The IFN gamma receptor: a paradigm for cytokine receptor signaling

Genetic variants in the IFNGR2 locus associated with severe chronic Q fever

Q fever is a highly contagious zoonosis capable of causing large outbreaks of important health and economic consequences. Host genetic factors are believed to influence the development of severe chronic Q fever following the infection by the etiological agent, Coxiella burnetii. Targetted next generation sequencing (NGS) was performed in a case-control genetic association study on 53 confirmed Q fever cases, including 38 compatible with acute and 15 with chronic disease, and 29 samples from the general Portuguese population. Four SNPs in the IFNGR2 locus, rs78407108 G > A, rs17879956 C > T, rs7277167 C > T, and rs9974603 C > A, showed a statistically significant association to chronic Q fever, resisting the Bonferroni correction. These belonged to haplotypes significantly associated with chronic Q fever. The individual SNPs are referenced in the GTEx database as possible eQTLs. Given the direct bearing of IFNGR2 on IFN-γ signaling, the possible involvement of the associated variants with higher IFNGR2 expression could be in line with observations suggesting that IFN-γ production in chronic Q fever patients is significantly higher than in healthy controls. Further investigations are required to clarify the role of IFNGR2 signaling in association with chronic Q fever.

Identification of Dinaciclib and Ganetespib as anti-inflammatory drugs using a novel HTP screening assay that targets IFNγ-dependent PD-L1

Introduction

IFNγ plays both positive and negative roles in the regulation of innate and adaptive immune responses against tumors and virally infected tissues by upregulating CXCL10 and PD-L1 expression.

Methods

To identify novel pathways and drugs that regulate the IFNγ-dependent PD-L1, we expressed GFP under the control of mouse PD-L1 promoter in mouse cancer cells that up regulate PD-L1 and CXCL10 in response to IFNγ stimulation. Using these cells, we screened an FDA approved library of 1496 small molecules known for their ability to inhibit IFNγ-dependent increase in PD-L1.

Results

We identified 46 drugs that up regulated and 4 that down regulated IFNγ-dependent PD-L1 expression. We discovered that in addition to the known JAK inhibitors Ruxolitinib and Baricitinib, Dinaciclib, a CDK1/2/5/9 inhibitor, and Ganetespib, a Hsp90 inhibitor, significantly inhibit both PD-L1 and CXCL10 expression in the model cells. Furthermore, both drugs suppressed IFNγ-dependent CXCL10 and PD-L1 expression in-vitro in primary human lung cells and human cancer cells. These drugs also significantly inhibited delayed-type hypersensitivity (DTH) in-vivo in an inflammation mouse model.

Discussion

Our novel screening platform can therefore be used in the future to identify novel immunomodulators and pathways in cancer and inflammation, expanding therapeutic horizons.

A panel of six immune-related mRNAs as biomarkers for tuberculosis diagnosis

Objective

This study aims to screen common immunological markers of lung tissues and blood for diagnosis of tuberculosis (TB).

Methods

Differentially expressed miRNAs (DEmRs) and mRNAs (DEGs) were obtained by whole-transcriptome sequencing profiles on 18F-FDG PET/CT high and low metabolic active regions in lung tissues of nine TB patients. Common miRNAs were screened by intersecting with DEmRs, four miRNA GEO datasets, and their target mRNAs were predicted through the miRTarbase and Tarbase databases. Then these mRNAs were intersected with DEGs, mRNAs from blood samples and immune-related genes, to construct a miRNA-mRNA interaction network, and the hub genes were identified by Cytoscape. The relationship between immune infiltration and hub genes were evaluated using Cibersort. Finally, a diagnostic model based on Lasso regression analysis was established and validated by qRT-PCR.

Results

Five common miRNAs were obtained in both blood and tissues. Six immune-related mRNAs (NEDD4, PLTP, RNASEL, SEMA7A, TAPBP, and THBS1) were screened out. A diagnostic model was established and validated in the blood samples of 30 pairs (TB/health volunteers). The AUC for the 6-mRNA combination was 0.79.

Conclusion

We screened six mRNAs as a combination for diagnosing tuberculosis.

Implication of Immunobiological Function of Melanocytes in Dermatology

Melanocytes are essential for regulating pigmentation and providing photoprotection in human skin. Originating from neural crest cells, these cells migrate to the basal layer of the epidermis and hair follicles during embryogenesis. Melanosomes, the specialized, membrane-bound organelles are essential for melanin synthesis. Beyond their role in pigmentation, melanocytes exhibit complex immune functions, expressing a variety of immune-related markers and receptors, such as pattern recognition receptors (PRRs), major histocompatibility complex class II (MHC-II) molecules, CD40, intercellular adhesion molecule 1 (ICAM-1), and programmed death-ligand 1 (PD-L1). These receptors allow melanocytes to detect environmental signals and engage in the innate immune response. Furthermore, melanocytes release various immunomodulatory substances, including proinflammatory cytokines, chemokines, and damage-associated molecular patterns (DAMPs), contributing to immune regulation. The immune functions of melanocytes are significantly influenced by external factors such as ultraviolet radiation (UVR), the microbiome, and oxidative stress. In different skin diseases, these immune functions may vary. For example, vitiligo, a common hypopigmentary disorder, is primarily driven by an autoimmune response targeting melanocytes, giving rise to depigmentation and the appearance of white patches. In contrast, melanoma, a form of skin cancer that arises from melanocytes, is closely linked to UV exposure. This review highlights the diverse immunobiological functions of melanocytes and their implications in dermatology.

Revolutionary Cancer Therapy for Personalization and Improved Efficacy: Strategies to Overcome Resistance to Immune Checkpoint Inhibitor Therapy

Cancer remains a significant public health issue worldwide, standing as a primary contributor to global mortality, accounting for approximately 10 million fatalities in 2020 [...].

The multifaceted role of SMAD4 in immune cell function

The Transforming Growth Factor-beta (TGF-β) signaling pathway, with SMAD4 as its central mediator, plays a pivotal role in regulating cellular functions, including growth, differentiation, apoptosis, and immune responses. While extensive research has elucidated SMAD4's role in tumorigenesis, its functions within immune cells remain underexplored. This review synthesizes current knowledge on SMAD4's diverse roles in various immune cells such as T cells, B cells, dendritic cells, and macrophages, highlighting its impact on immune homeostasis and pathogen response. Understanding SMAD4's role in immune cells is crucial, as its dysregulation can lead to autoimmune disorders, chronic inflammation, and immune deficiencies. The review emphasizes the significance of SMAD4 in immune regulation, proposing that deeper investigation could reveal novel therapeutic targets for immune-mediated conditions. Insights into SMAD4's involvement in processes like T cell differentiation, B cell class switch recombination, and macrophage polarization underscore its potential as a therapeutic target for a range of diseases, including autoimmune disorders and cancer.

Sequential JAK inhibition enhances antitumor immunity after combined anti-PD-1 and anti-CTLA4

While immune checkpoint inhibition (CPI) has reshaped cancer treatment, the majority of patients with cancer do not benefit from this approach, which can also cause immune-related adverse events. Induction of IFN-γ responses is thought be necessary for antitumor immunity, but growing evidence also implicates IFN-γ as a tumor-intrinsic mediator of CPI resistance. CPI-induced IFN-γ mediates activation-induced cell death in T cells as an immune-intrinsic mechanism of resistance. In this study, we found that transient block of IFN-γ signaling through administration of the JAK1 inhibitor ABT-317 enhanced antitumor T cell responses with CPI in preclinical models. Importantly, sequential but not concomitant ABT-317 treatment led to significantly reduced toxicity and improved tumor efficacy. Sequential treatment reduced activation-induced T cell death and enhanced expansion of tumor-reactive T cell subsets with increased effector function in vivo and ex vivo. Only CPI in combination with ABT-317 also enhanced memory responses by protecting mice from tumor rechallenge. These results demonstrate that JAK inhibition within a discrete time window following CPI addresses an immune-intrinsic mechanism of therapeutic resistance.

