Interferon Family Research Articles

Vascular endothelial growth factor A inhibition remodels the transcriptional signature of lipid metabolism in psoriasis non‐lesional skin in 12 h ex vivo culture

AbstractBackgroundVascular endothelial growth factor A (VEGF‐A)‐mediated angiogenesis is involved in the pathogenesis of psoriasis. VEGF‐A inhibitors are widely used to treat oncological and ophthalmological diseases but have not been used in psoriasis management. The molecular mechanisms underlying the effects of VEGF‐A inhibition in psoriatic skin remain unknown.ObjectivesTo identify the genes and canonical pathways affected by VEGF‐A inhibition in non‐lesional and plaque skin ex vivo.MethodsTotal RNA sequencing was performed on skin biopsies from patients with psoriasis (n = 6; plaque and non‐lesional skin) and healthy controls (n = 6) incubated with anti‐VEGF‐A monoclonal antibody (bevacizumab, Avastin®) or human IgG1 isotype control for 12 h in serum‐free organ culture. Differentially expressed genes between paired control and treated samples with adjusted p‐values <0.1 were considered significant. Gene ontology and ingenuity pathway analysis was used to identify enriched biological processes, canonical pathways and upstream regulators.ResultsVEGF‐A inhibition upregulated the expression of genes involved in lipid metabolism. Pathway enrichment analysis identified the activation of pathways involved in fatty acids and lipid biosynthesis and degradation in non‐lesional skin and ferroptosis in plaque skin. VEGF‐A inhibition downregulated endothelial cell apoptosis in non‐lesional psoriasis skin and members of the interferon family were identified as potential regulators of the effects of VEGF‐A inhibition in non‐lesional skin.ConclusionEarly response to VEGF‐A inhibition is associated with changes in lipid metabolism in non‐lesional psoriasis skin and cellular stress in psoriasis plaque. More investigation is needed to validate these findings.

The molecular dynamics simulation of coronavirus- based compound (6OHW structure) interaction with interferon beta-1a protein at different temperatures and pressures: Virus destruction process

The Interferon beta-1a protein is a cytokine in the Interferon family that is used to treat a variety of ailments. Molecular Dynamics simulation was used to characterize the atomic disintegration of 6OHW structure of a corona virus-based compound with Interferon beta-1a protein in this computational study. Molecular Dynamics simulation results on the atomic evolution of the 6OHW structure were presented with estimating physical variables. Physically, our simulations showed the attraction forces between the virus and the atomic protein in the presence of H2O molecules, resulting in viral annihilation after t = 10 ns. The molecular dynamics package's initial pressure and temperature (Temp) changes were important for virus-protein system evolution. Numerically, increasing primary T and P from 300 K and 1 bar to 350 K and 5 bar reduced the atomic distance between virus and protein structures from 10 Å to 2.71 Å and 2.45 Å. Bonding energy was another reported physical quantity in our Molecular Dynamics simulation work. The atomic parameter ranged from 152.57 kcal/mol to 148.54 kcal/mol due to changes in initial Temp and pressure. Ultimately, the diffusion coefficient of protein being simulated inside the atomic virus changed from 0.48 μm2/s to 0.59 μm2/s. This calculation demonstrated the suitable conduct of simulated protein throughout virus destruction process.

Targeting Interferon Signalling in Systemic Lupus Erythematosus: Lessons Learned.

The development of new medicines for systemic lupus erythematosus (SLE) has not addressed unmet clinical need, with only three drugs receiving regulatory approval for SLE in the last 60years, one of which was specifically licensed for lupus nephritis. In the last 20years it has become clear that activation of type 1 interferons (IFN) is reproducibly detected in the majority of SLE patients, and the actions of IFN in the immune system and on target tissues is consistent with a pathogenic role in SLE. These findings led to considerable drug discovery activity, first with agents directly targeting IFN family cytokines, with results that were encouraging but underwhelming. In contrast, targeting the type I IFN receptor with the monoclonal antibody anifrolumab, thereby blocking all IFN family members, was effective in a phase II clinical trial. This led to a pair of phase III trials, one of which was negative and the other positive, reflecting the difficulty of obtaining outcomes from trials in this complex disease. Nonetheless, the balance of evidence resulted in approval of anifrolumab in multiple jurisdictions from 2021 onwards. Multiple approaches to targeting the type 1 IFN pathway have subsequently had positive phase II clinical trials, including antibodies targeting cells that produce IFN, and small molecules targeting the receptor kinase TYK2, required for IFN signalling. Despite multiple hurdles, it is clear that IFN targeting in SLE is here to stay. The story of IFN-targeting therapy in SLE has lessons for drug development overall in this disease.

