Regulation Of Immune Responses Research Articles

Metabolic Regulation of Longevity and Immune Response in Caenorhabditis elegans by Ingestion of Lacticaseibacillus rhamnosus IDCC 3201 Using Multi-Omics Analysis.

Probiotics, specifically Lacticaseibacillus rhamnosus, have garnered attention for their potential health benefits. This study focuses on evaluating the probiotic properties of candidate probiotics L. rhamnosus IDCC 3201 (3201) using the Caenorhabditis elegans surrogate animal model, a well-established in vivo system for studying host-bacteria interactions. The adhesive ability to the host's gastrointestinal tract is a crucial criterion for selecting potential probiotic bacteria. Our findings demonstrated that 3201 exhibits significantly higher adhesive capabilities compared with Escherichia coli OP50 (OP50), a standard laboratory food source for C. elegans and is comparable with the widely recognized probiotic L. rhamnosus GG (LGG). In lifespan assay, 3201 significantly increased the longevity of C. elegans compared with OP50. In addition, preconditioning with 3201 enhanced C. elegans immune response against four different foodborne pathogenic bacteria. To uncover the molecular basis of these effects, transcriptome analysis elucidated that 3201 modulates specific gene expression related to the innate immune response in C. elegans. C-type lectin-related genes and lysozyme-related genes, crucial components of the immune system, showed significant upregulation after feeding 3201 compared with OP50. These results suggested that preconditioning with 3201 may enhance the immune response against pathogens. Metabolome analysis revealed increased levels of fumaric acid and succinic acid, metabolites of the citric acid cycle, in C. elegans fed with 3201 compared with OP50. Furthermore, there was an increase in the levels of lactic acid, a well-known antimicrobial compound. This rise in lactic acid levels may have contributed to the robust defense mechanisms against pathogens. In conclusion, this study demonstrated the probiotic properties of the candidate probiotic L. rhamnosus IDCC 3201 by using multi-omics analysis.

γδ T cells in oral diseases.

γδ T cells are a distinct subset of unconventional T cells, which link innate and adaptive immunity by secreting cytokines and interacting with other immune cells, thereby modulating immune responses. As the first line of host defense, γδ T cells are essential for mucosal homeostasis and immune surveillance. When abnormally activated or impaired, γδ T cells can contribute to pathogenic processes. Accumulating evidence has revealed substantial impacts of γδ T cells on the pathogenesis of cancers, infections, and immune-inflammatory diseases. γδ T cells exhibit dual roles in cancers, promoting or inhibiting tumor growth, depending on their phenotypes and the clinical stage of cancers. During infections, γδ T cells exert high cytotoxic activity in infectious diseases, which is essential for combating bacterial and viral infections by recognizing foreign antigens and activating other immune cells. γδ T cells are also implicated in the onset and progression of immune-inflammatory diseases. However, the specific involvement and underlying mechanisms of γδ T cells in oral diseases have not been systematically discussed. We conducted a systematic literature review using the PubMed/MEDLINE databases to identify and analyze relevant literature on the roles of γδ T cells in oral diseases. The literature review revealed that γδ T cells play a pivotal role in maintaining oral mucosal homeostasis and are involved in the pathogenesis of oral cancers, periodontal diseases, graft-versus-host disease (GVHD), oral lichen planus (OLP), and oral candidiasis. γδ T cells mainly influence various pathophysiological processes, such as anti-tumor activity, eradication of infection, and immune response regulation. This review focuses on the involvement of γδ T cells in oral diseases, with a particular emphasis on the main functions and underlying mechanisms by which γδ T cells influence the pathogenesis and progression of these conditions. This review underscores the potential of γδ T cells as therapeutic targets in managing oral health issues.

Comprehensive analysis and validation reveal DEPDC1 as a potential diagnostic biomarker associated with tumor immunity in non-small-cell lung cancer.

