Immune Gene Expression Profiles Research Articles

Koala ocular disease grades are defined by chlamydial load changes and increases in Th2 immune responses

IntroductionThis study employs bulk RNA sequencing, PCR, and ELISA assays to analyze the pathological factors affecting the outcomes of C. pecorum ocular infections in koalas. It investigates the immune responses and gene expression profiles associated with various stages of koala ocular chlamydiosis.MethodsA cohort of 114 koalas from Queensland, Australia were assessed, with 47% displaying clinical signs of ocular disease. Animals were classified into three cohorts: acute active disease (G1), chronic active disease (G2), and chronic inactive disease (G3), along with subclinical Chlamydia pecorum positive (H2) and healthy (H1) cohorts.ResultsAnalysis of clinical, microbiological, humoral immune and cellular immune biomarkers revealed varying chlamydial loads and anti-chlamydial IgG levels across disease grades, with a negative correlation observed between ocular chlamydial load and anti-chlamydial IgG. Koala ocular mucosa gene expression analysis from 27 koalas identified shared expression pathways across disease cohorts, with a significant upregulation of IFNγ expression and tryptophan metabolism in all disease stages.DiscussionThese findings help elucidate immune response dynamics and molecular pathways underlying koala ocular chlamydiosis, providing insights crucial for disease management strategies.

Reduction of myeloid-derived suppressor cells in prostate cancer murine models and patients following white button mushroom treatment.

In a previously reported Phase I trial, we observed therapy-associated declines in circulating myeloid-derived suppressor cells (MDSCs) with the administration of white button mushroom (WBM) tablets in prostate cancer (PCa) patients. These observations led us to hypothesise that WBM could mitigate PCa progression by suppressing MDSCs. We performed bidirectional translational research to examine the immunomodulatory effects of WBM consumption in both syngeneic murine PCa models and patients with PCa participating in an ongoing randomised Phase II trial (NCT04519879). In murine models, WBM treatment significantly suppressed tumour growth with a reduction in both the number and function of MDSCs, which in turn promoted antitumour immune responses mediated by T cells and natural killer (NK) cells. In patients, after consumption of WBM tablets for 3 months, we observed a decline in circulating polymorphonuclear MDSCs (PMN-MDSCs), along with an increase in cytotoxic CD8+ T and NK cells. Furthermore, single immune cell profiling of peripheral blood from WBM-treated patients showed suppressed STAT3/IRF1 and TGFβ signalling in circulating PMN-MDSCs. Subclusters of PMN-MDSCs presented transcriptional profiles associated with responsiveness to fungi, neutrophil chemotaxis, leukocyte aggregation, and regulation of inflammatory response. Finally, in mouse models of PCa, we found that WBM consumption enhanced the anticancer activity of anti-PD-1 antibodies, indicating that WBM may be used as an adjuvant therapy with immune checkpoint inhibitors. Our results from PCa murine models and patients provide mechanistic insights into the immunomodulatory effects of WBM and provide a scientific foundation for WBM as a nutraceutical intervention to delay or prevent PCa progression. White button mushroom (WBM) treatment resulted in a reduction in pro-tumoural MDSCs, notably polymorphonuclear MDSCs (PMN-MDSCs), along with activation of anti-tumoural T and NK cells. Human single immune cell gene expression profiling shed light on the molecular alterations induced by WBM, specifically on PMN-MDSCs. A proof-of-concept study combining WBM with PD-1 blockade in murine models revealed an additive effect on tumour regression and survival outcomes, highlighting the clinical relevance of WBM in cancer management.

Activin levels correlate with lymphocytic infiltration in epithelial ovarian cancer.