Alternative Splicing as a Modulator of the Interferon-Gamma Pathway

Interferon-gamma (IFN-γ) is a critical cytokine that plays a pivotal role in immune system regulation. It is a key mediator of both cellular defense mechanisms and antitumor immunity. As the sole member of the type II interferon family, IFN-γ modulates immune responses by activating macrophages, enhancing natural killer cell function, and regulating gene expression across multiple cellular processes. Alternative splicing is a post-transcriptional gene expression regulatory mechanism that generates multiple mature messenger RNAs from a single gene, dramatically increasing proteome diversity without the need of a proportional genome expansion. This process occurs in 90-95% of human genes, with alternative splicing events allowing for the production of diverse protein isoforms that can have distinct-or even opposing-functional properties. Alternative splicing plays a crucial role in cancer immunology, potentially generating tumor neoepitopes and modulating immune responses. However, how alternative splicing affects IFN-γ's activity is still poorly understood. This review explores how alternative splicing regulates the expression and function of both upstream regulators and downstream effectors of IFN-γ, revealing complex mechanisms of gene expression and immune response modulation. Key transcription factors and signaling molecules of the IFN-γ pathway are alternatively spliced, and alternative splicing can dramatically alter IFN-γ signaling, immune cell function, and response to environmental cues. Specific splice variants can enhance or inhibit IFN-γ-mediated immune responses, potentially influencing cancer immunotherapy, autoimmune conditions, and infectious disease outcomes. The emerging understanding of these splicing events offers promising therapeutic strategies for manipulating immune responses through targeted molecular interventions.

A comprehensive insights of cancer immunotherapy resistance

Cancer is a major global health issue that is usually treated with multiple therapies, such as chemotherapy and targeted therapies like immunotherapy. Immunotherapy is a new and alternative approach to treating various types of cancer that are difficult to treat with other methods. Although immune checkpoint inhibitors have shown promise for long-term efficacy, they have limited effectiveness in common cancer types such as breast, prostate, and lung. Some patients do not respond to immunotherapy, while others develop resistance to the treatment over time, which is classified as primary or acquired resistance. Cancer immunotherapy, specifically immune checkpoint inhibitor-based resistance involves multiple factors such as genes, metabolism, inflammation, and angiogenesis. However, cutting-edge research has identified the mechanisms of immunotherapy resistance and possible solutions. Current research may improve biomarker identification and modify treatment strategies, which will lead to better clinical outcomes. This review provides a comprehensive discussion of the current mechanisms of immunotherapy resistance, related biomarker modulation, and strategies to overcome resistance.

An artificial transcription factor that activates potent interferon-γ expression in human Jurkat T Cells

Interferon (IFN)-γ is a central regulator of cell-mediated immunity in human health and disease, but reduced expression of the target receptors impairs signaling activity and leads to immunotherapy resistance. Although intracellular expression of IFN-γ restores the signaling and downstream functions, we lack the tools to activate the IFNG gene instead of cell surface receptors. This paper introduces the design and characterization of an artificial transcription factor (ATF) protein that recognizes the IFNG gene with six zinc finger domains, which are dovetailed to a VP64 signaling domain that promotes gene transcription and translation. Biological studies with human Jurkat T cells reveal that the ATF amplifies IFNG gene transcription and translation, and also stimulates gene transcription for multiple class I and II HLA alleles and interferon-stimulated genes (ISGs). Biophysical characterization showed the recombinant ATF protein recognizes the human IFNG gene with nanomolar affinity (KD = 5.27 ± 0.3 nM), adopts a protein secondary structure associated with the ββα-fold of zinc finger domains, and is resistant to thermal denaturation. These studies demonstrate that transcriptional targeting of cytokine genes, rather than surface receptors, activates cytokine expression and shows significant potential for directing immune function.

A microglia-containing cerebral organoid model to study early life immune challenges

Prenatal infections and activation of the maternal immune system have been proposed to contribute to causing neurodevelopmental disorders (NDDs), chronic conditions often linked to brain abnormalities. Microglia are the resident immune cells of the brain and play a key role in neurodevelopment. Disruption of microglial functions can lead to brain abnormalities and increase the risk of developing NDDs. How the maternal as well as the fetal immune system affect human neurodevelopment and contribute to NDDs remains unclear. An important reason for this knowledge gap is the fact that the impact of exposure to prenatal risk factors has been challenging to study in the human context. Here, we characterized a model of cerebral organoids (CO) with integrated microglia (COiMg). These organoids express typical microglial markers and respond to inflammatory stimuli. The presence of microglia influences cerebral organoid development, including cell density and neural differentiation, and regulates the expression of several ciliated and mesenchymal cell markers. Moreover, COiMg and organoids without microglia show similar but also distinct responses to inflammatory stimuli. Additionally, IFN-γ induced significant transcriptional and structural changes in the cerebral organoids, that appear to be regulated by the presence of microglia. Specifically, interferon-gamma (IFN-γ) was found to alter the expression of genes linked to autism. This model provides a valuable tool to study how inflammatory perturbations and microglial presence affect neurodevelopmental processes.

Triggering immunogenic death of cancer cells by nanoparticles overcomes immunotherapy resistance

Immunotherapy resistance poses a significant challenge in oncology, necessitating novel strategies to enhance the therapeutic efficacy. Immunogenic cell death (ICD), including necroptosis, pyroptosis and ferroptosis, triggers the release of tumor-associated antigens and numerous bioactive molecules. This release can potentiate a host immune response, thereby overcoming resistance to immunotherapy. Nanoparticles (NPs) with their biocompatible and immunomodulatory properties, are emerging as promising vehicles for the delivery of ICD-inducing agents and immune-stimulatory adjuvants to enhance immune cells tumoral infiltration and augment immunotherapy efficacy. This review explores the mechanisms underlying immunotherapy resistance, and offers an in-depth examination of ICD, including its principles and diverse modalities of cell death that contribute to it. We also provide a thorough overview of how NPs are being utilized to trigger ICD and bolster antitumor immunity. Lastly, we highlight the potential of NPs in combination with immunotherapy to revolutionize cancer treatment.

Inhibition of CEACAM1 expression in cytokine-activated neutrophils using JAK inhibitors

OBJECTIVES

Carcinoembryonic-antigen-related cell-adhesion molecule 1 (CEACAM1) is an adhesion molecule that acts as a coinhibitory receptor in the immune system. We previously demonstrated that CEACAM1 is predominantly expressed on peripheral blood neutrophils in patients with RA. The aim of the present study was to investigate the effects of Janus kinase inhibitors (JAKi) on cytokine-activated human neutrophils and CEACAM1 expression.

METHODS

Peripheral blood neutrophils were obtained from healthy subjects. Isolated neutrophils were stimulated with tumor necrosis factor-alpha (TNF-α) or granulocyte-macrophage colony-stimulating factor (GM-CSF) in the presence or absence of JAKi. The expression of CEACAM1 in peripheral blood neutrophils was analyzed by flow cytometry. Protein phosphorylation of signal transducer and activator of transcription (STAT)1, STAT3, and STAT5 was assessed by western blot using phospho-specific antibodies.

RESULTS

We found that TNF-α-induced CEACAM1 expression was marginally suppressed after pretreatment with pan-JAK inhibitor, tofacitinib. Moreover, TNF-α induced STAT1 and STAT3 phosphorylation at the late stimulation phase (4 to 16 h). The expressions of CEACAM1 on neutrophils were markedly up-regulated by GM-CSF not by interleukin (IL)-6 stimulation. All JAKi inhibited GM-CSF-induced CEACAM1 expressions on neutrophils, however, the inhibitory effects of baricitinib were larger compared to those of tofacitinib or filgotinib. Moreover, CEACAM1 was marginally upregulated in interferon (IFN)-γ stimulated neutrophils. Similarly, JAKi inhibited IFN-γ-induced CEACAM1 expressions on neutrophils.

CONCLUSIONS

We demonstrated that JAKi prevent GM-CSF-induced CEACAM1 expression in neutrophils, and JAKi-induced inhibition depends on their selectivity against JAK isoforms. These findings suggest that JAKi can modulate the expression of CEACAM1 in cytokine-activated neutrophils, thereby limiting their activation.