Current evidence suggests that DEP domain containing 1 (DEPDC1) has an important effect on non-small-cell lung cancer (NSCLC). However, the diagnostic value and the regulatory function within NSCLC are largely unclear. This work utilized publicly available databases and in vitro experiments for exploring, DEPDC1 expression, clinical features, diagnostic significance and latent molecular mechanism within NSCLC. According to our results, DEPDC1 was remarkably upregulated in the tissues of NSCLC patients compared with non-carcinoma tissues, linked with gender, stage, T classification and N classification based on TCGA data and associated with smoking status and stage according to GEO datasets. Meanwhile, the summary receiver operating characteristic (sROC) curve analysis result showed that DEPDC1 had a high diagnostic value in NSCLC (AUC = 0.96, 95% CI: 0.94-0.98; diagnostic odds ratio = 99.08, 95%CI: 31.91-307.65; sensitivity = 0.89, 95%CI: 0.81-0.94; specificity = 0.92, 95%CI: 0.86-0.96; positive predictive value = 0.94, 95%CI: 0.89-0.98; negative predictive value = 0.78, 95%CI: 0.67-0.90; positive likelihood ratio = 11.77, 95%CI: 6.11-22.68; and negative likelihood ratio = 0.12, 95%CI: 0.06-0.22). Subsequently, quantitative real-time PCR (qRT-PCR) and western blotting indicated that DEPDC1 was high expressed in NSCLC cells. According to the in vitro MTS and apoptotic assays, downregulated DEPDC1 expression targeting P53 signaling pathway inhibited the proliferation of NSCLC cells while promoting apoptosis of NSCLC cells. Moreover, DEPDC1 was significantly correlated with immune cell infiltrating levels in NSCLC based on TCGA data, which were primarily associated with T cells CD4 memory activated, macrophages M1, B cells memory, mast cells resting, T cells regulatory, monocytes, and T cells CD4 memory resting. Compared with the group with high expression of DEPDC1, the group with low expression level had higher scores for immune checkpoint inhibitors (ICIs) treatment. GSEA confirmed that DEPDC1 was involved in gene expression and tumor-related signaling pathways. Finally, DEPDC1 and its associated immune-related genes were shown to be enriched in 'receptor ligand activity', 'external side of plasma membrane', 'regulation of innate immune response', and 'Epstein-Barr virus infection' pathways. The present study demonstrates that DEPDC1 may contribute to NSCLC tumorigenesis and can be applied as the biomarker for diagnosis and immunology.

Identification of exosome-related gene signature as a promising diagnostic and therapeutic tool for breast cancer

BackgroundExosomes are promising tools for the development of new diagnostic and therapeutic approaches. Exosomes possess the ability to activate signaling pathways that contribute to the remodeling of the tumor microenvironment, angiogenesis, and the regulation of immune responses. We aimed to develop a prognostic score based on exosomes derived from breast cancer. Materials and methodsTraining was conducted on the TCGA-BRCA dataset, while validation was conducted on GSE20685, GSE5764, GSE7904, and GSE29431. A total of 121 genes related to exosomes were retrieved from the ExoBCD database. The Cox proportional hazards model is used to develop risk score model. The GSVA package was utilized to analyze single-sample gene sets and identify exosome signatures, while the WGCNA package was utilized to identify gene modules associated with clinical outcomes. The clusterProfiler and GSVA R packages facilitated gene set enrichment and variation analyses. Furthermore, CIBERSORT quantified immune infiltration, and a correlation between gene expression and drug sensitivity was assessed using the TIDE algorithm. ResultsAn exosome-related prognostic score was established using the following selected genes: ABCC9, PIGR, CXCL13, DOK7, CD24, and IVL. Various immune cells that promote cancer immune evasion were associated with a high-risk prognostic score, which was an independent predictor of outcome. High-risk and low-risk groups exhibited significantly different infiltration abundances (p < 0.05). By conducting a sensitivity comparison, we found that patients with high-risk scores exhibited more favorable responses to immunotherapy than those with low-risk scores. ConclusionThe exosome-related gene signature exhibits outstanding performance in predicting the prognosis and cancer status of patients with breast cancer and guiding immunotherapy.

The experimental study of mir-99a-5p negative regulation of TLR8 receptor mediated-mediated innate immune response in rabbit knee cartilage injury.

Traumatic cartilage injury is an important cause of osteoarthritis (OA) and limb disability, and toll-like receptors (TLRs) mediated innate immune response has been confirmed to play a crucial role in cartilage injury. In the previous study, we found that the activation of TLR8 molecules in injured articular cartilage was more obvious than other TLRs by establishing an animal model of knee impact injury in rabbits, and the changes of TLR8 molecules could significantly affect the process of articular cartilage injury and repair. To verify how mir-99a-5p regulates TLR8 receptor mediated innate immune response to treat traumatic cartilage injury. The impact of a heavy object on the medial condyle of the rabbit's knee joint caused damage to the medial condylar cartilage. Through pathological and imaging analysis, it was demonstrated whether the establishment of an animal model of traumatic cartilage injury was successful. Establishing a cell model by virus transfection of chondrocytes to demonstrate the role of TLR8 in the innate immune response to impact cartilage injury. Through transcriptome sequencing, potential targets of TLR8, mir-99a-5p, were predicted, and basic experiments were conducted to demonstrate how they interact with innate immune responses to impact cartilage damage. TLR8 is a receptor protein of the immune system, which is widely expressed in immune cells. In our study, we found that TLR8 expression is localized in lysosomes and endosomes. Mir-99a-5p can negatively regulate TLR8 to activate PI3K-AKT molecular pathway and aggravate cartilage damage. Inhibiting TLR8expression can effectively reduce the incidence of articular cartilage damage. Based on the results from this study, mir-99a-5p may be an effective molecular marker for predicting traumatic cartilage injury and targeting TLR8 is a novel and promising approach for the prevention or early treatment of cartilage damage.