Osteoporosis: interferon-gamma-mediated bone remodeling in osteoimmunology.

As the world population ages, osteoporosis, the most common disease of bone metabolism, affects more than 200 million people worldwide. The etiology is an imbalance in bone remodeling process resulting in more significant bone resorption than bone remodeling. With the advent of the osteoimmunology field, the immune system's role in skeletal pathologies is gradually being discovered. The cytokine interferon-gamma (IFN-γ), a member of the interferon family, is an important factor in the etiology and treatment of osteoporosis because it mediates bone remodeling. This review starts with bone remodeling process and includes the cellular and key signaling pathways of bone remodeling. The effects of IFN-γ on osteoblasts, osteoclasts, and bone mass are discussed separately, while the overall effects of IFN-γ on primary and secondary osteoporosis are summarized. The net effect of IFN-γ on bone appears to be highly dependent on the environment, dose, concentration, and stage of cellular differentiation. This review focuses on the mechanisms of bone remodeling and bone immunology, with a comprehensive discussion of the relationship between IFN-γ and osteoporosis. Finding the paradoxical balance of IFN-γ in bone immunology and exploring the potential of its clinical application provide new ideas for the clinical treatment of osteoporosis and drug development.

Schlafens: Emerging Therapeutic Targets.

The interferon (IFN) family of immunomodulatory cytokines has been a focus of cancer research for over 50 years with direct and indirect implications in cancer therapy due to their properties to inhibit malignant cell proliferation and modulate immune responses. Among the transcriptional targets of the IFNs is a family of genes referred to as Schlafens. The products of these genes, Schlafen proteins, exert important roles in modulating cellular proliferation, differentiation, immune responses, viral replication, and chemosensitivity of malignant cells. Studies have demonstrated that abnormal expression of various Schlafens contributes to the pathophysiology of various cancers. Schlafens are now emerging as promising biomarkers and potentially attractive targets for drug development in cancer research. Here, we highlight research suggesting the use of Schlafens as cancer biomarkers and the rationale for the development of specific drugs targeting Schlafen proteins.

Unpaired cysteine insertions favor transmembrane dimerization and induce ligand-independent constitutive cytokine receptor signaling.

Naturally occurring gain-of-function (GOF) mutants have been identified in patients for a variety of cytokine receptors. Although this constitutive activation ofcytokine receptors is strongly associated with malignant disorders, ligand-independent receptor activation is also a useful tool in synthetic biology e.g. to improve adoptive cellular therapies with genetically modified T-cells. Balanced Interleukin (IL-)7 signaling via a heterodimer of IL-7 receptor (IL-7Rα) and the common γ-chain (γc) controls T- and B-cell development and expansion, whereas uncontrolled IL-7 signaling can drive acute lymphoid leukemia (ALL) development. The ALL-driver mutation PPCL in the transmembrane domain of IL-7Rα is a mutational insertion of the four amino acids proline-proline-cysteine-leucine and leads to ligand-independent receptor dimerization and constitutive activation. We showed here in the cytokine-dependent pre-B-cell line Ba/F3 that the PPCL-insertion in a synthetic version of the IL-7Rα induced γc-independent STAT5 and ERKphosphorylation and also proliferation of the cells and that booster-stimulation by arteficial ligands additionally generated non-canonical STAT3 phosphorylation via the synthetic IL-7Rα-PPCL-receptors. Transfer of theIL-7Rα transmembrane domain with the PPCL insertion intonatural and synthetic cytokine receptor chains of the IL-6, IL-12 and Interferon families also resulted in constitutive receptor signaling. In conclusion, our data suggested that the insertion of the mutated PPCL IL-7Rα transmembrane domain is an universal approach to generate ligand-independent, constitutively active cytokine receptors.

