Distinct Immune Cell Research Articles

Single-cell landscape and spatial transcriptomic analysis reveals macrophage infiltration and glycolytic metabolism in kidney renal clear cell carcinoma.

The present study investigates the clinical relevance of glycolytic factors, specifically PGAM1, in the tumor microenvironment of kidney renal clear cell carcinoma (KIRC). Despite the established role of glycolytic metabolism in cancer pathophysiology, the prognostic implications and key targets in KIRC remain elusive. We analyzed GEO and TCGA datasets to identify DEGs in KIRC and studied their relationship with immune gene expression, survival, tumor stage, gene mutations, and infiltrating immune cells. We explored Pgam1 gene expression in different kidney regions using spatial transcriptomics after mouse kidney injury analysis. Single-cell RNA-sequencing was used to assess the association of PGAM1 with immune cells. Findings were validated with tumor specimens from 60 KIRC patients, correlating PGAM1 expression with clinicopathological features and prognosis using bioinformatics and immunohistochemistry. We demonstrated the expression of central gene regulators in renal cancer in relation to genetic variants, deletions, and tumor microenvironment. Mutations in these hub genes were positively associated with distinct immune cells in six different immune datasets and played a crucial role in immune cell infiltration in KIRC. Single-cell RNA-sequencing revealed that elevated PGAM1 was associated with immune cell infiltration, specifically macrophages. Furthermore, pharmacogenomic analysis of renal cancer cell lines indicated that inactivation of PGAM1 was associated with increased sensitivity to specific small-molecule drugs. Altered PGAM1 in KIRC is associated with disease progression and immune microenvironment. It has diagnostic and prognostic implications, indicating its potential in precision medicine and drug screening.

Immune Profile Determines Response to Vaccination against COVID-19 in Kidney Transplant Recipients.

Immune status profile can predict response to vaccination, while lymphocyte phenotypic alterations represent its effectiveness. We prospectively evaluated these parameters in kidney transplant recipients (KTRs) regarding Tozinameran (BNT162b2) vaccination. In this prospective monocenter observational study, 39 adult KTRs, on stable immunosuppression, naïve to COVID-19, with no protective humoral response after two Tozinameran doses, received the third vaccination dose, and, based on their immunity activation, they were classified as responders or non-responders. Humoral and cellular immunities were assessed at predefined time points (T0: 48 h before the first, T1: 48 h prior to the third and T2: three weeks after the third dose). Responders, compared to non-responders, had a higher total and transitional B-lymphocyte count at baseline (96.5 (93) vs. 51 (52)cells/μL, p: 0.045 and 9 (17) vs. 1 (2)cells/μL, p: 0.031, respectively). In the responder group, there was a significant increase, from T0 to T1, in the concentrations of activated CD4+ (from 6.5 (4) to 10.08 (11)cells/μL, p: 0.001) and CD8+ (from 8 (19) to 14.76 (16)cells/μL, p: 0.004) and a drop in CD3+PD1+ T-cells (from 130 (121) to 30.44 (25)cells/μL, p: 0.001), while naïve and transitional B-cells increased from T1 to T2 (from 57.55 (66) to 1149.3 (680)cells/μL, p < 0.001 and from 1.4 (3) to 17.5 (21)cells/μL, p: 0.003). The percentages of memory and marginal zone B-lymphocytes, and activated CD4+, CD8+ and natural killer (NK) T-cells significantly increased, while those of naïve B-cells and CD3+PD1+ T-cells reduced from T0 to T1. Responders and non-responders to the third BNT162b2 dose demonstrated distinct initial immune cell profiles and changes in cellular subpopulation composition following vaccination.

Intercellular Mechanisms of Therapeutic Resistance at the Tumor-Stromal Interface Using Ultra High-Plex Single-Cell Spatial Transcriptomics and Genetically-Engineered Tumoroids