The TGF-β superfamily member activin, a dimer of the gene products of INHBA and/or INHBB, has been implicated in immune cell maturation and recruitment, but its immune impact within epithelial ovarian cancer (EOC) is not well characterized. We sought to explore differences in activin (INHBA/ Inhibin-βA and INHBB/ Inhibin-βB) between malignant and ovarian tissues at the RNA and protein level and assess the relationship between activin and immune cells in EOC. Publicly available RNA sequencing data were accessed from GEO (#GSE143897) with normalization and quantification performed via DESeq2. Immune gene expression profile was further explored within the TCGA-OV cohort derived from The Cancer Genome Atlas (TCGA). Immunohistochemical analysis was performed to evaluate activin A and T-cell markers CD8 and FoxP3 at the protein level. ELISA to activin-A was used to assess levels in the ascites of advanced EOC patients. Kaplan-Meier curves were generated to visualize survival outcomes. Gene expression levels of components of the activin signaling pathway were elevated within EOC when compared to a benign cohort, with differences in activin type I/II receptor gene profiles identified. Additionally, INHBA gene expression was linked to lymphocytic immune markers in EOC samples. Immunohistochemistry analysis revealed a positive correlation of CD8 and FOXP3 staining with activin A at the protein level in both primary and metastatic epithelial ovarian cancer samples. Furthermore, Activin-A (inhibin-βA) is significantly elevated in EOC patient ascites. INHBA expression is elevated within EOC, correlating with worse survival, with activin protein levels correlating with specific immune infiltration. Our findings suggest that activin-A may play a role in suppressing anti-tumor immunity in EOC, highlighting its potential as a therapeutic target.

Inferring Characteristics of the Tumor Immune Microenvironment of Patients with HNSCC from Single-Cell Transcriptomics of Peripheral Blood.

Our work offers a new and promising paradigm in liquid biopsies to unlock the power of blood single-cell transcriptomics in cancer immunotherapy.

Maternal immune cell gene expression associates with maternal gut microbiome, milk composition and infant gut microbiome

Background– Pre-pregnancy overweight and obesity promote deleterious health impacts on both mothers during pregnancy and the offspring. Significant changes in the maternal peripheral blood mononuclear cells (PBMCs) gene expression due to obesity are well-known. However, the impact of pre-pregnancy overweight on immune cell gene expression during pregnancy and its association with maternal and infant outcomes is not well explored. Methods– Blood samples were collected from healthy normal weight (NW, pre-pregnancy BMI 18.5-24.9) or overweight (OW, pre-pregnancy BMI 25-29.9) 2nd parity pregnant women at 12, 24 and 36 weeks of pregnancy. PBMCs were isolated from the blood and subjected to mRNA sequencing. Maternal and infant microbiota were analyzed by 16S rRNA gene sequencing. Integrative multi-omics data analysis was performed to evaluate the association of gene expression with maternal diet, gut microbiota, milk composition, and infant gut microbiota. ResultsGene expression analysis revealed that 453 genes were differentially expressed in the OW women compared to NW women at 12 weeks of pregnancy, out of which 354 were upregulated and 99 were downregulated. Several up-regulated genes in the OW group were enriched in inflammatory, chemokine-mediated signaling and regulation of interleukin-8 production-related pathways. At 36 weeks of pregnancy healthy eating index score was positively associated with several genes that include, DTD1, ELOC, GALNT8, ITGA6-AS1, KRT17P2, NPW, POT1-AS1 and RPL26. In addition, at 36 weeks of pregnancy, genes involved in adipocyte functions, such as NG2 and SMTNL1, were negatively correlated to human milk 2’FL and total fucosylated oligosaccharides content collected at 1 month postnatally. Furthermore, infant Akkermansia was positively associated with maternal PBMC anti-inflammatory genes that include CPS1 and RAB7B, at 12 and 36 weeks of pregnancy. Conclusions– These findings suggest that prepregnancy overweight impacts the immune cell gene expression profile, particularly at 12 weeks of pregnancy. Furthermore, deciphering the complex association of PBMC’s gene expression levels with maternal gut microbiome and milk composition and infant gut microbiome may aid in developing strategies to mitigate obesity-mediated effects.