Standing on Shoulders: Interferon Research From Viral Interference to Lupus Pathogenesis and Treatment.

The discovery of interferon in the 1950s represents much more than the identification of the first cytokine and the key mediator of antiviral host defense. Defining the molecular nature and complexity of the type I interferon family, as well as its inducers and molecular mechanisms of action, was the work of investigators working at the highest level and producing insights of great consequence. Current knowledge of receptor-ligand interactions, cell signaling, and transcriptional regulation derives from studies of type I interferon. It is on the shoulders of the giants who produced that knowledge that others stand and have revealed critical mechanisms of the pathogenesis of systemic lupus erythematosus and other autoimmune diseases. The design of novel therapeutics is informed by the advances in investigation of type I interferon, with the potential for important impact on patient management.

Abstract 94: Interrogation of STING induced cytokines in the tumor microenvironment using an Integrated MultiOmyx-RNAscope panel for spatial and quantitative profiling

Abstract The STING (Stimulator of Interferon Genes) pathway is a pivotal player in the innate immune response, responsible for detecting cytosolic accumulation of endogenous DNA and initiating a cascade of events leading to the production of pro-inflammatory type I interferons, which promote an antitumor environment through activation of T cells, dendritic cells, and natural killer cells. Therefore, STING agonists are currently being explored as a potential therapeutic for cancer treatment, often in combination with immune checkpoint inhibitors. While the STING pathway can be stimulated in multiple cell types, activation in antigen presenting cells, such as dendritic cells (DC), is crucial for antitumor activity in the tumor microenvironment (TME). Additionally, the type 1 interferon family consists of multiple subtypes, including IFNb and IFNa, which can produce differential biological responses. Although the STING pathway is known to induce expression of multiple cytokines, combined spatial characterization of STING and type I interferons in the TME has not been performed. To characterize STING-interferon expression in the TME, we use the Integrated MultiOmyx-RNAscope platform. MultiOmyxTM (NeoGenomics Laboratories, Inc) is a proprietary multiplex immunofluorescence (mIF) platform for the visualization and characterization of up to 60 protein biomarkers in a single formalin-fixed paraffin-embedded (FFPE) section and offers high-resolution spatial and quantitative analysis of protein expression in tissue samples. RNAscopeTM (Bio-Techne) Multiplex is a highly sensitive fluorescent in-situ hybridization (ISH) assay that can detect up to 3 RNA markers in a single FFPE section. The Integrated MultiOmyx-RNAscope assay allows for simultaneous detection of both protein and RNA markers in a single sample. Herein we report the design and use of a novel panel of commercially-available antibodies and ISH probes broad enough to characterize various immune subpopulations and cytokine expressing cells, including DCs and interferons, in the TME of a variety of tumor indications including melanoma and head and neck squamous cell carcinoma. Quantification and analysis will be performed using NeoLYTXTM, the proprietary MultiOmyx Analytics pipeline, to examine the spatial distribution and expression levels of key STING pathway induced cytokines to elucidate the dynamic communication of signaling molecules and their localization within specific cell populations. Understanding of the variety and phenotype of STING/cytokine expressing cells in the TME is crucial to define the populations being targeted by therapies for cancer treatment. Citation Format: Sandra Lam, Courtney Todorov, Jiong Fei, Harry Nunns, Eric Leones, Marianne Thio, Flora Sahafi, Erinn Parnell, Qingyan Au. Interrogation of STING induced cytokines in the tumor microenvironment using an Integrated MultiOmyx-RNAscope panel for spatial and quantitative profiling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 94.

Interferon inducible guanylate-binding protein 1 modulates the lipopolysaccharide-induced cytokines/chemokines and mitogen-activated protein kinases in macrophages.