There is a major gap in knowledge regarding how intercellular interactions in the tumor microenvironment (TME) mediate therapeutic resistance. Achievement of this goal has been limited by a lack of (1) spatial context in dissociated single-cell methods; (2) single-cell resolution in spatial profiling approaches; (3) high quality data and yield with FFPE patient specimens; and (4) computational methods for ligand-receptor analyses that consider both gene expression and spatial coordinates. We developed an innovative spatial biology paradigm that combines cutting-edge experimental and computational methods to enable high-resolution, spatially-guided discovery of critical mediators of therapeutic resistance. We applied this approach to dissect the single-cell spatial transcriptomic landscape of untreated vs. chemoradiotherapy-treated primary human pancreatic ductal adenocarcinoma (PDAC; n = 21) using ultra-high plex spatial molecular imaging (SMI) optimized for high-sensitivity, subcellular detection of up to 6000 gene transcripts in FFPE sections-an order of magnitude greater than contemporary methods. We recovered over 1,000,000 high-quality single cells in situ representing more than 20 distinct cell types, including epithelial, immune, endothelial, endocrine, and diverse stromal cells. We developed an optimal transport-based computational method to infer cell-cell communication at the cancer-stromal interface. Treatment with chemoradiotherapy was associated with the largest increase in fibroblast-malignant interactions. Comparing the SMI data with orthogonal single-nucleus RNA-sequencing and digital spatial profiling data, we identified CLCF1-CNTFR as the fibroblast-malignant interaction most associated with resistance to chemoradiotherapy in PDAC. CLCF1 is a gp130-family cytokine that activates Jak-STAT signaling and acts as a potent neurotrophic factor. Notably, the CLCF1-CNTRF (fibroblast-malignant) interaction has prominent pro-oncogenic effects in lung adenocarcinoma and an engineered CNTFR decoy receptor with therapeutic potential has been developed. To functionally validate the role of the CLCF1-CNTFR (fibroblast-malignant) interaction in mediating resistance to cytotoxic therapy, we created CRISPR-engineered cancer-fibroblast tumoroids and modulated expression of this ligand-receptor pair. Pancreatic cancer cell viability in the presence of 5-fluorouracil was better maintained with increased CLCF1-CNTFR signaling. In this study, we integrated ultra high-plex single-cell spatial transcriptomics, optimal transport ligand-receptor predictions, and genetically-engineered stromal tumoroids to identify and validate CLCF1-CNTFR as an important intercellular mechanism of resistance to chemoradiotherapy in PDAC-pioneering a paradigm for translating single-cell spatial biology to clinical oncology.

Type 1 invariant natural killer T cells in chronic inflammation and tissue fibrosis.

Chronic tissue inflammation often results in fibrosis characterized by the accumulation of extracellular matrix components remodeling normal tissue architecture and function. Recent studies have suggested common immune mechanisms despite the complexity of the interactions between tissue-specific fibroblasts, macrophages, and distinct immune cell populations that mediate fibrosis in various tissues. Natural killer T (NKT) cells recognizing lipid antigens bound to CD1d molecules have been shown to play an important role in chronic inflammation and fibrosis. Here we review recent data in both experimental models and in humans that suggest a key role of type 1 invariant NKT (iNKT) cell activation in the progression of inflammatory cascades leading to recruitment of neutrophils and activation of the inflammasome, macrophages, fibroblasts, and, ultimately, fibrosis. Emerging evidence suggests that iNKT-associated mechanisms contribute to type 1, type 2 and type 3 immune pathways mediating tissue fibrosis, including idiopathic pulmonary fibrosis (IPF). Thus, targeting a pathway upstream of these immune mechanisms, such as the inhibition of iNKT activation, may be important in modulating various fibrotic conditions.

DNA methylation-based depiction of the immune microenvironment and immune-associated long non-coding RNAs in oral cavity squamous cell carcinomas

Oral cavity squamous cell carcinoma (OSCC) is a complex and dynamic disease characterized by clinicopathological and molecular heterogeneity. Spatial and temporal heterogeneity of cell subpopulations has been associated with cancer progression and implicated in the prognosis and therapy response. Emerging evidence indicates that aberrant epigenetic profiles in OSCC may foster an immunosuppressive tumor microenvironment by modulating the expression of immune-related long non-coding RNAs (lncRNAs). DNA methylation analysis was performed in 46 matched OSCC and normal adjacent tissue samples using a genome-wide platform (Infinium HumanMethylation450 BeadChip). Reference-based computational deconvolution (MethylCIBERSORT) was applied to infer the immune cell composition of the bulk samples. The expression levels of genes encoding immune markers and differentially methylated lncRNAs were investigated using The Cancer Genome Atlas dataset. OSCC specimens presented distinct immune cell composition, including the enrichment of monocyte lineage cells, natural killer cells, cytotoxic T-lymphocytes, regulatory T-lymphocytes, and neutrophils. In contrast, B-lymphocytes, effector T-lymphocytes, and fibroblasts were diminished in tumor samples. The hypomethylation of three immune-associated lncRNAs (MEG3, MIR155HG, and WFDC21P) at individual CpG sites was confirmed by bisulfite-pyrosequencing. Also, the upregulation of a set of immune markers (FOXP3, GZMB, IL10, IL2RA, TGFB, IFNG, TDO2, IDO1, and HIF1A) was detected. The immune cell composition, immune markers alteration, and dysregulation of immune-associated lncRNAs reinforce the impact of the immune microenvironment in OSCC. These concurrent factors contribute to tumor heterogeneity, suggesting that epi-immunotherapy could be an efficient alternative to treat OSCC.