Tumour mutational burden: clinical utility, challenges and emerging improvements.

Tumour mutational burden (TMB), defined as the total number of somatic non-synonymous mutations present within the cancer genome, varies across and within cancer types. A first wave of retrospective and prospective research identified TMB as a predictive biomarker of response to immune-checkpoint inhibitors and culminated in the disease-agnostic approval of pembrolizumab for patients with TMB-high tumours based on data from the Keynote-158 trial. Although the applicability of outcomes from this trial to all cancer types and the optimal thresholds for TMB are yet to be ascertained, research into TMB is advancing along three principal avenues: enhancement of TMB assessments through rigorous quality control measures within the laboratory process, including the mitigation of confounding factors such as limited panel scope and low tumour purity; refinement of the traditional TMB framework through the incorporation of innovative concepts such as clonal, persistentor HLA-corrected TMB, tumour neoantigen load and mutational signatures; and integration of TMB with established and emerging biomarkers such as PD-L1 expression, microsatellite instability, immune gene expression profiles and the tumour immune contexture. Given its pivotal functions in both the pathogenesis of cancer and the ability of the immune system to recognize tumours, a profound comprehension of the foundational principles and the continued evolution of TMB are of paramount relevance for the field of oncology.

Immune checkpoint gene signature assesses immune infiltration profiles in bladder cancer and identifies KRT23 as an immunotherapeutic target

BackgroundIn the past few decades, researchers have made promising progress, including the development of immune checkpoint inhibitors (ICIs) in the therapy of bladder cancer (BLCA). Existing studies mainly focus on single immune checkpoint inhibitors but lack relevant studies on the gene expression profiles of multiple immune checkpoints.MethodsRNA-sequencing profiling data and clinical information of BLCA patients and normal human bladder samples were acquired from the Cancer Genome Atlas and Gene Expression Omnibus databases and analyzed to identify different expression profiles of immune checkpoint genes (ICGs) after consensus clustering analysis. Based on the 526 intersecting differentially expressed genes, the LASSO Cox regression analysis was utilized to construct the ICG signature.ResultsAccording to the expression of ICGs, BLCA patients were divided into three subtypes with different phenotypic and mechanistic characteristics. Furthermore, the developed ICG signature were independent predictors of outcome in BLCA patients, and was correlated with the immune infiltration, the expression of ICGs and chemotherapeutic effect.ConclusionsThis study systematically and comprehensively analyzed the expression profile of immune checkpoint genes, and established the ICG signature to investigate the differences in ICGs expression and tumor immune microenvironment, which will help risk stratification and accelerate precision medicine. Finally, we identified KRT23 as the most critical model gene, and highlighted KRT23 as a potential target to enhance immunotherapy against BLCA.

Targeting tumor-infiltrating CCR8+ regulatory T cells induces antitumor immunity through functional restoration of CD4+ Tconvs and CD8+ T cells in colorectal cancer