Microglia signaling in health and disease - Implications in sex-specific brain development and plasticity

Microglia, the intrinsic neuroimmune cells residing in the central nervous system (CNS), exert a pivotal influence on brain development, homeostasis, and functionality, encompassing critical roles during both aging and pathological states. Recent advancements in comprehending brain plasticity and functions have spotlighted conspicuous variances between male and female brains, notably in neurogenesis, neuronal myelination, axon fasciculation, and synaptogenesis. Nevertheless, the precise impact of microglia on sex-specific brain cell plasticity, sculpting diverse neural network architectures and circuits, remains largely unexplored. This article seeks to unravel the present understanding of microglial involvement in brain development, plasticity, and function, with a specific emphasis on microglial signaling in brain sex polymorphism. Commencing with an overview of microglia in the CNS and their associated signaling cascades, we subsequently probe recent revelations regarding molecular signaling by microglia in sex-dependent brain developmental plasticity, functions, and diseases. Notably, C-X3-C motif chemokine receptor 1 (CX3CR1), triggering receptors expressed on myeloid cells 2 (TREM2), calcium (Ca2+), and apolipoprotein E (APOE) emerge as molecular candidates significantly contributing to sex-dependent brain development and plasticity. In conclusion, we address burgeoning inquiries surrounding microglia's pivotal role in the functional diversity of developing and aging brains, contemplating their potential implications for gender-tailored therapeutic strategies in neurodegenerative diseases.

Tumor microenvironment governs the prognostic landscape of immunotherapy for head and neck squamous cell carcinoma: A computational model-guided analysis

Immune checkpoint inhibition (ICI) has emerged as a critical treatment strategy for squamous cell carcinoma of the head and neck (HNSCC) that halts the immune escape of the tumor cells. Increasing evidence suggests that the onset, progression, and lack of/no response of HNSCC to ICI are emergent properties arising from the interactions within the tumor microenvironment (TME). Deciphering how the diversity of cellular and molecular interactions leads to distinct HNSCC TME subtypes subsequently governing the ICI response remains largely unexplored. We developed a cellular-molecular model of the HNSCC TME that incorporates multiple cell types, cellular states, and transitions, and molecularly mediated paracrine interactions. An exhaustive simulation of the HNSCC TME network shows that distinct mechanistic balances within the TME give rise to the five clinically observed TME subtypes such as immune/non-fibrotic, immune/fibrotic, fibrotic only and immune/fibrotic desert. We predict that the cancer-associated fibroblast, beyond a critical proliferation rate, drastically worsens the ICI response by hampering the accessibility of the CD8+ killer T cells to the tumor cells. Our analysis reveals that while an Interleukin-2 (IL-2) + ICI combination therapy may improve response in the immune desert scenario, Osteopontin (OPN) and Leukemia Inhibition Factor (LIF) knockout with ICI yields the best response in a fibro-dominated scenario. Further, we predict Interleukin-8 (IL-8), and lactate can serve as crucial biomarkers for ICI-resistant HNSCC phenotypes. Overall, we provide an integrated quantitative framework that explains a wide range of TME-mediated resistance mechanisms for HNSCC and predicts TME subtype-specific targets that can lead to an improved ICI outcome.

Cloning and Functional Characterization of Novel Human Neutralizing Anti-IFN-α and Anti-IFN-β Antibodies

Type I IFNs play a pivotal role in immune response modulation, yet dysregulation is implicated in various disorders. Therefore, it is crucial to develop tools that facilitate the understanding of their mechanism of action and enable the development of more effective anti-IFN therapeutic strategies. In this study, we isolated, cloned, and characterized anti-IFN-α and anti-IFN-β Abs from PBMCs of individuals treated with IFN-α or IFN-β, harboring confirmed neutralizing Abs. Clones AH07856 and AH07857 were identified as neutralizing anti-IFN-α-specific with inhibition against IFN-α2a, -α2b, and -αK subtypes. Clones AH07859 and AH07866 were identified as neutralizing anti-IFN-β1a-specific signaling and able to block lipopolysaccharide or S100 calcium-binding protein A14-induced IFN-β signaling effects. Cloned Abs bind rhesus but not murine IFNs. The specificity of inhibition between IFN-α and IFN-β suggests potential for diverse research and clinical applications.

Genomic and molecular alterations associated with primary resistance to immune checkpoint inhibitors

The clinical response to immune checkpoint inhibitors may vary by tumor type and many tumors present with either primary or acquired resistance to immunotherapy. Improved understanding of the molecular and immunologic mechanisms underlying immunotherapy resistance is essential for developing biomarkers and for guiding the optimum approach to selecting treatment regimens and sequencing. This is increasingly important for tumors with primary resistance as effective biomarkers in this setting can guide clinicians about appropriate treatment regimen selection in the first-line setting. Multiple potential biological mechanisms of primary resistance have been proposed but most are yet to be validated in prospective clinical cohorts. Individual biomarkers have poor specificity and sensitivity, and the development of validated and integrated predictive models may guide which patient will benefit from monotherapy versus combination therapy. In this review, we discuss the emerging data identifying the molecular mechanisms of primary resistance to immunotherapy and explore potential therapeutic strategies to target these.

The I7L protein of African swine fever virus is involved in viral pathogenicity by antagonizing the IFN-γ-triggered JAK-STAT signaling pathway through inhibiting the phosphorylation of STAT1

Cell-passage-adapted strains of African swine fever virus (ASFV) typically exhibit substantial genomic alterations and attenuated virulence in pigs. We have indicated that the human embryonic kidney (HEK293T) cells-adapted ASFV strain underwent genetic alterations and the I7L gene in the right variable region was deleted compared with the ASFV HLJ/2018 strain (ASFV-WT). A recent study has revealed that the deletion of the I7L-I11L genes results in attenuation of virulent ASFV in vivo, but the underlying mechanism remains largely unknown. Therefore, we hypothesized that the deletion of the I7L gene may be related to the pathogenicity of ASFV in pigs. We generated the I7L gene-deleted ASFV mutant (ASFV-ΔI7L) and found that the I7L gene deletion does not influence the replication of ASFV in primary porcine alveolar macrophages (PAMs). Using transcriptome sequencing analysis, we identified that the differentially expressed genes in the PAMs infected with ASFV-ΔI7L were mainly involved in antiviral immune responses induced by interferon gamma (IFN-γ) compared with those in the ASFV-WT-infected PAMs. Meanwhile, we further confirmed that the I7L protein (pI7L) suppressed the IFN-γ-triggered JAK-STAT signaling pathway. Mechanistically, pI7L interacts with STAT1 and inhibits its phosphorylation and homodimerization, which depends on the tyrosine at position 98 (Y98) of pI7L, thereby preventing the nuclear translocation of STAT1 and leading to the decreased production of IFN-γ-stimulated genes. Importantly, ASFV-ΔI7L exhibited reduced replication and virulence compared with ASFV-WT in pigs, likely due to the increased production of IFN-γ-stimulated genes, indicating that pI7L is involved in the virulence of ASFV. Taken together, our findings demonstrate that pI7L is associated with pathogenicity and antagonizes the IFN-γ-triggered JAK-STAT signaling pathway via inhibiting the phosphorylation and homodimerization of STAT1 depending on the Y98 residue of pI7L and the Src homology 2 domain of STAT1, which provides more information for understanding the immunoevasion strategies and designing the live attenuated vaccines against ASFV infection.