Current understanding of the molecular mechanisms of circulating permeability factor in focal segmental glomerulosclerosis.

The pathogenetic mechanisms underlying the onset and the post-transplant recurrence of primary focal segmental glomerulosclerosis (FSGS) are complex and remain yet to be fully elucidated. However, a growing body of evidence emphasizes the pivotal role of the immune system in both initiating and perpetuating the disease. Extensive investigations, encompassing both experimental models and patient studies, have implicated T cells, B cells, and complement as crucial actors in the pathogenesis of primary FSGS, with various molecules being proposed as potential "circulating factors" contributing to the disease and its recurrence post kidney-transplantation. In this review, we critically assessed the existing literature to identify essential pathways for a comprehensive characterization of the pathogenesis of FSGS. Recent discoveries have shed further light on the intricate interplay between these mechanisms. We present an overview of the current understanding of the engagement of distinct molecules and immune cells in FSGS pathogenesis while highlighting critical knowledge gaps that require attention. A thorough characterization of these intricate immune mechanisms holds the potential to identify noninvasive biomarkers that can accurately identify patients at high risk of post-transplant recurrence. Such knowledge can pave the way for the development of targeted and personalized therapeutic approaches in the management of FSGS.

Identification and validation of ferroptosis-related biomarkers in steroid-induced osteonecrosis of the femoral head

ObjectivesTreatment of steroid-induced osteonecrosis of the femoral head (SIONFH) is challenging. Due to the limited understanding of its molecular mechanisms, investigating the potential mechanisms of ferroptosis will shed light on SIONFH and provide directions for treating this disease. MethodsThe GSE123568 dataset was utilized to apply various bioinformatics methodologies to identify ferroptosis-related hub genes (FRHGs). Subsequently, the importance of these genes and the reliability of the results were confirmed using protein data-independent acquisition (DIA) and cell experiments. Finally, we assessed the correlation between FRHG expression and immune cell infiltration. ResultsThirty-one hub genes were identified and validated by constructing a protein–protein interaction network and subsequent screening using experimentally determined interactions. These 31 hub genes were enriched in immunity, the AMPK signaling pathway, and the Toll-like receptor signaling pathway. Next, we identified a diagnostic marker comprising two ferroptosis-related genes, NCF2 and SLC2A1. The differential expression of these two genes in healthy and necrotic regions was confirmed by protein DIA analysis. Cell experiments verified the link between FRHGs and ferroptosis and preliminarily explored the potential mechanism of the antioxidant vitexin in promoting osteogenic differentiation in cells. The diagnostic efficiency of these two markers was confirmed by receiver operating characteristic curve (ROC) curves, yielding an area under the curve of 1.0. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) indicated enrichment of FRHGs in the superoxide anion and HIF-1 signaling pathways. A significant correlation was observed between FRHGs and various immune cell populations. ConclusionNCF2 and SLC2A1 are promising ferroptosis-related diagnostic biomarkers of SIONFH. Concurrently, we embarked on a preliminary investigation to elucidate the potential mechanism underlying the promotion of osteogenic differentiation by the antioxidant vitexin. Moreover, these biomarkers are associated with distinct immune cell populations.

SARS-CoV-2 variants of concern elicit divergent early immune responses in hACE2 transgenic mice.