Guanylate-binding proteins (GBPs) are a family of interferon (IFN)-inducible GTPases and play a pivotal role in the host immune response to microbial infections. These are upregulated in immune cells after recognizing the lipopolysaccharides (LPS), the major membrane component of Gram-negative bacteria. In the present study, the expression pattern of GBP1-7 was initially mapped in phorbol 12-myristate 13-acetate-differentiated human monocytes THP-1 and mouse macrophages RAW 264.7 cell lines stimulated with LPS. A time-dependent significant expression of GBP1-7 was observed in these cells. Moreover, among the various GBPs, GBP1 has emerged as a central player in regulating innate immunity and inflammation. Therefore, to study the specific role of GBP1 in LPS-induced inflammation, knockdown of the Gbp1 gene was carried out in both cells using small interfering RNA interference. Altered levels of different cytokines (interleukin [IL]-4, IL-10, IL-12β, IFN-γ, tumor necrosis factor-α), inducible nitric oxide synthase, histocompatibility 2, class II antigen A, protein kinase R, and chemokines (chemokine (C-X-C motif) ligand 9[CXCL9],CXCL10, and CXCL11) in GBP1 knockdown cells were reported compared to control cells. Interestingly, the extracellular-signal-regulated kinase 1/2 mitogen-activated protein (MAP) kinases and signal transducer and activator of transcription 1 (STAT1) transcription factor levels were considerably induced in knockdown cells compared to the control cells. However, no change in the level of phosphorylated nuclear factor-kB, c-Jun, and p38 transcription factors was observed in GBP1 knockdown cells compared to the control cells. This study concludes that GBP1 may alter the expression of cytokines, chemokines, and effector molecules mediated by MAP kinases and STAT1 transcription factors.

SOCS1 is a critical checkpoint in immune homeostasis, inflammation and tumor immunity.

The Suppressor of Cytokine Signaling (SOCS) family proteins are important negative regulators of cytokine signaling. SOCS1 is the prototypical member of the SOCS family and functions in a classic negative-feedback loop to inhibit signaling in response to interferon, interleukin-12 and interleukin-2 family cytokines. These cytokines have a critical role in orchestrating our immune defence against viral pathogens and cancer. The ability of SOCS1 to limit cytokine signaling positions it as an important immune checkpoint, as evidenced by the detection of detrimental SOCS1 variants in patients with cytokine-driven inflammatory and autoimmune disease. SOCS1 has also emerged as a key checkpoint that restricts anti-tumor immunity, playing both a tumor intrinsic role and impacting the ability of various immune cells to mount an effective anti-tumor response. In this review, we describe the mechanism of SOCS1 action, focusing on the role of SOCS1 in autoimmunity and cancer, and discuss the potential for new SOCS1-directed cancer therapies that could be used to enhance adoptive immunotherapy and immune checkpoint blockade.

Crosstalk Between Microbiota, Microbial Metabolites, and Interferons in the Inflammatory Bowel Disease Gut.

With the prevalence of inflammatory bowel diseases (IBD) continuing to rise in Canada and globally, developing improved therapeutics that successfully treat greater percentages of patients with reduced complications is paramount. A better understanding of pertinent immune pathways in IBD will improve our ability to both successfully dampen inflammation and promote gut healing, beyond just inhibiting specific immune proteins; success of combination therapies supports this approach. Interferons (IFNs) are key cytokines that protect mucosal barrier surfaces, and their roles in regulating gut homeostasis and inflammation differ between the three IFN families (type I, II, and III). Interestingly, the gut microbiota and microbial metabolites impact IFN-signaling, yet how this system is impacted in IBD remains unclear. In this review, we discuss the current knowledge of how gut microbiota directly or indirectly impact IFN levels/responses, and what is known about IFNs differentially regulating gut homeostasis and inflammation in animal models or patients with IBD.

IFN-γ lowers tumor growth by increasing glycolysis and lactate production in a nitric oxide-dependent manner: implications for cancer immunotherapy.