BackgroundChemokine (C-C motif) receptor 8 (CCR8) is a chemokine receptor selectively expressed on tumor-infiltrating regulatory T cells (Tregs). Strong immunosuppression mediated by CCR8+ Tregs observed in breast and lung malignancies suggest for their functional significance in cancer therapy. To date, detailed characterization of tumor-infiltrating CCR8+ Tregs cells in colorectal cancer (CRC) is limited.MethodsTo study the presence and functional involvement of CCR8+ Tregs in CRC, we analyzed the proportions of CCR8-expressing T cells in different T cell subsets in tumor and adjacent normal tissues and peripheral blood mononuclear cells (PBMCs) from CRC patients by Flow cytometry. Also, we compared the distribution of CCR8+ T cells in malignant tissues and peripheral lymphoid organs from a subcutaneous CRC murine model. Bioinformatic analysis was performed to address the significance of CCR8 expression levels in CRC prognosis, immune regulatory gene expression profiles and potential molecular mechanisms associated with CCR8+ Tregs in CRC tumors. Further, we administrated an anti-CCR8 monoclonal antibody to CT26 tumor-bearing mice and examined the antitumor activity of CCR8-targeted therapy both in vivo and in an ex vivo confirmative model.ResultsHere, we showed that Tregs was predominantly presented in the tumors of CRC patients (13.4 ± 5.8, p < 0.0001) and the CRC subcutaneous murine model (35.0 ± 2.6, p < 0.0001). CCR8 was found to be preferentially expressed on these tumor-infiltrating Tregs (CRC patients: 63.6 ± 16.0, p < 0.0001; CRC murine model: 65.3 ± 9.5, p < 0.0001), which correlated with poor survival. We found that majority of the CCR8+ Tregs expressed activation markers and exhibited strong suppressive functions. Treatment with anti-CCR8 antibody hampered the growth of subcutaneous CRC tumor through effectively restoring the anti-tumor immunity of CD4+ conventional T cells (CD4+ Tconvs) and CD8+ T cells, which was confirmed in the ex vivo examinations.ConclusionsCollectively, these findings illustrate the importance of CCR8+ Tregs for an immunosuppressive microenvironment in CRC tumors by functional inhibition of CD4+ Tconvs and CD8+ T cells, and suggest for the applicable value of CCR8-targeted therapy for CRC.

Exploring markers of immunoresponsiveness in papillary thyroid carcinoma and future treatment strategies

BackgroundThe study summarizes the potential use of immunotherapy for BRAF-mutated papillary thyroid cancer (PTC) by analyzing the immune profile of City of Hope PTC patient samples and comparing them to...

Evaluation of pathological response to neoadjuvant chemotherapy in locally advanced cervical cancer

Neoadjuvant chemotherapy (NACT) is a viable therapeutic option for women diagnosed locally advanced cervical cancer (LACC). However, the factors influencing pathological response are still controversial. We collected pair specimens of 185 LACC patients before and after receiving NACT and conducted histological evaluation. 8 fresh tissues pre-treatment were selected from the entire cohort to conducted immune gene expression profiling. A novel pathological grading system was established by comprehensively assessing the percentages of viable tumor, inflammatory stroma, fibrotic stroma, and necrosis in the tumor bed. Then, 185 patients were categorized into either the good pathological response (GPR) group or the poor pathological response (PPR) group post-NACT, with 134 patients (72.4%, 134/185) achieving GPR. Increasing tumor-infiltrating lymphocytes (TILs) and tumor-infiltrating lymphocytes volume (TILV) pre-treatment were correlated with GPR, with TILV emerging as an independent predictive factor for GPR. Additionally, CIBERSORT analysis revealed noteworthy differences in the expression of immune makers between cPR and non-cPR group. Furthermore, a significantly heightened density of CD8 + T cells and a reduced density of FOXP3 + T cells were observed in GPR than PPR. Importantly, patients exhibiting GPR or inflammatory type demonstrated improved overall survival and disease-free survival. Notably, stromal type was an independent prognostic factor in multivariate analysis. Our study indicates the elevated TILV in pre-treatment specimens may predict a favorable response to NACT, while identifying stromal type in post-treatment specimens as an independent prognostic factor. Moreover, we proposed this pathological grading system in NACT patients, which may offer a more comprehensive understanding of treatment response and prognosis.