Knowledge about early immunity to SARS-CoV-2 variants of concern mainly comes from the analysis of human blood. Such data provide limited information about host responses at the site of infection and largely miss the initial events. To gain insights into compartmentalization and the early dynamics of host responses to different SARS-CoV-2 variants, we utilized human angiotensin converting enzyme 2 (hACE2) transgenic mice and tracked immune changes during the first days after infection by RNAseq, multiplex assays, and flow cytometry. Viral challenge infection led to divergent viral loads in the lungs, distinct inflammatory patterns, and innate immune cell accumulation in response to ancestral SARS-CoV-2, Beta (B.1.351) and Delta (B.1.617.2) variant of concern (VOC). Compared to other SARS-CoV-2 variants, infection with Beta (B.1.351) VOC spread promptly to the lungs, leading to increased inflammatory responses. SARS-CoV-2-specific antibodies and T cells developed within the first 7 days postinfection and were required to reduce viral spread and replication. Our studies show that VOCs differentially trigger transcriptional profiles and inflammation. This information contributes to the basic understanding of immune responses immediately postexposure to SARS-CoV-2 and is relevant for developing pan-VOC interventions including prophylactic vaccines.

Spatiotemporal insight into early pregnancy governed by immune-featured stromal cells

Endometrial decidualization connecting embryo implantation and placentation is transient but essential for successful pregnancy, which, however, is not systematically investigated. Here, we use a scStereo-seq technology to spatially visualize and define the dynamic functional decidual hubs assembled by distinct immune, endothelial, trophoblast, and decidual stromal cells (DSCs) in early pregnant mice. We unravel the DSC transdifferentiation trajectory and surprisingly discover a dual-featured type of immune-featured DSCs (iDSCs). We find that immature DSCs attract immune cells and induce decidual angiogenesis at the mesenchymal-epithelial transition hub during decidualization initiation. iDSCs enable immune cell recruitment and suppression, govern vascularization, and promote cytolysis at immune cell assembling and vascular hubs, respectively, to establish decidual homeostasis at a later stage. Interestingly, dysfunctional and spatially disordered iDSCs cause abnormal accumulation of immune cells in the vascular hub, which disrupts decidual hub specification and eventually leads to pregnancy complications in DBA/2-mated CBA/J mice.

Integrating Single-Cell RNA-Seq and Bulk RNA-Seq Data to Explore the Key Role of Fatty Acid Metabolism in Breast Cancer.

Cancer immune escape is associated with the metabolic reprogramming of the various infiltrating cells in the tumor microenvironment (TME), and combining metabolic targets with immunotherapy shows great promise for improving clinical outcomes. Among all metabolic processes, lipid metabolism, especially fatty acid metabolism (FAM), plays a major role in cancer cell survival, migration, and proliferation. However, the mechanisms and functions of FAM in the tumor immune microenvironment remain poorly understood. We screened 309 fatty acid metabolism-related genes (FMGs) for differential expression, identifying 121 differentially expressed genes. Univariate Cox regression models in The Cancer Genome Atlas (TCGA) database were then utilized to identify the 15 FMGs associated with overall survival. We systematically evaluated the correlation between FMGs' modification patterns and the TME, prognosis, and immunotherapy. The FMGsScore was constructed to quantify the FMG modification patterns using principal component analysis. Three clusters based on FMGs were demonstrated in breast cancer, with three patterns of distinct immune cell infiltration and biological behavior. An FMGsScore signature was constructed to reveal that patients with a low FMGsScore had higher immune checkpoint expression, higher immune checkpoint inhibitor (ICI) scores, increased immune microenvironment infiltration, better survival advantage, and were more sensitive to immunotherapy than those with a high FMGsScore. Finally, the expression and function of the signature key gene NDUFAB1 were examined by in vitro experiments. This study significantly demonstrates the substantial impact of FMGs on the immune microenvironment of breast cancer, and that FMGsScores can be used to guide the prediction of immunotherapy efficacy in breast cancer patients. In vitro experiments, knockdown of the NDUFAB1 gene resulted in reduced proliferation and migration of MCF-7 and MDA-MB-231 cell lines.

Identification of the Immune Landscapes and Follicular Helper T Cell-Related Genes for the Diagnosis of Age-Related Macular Degeneration.

