN subtypes upregulated interferon inducible protein 10 production from treated co-cultures while suppressing angiogenesis. Furthermore, intracellular NO generation was reduced by IFN-α2a and IFN-β1a, whereas prostacyclin release from HUVECs was not affected by IFN. Importantly, both IFN-β1a- and IFN-β1b-treated HUVECs showed a marked reduction in urokinase-type plasminogen activator release and a much greater secretion of plasminogen activator inhibitor-1 than tissue-type plasminogen activator compared with untreated cells, suggesting decreased fibrinolytic activity. IFN-α, however was less effective in modulating the fibrinolysis system.

CONCLUSIONS

We demonstrate the detrimental effects of IFN on endothelial cell functions mediated with angiogenesis and fibrinolysis, which could potentially cause the loss of physiological endothelium thromboresistance and facilitate the development of vascular complications in a clinical setting. Mechanistically, our findings have implications for understanding how IFN therapy can foster the development of TMA.

PLZF inhibits proliferation and metastasis of gallbladder cancer by regulating IFIT2

Gallbladder cancer (GBC) is a malignant cancer with very poor prognosis. Although promyelocytic leukemia zinc-finger protein (PLZF) was reported to be deregulated in numerous cancers and also relevant to clinical prognosis, its role in GBC progression has been little known. In this study, we found PLZF expression was decreased in GBC, correlating to advanced TNM stage, distant metastasis, and shorter overall survival. Moreover, ectopic PLZF expression in GBC cells (NOZ and GBC-SD) significantly reduced the cell proliferation, migration, and invasion. Consistently, overexpression of PLZF in xenograft mice model could suppress tumor growth and liver metastasis. Mechanical investigations verified PLZF could regulate the expression of cell cycle arrest-associated gene p21 and epithelial–mesenchymal transition (EMT)-related genes (E-cadherin and N-cadherin) in GBC cell lines. Importantly, PLZF remarkably increased the mRNA transcription of interferon-induced protein with tetratricopeptide repeat 2 (IFIT2) by increasing STAT1 protein level, a known factor involved in tumor progression. Furthermore, ablation of IFIT2 in PLZF overexpression cells abrogated the tumor-suppressive function of PLZF, at least partially, leading to impaired tumor growth and EMT program. These studies indicated PLZF inhibited the proliferation and metastasis via regulation of IFIT2. In conclusion, our study demonstrated PLZF could be a promising tumor biomarker for GBC, and also be a potential therapeutic target.

Human SLFN5 is a transcriptional co-repressor of STAT1-mediated interferon responses and promotes the malignant phenotype in glioblastoma

We provide evidence that the IFN-regulated member of the Schlafen (SLFN) family of proteins, SLFN5, promotes the malignant phenotype in glioblastoma multiforme (GBM). Our studies indicate that SLFN5 expression promotes motility and invasiveness of GBM cells, and that high levels of SLFN5 expression correlate with high grade gliomas and shorter overall survival in patients suffering from GBM. In efforts to uncover the mechanism by which SLFN5 promotes GBM tumorigenesis, we found that this protein is a transcriptional co-repressor of STAT1. Type-I IFN treatment triggers the interaction of STAT1 with SLFN5, and the resulting complex negatively controls STAT1-mediated gene transcription via interferon stimulated response elements (ISRE). Thus, SLFN5 is both an IFN-stimulated response gene and a repressor of IFN-gene transcription, suggesting the existence of a negative-feedback regulatory loop that may account for suppression of antitumor immune responses in glioblastoma.

Expression of the IFNAR1 chain of type 1 interferon receptor in benign cells protects against progression of acute leukemia

Type I interferons (IFN) were widely used for leukemia treatment. These cytokines act on cell surface receptor consisting of the IFNAR1/2 chains to induce anti-tumorigenic effects. Given that levels of IFNAR1 can be regulated by phosphorylation-driven ubiquitination and degradation that undermines IFN signaling and anti-tumorigenic effects, we sought to determine the importance of IFNAR1 downregulation in progression of acute leukemia. Using knock-in mice deficient in downregulation of IFNAR1, we uncovered that IFNAR1 expression in stromal benign cells functions to protect against progression of leukemia. We discuss putative mechanisms of this regulation and potential of therapeutic targeting of IFNAR1 downregulation to treat leukemia.

Primary Resistance to PD-1 Blockade Mediated by JAK1/2 Mutations

Loss-of-function mutations in JAK1/2 can lead to acquired resistance to anti-programmed death protein 1 (PD-1) therapy. We reasoned that they may also be involved in primary resistance to anti-PD-1 therapy. JAK1/2-inactivating mutations were noted in tumor biopsies of 1 of 23 patients with melanoma and in 1 of 16 patients with mismatch repair-deficient colon cancer treated with PD-1 blockade. Both cases had a high mutational load but did not respond to anti-PD-1 therapy. Two out of 48 human melanoma cell lines had JAK1/2 mutations, which led to a lack of PD-L1 expression upon interferon gamma exposure mediated by an inability to signal through the interferon gamma receptor pathway. JAK1/2 loss-of-function alterations in The Cancer Genome Atlas confer adverse outcomes in patients. We propose that JAK1/2 loss-of-function mutations are a genetic mechanism of lack of reactive PD-L1 expression and response to interferon gamma, leading to primary resistance to PD-1 blockade therapy.

SIGNIFICANCE

A key functional result from somatic JAK1/2 mutations in a cancer cell is the inability to respond to interferon gamma by expressing PD-L1 and many other interferon-stimulated genes. These mutations result in a genetic mechanism for the absence of reactive PD-L1 expression, and patients harboring such tumors would be unlikely to respond to PD-1 blockade therapy. Cancer Discov; 7(2); 188-201. ©2016 AACR.See related commentary by Marabelle et al., p. 128This article is highlighted in the In This Issue feature, p. 115.

Primary Resistance to PD-1 Blockade Mediated by JAK1/2 Mutations

Loss-of-function mutations in JAK1/2 can lead to acquired resistance to anti-programmed death protein 1 (PD-1) therapy. We reasoned that they may also be involved in primary resistance to anti-PD-1 therapy. JAK1/2-inactivating mutations were noted in tumor biopsies of 1 of 23 patients with melanoma and in 1 of 16 patients with mismatch repair-deficient colon cancer treated with PD-1 blockade. Both cases had a high mutational load but did not respond to anti-PD-1 therapy. Two out of 48 human melanoma cell lines had JAK1/2 mutations, which led to a lack of PD-L1 expression upon interferon gamma exposure mediated by an inability to signal through the interferon gamma receptor pathway. JAK1/2 loss-of-function alterations in The Cancer Genome Atlas confer adverse outcomes in patients. We propose that JAK1/2 loss-of-function mutations are a genetic mechanism of lack of reactive PD-L1 expression and response to interferon gamma, leading to primary resistance to PD-1 blockade therapy.

SIGNIFICANCE

A key functional result from somatic JAK1/2 mutations in a cancer cell is the inability to respond to interferon gamma by expressing PD-L1 and many other interferon-stimulated genes. These mutations result in a genetic mechanism for the absence of reactive PD-L1 expression, and patients harboring such tumors would be unlikely to respond to PD-1 blockade therapy. Cancer Discov; 7(2); 188-201. ©2016 AACR.See related commentary by Marabelle et al., p. 128This article is highlighted in the In This Issue feature, p. 115.