Single-cell RNA sequencing of peripheral blood mononuclear cells from pregnant women with Systemic lupus erythematosus

Systemic lupus erythematosus (SLE), an autoimmune condition, presents pregnancy-related risks, impacting maternal and fetal health. The immune cell composition and gene expression profiles in pregnant SLE patients, as well as the molecular mechanisms of active SLE patients during pregnancy, remain unclear. In our study, we enrolled 12 patients: three active SLE individuals (SLE-AT group, SLEDAI > 12, non-pregnant women), three inactive SLE individuals (SLE-NP group, SLEDAI ranging 0 to 6, non-pregnant women), three pregnant women with active SLE (SLE-C group, SLEDAI > 12), and three pregnant women with inactive SLE (SLE-NC group, SLEDAI range 0 to 6 score). Transcriptome analysis of peripheral blood mononuclear cells (PBMCs) was conducted using the 10x Genomics technique. We observed upregulation of genes like CCDC15 and TRBV4-2 in T cells and CMPK2, IFIT1, and OAS2 in monocytes in the SLE-C group. Notably, gene sets related to Cell Cycle and IFN Response showed significant differences between the SLE-C and SLE-NC groups in naïve CD8 T cells. Our comparison of immune cell type ratios and transcriptional patterns between active and inactive SLE during pregnancy sheds light on the single-cell level changes in SLE status during pregnancy, offering insights for future SLE prediction and treatment strategies.

Assessing the implications of sentinel lymph node removal in cervical cancer: an immunogenetic perspective – a SENTICOL ancillary study

BackgroundCervical cancer’s lymphatic spread primarily begins from the sentinel lymph nodes (SLNs), underlining their pivotal role in disease metastasis. However, these nodes’ immune gene expression profiles and immunoregulation mechanisms have...

Identification of novel disulfidptosis-related lncRNA signatures to predict the prognosis and immune microenvironment of skin cutaneous melanoma patients.

Skin cutaneous melanoma (SKCM) is an aggressive form of malignant melanoma with poor prognosis and high mortality rates. Disulfidptosis is a newly discovered cell death regulatory mechanism caused by the abnormal accumulation of disulfides. This unique pathway is guiding significant new research to understand cancer progression for targeted treatment. However, the correlation between disulfidptosis with long non-coding RNAs (lncRNAs) in SKCM remains unknown at present. The Cancer Genome Atlas database furnished lncRNA expression data and clinical information for SKCM patients. Pearson correlation and Cox regression analyses identified disulfidptosis-related lncRNAs associated with SKCM prognosis. ROC curves and a nomogram validated the model. TME, immune infiltration, GSEA analysis, immune checkpoint gene expression profiling, and drug sensitivity were assessed in high and low-risk groups. Consistent clustering categorized SKCM patients for personalized clinical treatment guidance. A total of twelve disulfidptosis-related lncRNAs were identified for the development of prognosis prediction models. The area under the curve (AUC) values of the ROC curve and the nomogram provided reliable discrimination to evaluate the prognostic potential for SKCM patients. The TME played a crucial role in tumorigenesis, progression and prognosis, and the risk scores were closely related to immune cell infiltration. Meanwhile, the combination of chemotherapy, targeted therapy, and immunotherapy was recommended for low-risk patients based on drug sensitivity and immune efficacy analyses. We identified a risk model of twelve disulfidptosis-related lncRNAs that could be used to predict the prognosis of SKCM patients and help guide immunotherapy and chemotherapy for personalized treatment plans.

Autoimmune uveitis attenuated in diabetic mice through imbalance of Th1/Th17 differentiation via suppression of AP-1 signaling pathway in Th cells.

Inflammation is involved in the pathogenesis of diabetes, however the impact of diabetes on organ-specific autoimmune diseases remains unexplored. Experimental autoimmune uveoretinitis (EAU) is a widely accepted animal model of human endogenous uveitis. In this study, we investigated the effects of diabetic conditions on the development of EAU using a mouse diabetes model. EAU was induced in wild-type C57BL/6 (WT) mice and Ins2Akita (Akita) mice with spontaneous diabetes by immunization with IRBP peptide. Clinical and histopathological examinations, and analysis of T cell activation state were conducted. In addition, alternations in the composition of immune cell types and gene expression profiles of relevant immune functions were identified using single-cell RNA sequencing. The development of EAU was significantly attenuated in immunized Akita (Akita-EAU) mice compared with immunized WT (WT-EAU) mice, although T cells were fully activated in Akita-EAU mice, and the differentiation into Th17 cells and regulatory T (Treg) cells was promoted. However, Th1 cell differentiation was inhibited in Akita-EAU mice, and single-cell analysis indicated that gene expression associated AP-1 signaling pathway (JUN, FOS, and FOSB) was downregulated not only in Th1 cells but also in Th17, and Treg cells in Akita-EAU mice at the onset of EAU. In diabetic mice, EAU was significantly attenuated. This was related to selective inhibition of Th1 cell differentiation and downregulated AP-1 signaling pathway in both Th1 and Th17 cells.