Age-related macular degeneration (AMD) is a progressive ocular ailment causing age-associated vision deterioration, characterized by dysregulated immune cell activity. Notably, follicular helper T (Tfh) cells have emerged as pivotal contributors to AMD pathogenesis. Nonetheless, investigations into Tfh-associated gene biomarkers for this disorder remain limited. Utilizing gene expression data pertinent to AMD procured from the Gene Expression Omnibus (GEO) repository, we employed the "DESeq2" R software package to standardize and preprocess expression levels. Concurrently, CIBERSORT analysis was utilized to compute the infiltration proportions of 22 distinct immune cell types. Subsequent to weighted gene correlation network analysis (WGCNA), coupled with differential expression scrutiny, we pinpointed genes intricately linked with Tfh cells. These potential genes underwent further screening using the MCODE function within Cytoscape software. Ultimately, a judicious selection of pivotal genes from these identified clusters was executed through the LASSO algorithm. Subsequently, a diagnostic nomogram was devised based on these selected genes. Evident Tfh cell disparities between AMD and control cohorts were observed. Our amalgamated analysis, amalgamating differential expression data with co-expression patterns, unveiled six genes closely associated with Tfh cells in AMD. Subsequent employment of the LASSO algo-rithm facilitated identification of the most pertinent genes conducive to predictive modeling. From these, GABRB3, MFF, and PROX1 were elected as prospective diagnostic biomarkers for AMD. This investigation discerned three novel biomarker genes, linked to inflammatory mechanisms and pivotal in diagnosing AMD. Further exploration of these genes holds potential to foster novel therapeutic modalities and augment comprehension of AMD's disease trajectory.

Identification of Immune-Linked Hub Genes and Diagnostic Model Construction in Schizophrenia.

Schizophrenia (SCZ) is a prevalent, severe, and persistent mental disorder with an unknown etiology. Growing evidence indicates that immunological dysfunction is vital in the development of SCZ. Our study aims to uncover potential immune-linked hub genes and immune infiltration characteristics of SCZ, as well as to develop a diagnostic model based on immune-linked central genes. GSE38484 and GSE54913 chip expression data for patients with SCZ and healthy controls were retrieved. Weighted gene co-expression network analysis (WGCNA) was performed to identify major module genes and critical immune-linked genes. Functional enrichment analysis was conducted to elucidate the involvement of key genes in the immunological response to SCZ, along with the examination of their protein interactions. Moreover, 202 peripheral blood samples were examined using the single-sample gene set enrichment analysis (ssGSEA) method to detect distinct immune cell types. Hub immune-linked genes in SCZ were identified using the minimal absolute contraction and selection operator analysis. Receptor profiles of central immune-linked genes were analyzed to distinguish the two groups. Finally, the association between immune-linked hub genes and various types of immune cells was assessed. Our findings revealed ten immune cell types and nine key genes involved in SCZ, including effector memory CD4+ T cells, activated CD8+ T cells, mast cells, naive CD8+ T cells, PBMC, type 17 helper cells (Th17), central memory CD8+ T cells, CD56 bright NK cells, memory B cells, and regulatory T cells. Diagnostic models constructed using LASSO regression exhibited an average area under the curve (AUC) of 0.866. Our results indicate immunological dysfunction as a factor in the development of SCZ. ASGR2, ADRM1, AHANK, S100A8, FUCA1, AKNA, GATA3, AHCYL2, and PTRH2 are the key regulatory genes of immune cells, highlighting their potential as novel therapeutic targets for SCZ.

Surveying the Metabolic and Dysfunctional Profiles of T Cells and NK Cells in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Millions globally suffer from myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). The inflammatory symptoms, illness onset, recorded outbreak events, and physiological variations provide strong indications that ME/CFS, at least sometimes, has an infectious origin, possibly resulting in a chronic unidentified viral infection. Meanwhile, studies exposing generalized metabolic disruptions in ME/CFS have stimulated interest in isolated immune cells with an altered metabolic state. As the metabolism dictates the cellular function, dissecting the biomechanics of dysfunctional immune cells in ME/CFS can uncover states such as exhaustion, senescence, or anergy, providing insights into the consequences of these phenotypes in this disease. Despite the similarities that are seen metabolically between ME/CFS and other chronic viral infections that result in an exhausted immune cell state, immune cell exhaustion has not yet been verified in ME/CFS. This review explores the evidence for immunometabolic dysfunction in ME/CFS T cell and natural killer (NK) cell populations, comparing ME/CFS metabolic and functional features to dysfunctional immune cell states, and positing whether anergy, exhaustion, or senescence could be occurring in distinct immune cell populations in ME/CFS, which is consistent with the hypothesis that ME/CFS is a chronic viral disease. This comprehensive review of the ME/CFS immunometabolic literature identifies CD8+ T cell exhaustion as a probable contender, underscores the need for further investigation into the dysfunctional state of CD4+ T cells and NK cells, and explores the functional implications of molecular findings in these immune-cell types. Comprehending the cause and impact of ME/CFS immune cell dysfunction is critical to understanding the physiological mechanisms of ME/CFS, and developing effective treatments to alleviate the burden of this disabling condition.