T lymphocyte-derived IFN-γ facilitates breast cancer cells to pass the blood-brain barrier: An in vitro study corroborating translational data

The appearance of brain metastasis is the most serious complication of breast cancer with mostly fatal outcomes. To reach the brain, tumor cells need to pass the blood-brain barrier (BBB). The molecular mechanisms underlying penetration of the BBB are largely unknown. Previously we found that tumor-infiltrating T lymphocytes enhance the development of brain metastasis of estrogen receptor-negative (ER-) breast cancer. In the current study, we investigate the contribution of T lymphocytes and the IFN-γ pathway in enabling breast cancer cells to pass the in vitro BBB. CD8+ cells display the strongest stimulatory effect on breast cancer cell passage. We show that inhibition of the IFN-γ receptor in MDA-MB-231 breast cancer cells, or neutralization of soluble IFN-γ, impairs the in vitro trespassing of breast cancer cells. Importantly, we validated our findings using gene expression data of breast cancer patients. The CXCL-9,-10,-11/CXCR3 axis, dependent on IFN-γ signaling activity, was overexpressed in primary breast cancer samples of patients who developed brain metastasis. The data support a role for T-lymphocytes and the IFN-γ pathway in the formation of brain metastasis of ER-breast cancer, and offer targets to design future therapies for preventing breast cancer cells to cross the BBB.

Kynurenines and Inflammation: A Remarkable Axis for Multiple Sclerosis Treatment

Multiple sclerosis (MS) is a chronic inflammatory autoimmune neurological disease characterized by the recurrent appearance of demyelinating lesions and progressive disability. Currently, there are multiple disease-modifying treatments, however, there is a significant need to develop new therapeutic targets, especially for the progressive forms of the disease. This review article provides an overview of the most recent studies aimed at understanding the inflammatory processes that are activated in response to the accumulation of kynurenine pathway (KP) metabolites, which exacerbate an imbalance between immune system cells (e.g., Th1, Th2, and T reg) and promote the release of pro-inflammatory interleukins that modulate different mechanisms: membrane-receptors function; nuclear factors expression; and cellular signals. Together, these alterations trigger cell death mechanisms in brain cells and promote neuron loss and axon demyelination. This hypothesis could represent a remarkable approach for disease-modifying therapies for MS. Here, we also provide a perspective on the repositioning of some already approved drugs involved in other signaling pathways, which could represent new therapeutic strategies for MS treatment.

Crucial Roles of RSAD2/viperin in Immunomodulation, Mitochondrial Metabolism and Autoimmune Diseases

Autoimmune diseases are typically characterized by aberrant activation of immune system that leads to excessive inflammatory reactions and tissue damage. Nevertheless, precise targeted and efficient therapies are limited. Thus, studies into novel therapeutic targets for the management of autoimmune diseases are urgently needed. Radical S-adenosyl methionine domain-containing 2 (RSAD2) is an interferon-stimulated gene (ISG) renowned for the antiviral properties of the protein it encodes, named viperin. An increasing number of studies have underscored the new roles of RSAD2/viperin in immunomodulation and mitochondrial metabolism. Previous studies have shown that there is a complex interplay between RSAD2/vipeirn and mitochondria and that binding of the iron-sulfur (Fe-S) cluster is necessary for the involvement of viperin in mitochondrial metabolism. Viperin influences the proliferation and development of immune cells as well as inflammation via different signaling pathways. However, the function of RSAD2/viperin varies in different studies and a comprehensive overview of this emerging theme is lacking. This review will describe the characteristics of RSAD2/viperin, decipher its function in immunometabolic processes, and clarify the crosstalk between RSAD2/viperin and mitochondria. Furthermore, we emphasize the crucial roles of RSAD2 in autoimmune diseases and its potential application value.

A microglia-containing cerebral organoid model to study early life immune challenges

Prenatal infections and activation of the maternal immune system have been proposed to contribute to causing neurodevelopmental disorders (NDDs), chronic conditions often linked to brain abnormalities. Microglia are the resident immune cells of the brain and play a key role in neurodevelopment. Disruption of microglial functions can lead to brain abnormalities and increase the risk of developing NDDs. How the maternal as well as the fetal immune system affect human neurodevelopment and contribute to NDDs remains unclear. An important reason for this knowledge gap is the fact that the impact of exposure to prenatal risk factors has been challenging to study in the human context. Here, we characterized a model of cerebral organoids (CO) with integrated microglia (COiMg). These organoids express typical microglial markers and respond to inflammatory stimuli. The presence of microglia influences cerebral organoid development, including cell density and neural differentiation, and regulates the expression of several ciliated mesenchymal cell markers. Moreover, COiMg and organoids without microglia show similar but also distinct responses to inflammatory stimuli. Additionally, IFN-γ induced significant transcriptional and structural changes in the cerebral organoids, that appear to be regulated by the presence of microglia. Specifically, interferon-gamma (IFN-γ) was found to alter the expression of genes linked to autism. This model provides a valuable tool to study how inflammatory perturbations and microglial presence affect neurodevelopmental processes.

Cloning and functional characterization of novel human neutralizing anti-interferon-alpha and anti-interferon-beta antibodies

Type I interferons (IFNs) play a pivotal role in immune response modulation, yet dysregulation is implicated in various disorders. Therefore, it is crucial to develop tools that facilitate the understanding of their mechanism of action and enable the development of more effective anti-IFN therapeutic strategies. In this study, we isolated, cloned, and characterized anti-IFN-α and anti-IFN-β antibodies (Abs) from peripheral blood mononuclear cells of individuals treated with IFN-α or IFN-β, harboring confirmed neutralizing Abs. Clones AH07856 and AH07857 were identified as neutralizing anti-IFN-α-specific with inhibition against IFN-α2a, -α2b, and -αK subtypes. Clones AH07859 and AH07866 were identified as neutralizing anti-IFN-β1a-specific signaling, and able to block Lipopolysaccharide or S100 calcium binding protein A14-induced IFN-β signaling effects. Cloned Abs bind rhesus but not murine IFNs. The specificity of inhibition between IFN-α and IFN-β suggests potential for diverse research and clinical applications.

Type I gamma phosphatidylinositol phosphate 5-kinase i5 controls cell sensitivity to interferon

The interferon signaling pathway is critical for host defense by serving diverse functions in both innate and adaptive immune responses. Here, we show that type I gamma phosphatidylinositol phosphate 5-kinase i5 (PIPKIγi5), an enzyme that synthesizes phosphatidylinositol-4,5-bisphosphate (PI4,5P2), controls the sensitivity to interferon in both human and mouse cells. PIPKIγi5 directly binds to the interferon-gamma (IFN-γ) downstream effector signal transducer and activator of transcription 1 (STAT1), which suppresses the STAT1 dimerization, IFN-γ-induced STAT1 nuclear translocation, and transcription of IFN-γ-responsive genes. Depletion of PIPKIγi5 significantly enhances IFN-γ signaling and strengthens an antiviral response. In addition, PIPKIγi5-synthesized PI4,5P2 can bind to STAT1 and promote the PIPKIγi5-STAT1 interaction. Similar to its interaction with STAT1, PIPKIγi5 is capable of interacting with other members of the STAT family, including STAT2 and STAT3, thereby suppressing the expression of genes mediated by these transcription factors. These findings identify the function of PIPKIγi5 in immune regulation.

Cancer biomarkers: Emerging trends and clinical implications for personalized treatment

The integration of cancer biomarkers into oncology has revolutionized cancer treatment, yielding remarkable advancements in cancer therapeutics and the prognosis of cancer patients. The development of personalized medicine represents a turning point and a new paradigm in cancer management, as biomarkers enable oncologists to tailor treatments based on the unique molecular profile of each patient's tumor. In this review, we discuss the scientific milestones of cancer biomarkers and explore future possibilities to improve the management of patients with solid tumors. This progress is primarily attributed to the biological characterization of cancers, advancements in testing methodologies, elucidation of the immune microenvironment, and the ability to profile circulating tumor fractions. Integrating these insights promises to continually advance the precision oncology field, fostering better patient outcomes.

Deregulation of interferon-gamma receptor 1 expression and its implications for lung adenocarcinoma progression

Interferon-gamma (IFN-γ) plays a dual role in cancer; it is both a pro- and an antitumorigenic cytokine, depending on the type of cancer. The deregulation of the IFN-γ canonic pathway is associated with several disorders, including vulnerability to viral infections, inflammation, and cancer progression. In particular, the interplay between lung adenocarcinoma (LUAD) and viral infections appears to exist in association with the deregulation of IFN-γ signaling. In this mini-review, we investigated the status of the IFN-γ signaling pathway and the expression level of its components in LUAD. Interestingly, a reduction in IFNGR1 expression seems to be associated with LUAD progression, affecting defenses against viruses such as severe acute respiratory syndrome coronavirus 2. In addition, alterations in the expression of IFNGR1 may inhibit the antiproliferative action of IFN-γ signaling in LUAD.