Identification of molecular characteristics of hepatocellular carcinoma with microvascular invasion based on deep targeted sequencing.

As an indicator of tumor invasiveness, microvascular invasion (MVI) is a crucial risk factor for postoperative relapse, metastasis, and unfavorable prognosis in hepatocellular carcinoma (HCC). Nevertheless, the genetic mechanisms underlying MVI, particularly for Chinese patients, remain mostly uncharted. We applied deep targeted sequencing on 66 Chinese HCC samples. Focusing on the telomerase reverse transcriptase (TERT) promoter (TERTp) and TP53 co-mutation (TERTp+/TP53+) group, gene set enrichment analysis (GSEA) was used to explore the potential molecular mechanisms of the TERTp+/TP53+ group on tumor progression and metastasis. Additionally, we evaluated the tumor immune microenvironment of the TERTp+/TP53+ group in HCC using multiplex immunofluorescence (mIF) staining. Among the 66 HCC samples, the mutated genes that mostly appeared were TERT, TP53, and CTNNB1. Of note, we found 10 cases with TERTp+/TP53+, of which nine were MVI-positive and one was MVI-negative, and there was a co-occurrence of TERTp and TP53 (p < 0.05). Survival analysis demonstrated that patients with the TERTp+/TP53+ group had lower the disease-free survival (DFS) (p = 0.028). GSEA results indicated that telomere organization, telomere maintenance, DNA replication, positive regulation of cell cycle, and negative regulation of immune response were significantly enriched in the TERTp+/TP53+ group (all adjusted p-values (p.adj) < 0.05). mIF revealed that the TERTp+/TP53+ group decreased CD8+ T cells infiltration (p = 0.25) and enhanced PDL1 expression (p = 0.55). TERTp+/TP53+ was significantly enriched in MVI-positive patients, leading to poor prognosis for HCC patients by promoting proliferation of HCC cell and inhibiting infiltration of immune cell surrounding HCC. TERTp+/TP53+ can be utilized as a potential indicator for predicting MVI-positive patients and poor prognosis, laying a preliminary foundation for further exploration of co-mutation in HCC with MVI and clinical treatment.

What is slough? Defining the proteomic and microbial composition of slough and its implications for wound healing.

Slough is a well-known feature of non-healing wounds. This pilot study aims to determine the proteomic and microbiologic components of slough as well as interrogate the associations between wound slough components and wound healing. Ten subjects with slow-to-heal wounds and visible slough were enrolled. Aetiologies included venous stasis ulcers, post-surgical site infections and pressure ulcers. Patient co-morbidities and wound healing outcome at 3-months post-sample collection was recorded. Debrided slough was analysed microscopically, through untargeted proteomics, and high-throughput bacterial 16S-ribosomal gene sequencing. Microscopic imaging revealed wound slough to be amorphous in structure and highly variable. 16S-profiling found slough microbial communities to associate with wound aetiology and location on the body. Across all subjects, slough largely consisted of proteins involved in skin structure and formation, blood-clot formation and immune processes. To predict variables associated with wound healing, protein, microbial and clinical datasets were integrated into a supervised discriminant analysis. This analysis revealed that healing wounds were enriched for proteins involved in skin barrier development and negative regulation of immune responses. While wounds that deteriorated over time started off with a higher baseline Bates-Jensen Wound Assessment Score and were enriched for anaerobic bacterial taxa and chronic inflammatory proteins. To our knowledge, this is the first study to integrate clinical, microbiome, and proteomic data to systematically characterise wound slough and integrate it into a single assessment to predict wound healing outcome. Collectively, our findings underscore how slough components can help identify wounds at risk of continued impaired healing and serves as an underutilised biomarker.