Autoimmune thyroid disease disrupts immune homeostasis in the endometrium of unexplained infertility women-a single-cell RNA transcriptome study during the implantation window.

Autoimmune thyroid disease (AITD) is known to be associated with unexplained infertility in women. Although the presence of antithyroid antibodies have been speculated to be a marker of an immune imbalance that might lead to implantation failure, its underlying mechanism influencing the endometrial receptivity remains to be elucidated. In this study, we used single-cell RNA sequencing (scRNA-seq) to dissect immune microenvironment in endometrium of AITD patients during window of implantation (WOI). We collected CD45+ immune cell populations of endometrium samples of unexplained infertile women with AITD (n=3), as well as samples of AITD- controls (n=3). The cells were then processed with 10X Genomics Chromium for further analysis. We characterized 28 distinct immune cell subtypes totally, and uncovered differences in the composition and gene expression patterns between AITD patients and controls. The proportions of T CD4+, cNK, ILC3, T CD8+ GZMK+, T CD8+ Cytotoxic and ILC3 CD3E - cells were increased, and CD366+ uNK1 was decreased in AITD+ patients. And the abnormal expression of GNLY and chemokines was observed in AITD patients. In addition, uNK and T CD8+ Cytotoxic cells showed lower cytotoxicity but activation of immune response. Genes enriched in cell adhesion of ILC3 and Tregs were downregulated, while the number of ILC3 and Tregs were increased. Immune imbalance exists in endometrium during WOI, which may impact embryo implantation.

An immune-related gene prognostic index for predicting prognosis in patients with colorectal cancer.

Colorectal cancer (CRC) is one of the most common solid malignant burdens worldwide. Cancer immunology and immunotherapy have become fundamental areas in CRC research and treatment. Currently, the method of generating Immune-Related Gene Prognostic Indices (IRGPIs) has been found to predict patient prognosis as an immune-related prognostic biomarker in a variety of tumors. However, their role in patients with CRC remains mostly unknown. Therefore, we aimed to establish an IRGPI for prognosis evaluation in CRC. RNA-sequencing data and clinical information of CRC patients were retrieved from The Cancer Genome Atlas (TCGA) and The Gene Expression Omnibus (GEO) databases as training and validation sets, respectively. Immune-related gene data was obtained from the ImmPort and InnateDB databases. The weighted gene co-expression network analysis (WGCNA) was used to identify hub immune-related genes. An IRGPI was then constructed using Cox regression methods. Based on the median risk score of IRGPI, patients could be divided into high-risk and low-risk groups. To further investigate the immunologic differences, Gene set variation analysis (GSVA) studies were conducted. In addition, immune cell infiltration and related functional analysis were used to identify the differential immune cell subsets and related functional pathways. We identified 49 immune-related genes associated with the prognosis of CRC, 17 of which were selected for an IRGPI. The IRGPI model significantly differentiates the survival rates of CRC patients in the different groups. The IRGPI as an independent prognostic factor significantly correlates with clinico-pathological factors such as age and tumor stage. Furthermore, we developed a nomogram to improve the clinical utility of the IRGPI score. Immuno-correlation analysis in different IRGPI groups revealed distinct immune cell infiltration (CD4+ T cells resting memory) and associated pathways (macrophages, Type I IFNs responses, iDCs.), providing new insights into the tumor microenvironment. At last, drug sensitivity analysis revealed that the high-risk IRGPI group was sensitive to 11 and resistant to 15 drugs. Our study established a promising immune-related risk model for predicting survival in CRC patients. This could help to better understand the correlation between immunity and the prognosis of CRC providing a new perspective for personalized treatment of CRC.

Exploration of prognosis and immunometabolism landscapes in ER+ breast cancer based on a novel lipid metabolism-related signature.