The role of intestinal flora on tumor immunotherapy: recent progress and treatment implications

Immunotherapy, specifically immune checkpoint inhibitors, has emerged as a promising approach for treating malignant tumors. The gut, housing approximately 70 % of the body's immune cells, is abundantly populated with gut bacteria that actively interact with the host's immune system. Different bacterial species within the intestinal flora are in a delicate equilibrium and mutually regulate each other. However, when this balance is disrupted, pathogenic microorganisms can dominate, adversely affecting the host's metabolism and immunity, ultimately promoting the development of disease. Emerging researches highlight the potential of interventions such as fecal microflora transplantation (FMT) to improve antitumor immune response and reduce the toxicity of immunotherapy. These remarkable findings suggest the major role of intestinal flora in the development of cancer immunotherapy and led us to the hypothesis that intestinal flora transplantation may be a new breakthrough in modifying immunotherapy side effects.

Cloning of human Type I interferon cDNAs

In the late 1970s, crude interferon samples were found to exhibit anti-tumour activity. This discovery led to the interferon as a "magic drug" for cancer patients. Many groups, including those in Tokyo, Zürich, and San Francisco, attempted to identify human interferon cDNAs. Tadatsugu Taniguchi was the first to announce the cloning of human interferon-β cDNA in the December 1979 issue of Proc. Jpn. Acad. Ser. B. This was followed by the cloning of human interferon-α by a Zürich group and interferon-γ by a group in Genentech in San Francisco. Recombinant interferon proteins were produced on a large scale, and interferon-α was widely used to treat C-type hepatitis patients. The biological functions of interferons were quickly elucidated with the purified recombinant interferons. The molecular mechanisms underlying virus-induced interferon gene expression were also examined using cloned chromosomal genes. The background that led to interferon gene cloning and its impact on cytokine gene hunting is described herein.

Upregulation of the canonical signaling pathway of interferon-gamma is associated with glioblastoma progression

BACKGROUND

Glioblastoma is a brain malignant tumor grade IV, highly invasive. Alterations in several signaling pathways are involved in glioblastoma development. In this work, we evaluated the IFN-γ canonical signaling pathway in glioblastoma cells and its effect on cell viability and migration.

METHODS

The levels of STAT1/pSTAT1, IRF1, and PD-L1 in LN-18 glioblastoma cells were analyzed using western blotting. Cell viability was evaluated by calcein-AM/propidium iodide assays, and a wound healing assay was used to study the migration of glioblastoma cells treated with IFN-γ. Our aim was to determine the expression of IFN-γ signaling elements in cell lines and tissue from glioblastoma samples and examine the relationship between these elements and the survival of glioblastoma patients. The following platforms were utilized for analysis: the CCLE (Cancer Cell Line Encyclopedia), UALCAN (University of Alabama at Birmingham Cancer data analysis Portal), GEPIA (Gene Expression Profiling Interactive Analysis), and GENT2 (Gene Expression patterns across Normal and Tumor tissues).

RESULTS

Our results evidenced that IFN-γ signaling increases non-phosphorylated and phosphorylated STAT1 levels and promotes the upregulation of IRF1 and PD-L1 in glioblastoma cells. The activation of IFN-γ signaling increased cell migration without affecting the viability of glioblastoma cells. Furthermore, in silico analysis showed that the elements of IFN-γ signaling pathways (IFNGR1/IFNGR2/STAT1/IRF1) are upregulated in human glioblastoma samples. The upregulation of IFN-γ signaling was associated with shorter survival in glioblastoma patients.

CONCLUSION

IFN-γ signaling pathway is upregulated in glioblastoma, displaying pro-tumor activity. Thus, IFN-γ signaling elements may be potential biomarkers and targets for treating glioblastoma.

Identification, functional characterization and expression pattern of interferon-gamma (IFN-γ) and interferon-gamma receptor 1 (IFNGR1) in Nibea albiflora

Interferon-gamma (IFN-γ) is an inflammatory cytokine that plays a crucial role in regulating both innate and cell-mediated immune responses by binding to a receptor complex made up of IFNGR1 and IFNGR2. In this study, the complete cDNA of IFN-γ and IFNGR1 from Nibea albiflora were cloned and functionally characterized (named NaIFN-γ and NaIFNGR1), whose complete cDNA sequences were 1593 bp and 2792 bp, encoding 201 and 399 amino acids, respectively. Multiple sequence alignment and phylogenetic analysis showed that the concluded amino acids sequences of NaIFN-γ and NaIFNGR1 shared high identity with their teleost orthologues including the IFN-γ signature and nuclear localization signal (NLS) motif in NaIFN-γ and FN Ⅲ domain in NaIFNGR1. Real-time PCR showed that NaIFN-γ and NaIFNGR1 constitutively expressed in all tested tissues, such as the head-kidney, spleen, liver, kidney, gill, muscle, blood, and intestine with the highest expression of NaIFN-γ and NaIFNGR1 appearing in the liver and gill, respectively. After experiencing stimulation with Polyinosinic-polycytidylic acid (Poly (I:C)), Vibrio alginolyticus (V. alginolyticus) or Vibrio parahaemolyticus (V. parahaemolyticus), NaIFN-γ and NaIFNGR1 mRNA were up-regulated with the time-dependent model. Due to the presence of a nuclear localization signal (NLS), the subcellular localization revealed that NaIFN-γ dispersed throughout the cytoplasm and nucleus. NaIFNGR1, as a member of Cytokine receptor family B, was primarily expressed on the cell membrane. When NaIFN-γ and NaIFNGR1 were co-transfected, their fluorescence signals overlapped on the membrane of HEK 293T cells indicating the potential interaction between IFN-γ and IFNGR1. The GST-pull-down results further showed that NaIFN-γ could directly interact with the extracellular region of NaIFNGR1, further confirming the affinity between IFN-γ and IFNGR1. Taken together, the results firstly demonstrated that the NaIFN-γ ligand-receptor system existed in N.albiflora and played a pivotal part in N.albiflora's immune response against pathogenic bacterial infections, which contributed to the better understanding of the role of IFN-γ in the immunomodulatory mechanisms of teleost.

A Review on Role of Inflammation in Coronavirus Disease

The respiratory illness known as COVID-19 is caused by the novel coronavirus, SARS-CoV-2. While the precise pathogenic mechanism of COVID-19 remains unclear, the occurrence of a cytokine storm subsequent to viral infection plays a pivotal role in the initiation and advancement of the disease. The infection of SARS-CoV-2 induces a state of immune system hyperactivity, leading to an excessive production of inflammatory cytokines. Consequently, the identification of the various signaling pathways implicated in the inflammation induced by COVID-19 will enable researchers to investigate new targets for therapeutic intervention.

Crosstalk of RNA methylation writers defines tumor microenvironment and alisertib resistance in breast cancer

Background

The five major RNA methylation modifications (m6A, m1A, m6Am, m5C, and m7G) exert biological roles in tumorigenicity and immune response, mediated mainly by "writer" enzymes. Here, the prognostic values of the "writer" enzymes and the TCP1 role in drug resistance in breast cancer (BC) were explored for further therapeutic strategies.

Methods

We comprehensively characterized clinical, molecular, and genetic features of subtypes by consensus clustering. RNA methylation modification "Writers" and related genes_risk (RMW_risk) model for BC was constructed via a machine learning approach. Moreover, we performed a systematical analysis for characteristics of the tumor microenvironment (TME), alisertib sensitivity, and immunotherapy response. A series of experiments in vitro were carried out to assess the association of TCP1 with drug resistance.