PROGNOSTIC SIGNIFICANCE OF SOCS IN REGULATING CANCER PROGRESSION

Suppressor of cytokine signalling (SOCS) proteins have emerged as crucial regulators in cancer progression, exhibiting significant prognostic implications. This review explores the prognostic significance of SOCS in various cancer types and their role in modulating key signalling pathways involved in tumour growth, metastasis, and immune evasion. Understanding the intricate interplay between SOCS proteins and cancer progression provides valuable insights into developing targeted therapies and prognostic markers for improved patient management and outcomes. SOCS proteins are pivotal regulators of immune responses and inflammation, but their dysregulation has been implicated in cancer development and progression. We explore the mechanisms by which SOCS proteins exert their effects on oncogenic signalling pathways, such as JAK/STAT, PI3K/AKT, and MAPK pathways, highlighting their potential as therapeutic targets. Furthermore, understanding the complex interplay between SOCS proteins and cancer holds promise for the development of novel therapeutic strategies and precision medicine approaches tailored to individual patients.

Type I/II Immune Balance Contributes to the Protective Effect of AIF-1 on Hepatic Immunopathology Induced by Schistosoma japonicum in a Transgenic Mouse Model.

Schistosomiasis is the second most debilitating neglected tropical disease in the world. Liver egg granuloma and fibrosis are the main damage of schistosomiasis. In this study, the role of allograft inflammatory factor-1 (AIF-1) in liver pathology and its regulation in immune responses were investigated in a transgenic mouse infected with Schistosoma japonicum. We found that AIF-1 overexpression reduced worm burden and decreased egg granuloma sizes and serum alanine aminotransferase levels, along with inhibited hepatic collagen deposition and serum hydroxyproline levels during S. japonicum infection. Moreover, AIF-1 overexpression resulted in an increased ratio of Th1/Th2, increased levels of IFN-γ and T-bet, and lower levels of GATA-3 in the spleen, accompanied by increased M1 percentages, decreased M2 percentages, and thus a higher ratio of M1/M2 in the peritoneal cavity and liver. AIF-1 induced CD68 and iNOS mRNA expression and protein levels of cytoplasmic p-P38 and nuclear NF-κB, along with enhanced levels of TNF-α and TGF-β in macrophages in vitro. Moreover, the hepatic pathology had a negative correlation with Th1/Th2 and M1/M2 ratios in the infected mice. The findings reveal that the beneficial role of AIF-1 in alleviating hepatic damage is related to restoring type I/II immune balance in S. japonicum infection.

Myeloid-derived suppressor cell mitochondrial fitness governs chemotherapeutic efficacy in hematologic malignancies

Myeloid derived suppressor cells (MDSCs) are key regulators of immune responses and correlate with poor outcomes in hematologic malignancies. Here, we identify that MDSC mitochondrial fitness controls the efficacy of doxorubicin chemotherapy in a preclinical lymphoma model. Mechanistically, we show that triggering STAT3 signaling via β2-adrenergic receptor (β2-AR) activation leads to improved MDSC function through metabolic reprograming, marked by sustained mitochondrial respiration and higher ATP generation which reduces AMPK signaling, altering energy metabolism. Furthermore, induced STAT3 signaling in MDSCs enhances glutamine consumption via the TCA cycle. Metabolized glutamine generates itaconate which downregulates mitochondrial reactive oxygen species via regulation of Nrf2 and the oxidative stress response, enhancing MDSC survival. Using β2-AR blockade, we target the STAT3 pathway and ATP and itaconate metabolism, disrupting ATP generation by the electron transport chain and decreasing itaconate generation causing diminished MDSC mitochondrial fitness. This disruption increases the response to doxorubicin and could be tested clinically.

Exploring the Role of Extracellular Vesicles in the Pathogenesis of Tuberculosis.

Tuberculosis (TB) remains a significant global health concern, necessitating accurate diagnosis and treatment monitoring. Extracellular vesicles (EVs), including exosomes, play crucial roles in disease progression, with their associated genes serving as potential biomarkers and therapeutic targets. Leveraging publicly available RNA-Seq datasets of TB patients and healthy controls (HCs), to identify differentially expressed genes (DEGs) and their associated protein-protein interaction networks and immune cell profiles, the common EV-related DEGs were identified and validated in the GSE42830 and GSE40553 datasets. We have identified nine common EV-related DEGs (SERPINA1, TNFAIP6, MAPK14, STAT1, ITGA2B, VAMP5, CTSL, CEACAM1, and PLAUR) upregulated in TB patients. Immune cell infiltration analysis revealed significant differences between TB patients and HCs, highlighting increased proportions of various immune cells in TB patients. These DEGs are involved in crucial cellular processes and pathways related to exocytosis and immune response regulation. Notably, VAMP5 exhibited excellent diagnostic performance (AUC-0.993, sensitivity-93.8%, specificity-100%), with potential as a novel biomarker for TB. The EV-related genes can serve as novel potential biomarkers that can distinguish between TB and HCs. VAMP5, which functions in exosome biogenesis and showed significant upregulation in TB, can be targeted for therapeutic interventions and treatment outcomes.