Lipid metabolic reprogramming is gaining attention as a hallmark of cancers. Recent mounting evidence indicates that the malignant behavior of breast cancer (BC) is closely related to lipid metabolism. Here, we focus on the estrogen receptor-positive (ER+) subtype, the most common subgroup of BC, to explore immunometabolism landscapes and prognostic significance according to lipid metabolism-related genes (LMRGs). Samples from The Cancer Genome Atlas (TCGA) database were used as training cohort, and samples from the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC), Gene Expression Omnibus (GEO) datasets and our cohort were applied for external validation. The survival-related LMRG molecular pattern and signature were constructed by unsupervised consensus clustering and least absolute shrinkage and selection operator (LASSO) analysis. A lipid metabolism-related clinicopathologic nomogram was established. Gene enrichment and pathway analysis were performed to explore the underlying mechanism. Immune landscapes, immunotherapy and chemotherapy response were further explored. Moreover, the relationship between gene expression and clinicopathological features was assessed by immunohistochemistry. Two LMRG molecular patterns were identified and associated with distinct prognoses and immune cell infiltration. Next, a prognostic signature based on nine survival-related LMRGs was established and validated. The signature was confirmed to be an independent prognostic factor and an optimal nomogram incorporating age and T stage (AUC of 5-year overall survival: 0.778). Pathway enrichment analysis revealed differences in immune activities, lipid biosynthesis and drug metabolism by comparing groups with low- and high-risk scores. Further exploration verified different immune microenvironment profiles, immune checkpoint expression, and sensitivity to immunotherapy and chemotherapy between the two groups. Finally, arachidonate 15-lipoxygenase (ALOX15) was selected as the most prominent differentially expressed gene between the two groups. Its expression was positively related to larger tumor size, more advanced tumor stage and vascular invasion in our cohort (n = 149). This is the first lipid metabolism-based signature with value for prognosis prediction and immunotherapy or chemotherapy guidance for ER+ BC.

A Novel Tumor Mutation Burden Related lncRNA Signature Identified Prognosis and Tumor Immune Microenvironment Features in Clear Cell Renal Cell Carcinoma.

Emerging evidence indicates that long noncoding RNA (lncRNA) plays an important biological role in clear cell renal cell carcinoma (ccRCC); however, the clinical value of tumor mutation burden-related lncRNA in ccRCC patients is unknown yet. Somatic mutation profiles and lncRNA expression data of ccRCC were downloaded from the TCGA database. We retrospectively analyzed lncRNA expression data and survival information from 116 patients with ccRCC fromJanuary 2013 to January 2014. Univariate and multivariate Cox regression analyses were performed to construct lncRNA signature, and the prognosis value was determined by Kaplan-Mayer and receiver operating characteristic curve (ROC) analysis. Based on 160 differentially expressed TMB-related lncRNAs, two TMB-related molecular clusters with distinct immune checkpoints expression and immune cells infiltration were established for ccRCC patients. Moreover, a novel TMB-related lncRNA signature was constructed based on five lncRNAs for individualized prognosis assessment. High-risk group represents significantly worse overall survival in all cohorts. The area under the ROC curve was 0.716, 0.775 and 0.744 in the training cohort, testing cohort and TCGA cohort, respectively. Results of qRT-PCR successfully validated the expression levels of AP002360.3, LINC00460, AL590094.1, LINC00944 and LINC01843 in HK-2, 786-O, 769-P and ACHN cells. More importantly, the predictive performance of TMB-related lncRNA signature was successfully validated in an independent cohort of 116 ccRCC patients at our institution. This study successfully developed and validated a novel TMB-related lncRNA signature for individualized prognosis assessment of ccRCC patients.

1666-P: ScRNAseq–Based Analysis of the Stromal Immune Cell Composition in Murine Preweaning and Adult White Adipose Tissues

Early postnatal adipose growth is essential to establish a functional metabolism. Conversely, proportional adipose expansion in adults results in insulin resistance. Despite adipocytes, immune cells play a pivotal role in orchestrating adipose tissue function and expansion. To this end, we performed an in-depth analysis of scRNAseq data of immune cell populations of 2 weeks (pre-weaning) and 8 weeks old (adult) murine subcutaneous and perigonadal adipose depots. Our analysis revealed 15 distinct immune cell clusters. Most immune cell types were found in all depots and ages. Among the detected T-cell populations, we only observed differences in the abundance of naïve T cells, which were predominantly found in in subcutaneous white adipose tissue, irrespective of age. Similar to human, we could define several murine macrophage subtypes. Among them, perivascular macrophages (PVM) were predominantly found in subcutaneous white adipose tissue of 2 weeks old mice. RNA-velocity analysis and pseudotime trajectory construction suggested a developmental trajectory from lipid-associated macrophages (LAM) to PVM, which was further corroborated by analysis of gene expression dynamics resolved along latent time of white adipose tissue macrophages from 2 weeks old mice. Further analysis revealed that the top-ranked 100 genes of LAM were associated with the regulation of endothelial cell migration and proliferation (Nrp1, Grn, Glul, Sash1, Ccl24), blood vessel morphogenesis (Nrp1, Tgfbr2) and the regulation of epithelial cell proliferation. In summary, we provide a comprehensive overview of the immune cell composition of pre-weaning and adults murine adipose tissues. Moreover, we provide in-depth analysis of T-cell and macrophage populations and their relationship and dependency based on mRNA expression analysis. Disclosure X. Yan: None. V. Miok: None. R. Karlina: None. A. Böttcher: None. D. Lutter: None. H. Lickert: Research Support; Eli Lilly and Company. C. Garcia Caceres: None. S. Ussar: Research Support; Novo Nordisk. Funding China Scholarship Council (201908370218)