Interferon-gamma (IFN-γ), the sole member of the type-II interferon family, is well known to protect the host from infectious diseases as well as mount anti-tumor responses. The amounts of IFN-γ in the tumor microenvironment determine the host responses against tumors; however, several tumors employ evasive strategies by responding to low IFN-γ signaling. In this study, the response of various tumor cell lines to IFN-γ was studied in vitro. IFN-γ-activation increases glycolytic flux and reduces mitochondrial function in a nitric oxide (NO)- and reactive oxygen species (ROS)-dependent manner in the H6 hepatoma tumor cell line. The higher glycolysis further fueled NO and ROS production, indicating a reciprocal regulation. These processes are accompanied by Hypoxia inducing factor (HIF)-1α stabilization and HIF-1α-dependent augmentation of the glycolytic flux. The IFN-γ enhancement of lactate production also occurred in other NO-producing cell lines: RAW 264.7 monocyte/macrophage and Renca renal adenocarcinoma. However, two other tumor cell lines, CT26 colon carcinoma and B16F10 melanoma, did not produce NO and lactate upon IFN-γ-activation. HIF-1α stabilization upon IFN-γ-activation led to lower cell growth of B16F10 but not CT26 cells. Importantly, the IFN-γ-activation of both CT26 and B16F10 cells demonstrated significant cellular growth reduction upon metabolic rewiring by exogenous administration of potassium lactate. Clinical studies have shown the crucial roles of IFN-γ for successful cancer immunotherapies involving checkpoint inhibitors and chimeric antigen receptor T cells. The positive implications of this study on the metabolic modulation of IFN-γ activation on heterogeneous tumor cells are discussed.

Unveiling the Role of MX1 and MX2 Gene Expression in Early Pregnancy of Kari Ewes: Insights into INF-tau Signaling and Potential as a Predictive Biomarker for Pregnancy Detection in Domestic Ruminants

Myxovirus resistance (MX) genes are relevant to a family of interferon (IFN)-stimulated genes. In domestic ruminants such as ewes and cattle, the MX genes have two isoforms called the Myxovirus Resistance 1 (MX1) gene and the Myxovirus Resistance 2 (MX2) gene. INF-tau (INFt) is released from embryonic trophoblast cells in the early days of pregnancy and induces expression of MX genes in the uterine endometrium. In the present study, we summarized the relative expression of the MX1 and MX2 genes during the early days of pregnancy in Kari ewes. Blood samples were taken from inseminated and non-inseminated (control) ewes on different days. Peripheral Blood Monocytes (PBMC) were isolated, and with the addition of MX1 and MX2 gene primers, complementary deoxyribonucleic acid (cDNA) was synthesized by Reverse Transcriptase Polymerase Chain Reaction (RT-PCR). The cDNA was then amplified by rounds of PCR amplification. The amplified product was run on a 2% Agarose gel. The results showed expression of the MX1 and MX2 genes only in pregnant ewes, while no expression was observed in non-pregnant or control ewes. Expression in pregnant ewes was observed on days 14, 16, 17, and 18 after insemination. When comparing the MX1 and MX2 genes, the expression of the MX2 gene was relatively higher than that of the MX1 gene on all experimental days. The result suggested that INF-tau MX genes are expressed during the early days of pregnancy and are involved in the establishment of pregnancy. These results justify the development of this biomarker as a predictive tool for the early detection of pregnancy in ewes and other domestic ruminants.

Auraptene Has Antiviral Activity against Human Coronavirus OC43 in MRC-5 Cells

Auraptene (7-geranyloxycoumarin) is the abundant prenyloxycoumarin found in the fruits of Citrus spp. Auraptene has a variety of pharmacological and therapeutic functions, such as anticancer, antioxidant, immunomodulatory, and anti-inflammation activities, with excellent safety profiles. In this study, we evaluated the anticoronaviral activity of auraptene in HCoV-OC43-infected human lung fibroblast MRC-5 cells. We found that auraptene effectively inhibited HCoV-OC43-induced cytopathic effects with 4.3 μM IC50 and 6.1 μM IC90, resulting in a selectivity index (CC50/IC50) of >3.5. Auraptene treatment also decreased viral RNA levels in HCoV-OC43-infected cells, as detected through quantitative real-time PCR, and decreased the expression level of spike proteins and nucleocapsid proteins in virus-infected cells, as detected through the Western blot analysis and immunofluorescence staining. Time-of-addition analysis showed auraptene’s inhibitory effects at the post-entry stage of the virus life cycle; however, auraptene did not induce the antiviral interferon families, IFN-α1, IFN-β1, and IFN-λ1. Additionally, auraptene-treated MRC-5 cells during HCoV-OC43 infection decreased the MMP-9 mRNA levels which are usually increased due to the infection, as auraptene is a previously reported MMP-9 inhibitor. Therefore, auraptene showed antiviral activity against HCoV-OC43 infection, and we suggest that auraptene has the potential to serve as a therapeutic agent against human coronavirus.