Species-specific responses during Seoul orthohantavirus infection in human and rat lung microvascular endothelial cells.

Seoul orthohantavirus (SEOV) is a rat-borne zoonotic virus that is transmitted via inhalation of aerosolized infectious excreta, and can cause hemorrhagic fever with renal syndrome (HFRS) in humans worldwide. In rats, SEOV predominantly exists as a persistent infection in the absence of overt clinical signs. Lack of disease in rats is attributed to downregulation of pro-inflammatory and upregulation of regulatory host responses. As lung microvascular endothelial cells (LMECs) represent a primary target of infection in both human and rats, infections in these cells provide a unique opportunity to study the central role of LMECs in the dichotomy between pathogenicity in both species. In this study, host responses to SEOV infection in primary human and rat LMECs were directly compared on a transcriptional level. As infection of rat LMECs was more efficient than human LMECs, the majority of anti-viral defense responses were observed earlier in rat LMECs. Most prominently, SEOV-induced processes in both species included responses to cytokine stimulus, negative regulation of innate immune responses, responses to type I and II interferons, regulation of pattern recognition receptor signaling and MHC-I signaling. However, over time, in the rat LMECs, responses shifted from an anti-viral state towards a more immunotolerant state displayed by a PD-L1, B2M-, JAK2-focused interaction network aiding in negative regulation of cytotoxic CD8-positive T cell activation. This suggests a novel mechanism by which species-specific orthohantavirus-induced endothelium and T cell crosstalk may play a crucial role in the development of acute disease in humans and persistence in rodents.

Preclinical characterization of Pan-NKG2D ligand-binding NKG2D receptor decoys

NKG2D and its ligands are critical regulators of protective immune responses controlling infections and cancer, defining a crucial immune signaling axis. Current therapeutic efforts targeting this axis almost exclusively aim at enhancing NKG2D-mediated effector functions. However, this axis can drive disease processes when dysregulated, in particular, driving stem-like cancer cell reprogramming and tumorigenesis through receptor/ligand self-stimulation on tumor cells. Despite complexities with its structure and biology, we developed multiple novel engineered proteins that functionally serve as axis-blocking NKG2D “decoys” and report biochemical, structural, in vitro, and in vivo evaluation of their functionality.

MRNA epitranscriptomics.

Epitranscriptomics refers to chemical changes in RNAs and includes numerous chemical types with varying stoichiometry and functions. RNA modifications are highly diverse in chemistry and respond in cell-type- and cell-state-dependent manners that enable and facilitate the execution of a wide array of biological functions. This includes roles in the regulation of transcription, translation, chromatin maintenance, immune response, and many other processes. This special issue presents the past, present, and future of epitranscriptomics research with a focus on mRNA. It includes perspectives from experts in the field, with the goal of encouraging discussions and debates that will further advance this area of research and enable it to realize its full potential in basic research and applications to human health and disease.

Gut microbiota and prospects for probiotics in paediatric celiac disease

Celiac disease is a chronic disease, with predominant damage to the small intestine and provoked by gluten consumption in genetically predisposed individuals. Previous large-scale studies suggest a possible role of the gut microbiota in the pathogenesis of this disease. Changes in the qualitative and quantitative characteristics of microbiota of different genesis can lead to impaired regulation of immune response, which, in turn, may contribute to the development of gluten intolerance. In this context, it is relevant to analyse the data on changes in the intestinal microbiota in celiac disease and the possibility of its correction with probiotics as one of the strategies for the treatment of children with celiac disease, suffering from celiac disease.