Results

One "writer" (RBM15B) and two related genes (TCP1 and ANKRD36) were identified for prognostic model construction, validated by GSE1456, GSE7390, and GSE20685 cohorts and our follow-up data. Based on the patterns of the genes related to prognosis, patients were classified into RMW_risk-high and RMW_risk-low subtypes. Lower RMW_Score was associated with better overall survival and the infiltration of immune cells such as memory B cells. Further analysis revealed that RMW_Score presented potential values in predicting drug sensitivity and response for chemo- and immunotherapy. In addition, TCP1 was confirmed to promote BC alisertib-resistant cell proliferation and migration in vitro.

Conclusion

RMW_Score could function as a robust biomarker for predicting BC patient survival and therapeutic benefits. This research revealed a potential TCP1 role regarding alisertib resistance in BC, providing new sights into more effective therapeutic plans.

Inflammatory Licensed hMSCs Exhibit Enhanced Immunomodulatory Capacity in a Biomaterial Mediated Manner

Craniomaxillofacial (CMF) bone injuries represent particularly challenging environments for regenerative healing due to their large sizes, irregular and unique defect shapes, angiogenic requirements, and mechanical stabilization needs. These defects also exhibit a heightened inflammatory environment that can complicate the healing process. This study investigates the influence of the initial inflammatory stance of human mesenchymal stem cells (hMSCs) on key osteogenic, angiogenic, and immunomodulatory criteria when cultured in a class of mineralized collagen scaffolds under development for CMF bone repair. We previously showed that changes in scaffold pore anisotropy and glycosaminoglycan content can significantly alter the regenerative activity of both MSCs and macrophages. While MSCs are known to adopt an immunomodulatory phenotype in response to inflammatory stimuli, here, we define the nature and persistence of MSC osteogenic, angiogenic, and immunomodulatory phenotypes in a 3D mineralized collagen environment, and further, whether changes to scaffold architecture and organic composition can blunt or accentuate this response as a function of inflammatory licensing. Notably, we found that a one-time licensing treatment of MSCs induced higher immunomodulatory potential compared to basal MSCs as observed by sustained immunomodulatory gene expression throughout the first 7 days as well as an increase in immunomodulatory cytokine (PGE2 and IL-6) expression throughout a 21-day culture period. Further, heparin scaffolds facilitated higher osteogenic cytokine secretion but lower immunomodulatory cytokine secretion compared to chondroitin-6-sulfate scaffolds. Anisotropic scaffolds facilitated higher secretion of both osteogenic protein OPG and immunomodulatory cytokines (PGE2 and IL-6) compared to isotropic scaffolds. These results highlight the importance of scaffold properties on the sustained kinetics of cell response to an inflammatory stimulus. The development of a biomaterial scaffold capable of interfacing with hMSCs to facilitate both immunomodulatory and osteogenic responses is an essential next step to determining the quality and kinetics of craniofacial bone repair.

Biological therapies for hemophagocytic lymphohistiocytosis: current knowledge and future perspectives

INTRODUCTION

Hemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory syndrome with a dismal prognosis. The underlying causes of HLH are diverse. However, the overabundance of cytokines was shared by all forms of HLH. Cytokine-targeted biotherapies have been increasingly used in HLH treatment.

AREAS COVERED

In this review, we aim to provide an overview of biological treatment options for HLH.

EXPERT OPINION

Biological therapies offer alternative treatment options for patients with refractory/relapsed HLH or who are intolerant to conventional chemotherapies. As a complement to traditional treatment, biological agents improve response rates, maintain more protracted periods of remission, and reduce treatment related toxicity. A combination of biological agents may be a promising direction for HLH treatment. However, they may induce HLH to deteriorate and even trigger HLH.

Immune Resistance Mechanisms and the Road to Personalized Immunotherapy

What does the future of cancer immunotherapy look like and how do we get there? Find out where we've been and where we're headed in A Report on Resistance: The Road to personalized immunotherapy.

The Immunotherapeutic Role of Type I and III Interferons in Melanoma and Non-Melanoma Skin Cancers

Interferons (IFNs) have demonstrated therapeutic potential in various skin cancers, specifically squamous cell carcinoma (SCC), basal cell carcinoma (BCC), and melanoma. The precise mechanism through which type I IFNs exert their antitumor effects in skin cancers is still being studied. However, intralesional type I IFN can be used as an alternative to surgery for select patient populations, and high-dose systemic IFN therapy has been shown to be promising in patients with operable high-risk or metastatic melanoma. Despite the therapeutic potential of IFNs in skin cancer treatment, the toxicity profile often prevents the completion of treatment and further expansion of its clinical application. Type I and III IFNs use the same Janus Kinases (JAKs) for signal transduction, which are pathways initiated at a cell surface receptor that mediates the activation of target genes in the nucleus, based on this shared signaling pathway. Due to selective tumor targeting and the ability to generate both innate and adaptive immune responses, we concluded that type III IFNs have minimal side effects compared with established treatments due to selective tumor targeting. While IFN-λ, a type III IFN, shows therapeutic potential as stand-alone or in combination with another IFN, further studies need to be conducted to explore the therapeutic potential of IFN-λ in skin cancer and the underlying physiological roles and mechanisms of action. In this review, we evaluate whether treatment of skin cancer with type III IFN will have minimal side effects compared with established treatments.

Cancer immunotherapy with immune checkpoint inhibitors (ICIs): potential, mechanisms of resistance, and strategies for reinvigorating T cell responsiveness when resistance is acquired

Cancer is still the leading cause of death globally. The approval of the therapeutic use of monoclonal antibodies against immune checkpoint molecules, notably those that target the proteins PD-1 and PD-L1, has changed the landscape of cancer treatment. In particular, first-line PD-1/PD-L1 inhibitor drugs are increasingly common for the treatment of metastatic cancer, significantly prolonging patient survival. Despite the benefits brought by immune checkpoint inhibitors (ICIs)-based therapy, the majority of patients had their diseases worsen following a promising initial response. To increase the effectiveness of ICIs and advance our understanding of the mechanisms causing cancer resistance, it is crucial to find new, effective, and tolerable combination treatments. In this article, we addressed the potential of ICIs for the treatment of solid tumors and offer some insight into the molecular pathways behind therapeutic resistance to ICIs. We also discuss cutting-edge therapeutic methods for reactivating T-cell responsiveness after resistance has been established.

Nivolumab plus ipilimumab combination therapy in cancer: Current evidence to date

Immune checkpoint inhibitors (ICIs) have revolutionized cancer immunotherapy, yielding significant antitumor responses across multiple cancer types. Combination ICI therapy with anti-CTLA-4 and anti-PD-1 antibodies outperforms either antibody alone in terms of clinical efficacy. As a consequence, the U.S. Food and Drug Administration (FDA) approved ipilimumab (anti-CTLA-4) plus nivolumab (anti-PD-1) as the first-ever approved therapies for combined ICI in patients with metastatic melanoma. Despite the success of ICIs, treatment with checkpoint inhibitor combinations poses significant clinical challenges, such as increased rates of immune-related adverse events (irAEs) and drug resistance. Thus, identifying optimal prognostic biomarkers could help to monitor the safety and efficacy of ICIs and identify patients who may benefit the most from these treatments. In this review, we will first go over the fundamentals of the CTLA-4 and PD-1 pathways, as well as the mechanisms of ICI resistance. The results of clinical findings that evaluated the combination of ipilimumab and nivolumab are then summarized to support future research in the field of combination therapy. Finally, the irAEs associated with combined ICI therapy, as well as the underlying biomarkers involved in their management, are discussed.