Occludin Regulates HIV-1 Infection by Modulation of the Interferon Stimulated OAS Gene Family

HIV-1-associated blood brain barrier (BBB) alterations and neurocognitive disorders are frequent clinical manifestations in HIV-1 infected patients. The BBB is formed by cells of the neurovascular unit (NVU) and sealed together by tight junction proteins, such as occludin (ocln). Pericytes are a key cell type of NVU that can harbor HIV-1 infection via a mechanism that is regulated, at least in part, by ocln. After viral infection, the immune system starts the production of interferons, which induce the expression of the 2'-5'-oligoadenylate synthetase (OAS) family of interferon stimulated genes and activate the endoribonuclease RNaseL that provides antiviral protection by viral RNA degradation. The current study evaluated the involvement of the OAS genes in HIV-1 infection of cells of NVU and the role of ocln in controlling OAS antiviral signaling pathway. We identified that ocln modulates the expression levels of the OAS1, OAS2, OAS3, and OASL genes and proteins and, in turn, that the members of the OAS family can influence HIV replication in human brain pericytes. Mechanistically, this effect was regulated via the STAT signaling. HIV-1 infection of pericytes significantly upregulated expression of all OAS genes at the mRNA level but selectively OAS1, OAS2, and OAS3 at the protein level. Interestingly no changes were found in RNaseL after HIV-1 infection. Overall, these results contribute to a better understanding of the molecular mechanisms implicated in the regulation of HIV-1 infection in human brain pericytes and suggest a novel role for ocln in controlling of this process.

Interferons and Resistance Mechanisms in Tumors and Pathogen-Driven Diseases-Focus on the Major Histocompatibility Complex (MHC) Antigen Processing Pathway.

Interferons (IFNs), divided into type I, type II, and type III IFNs represent proteins that are secreted from cells in response to various stimuli and provide important information for understanding the evolution, structure, and function of the immune system, as well as the signaling pathways of other cytokines and their receptors. They exert comparable, but also distinct physiologic and pathophysiologic activities accompanied by pleiotropic effects, such as the modulation of host responses against bacterial and viral infections, tumor surveillance, innate and adaptive immune responses. IFNs were the first cytokines used for the treatment of tumor patients including hairy leukemia, renal cell carcinoma, and melanoma. However, tumor cells often develop a transient or permanent resistance to IFNs, which has been linked to the escape of tumor cells and unresponsiveness to immunotherapies. In addition, loss-of-function mutations in IFN signaling components have been associated with susceptibility to infectious diseases, such as COVID-19 and mycobacterial infections. In this review, we summarize general features of the three IFN families and their function, the expression and activity of the different IFN signal transduction pathways, and their role in tumor immune evasion and pathogen clearance, with links to alterations in the major histocompatibility complex (MHC) class I and II antigen processing machinery (APM). In addition, we discuss insights regarding the clinical applications of IFNs alone or in combination with other therapeutic options including immunotherapies as well as strategies reversing the deficient IFN signaling. Therefore, this review provides an overview on the function and clinical relevance of the different IFN family members, with a specific focus on the MHC pathways in cancers and infections and their contribution to immune escape of tumors.