Regulatory SVA retrotransposons and classical HLA genotyped-transcripts associated with Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative and polygenic disorder characterised by the progressive loss of neural dopamine and onset of movement disorders. We previously described eight SINE-VNTR-Alu (SVA) retrotransposon-insertion-polymorphisms (RIPs) located and expressed within the Human Leucocyte Antigen (HLA) genomic region of chromosome 6 that modulate the differential co-expression of 71 different genes including the HLA classical class I and class II genes in a Parkinson's Progression Markers Initiative (PPMI) cohort. In the present study, we (1) reanalysed the PPMI genomic and transcriptomic sequencing data obtained from whole blood of 1521 individuals (867 cases and 654 controls) to infer the genotypes of the transcripts expressed by eight classical HLA class I and class II genes as well as DRA and the DRB3/4/5 haplotypes, and (2) examined the statistical differences between three different PD subgroups (cases) and healthy controls (HC) for the HLA and SVA transcribed genotypes and inferred haplotypes. Significant differences for 57 expressed HLA alleles (21 HLA class I and 36 HLA class II alleles) up to the three-field resolution and four of eight expressed SVA were detected at p<0.05 by the Fisher's exact test within one or other of three different PD subgroups (750 individuals with PD, 57 prodromes, 60 individuals who had scans without evidence of dopamine deficits [SWEDD]), when compared against a group of 654 HCs within the PPMI cohort and when not corrected by the Bonferroni test for multiple comparisons. Fourteen of 20 significant alleles were unique to the PD-HC comparison, whereas 31 of the 57 alleles overlapped between two or more different subgroup comparisons. Only the expressed HLA-DRA*01:01:01 and -DQA1*03:01:01 protective alleles (PD v HC), the -DQA1*03:03:01 risk (HC v Prodrome) or protective allele (PD v Prodrome), the -DRA*01:01:02 and -DRB4*01:03:02 risk alleles (SWEDD v HC), and the NR_SVA_381 present genotype (PD v HC) at a 5% homozygous insertion frequency near HLA-DPA1, were significant (Pc<0.1) after Bonferroni corrections. The homologous NR_SVA_381 insertion significantly decreased the transcription levels of HLA-DPA1 and HLA-DPB1 in the PPMI cohort and its presence as a homozygous genotype is a risk factor (Pc=0.012) for PD. The most frequent NR_SVA_381 insertion haplotype in the PPMI cohort was NR_SVA_381/DPA1*02/DPB1*01 (3.7%). Although HLA C*07/B*07/DRB5*01/DRB1*15/DQB1*06 was the most frequent HLA 5-loci phased-haplotype (n, 76) in the PPMI cohort, the NR_SVA_381 insertion was present in only six of them (8%). These data suggest that expressed SVA and HLA gene alleles in circulating white blood cells are coordinated differentially in the regulation of immune responses and the long-term onset and progression of PD, the mechanisms of which have yet to be elucidated.

Foot-and-mouth disease virus VP1 degrades YTHDF2 through autophagy to regulate IRF3 activity for viral replication

ABSTRACT Many viruses, including foot-and-mouth disease virus (FMDV), can promote the degradation of host proteins through macroautophagy/autophagy, thereby promoting viral replication. However, the regulatory mechanism between autophagy and innate immune responses is not fully understood during FMDV infection. Here, we found that the host GTPBP4/NOG1 (GTP binding protein 4) is a negative regulator of innate immune responses. GTPBP4 deficiency promotes the antiviral innate immune response, resulting in the ability of GTPBP4 to promote FMDV replication. Meanwhile, GTPBP4-deficient mice are more resistant to FMDV infection. To antagonize the host’s antiviral immunity, FMDV structural protein VP1 promotes the expression of GTPBP4, and the 209th site of VP1 is responsible for this effect. Mechanically, FMDV VP1 promotes autophagy during virus infection and interacts with and degrades YTHDF2 (YTH N6-methyladenosine RNA binding protein F2) in an AKT-MTOR-dependent autophagy pathway, resulting in an increase in GTPBP4 mRNA and protein levels. Increased GTPBP4 inhibits IRF3 binding to the Ifnb/Ifn-β promoter, suppressing FMDV-induced type I interferon production. In conclusion, our study revealed an underlying mechanism of how VP1 negatively regulates innate immunity through the autophagy pathway, which would contribute to understanding the negative regulation of host innate immune responses and the function of GTPBP4 and YTHDF2 during FMDV infection. Abbreviation: 3-MA:3-methyladenine; ACTB: actin beta; ATG: autophagy related; ChIP:chromatin immunoprecipitation; CQ: chloroquine; DAPI:4’,6-diamidino-2-phenylindole; dpi: days post-infection; EV71:enterovirus 71; FMDV: foot-and-mouth disease virus; GTPBP4/NOG1: GTPbinding protein 4; HIF1A: hypoxia inducible factor 1 subunit alpha;hpt:hours post-transfection; IFNB/IFN-β:interferon beta; IRF3: interferon regulatory factor 3; MAP1LC3/LC3:microtubule associated protein 1 light chain 3; MAVS: mitochondriaantiviral signaling protein; MOI: multiplicity of infection; MTOR:mechanistic target of rapamycin kinase; m6A: N(6)-methyladenosine;qPCR:quantitativePCR; SIRT3:sirtuin 3; SQSTM1/p62: sequestosome 1; STING1: stimulator ofinterferon response cGAMP interactor 1; siRNA: small interfering RNA;TBK1: TANK binding kinase 1; TCID50:50% tissue culture infectious doses; ULK1: unc-51 like autophagyactivating kinase 1; UTR: untranslated region; WT: wild type; YTHDF2:YTH N6-methyladenosine RNA binding protein F2