Functional and Phenotypic Characterisations of Common Syngeneic Tumour Cell Lines as Estrogen Receptor-Positive Breast Cancer Models

Estrogen receptor-positive breast cancers (ER+ BCas) are the most common form of BCa and are increasing in incidence, largely due to changes in reproductive practices in recent decades. Tamoxifen is prescribed as a component of standard-of-care endocrine therapy for the treatment and prevention of ER+ BCa. However, it is poorly tolerated, leading to low uptake of the drug in the preventative setting. Alternative therapies and preventatives for ER+ BCa are needed but development is hampered due to a paucity of syngeneic ER+ preclinical mouse models that allow pre-clinical experimentation in immunocompetent mice. Two ER-positive models, J110 and SSM3, have been reported in addition to other tumour models occasionally shown to express ER (for example 4T1.2, 67NR, EO771, D2.0R and D2A1). Here, we have assessed ER expression and protein levels in seven mouse mammary tumour cell lines and their corresponding tumours, in addition to their cellular composition, tamoxifen sensitivity and molecular phenotype. By immunohistochemical assessment, SSM3 and, to a lesser extent, 67NR cells are ER+. Using flow cytometry and transcript expression we show that SSM3 cells are luminal in nature, whilst D2.0R and J110 cells are stromal/basal. The remainder are also stromal/basal in nature; displaying a stromal or basal Epcam/CD49f FACS phenotype and stromal and basal gene expression signatures are overrepresented in their transcript profile. Consistent with a luminal identity for SSM3 cells, they also show sensitivity to tamoxifen in vitro and in vivo. In conclusion, the data indicate that the SSM3 syngeneic cell line is the only definitively ER+ mouse mammary tumour cell line widely available for pre-clinical research.

Pathogenicity of Type I Interferons in Mycobacterium tuberculosis

Tuberculosis (TB) is a leading cause of mortality due to infectious disease and rates have increased during the emergence of COVID-19, but many of the factors determining disease severity and progression remain unclear. Type I Interferons (IFNs) have diverse effector functions that regulate innate and adaptive immunity during infection with microorganisms. There is well-documented literature on type I IFNs providing host defense against viruses; however, in this review, we explore the growing body of work that indicates high levels of type I IFNs can have detrimental effects to a host fighting TB infection. We report findings that increased type I IFNs can affect alveolar macrophage and myeloid function, promote pathological neutrophil extracellular trap responses, inhibit production of protective prostaglandin 2, and promote cytosolic cyclic GMP synthase inflammation pathways, and discuss many other relevant findings.

IFNγ signaling in cytotoxic T cells restricts anti-tumor responses by inhibiting the maintenance and diversity of intra-tumoral stem-like T cells

IFNγ is an immune mediator with concomitant pro- and anti-tumor functions. Here, we provide evidence that IFNγ directly acts on intra-tumoral CD8 T cells to restrict anti-tumor responses. We report that expression of the IFNγ receptor β chain (IFNγR2) in CD8 T cells negatively correlates with clinical responsiveness to checkpoint blockade in metastatic melanoma patients, suggesting that the loss of sensitivity to IFNγ contributes to successful antitumor immunity. Indeed, specific deletion of IFNγR in CD8 T cells promotes tumor control in a mouse model of melanoma. Chronic IFNγ inhibits the maintenance, clonal diversity and proliferation of stem-like T cells. This leads to decreased generation of T cells with intermediate expression of exhaustion markers, previously associated with beneficial anti-tumor responses. This study provides evidence of a negative feedback loop whereby IFNγ depletes stem-like T cells to restrict anti-tumor immunity. Targeting this pathway might represent an alternative strategy to enhance T cell-based therapies.

Resistance mechanisms of immune checkpoint inhibition in lymphoma: Focusing on the tumor microenvironment

Immune checkpoint inhibitors (ICIs) have revolutionized the therapeutic strategies of multiple types of malignancies including lymphoma. However, efficiency of ICIs varies dramatically among different lymphoma subtypes, and durable response can only be achieved in a minority of patients, thus requiring unveiling the underlying mechanisms of ICI resistance to optimize the individualized regimens and improve the treatment outcomes. Recently, accumulating evidence has identified potential prognostic factors for ICI therapy, including tumor mutation burden and tumor microenvironment (TME). Given the distinction between solid tumors and hematological malignancies in terms of TME, we here review the clinical updates of ICIs for lymphoma, and focus on the underlying mechanisms for resistance induced by TME, which play important roles in lymphoma and remarkably influence its sensitivity to ICIs. Particularly, we highlight the value of multiple cell populations (e.g., tumor infiltrating lymphocytes, M2 tumor-associated macrophages, and myeloid-derived suppressor cells) and metabolites (e.g., indoleamine 2, 3-dioxygenase and adenosine) in the TME as prognostic biomarkers for ICI response, and also underline additional potential targets in immunotherapy, such as EZH2, LAG-3, TIM-3, adenosine, and PI3Kδ/γ.

The interferon-inducible protein viperin controls cancer metabolic reprogramming to enhance cancer progression

Metabolic reprogramming is an important cancer hallmark. However, the mechanisms driving metabolic phenotypes of cancer cells are unclear. Here, we show that the interferon-inducible (IFN-inducible) protein viperin drove metabolic alteration in cancer cells. Viperin expression was observed in various types of cancer and was inversely correlated with the survival rates of patients with gastric, lung, breast, renal, pancreatic, or brain cancer. By generating viperin knockdown or stably expressing cancer cells, we showed that viperin, but not a mutant lacking its iron-sulfur cluster-binding motif, increased lipogenesis and glycolysis via inhibition of fatty acid β-oxidation in cancer cells. In the tumor microenvironment, deficiency of fatty acids and oxygen as well as production of IFNs upregulated viperin expression via the PI3K/AKT/mTOR/HIF-1α and JAK/STAT pathways. Moreover, viperin was primarily expressed in cancer stem-like cells (CSCs) and functioned to promote metabolic reprogramming and enhance CSC properties, thereby facilitating tumor growth in xenograft mouse models. Collectively, our data indicate that viperin-mediated metabolic alteration drives the metabolic phenotype and progression of cancer.

Novel Dimeric Architecture of an IFN-γ-Related Cytokine Provides Insights into Subfunctionalization of Type II IFNs in Teleost Fish

Gene duplication leads to subfunctionalization of paralogs. In mammals, IFN-γ is the sole member of the type II IFN family and binds to a receptor complex consisting of IFN-γR1 and IFN-γR2. In teleost fish, IFN-γ and its receptors have been duplicated due to the teleost-specific whole-genome duplication event. In this study, the functions of an IFN-γ-related (IFN-γrel) cytokine were found to be partially retained relative to IFN-γ in grass carp (Ctenopharyngodon idella [CiIFN-γrel]). CiIFN-γrel upregulated the expression of proinflammatory genes but had lost the ability to activate genes involved in Th1 response. The results suggest that CiIFN-γrel could have been subfunctionalized from CiIFN-γ. Moreover, CiIFN-γrel induced STAT1 phosphorylation via interaction with duplicated homologs of IFN-γR1 (cytokine receptor family B [CRFB] 17 and CRFB13). Strikingly, CiIFN-γrel did not bind to the IFN-γR2 homolog (CRFB6). To gain insight into the subfunctionalization, the crystal structure of CiIFN-γrel was solved at 2.26 Å, revealing that it forms a homodimer that is connected by two pairs of disulfide bonds. Due to the spatial positions of helix A, loop AB, and helix B, CiIFN-γrel displays a unique topology that requires elements from two identical monomers to form a unit that is similar to IFN-γ. Further, mutagenesis analyses identified key residues interacting with CiIFN-γrel receptors and those required for the biological functions. Our study can help understand the subfunctionalization of duplicated IFN-γ paralogs in fish.

Modification of the Tumor Microenvironment Enhances Anti-PD-1 Immunotherapy in Metastatic Melanoma

Resistance to checkpoint-blockade treatments is a challenge in the clinic. Both primary and acquired resistance have become major obstacles, greatly limiting the long-lasting effects and wide application of blockade therapy. Many patients with metastatic melanoma eventually require further therapy. The absence of T-cell infiltration to the tumor site is a well-accepted contributor limiting immune checkpoint inhibitor efficacy. In this study, we combined intratumoral injection of plasmid IL-12 with electrotransfer and anti-PD-1 in metastatic B16F10 melanoma tumor model to increase tumor-infiltrating lymphocytes and improve therapeutic efficacy. We showed that effective anti-tumor responses required a subset of tumor-infiltrating CD8+ and CD4+ T cells. Additionally, the combination therapy induced higher MHC-I surface expression on tumor cells to hamper tumor cells escaping from immune recognition. Furthermore, we found that activating T cells by exposure to IL-12 resulted in tumors sensitized to anti-PD-1 treatment, suggesting a therapeutic strategy to improve responses to checkpoint blockade.