Innate and Adaptive Immune Parameters following mRNA Vaccination in Mice.

The COVID-19 pandemic has raised the standard regarding the current vaccine development pace, as several messenger RNA (mRNA)-lipid nanoparticle (LNP) vaccines have proved their ability to induce strong immunogenicity and protective efficacy. We developed 1-methylpseudouridine-containing mRNA-LNP vaccines, expressing either the more conserved SARS-CoV-2 nucleoprotein (mRNA-N) or spike protein (mRNA-S), both based on the prototypic viral sequences. When combining both mRNA-S and mRNA-N together (mRNA-S+N), the vaccine showed high immunogenicity and broad protection against different SARS-CoV-2 variants, including wildtype, Delta, BA.1, BA.5, and BQ.1. To better understand the mechanisms behind this broad protection obtained by mRNA-S+N, we analyzed innate and adaptive immune parameters following vaccination in mice. Compared to either mRNA-S or mRNA-N alone, mice vaccinated with mRNA-S+N exhibited an increase in the innate immune response, as depicted by the higher cytokine (IL-6 and chemokine (MCP-1) levels. In addition, lymph node immunophenotyping showed the maturation and activation of dendritic cells and natural killer cells, respectively. To understand the adaptive immune response, RNA-Seq analyses of the lung and spleen samples of the vaccinated mice were performed in parallel and revealed a stronger immune gene-expression profile in the lung than that in the spleen. Compared to mRNA-S alone, mRNA-S+N vaccination elicited higher levels of expression for genes involved in multiple immune pathways, including T cells, cytokine signaling, antigen presentation, B cells, and innate immunity. Together, our studies provide immunological insights into the mechanisms of broad protection conferred by dual mRNA vaccination against SARS-CoV-2 variants.

Characteristics of RNA Stabilizer RNApro for Peripheral Blood Collection.

Peripheral blood is the most practical tissue for human immune system gene expression profiling because it is easily accessible, whereas the site of primary infection in certain diseases may not be easily accessible. Due to the ex vivo instability of RNA transcripts, a key challenge in the gene expression analysis of blood samples is the rapid sample handling and stabilization of the mRNA by adding an RNA preservative (PAXgeneTM Blood RNA Tubes, TempusTM Blood RNA tubes, RNAlater Stabilization Reagent, RNAgard® Blood Tubes). BioMole (Turin, Italy) has developed a novel blood stabilizer, called RNApro, in which RNA is stabilized during phlebotomy and sample storage. In this study, RNApro performance intended as RNA yield, integrity, and stability was evaluated. Our results show that blood samples stored at -80 °C and re-extracted after 7 years show no differences in terms of quantity, quality, and amplificability. The samples in the RNAlater stabilization solution can be stored at room temperature for up to one week or at 4 °C for up to one month. Similar results can also be observed for PAXgene tubes, Tempus tubes, and RNAgard tubes. In agreement with these data, the RNApro stabilization solution preserves the RNA from degradation for up to 1 month at 4 °C and 1 week at room temperature. RNApro can be stored indifferently at -80, -20, 4 °C, or room temperature for up to 2 months after, and then could be stored at -80 °C for up to seven years. In summary, our study is the first to analyze the performance of an RNA stabilizer called RNApro. We can conclude that several studies have shown significant differences in gene expression analysis when the sample was preserved in different RNA stabilizers. Therefore, it is desirable to standardize the method of nucleic acid conservation when comparing data from transcriptomic analyses.