Abstract 1394: The CXCL10-CXCR3 axis as Jekyll and Hyde: A regulator of metastasis and immune response in osteosarcoma

Abstract The CXCL10-CXCR3 axis is known to promote tumor growth and metastasis via autocrine signaling, while it can also elicit anti-tumor responses by paracrine signaling. However, its roles are still elusive in osteosarcoma (OS), the most common malignant bone tumor in children. In this study, we utilized in vitro assays, mouse models, and gene expression analysis to characterize the roles of the CXCL10-CXCR3 axis in OS. To understand the autocrine signaling, we performed in vitro phenotypic assays on three OS cell lines with and without CXCL10. The results showed that the chemokine increased AKT phosphorylation and tumor cell migration. Using a CRISPR-based CXCR3 deletion mutant, we demonstrated that the lack of the receptor inhibited OS tumor growth and pulmonary metastasis in an orthotopic xenograft mouse model. The results indicate that the CXCL10-CXCR3 axis is sufficient and necessary to promote aggressive phenotypes in OS via autocrine signaling. Next, using gene expression datasets from two cohorts of OS patients, we showed that high expression of CXCL10 or its cognate receptor CXCR3 was associated with a better prognosis. Since CXCL10 is known to recruit CXCR3+ immune cells to fight against cancer, we further found that the expression of the T cell marker CD3D was associated with a better prognosis. These results suggest that the chemokine may also play a protective role in osteosarcoma by recruiting anti-tumor immune cells via paracrine signaling. Lastly, we have previously reported that a high circulating level of CXCL10 correlates with a poor prognosis in osteosarcoma patients. In this study, we demonstrated that increasing the circulating CXCL10 level in immunodeficient orthotopic xenograft mouse models of OS did not significantly promote the development of pulmonary metastases, suggesting circulating CXCL10 may exert its chemotactic effect mainly on immune cells, not on tumor cells. Taken together, we propose a model that tumor expression of CXCL10 promotes osteosarcoma growth and metastasis development via autocrine signaling. The increase of the local level of CXCL10 attracts CXCR3+ immune cells to the tumor site and promotes anti-tumor function via paracrine signaling. Metastatic cells colonize the lungs and cause tissue damage and inflammation, which increases the production of CXCL10 in the circulation. The higher circulating CXCL10 recruits T cells away from the primary tumor site and indicates the occurrence of metastasis and, hence, correlates with a worse outcome in patients. Our research highlights the importance of understanding the opposite effects of CXCL10 on tumor and immune cells as well as in the tumor microenvironment and circulation. Identification of the mechanistic differences in the CXCL10-CXCR3 signaling between tumor and immune cells will provide a novel therapeutic approach against tumor cells while promoting anti-tumor immune response in OS. Citation Format: Benjamin B. Gyau, Xiang Chen, Junyan Wang, Margaret A. Clement, Angela M. Major, Jun Xu, M. John Hicks, Tsz-Kwong Man. The CXCL10-CXCR3 axis as Jekyll and Hyde: A regulator of metastasis and immune response in osteosarcoma [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 1394.

Abstract 6003: The TNF-α-induced protein 3-interacting protein1 (TNIP1) suppresses HGF mediated NF-kB pathway activation and growth in gastric cancer cells