Potential roles of IFI44 genes in high resistance to Vibrio in hybrids of Argopecten scallops

Vibrio bacteria are often fatal to aquatic organisms and selection of Vibrio-resistant strains is warranted for aquaculture animals. In this study, we found that hybrids between bay scallops and Peruvian scallops exhibited significantly higher resistance to Vibrio challenge, but little is available on its mechanism. Interferon induced protein 44 (IFI44), a member of the type I interferon (IFN) family, plays an important role in the IFN immune response in invertebrates, which may also participate in the resistance to Vibrio in scallops. To explore the roles of IFI44 genes in the resistance to Vibrio, they were identified and characterized in the bay scallop (designated as AiIFI44), the Peruvian scallop (designated as ApIFI44), and their reciprocal hybrids (designated as AipIFI44 and ApiIFI44, respectively). Their open reading frame (ORF) sequences were all 1434 bp, encoding 477 amino acids, but with large variations among the four genes. The AipIFI44 and ApiIFI44 exhibited higher similarity with ApIFI44 than with AiIFI44. All four genes have a TLDc structural domain with significant variations in sequences among them. Predicted differences in conformation and posttranslational modifications may lead to altered protein activity. We further demonstrated that the AiIFI44, AipIFI44 and ApiIFI44 expressed in all the tested tissues, with the highest expression in the gills and hepatopancreas. In response to Vibrio anguillarum challenge, the profile of mRNA expression of IFI44 gene differed among the bay scallops and the two hybrids. In the bay scallops, it increased at 6 h but dramatically decreased after 12–48 h. However, the mRNA expression of both AipIFI44 and ApiIFI44 decreased at 6 h but continuously increased thereafter and reached the highest value at 48 h. The results in the present study suggest the immune responds of IFI44 in scallops and it may be related to the higher resistance to Vibrio bacterial in hybrids.

Transcriptomic and antiviral analyses of PoIFN-Delta5 against porcine enteric viruses in porcine intestinal epithelial cells

The interferon-delta family was first reported in domestic pigs and belongs to the type I interferon (IFN-I) family. The enteric viruses could cause diarrhea in newborn piglets with high morbidity and mortality. We researched the function of the porcine IFN-delta (PoIFN-δ) family in the porcine intestinal epithelial cells (IPEC-J2) cells infected with porcine epidemic diarrhea virus (PEDV). Our study found that all PoIFN-δs shared a typical IFN-I signature and could be divided into five branches in the phylogenic tree. Different strains of PEDV could induce typical IFN transitorily, and the virulent strain AH2012/12 had the strongest induction of porcine IFN-δ and IFN-alpha (PoIFN-α) in the early stage of infection. In addition, it was found that PoIFN-δ5/6/9/11 and PoIFN-δ1/2 were highly expressed in the intestine. PoIFN-δ5 had a better antiviral effect on PEDV compared to PoIFN-δ1 due to its higher induction of ISGs. PoIFN-δ1 and PoIFN-δ5 also activated JAK-STAT and IRS signaling. For other enteric viruses, transmissible gastroenteritis virus (TGEV), porcine deltacoronavirus (PDCoV), and porcine rotavirus (PoRV), PoIFN-δ1 and PoIFN-δ5 both showed an excellent antiviral effect. Transcriptome analyses uncovered the differences in host responses to PoIFN-α and PoIFN-δ5 and revealed thousands of differentially expressed genes were mainly enriched in the inflammatory response, antigen processing and presentation, and other immune-related pathways. PoIFN-δ5 would be a potential antiviral drug, especially against porcine enteric viruses. These studies were the first to report the antiviral function against porcine enteric viruses and broaden the new acquaintances of this type of interferon though not novelly discovered.

Abstract P1-04-02: Gut microbiome diversity correlates with tumor PD-L1 status in metastatic triple negative breast cancer (mTNBC): correlative analysis of gut microbiome and tumoral biomarkers