RNA sequencing methods enable immune cell gene expression profiling and clonality determination

Abstract The adaptive immune system defends the human body from pathogens through B/T cell functions in various organs. Abnormality of these cells may reflect immunological disorder, presence of neoplastic tissue, or response to infectious agents. High-throughput sequencing technology has facilitated understanding gene expression and related cell functions. Still, an in-depth understanding of B and T cell phenotype and clonotype profiling is an emerging application that has yet to take full advantage of sequencing technology for disease diagnosis and prognosis. Here, we share results of RNA sequencing of immune system tissues, including healthy donor peripheral blood mononuclear cells (PBMC), lymph nodes, bone marrow, spleen, thyroid, thymus, and colon, as well as diseased PBMC and colon samples. Sequencing libraries were constructed and sequenced for B and T cell-specific gene expression and full-length immune repertoire profiling. We have identified tissue-specific B/T cell phenotype and clonality patterns related to tissue functions and disease progression. RNA-seq enables highly multiplex immunophenotyping and clonality determination for high-abundant clones that correlate with Immune-seq, with the latter targeted approach providing more in-depth clonality signatures. Integrating both RNA sequencing and immune repertoire sequencing approaches allows accurate phenotype and clonotype determination for the immune landscape in various tissues.

Expanding the split-pool combinatorial barcoding toolkit to characterize the effects of aging in mouse TCR diversity.

Abstract We recently released a flexible and high throughput single-cell sequencing method that leverages split-pool combinatorial barcoding to simultaneously profile the whole transcriptome and T cell receptor (TCR) sequences of up to 1 million human T cells from up to 96 samples. This technology is able to recover reproducibly paired TCR sequences in the majority of assayed T cells across different sample types (CAR-Ts, culture activated T cells, etc). Here, we report on the extension of our method to be able to recover the immune repertoire and gene expression profiles from mouse T cells. We use our assay to characterize TCR diversity changes during the mouse lifecycle. Specifically, we profile hundreds of thousands of mouse spleen-resident T cells at different stages of life. We perform transcriptome-based clustering and demonstrate that this approach identifies all major T cell populations (CD4+, CD8+, Tregs, etc.) while efficiently detecting paired TCR sequences. Furthermore, consistent with previous findings, we show differences in clonotype diversity that correlate with age. Overall, we present an extension of our TCR technology that allows for the characterization of mouse TCR sequences and showcases its utility in studying the effects of aging in TCR repertoire diversity. We envision our method will help researchers gain additional insights in mouse models of autoimmune and infectious diseases, as well as cancer.

Abstract 1526: The distinct tumor microenvironment of advanced hepatocellular carcinoma with high PVR or high PD-L1 expression