Abstract Background: TNF-α-induced protein 3-interacting protein 1 (TNIP1), an integral component in the regulation of immune responses and cellular pathways, is gaining increased attention in the scientific community. Its ability to interact with A20, a crucial ubiquitin-editing enzyme, forms a significant part of the body's mechanism to control inflammation and prevent unregulated immune responses, which are pivotal in the pathogenesis of autoimmune diseases. TNIP1's role extends beyond autoimmunity; it is also implicated in the regulation of cancer cell proliferation and survival, making it a potential target in cancer therapy. However, TNIP1 has not yet been elucidated on the tumorigenesis, proliferation, and invasion of human gastric cancer, and needs to be researched and discovered. In this study, the HGF-mediated association of TNIP1, nuclear factor kappa-B (NF-κB), and matrix metalloproteinase 9 (MMP9) and cancer cell proliferation and invasion were investigated in two types of human gastric cancer cell lines. Methods: In this study, cell culture, cDNA microarray analysis, western blotting, Real-Time Polymerase chain reaction, Zymography, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, TNIP1 knock-down with short hairpin RNA (shRNA), apoptosis, reagents and antibodies, standard two chamber invasion assay. Results: In our study on gastric cancer cells, we found that hepatocyte growth factor (HGF) stimulation altered TNIP1 expression at both mRNA and protein levels, indicating a dynamic interaction between HGF and TNIP1. The use of LY294002, a PI3K/AKT pathway inhibitor, revealed TNIP1's involvement in the NF-kB pathway, showing changes in NFkB and TNIP1 expression post-HGF stimulation. TNIP1-shRNA expressing cells exhibited altered expression of p53, BCL-2, NFkB, and MMP9, markers crucial for tumor progression and metastasis. Notably, TNIP1 knockdown led to increased cell proliferation and enhanced invasion capabilities in gastric cancer cells. Furthermore, TNIP1 knockdown cells showed a significant decrease in apoptosis rates upon HGF treatment, as confirmed by propidium iodide staining and FACS analysis. Conclusions: In conclusion, our results demonstrate that TNIP1 is closely associated with the NF-kB pathway and plays a critical role in modulating tumor invasion and apoptosis in gastric cancer cells. These findings suggest that TNIP1 could be a potential therapeutic target for the treatment of gastric cancer, providing new insights into the mechanisms of tumor progression and the development of targeted therapies. Citation Format: Jiyoon Jung, Sungae Koh, Kyunghee Lee. The TNF-α-induced protein 3-interacting protein1 (TNIP1) suppresses HGF mediated NF-kB pathway activation and growth in gastric cancer cells [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 6003.

Abstract 7517: Integrating in situ proximity ligation assay for PD1-PDL1 interaction with multiplexed immunofluorescence imaging

Abstract Background: Programmed cell death protein 1 (PD1) and its ligand PD-L1 are pivotal components of the immune checkpoint machinery, playing a crucial role in the regulation of immune responses in cancer. The interaction between PD1 and PD-L1 is a significant therapeutic target in oncology, as its inhibitors have shown improved outcomes across a variety of malignancies. However, the treatment response to immunotherapies such as pembrolizumab has shown a modest response (~30%) in previous studies. This could be explained by the lack of molecular insight pertaining to the interaction of PD1 on T-cells and PD-L1 in the tumor cells in malignant tissues at the time of clinical diagnosis. The recent development of in situ Proximity Ligation Assay (isPLA), marks a significant advancement in the field. This method allows for the visualization of direct protein interactions within tissues, for example between PD1 and PD-L1. This adds an important layer of information compared to multiplexed immunofluorescence, which is useful for deep phenotyping of cell types in a tissue but lacks the ability to detect direct interactions between specific cells. Methods: PD-L1-PD1 interactions in human FFPE tonsil and bladder cancer tissue were identified using the NaveniFlex Tissue Atto647N kit, following the guidelines provided by the manufacturer. This method is capable of detecting proteins within a proximity of less than 40 nm, utilizing oligonucleotide-antibody conjugates that generate an enhanced fluorescent signal. After completing the Naveni® detection process, we performed multiplexed immunofluorescence (IF) using the Phenocycler platform and a panel of 14 barcoded antibodies, to generate isPLA and multiplexed IF data on the same tissue section. Results &amp; Discussion: We have successfully established an automated workflow for the isPLA protocol. In this work, we aim to continue this effort and combine the isPLA, with downstream highly multiplexed immunofluorescence using the Phenocycler platform. We have generated proof of concept data for the successful integration of the two methods, using tonsil and bladder cancer tissue to detect protein interactions between PD1 and PD-L1, as well as phenotypic profiling of the tumor microenvironment with a 14 plex panel. This panel allows us to phenotype the relevant cell types (B cells, dendritic cells, T cells, macrophages, tumor cells and their proliferation status) and subsets of T-cells like cytotoxic CD8+ cells. The integration of the isPLA and multiplexed IF is poised to significantly advance our understanding of the TME and hopefully aid in patient stratification for immune checkpoint inhibition therapy. The clinical significance of this method integration will later be explored in a retrospective cohort of muscle invasive bladder cancer, receiving immune checkpoint inhibition therapy with pembrolizumab as a second line treatment. Citation Format: Tony Ullman, David Krantz, Hampus Elofsson, Carolina Oses Sepulveda, Agata Zieba-Wicher, Päivi Östling, Anders Ullén, Subham Basu, Charlotte Stadler. Integrating in situ proximity ligation assay for PD1-PDL1 interaction with multiplexed immunofluorescence imaging [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 7517.