#6818 UNVEIL THE IMMUNE CELL LANDSCAPE IN AGEING KIDNEYS WITH AKI AND CKD

Abstract Background and Aims Immunosenescence, or aging process of the immune system, leads to either defective immune response or increased systemic inflammation. Previous studies have shown that kidney immune system may coordinate the process of kidney inflammation, resolution, or progressive fibrosis in kidney diseases. However, the exact role of individual immune cell type has not been systematically characterized, especially in the context of ageing kidneys. Method Firstly, we induced acute and chronic aristolochic acid nephropathy (AAN) in 15-month-old mice. At different stages of AAN (Steady state, acute inflammation, recovery from acute injury, and chronic fibrosis), mice were then sacrificed, and kidneys were harvested for further processing. We flow-sorted kidney CD45+ immune cells (live cells) and applied to 10 x Genomics platform for single cell isolation and cDNA library construction. Illumina NovaSeq 6000 system was used for RNA sequencing. Finally, we performed downstream bioinformatics analysis through CellRanger and Seurat pipelines. Results Utilizing AAN mouse model, we successfully conducted flow sorted kidney immune cells single-cell RNA sequencing (scRNAseq) from 15 M/O kidneys with AKI and CKD. We clearly identified 25 distinctive immune cell types, representing distinctive lymphoid and myeloid populations (Figure 1a). We showed dynamic change of immune cell compositions upon different phases of AAN (i.e., CCR2+ monocytes and proliferative macrophages increased during acute inflammation, activated T cells expanded during recovery phase, CD206+CCL8+ macrophages enriched within the fibrotic kidneys) (Figure 1b). By analysis of differentially expressed genes (DEG), we identified 30 top-ranked genes, which uniquely enriched in specific cell subset (Figure 1c). Conclusion We have successfully unveiled the immune cell landscape in ageing kidneys with AKI and CKD. Our preliminary data has demonstrated that distinct immune cell subsets at different phases of injury may have unique roles. Future work will focus on the cell-cell interactions and immune cell activation/differentiation.

Characterization and clinical impact of the tumor microenvironment in post-transplant aggressive B-cell lymphomas.

Post-transplant lymphoproliferative disorders (PTLDs) are iatrogenic immune deficiencyassociated lymphoid/plasmacytic proliferations developing due to immunosuppression in solid organ or hematopoietic stem cell allograft patients. PTLDs are characterized by abnormal proliferation of lymphoid cells and have a heterogeneous clinical behavior. We profiled expression of >700 tumor microenvironment (TME)-related genes in 75 post-transplant aggressive B-cell lymphomas (PT-ABCLs). EBV-positive PT-ABCLs clustered together and were enriched for type I interferon pathway and antiviral response genes. Additionally, a cytotoxicity gene signature associated with EBV-positivity and favorable overall survival (OS; HR 0.61, P=0.019). In silico immunophenotyping revealed two subgroups with distinct immune cell compositions. The inflamed subgroup with higher proportions of immune cells had better outcome compared to non-inflamed subgroup (median OS >200.0 vs. 15.2 months, P=0.006). In multivariable analysis with EBV status, International Prognostic Index, and rituximab-containing treatment, the inflamed TME remained as an independent predictor for favorable outcome. We also compared the TME between posttransplant and immunocompetent host diffuse large B-cell lymphomas (DLBCLs) (n=75) and discovered that the proportions of T cells were lower in PT-DLBCL. In conclusion, we provide a comprehensive phenotypic characterization of PT-ABCLs, highlighting the importance of immune cell composition of TME in determining the clinical behavior and prognosis of PT-ABCL.