Abstract Background: Greater gut microbiome diversity is observed in patients with a clinical response to immune checkpoint inhibitor (ICI) therapy in solid tumors and in preclinical models targeting the gut microbiome is a promising strategy to improve ICI efficacy. The investigation of the immunomodulatory effects of the gut microbiome and tumor biology is in its infancy and whether interindividual microbiome variations correlate with tumor biology in breast cancer is unknown. Here we report a correlative analysis of gut microbiome diversity with tumor biomarkers: PD-L1, tumor immune cell density, tumor infiltrating lymphocytes (TILs), MutSig3, and interferon (IFN) gene signatures in a cohort of mTNBC patients treated with olaparib and durvalumab of the Adaptive Multi-Drug Treatment of Evolving Cancers (AMTEC) trial (NCT03801369). Methods: AMTEC participants undergo a baseline biopsy (bx) and fecal sample collection, then start olaparib monotherapy on a 28-day cycle. Following the first cycle, an on-treatment (on-tx) bx and fecal sample are collected, then as part of enrollment to Arm 1, durvalumab is added to the treatment regimen. Ten patients with stool collections and tissue biopsies were used in this analysis, eight had paired pre- and on-tx collections. At interim-analysis, participants were categorized as responders (PR/SD) or non-responders (PD). Gut microbiome composition in fecal samples collected pre- and on-olaparib monotherapy was assessed by 16S rRNA sequencing and alpha diversity was quantified by observed diversity, Fisher, Inverse Simpson, Pielou, and Shannon indices. Response, PDL1 expression (Positive CPS >1), multiplex immunohistochemistry (mIHC) immune cell density and immune cell signature, TILs, RNA signatures including interferon (INF) family signatures, and mutational significance (MutSig3) were correlated to alpha diversity by T-test. Results: Average baseline alpha diversity of the fecal microbiome did not vary based on response (6 non-responses and 4 responses). However, in the on-tx samples, Fisher (CB: mean = 21.81, std. dev. = 3.6; PD: mean = 17.04, std. dev. = 2.3; p=0.048) and Observed alpha diversity (CB: mean = 260, std. dev. = 38.8; PD: mean = 209, std. dev. = 25.8; p = 0.049) were higher in responders. Average baseline alpha diversity of the gut microbiome as measured across all examined indices was significantly lower in participants with PD-L1 expressing tumors (p < 0.05 for each, T-test). Among on-tx samples, there was a trend toward lower alpha diversity in PD-L1 expressing tumors, but PD-L1 expression did not correlate with clinical response. There was a notable trend toward greater alpha diversity in on-tx bx and high TILs. Alpha diversity did not differ by immune cell densities by mIHC (CD8+ T cell, B cell, and regulatory T cells), hypo-inflamed/pro-inflammatory signature, IFN gene signature, nor MutSig3 score. Conclusion: Our preliminary data reveal that higher alpha diversity following olaparib monotherapy correlated with response to therapy with combination olaparib and durvalumab and correlated with tumor PD-L1 status. Whether gut microbiome features represent a meaningful biomarker for ICI treatment of mTNBC warrants further study. Enrollment to stage 2 of AMTEC Arm 1 is ongoing. Citation Format: Brie Chun, Shaun Goodyear, Travis Rice-Stitt, Lisa Karstens, Erin Dahl, Allen Li, Evthokia Hobbs, Mitri Zahi. Gut microbiome diversity correlates with tumor PD-L1 status in metastatic triple negative breast cancer (mTNBC): correlative analysis of gut microbiome and tumoral biomarkers [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-04-02.

The Complexity of Interferon Signaling in Host Defense against Protozoan Parasite Infection.

Protozoan parasites, such as Plasmodium, Leishmania, Toxoplasma, Cryptosporidium, and Trypanosoma, are causative agents of health-threatening diseases in both humans and animals, leading to significant health risks and socioeconomic losses globally. The development of effective therapeutic and prevention strategies for protozoan-caused diseases requires a full understanding of the pathogenesis and protective events occurring in infected hosts. Interferons (IFNs) are a family of cytokines with diverse biological effects in host antimicrobial defense and disease pathogenesis, including protozoan parasite infection. Type II IFN (IFN-γ) has been widely recognized as the essential defense cytokine in intracellular protozoan parasite infection, whereas recent studies also revealed the production and distinct function of type I and III IFNs in host defense against these parasites. Decoding the complex network of the IFN family in host-parasite interaction is critical for exploring potential new therapeutic strategies against intracellular protozoan parasite infection. Here, we review the complex effects of IFNs on the host defense against intracellular protozoan parasites and the crosstalk between distinct types of IFN signaling during infections.