Mechanistic and pharmacodynamic studies of DuoBody-CD3x5T4 in preclinical tumor models

CD3 bispecific antibodies (bsAbs) show great promise as anticancer therapeutics. Here, we show in-depth mechanistic studies of a CD3 bsAb in solid cancer, using DuoBody-CD3x5T4. Cross-linking T cells with tumor cells expressing the oncofetal antigen 5T4 was required to induce cytotoxicity. Naive and memory CD4+ and CD8+ T cells were equally effective at mediating cytotoxicity, and DuoBody-CD3x5T4 induced partial differentiation of naive T-cell subsets into memory-like cells. Tumor cell kill was associated with T-cell activation, proliferation, and production of cytokines, granzyme B, and perforin. Genetic knockout of FAS or IFNGR1 in 5T4+ tumor cells abrogated tumor cell kill. In the presence of 5T4+ tumor cells, bystander kill of 5T4− but not of 5T4−IFNGR1− tumor cells was observed. In humanized xenograft models, DuoBody-CD3x5T4 antitumor activity was associated with intratumoral and peripheral blood T-cell activation. Lastly, in dissociated patient-derived tumor samples, DuoBody-CD3x5T4 activated tumor-infiltrating lymphocytes and induced tumor-cell cytotoxicity, even when most tumor-infiltrating lymphocytes expressed PD-1. These data provide an in-depth view on the mechanism of action of a CD3 bsAb in preclinical models of solid cancer.

Chemokines network in bone metastasis: Vital regulators of seeding and soiling

Chemokines are well equipped with chemo-attractive signals that can regulate cancer cell trafficking to specific organ sites. Currently, updated concepts have revealed the diverse role of chemokines in the biology of cancer initiation and progression. Genomic instabilities and alterations drive tumor heterogeneity, providing more options for the selection and metastatic progression to cancer cells. Tumor heterogeneity and acquired drug resistance are the main obstacles in managing cancer therapy and the primary root cause of metastasis. Studies emphasize that multiple chemokine/receptor axis are involved in cancer cell-mediated organ-specific distant metastasis. One of the persuasive mechanisms for heterogeneity and subsequent events is sturdily interlinked with the crosstalk between chemokines and their receptors on cancer cells and tissue-specific microenvironment. Among different metastatic niches, skeletal metastasis is frequently observed in the late stages of prostate, breast, and lung cancer and significantly reduces the survival of cancer patients. Therefore, it is crucial to elucidate the role of chemokines and their receptors in metastasis and bone remodeling. Here, we review the potential chemokine/receptor axis in tumorigenesis, tumor heterogeneity, metastasis, and vicious cycle in bone microenvironment.

Molecular Mechanisms of RSV and Air Pollution Interaction: A Scoping Review

RSV is one of the major infectious agents in paediatrics, and its relationship with air pollution is frequently observed. However, the molecular basis of this interaction is sparsely reported. We sought to systematically review the existing body of literature and identify the knowledge gaps to answer the question: which molecular mechanisms are implied in the air pollutants-RSV interaction? Online databases were searched for original studies published before August 2022 focusing on molecular mechanisms of the interaction. The studies were charted and a narrative synthesis was based upon three expected directions of influence: a facilitated viral entry, an altered viral replication, and an inappropriate host reaction. We identified 25 studies published between 1993 and 2020 (without a noticeable increase in the number of studies) that were performed in human (n = 12), animal (n = 10) or mixed (n = 3) models, and analysed mainly cigarette smoke (n = 11), particulate matter (n = 4), nanoparticles (n = 3), and carbon black (n = 2). The data on a damage to the epithelial barrier supports the hypothesis of facilitated viral entry; one study also reported accelerated viral entry upon an RSV conjugation to particulate matter. Air pollution may result in the predominance of necrosis over apoptosis, and, as an effect, an increased viral load was reported. Similarly, air pollution mitigates epithelium function with decreased IFN-γ and Clara cell secretory protein levels and decreased immune response. Immune response might also be diminished due to a decreased viral uptake by alveolar macrophages and a suppressed function of dendritic cells. On the other hand, an exuberant inflammatory response might be triggered by air pollution and provoke airway hyperresponsiveness (AHR), prolonged lung infiltration, and tissue remodeling, including a formation of emphysema. AHR is mediated mostly by increased IFN-γ and RANTES concentrations, while the risk of emphysema was related to the activation of the IL-17 → MCP-1 → MMP-9 → MMP-12 axis. There is a significant lack of evidence on the molecular basics of the RSV-air pollution interaction, which may present a serious problem with regards to future actions against air pollution effects. The major knowledge gaps concern air pollutants (mostly the influence of cigarette smoke was investigated), the mechanisms facilitating an acute infection or a worse disease course (since it might help plan short-term, especially non-pharmacological, interventions), and the mechanisms of an inadequate response to the infection (which may lead to a prolonged course of an acute infection and long-term sequelae). Thus far, the evidence is insufficient regarding the broadness and complexity of the interaction, and future studies should focus on common mechanisms stimulated by various air pollutants and a comparison of influence of the different contaminants at various concentrations.

Functional Downregulation of PD-L1 and PD-L2 by CpG and non-CpG Oligonucleotides in Melanoma Cells

Simple Summary

Although metastatic melanoma is still not a curable disease, targeting of immunologically relevant checkpoints represents a turning point in the treatment. Particularly, targeting the interaction between PD-L1 and its referring receptor PD-1 with antibodies has been shown to activate T-cell function abrogating the evasion of tumor cells from immune recognition. Here, we present another approach that interferes with this system by showing that treatment of melanoma cells with oligonucleotides reduces the expression of PD-L1 (and PD-L2) on tumor cells. Specifically, non-CpG-6-PTO, an ODN that forms superstructures known as G-quartets, has been found to inhibit the interferon-γ-induced signaling cascade which fosters PD-L1 expression. These findings suggest a new therapeutic strategy to interfere with one of the most important immune checkpoints.

Abstract

The clinical application of immune checkpoint inhibitors represents a breakthrough progress in the treatment of metastasized melanoma and other tumor entities. In the present study, it was hypothesized that oligonucleotides (ODNs), known as modulators of the immune response, have an impact on the endogenous expression of checkpoint molecules, namely PD-L1 and PD-L2 (PD-L1/2). IFNγ-stimulated melanoma cells (A375, SK-Mel-28) were treated with different synthetically manufactured oligonucleotides which differed in sequence, length and backbone composition. It was found that a variety of different ODN sequences significantly suppressed PD-L1/2 expression. This effect was dependent on length and phosphorothioate (PTO) backbone. In particular, a sequence containing solely guanines (nCpG-6-PTO) was highly effective in downregulating PD-L1/2 at the protein, mRNA and promoter levels. Mechanistically, we gave evidence that ODNs with G-quartet-forming motifs suppress the interferon signaling axis (JAK/STAT/IRF1). Our findings identify a subset of ODNs as interesting pharmacological compounds that could expand the arsenal of targeted therapies to combat the immunological escape of tumor cells.

Mechanisms of tumor resistance to immune checkpoint blockade and combination strategies to overcome resistance

Immune checkpoint blockade (ICB) has rapidly transformed the treatment paradigm for various cancer types. Multiple single or combinations of ICB treatments have been approved by the US Food and Drug Administration, providing more options for patients with advanced cancer. However, most patients could not benefit from these immunotherapies due to primary and acquired drug resistance. Thus, a better understanding of the mechanisms of ICB resistance is urgently needed to improve clinical outcomes. Here, we focused on the changes in the biological functions of CD8⁺ T cells to elucidate the underlying resistance mechanisms of ICB therapies and summarized the advanced coping strategies to increase ICB efficacy. Combinational ICB approaches and individualized immunotherapies require further in-depth investigation to facilitate longer-lasting efficacy and a more excellent safety of ICB in a broader range of patients.