Abstract Background: The combination of anti-PD-L1 and anti-VEGF has been the standard-of-care for advanced hepatocellular carcinoma (HCC), while additionally targeting TIGIT is under active investigation. We aimed to explore the expression and clinical significance of PVR (CD155), the ligand of TIGIT, within the tumor microenvironment (TME) of advanced HCC. Methods: All HCC tumor specimens were obtained at the advanced stage of HCC. Immunohistochemistry (IHC) was employed to evaluate membranous staining of PVR and PD-L1 of tumor specimens, and semiquantitative scores with IHC 0, 1, 2, or 3 were given if &amp;lt; 1%, ≥1% but &amp;lt; 5%, ≥5% but &amp;lt; 10%, or ≥10% of tumor cells (TCs) and tumor-infiltrating immune cells (ICs) were PVR or PD-L1 positive. Selected tumor specimens underwent immune gene expression profiling using the nCounter Analysis System (NanoString Technologies, Inc.) with the PanCancer Immune Profiling Panel. Results: The study enrolled 67 advanced HCC patients, with median age of 59.2 years (male:female = 57:10). Forty-eight (71.6%) of the patients were hepatitis B virus (HBV) surface antigen positive, and 23 (34.3%) had received sorafenib before the study. Thirteen (19.4%) and 18 (26.9%) tumor tissues showed positive PVR expressions (IHC scores ≥1) in TCs and ICs, respectively; Seventeen (25.4%) and 36 (53.7%) tumor tissues showed positive PD-L1 expressions in TCs and ICs, respectively. The expressions of PVR in TCs or ICs showed no association with clinical factors, such as sex, age, HBV infection, sorafenib treatment, or overall survival. Interestingly, in both TCs and ICs, the intensities of PVR and PD-L1 expression were inversely correlated for those with at least IHC scores ≥1 in either PVR or PD-L1 (TCs, n = 26, r = -0.6966, p &amp;lt; 0.0001; ICs, n = 46, r = -0.4548, p = 0.0015). Immune profiling of the selected tumor specimens showed that those with high PVR but low PD-L1 expressions had significantly lower CD8 T cells scores, lower cytotoxic cells scores, and lower CD8/Treg ratio than those with high PD-L1 but low PVR expressions. Conclusions: There was an inverse correlation observed between expressions of PVR and PD-L1 in the advanced HCC tissues. The TME of those with high PVR expression was distinct from those with high PD-L1 expression. These findings may have important clinical implications for developing combination immunotherapy in advanced HCC. (This work is supported by grants from the Ministry of Science and Technology, Taiwan, MOST 110-2314-B-002-204-MY3). Citation Format: Li-Chun Lu, Yi-Hsuan Lee, Tsung-hao Liu, Yu-Yun Shao, Ann-Lii Cheng, Chih-Hung Hsu. The distinct tumor microenvironment of advanced hepatocellular carcinoma with high PVR or high PD-L1 expression [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 1526.

Immune landscape in APC and TP53 related tumor microenvironment in colon adenocarcinoma: A bioinformatic analysis.

APC and TP53 are the two most regularly mutated genes in colon adenocarcinoma (COAD), especially in progressive malignancies and antitumoral immune response. The current bioinformatics analysis investigates the APC and TP53 gene expression profile in colon adenocarcinoma as a prognostic characteristic for survival, particularly concentrating on the correlated immune microenvironment. Clinical and genetic data of colon cancer and normal tissue samples were obtainedfrom The Cancer Genome Atlas (TCGA)-COAD and Genotype-Tissue Expression (GTEx) online databases, respectively. The genetic differential expressions were analyzed in both groups via the one-way ANOVA test. Kaplan-Meier survival curves were applied to estimate the overall survival (OS). P < 0.05 was fixed as statistically significant. On Tumor Immune Estimation Resource and Gene Expression Profiling Interactive Analysis databases, the linkage between immune cell recruitment and APC and TP53 status was assessed through Spearman's correlation analysis. APC and TP53 were found mutated in 66.74% and 85.71% of the 454 and 7 TCGA-COAD patients in colon and rectosigmoid junction primary sites, respectively with a higher log2-transcriptome per million reads compared to the GTEx group (318 samples in sigmoid and 368 samples in transverse). Survival curves revealed a worse significant OS for the high-APC and TP53 profile colon. Spearman's analysis of immune cells demonstrated a strong positive correlation between the APC status and infiltration of Tcell CD4+, T cell CD8+, NK cell, and macrophages and also a positive correlation between status and infiltration of T cell CD4+, T cell CD8+. APC and TP53 gene mutations prevail in colon cancer and are extremely associated with poor prognosis and shortest survival. The infiltrating T cell CD4+, T cell CD8+, NK cell, and macrophages populate the colon microenvironment and regulate the mechanisms of tumor advancement, immune evasion, and sensitivity to standard chemotherapy. More comprehensive research is needed to demonstrate these results and turn them into new therapeutic outlooks.