Chemokines and the immune response to cancer

Safety and feasibility of anti-CD19 CAR T cells expressing inducible IL-7 and CCL19 in patients with relapsed or refractory large B-cell lymphoma

Although CD19-specific chimeric antigen receptor (CAR) T cells are curative for patients with relapsed or refractory large B-cell lymphoma (R/R LBCL), disease relapse with tumor antigen-positive remains a challenge. Cytokine/chemokine-expressing CAR-T cells could overcome a suppressive milieu, but the clinical safety and efficacy of this CAR-T therapy remain unclear. Here we report the preclinical development of CD19-specific CAR-T cells capable of expressing interleukin (IL)-7 and chemokine (C-C motif) ligand (CCL)-19 upon CD19 engagement (referred to as 7 × 19 CAR-T cells) and results from a phase 1 and expansion phase trial of 7 × 19 CAR-T cell therapy in patients with R/R LBCL (NCT03258047). In dose-escalation phase, there were no dose-limiting toxicities observed. 39 patients with R/R LBCL received 7 × 19 CAR-T with doses ranged from 0.5 × 106-4.0 × 106 cells per kg body weight. Grade 3 cytokine release syndrome occurred in 5 (12.8%) patients and ≥ grade 3 neurotoxicity in 4 (10.3%) patients. The overall response rate at 3 months post-single infusion was 79.5% (complete remission, 56.4%; partial response, 23.1%). With a median follow-up of 32 months, the median progression-free survival was 13 months, and median overall survival was not reached, with an estimated rate of 53.8% (95% CI, 40.3% to 72.0%) at two years. Together, these long-term follow-up data from the multicenter clinical study suggest that 7 × 19 CAR-T cells can induce durable responses with a median overall survival of greater than 2 years, and have a manageable safety profile in patients with R/R LBCL.

Single-cell analysis reveals the stromal dynamics and tumor-specific characteristics in the microenvironment of ovarian cancer

High-grade serous ovarian carcinoma (HGSOC) is a heterogeneous disease, and a highstromal/desmoplastic tumor microenvironment (TME) is associated with a poor outcome. Stromal cell subtypes, including fibroblasts, myofibroblasts, and cancer-associated mesenchymal stem cells, establish a complex network of paracrine signaling pathways with tumor-infiltrating immune cells that drive effector cell tumor immune exclusion and inhibit the antitumor immune response. In this work, we integrate single-cell transcriptomics of the HGSOC TME from public and in-house datasets (n = 20) and stratify tumors based upon high vs. low stromal cell content. Although our cohort size is small, our analyses suggest a distinct transcriptomic landscape for immune and non-immune cells in high-stromal vs. low-stromal tumors. High-stromal tumors have a lower fraction of certain T cells, natural killer (NK) cells, and macrophages, and increased expression of CXCL12 in epithelial cancer cells and cancer-associated mesenchymal stem cells (CA-MSCs). Analysis of cell-cell communication indicate that epithelial cancer cells and CA-MSCs secrete CXCL12 that interacte with the CXCR4 receptor, which is overexpressed on NK and CD8+ T cells. Dual IHC staining show that tumor infiltrating CD8 T cells localize in proximity of CXCL12+ tumor area. Moreover, CXCL12 and/or CXCR4 antibodies confirm the immunosuppressive role of CXCL12-CXCR4 in high-stromal tumors.

Urinary IL-6 and IL-8 as predictive markers in bladder urothelial carcinoma: A pilot study

BACKGROUND

Cytokines are known to be a key a factor in numerous malignancies and to exert an important regulatory role in the tumor microenvironment. Interest has grown in understanding how cytokines modulate the tumor microenvironment and which cytokines may serve as markers of the tumor process; however, a complete picture of the cytokine landscape in bladder cancer remains unclear.

METHODS

Fresh urine specimens with sufficient volume were collected at random intervals. The urine concentrations of IL-8 (CXCL8), CCL18, and CXCL9 were determined using the standard commercially available enzyme immunoassay. The urine concentrations of IL-6 were determined using the high sensitivity enzyme immunoassay kit. Urinary cytokine concentrations were normalized with urinary creatinine concentrations.

RESULTS

Significantly elevated concentrations of IL-6 and IL-8 were detected in the urine from patients with urothelial carcinoma on follow-up compared to patients with benign follow-up. The presence of both IL-6 and IL-8 in the urine samples from the high grade urothelial carcinoma (HGUC) cohort revealed a clear discrimination when compared to samples from patients with benign follow-up. The presence of the combination of both IL-6 and IL-8 had a sensitivity of 90.0% and a specificity of 81.25%. Similar data were obtained when receiver operating characteristic analysis was performed on both IL-6 and IL-8 concentrations in the urine from patients with HGUC vs. the hematuria cohort.

CONCLUSIONS

The presence of IL-6 and IL-8 in urine specimens may have predictive value for urothelial carcinoma. However, a large longitudinal study is required to statistically eliminate confounding factors and support this theory.

Strategies for studying immune and non-immune human and canine mammary gland cancer tumour infiltrate

The tumour microenvironment (TME) is usually defined as a cell environment associated with tumours or cancerous stem cells where conditions are established affecting tumour development and progression through malignant cell interaction with non-malignant cells. The TME is made up of endothelial, immune and non-immune cells, extracellular matrix (ECM) components and signalling molecules acting specifically on tumour and non-tumour cells. Breast cancer (BC) is the commonest malignant neoplasm worldwide and the main cause of mortality in women globally; advances regarding BC study and understanding it are relevant for acquiring novel, personalised therapeutic tools. Studying canine mammary gland tumours (CMGT) is one of the most relevant options for understanding BC using animal models as they share common epidemiological, clinical, pathological, biological, environmental, genetic and molecular characteristics with human BC. In-depth, detailed investigation regarding knowledge of human BC-related TME and in its canine model is considered extremely relevant for understanding changes in TME composition during tumour development. This review addresses important aspects concerned with different methods used for studying BC- and CMGT-related TME that are important for developing new and more effective therapeutic strategies for attacking a tumour during specific evolutionary stages.

LncRNA CRNDE Drives the Progression of Hepatocellular Carcinoma by inducing the Immunosuppressive Niche

As a crucial protumorigenic long noncoding RNA, colorectal tumor differential expression (CRNDE) has been confirmed to facilitate the progression of various cancers. However, its role in the tumor microenvironment (TME) of hepatocellular carcinoma (HCC) is still unclear. Here we determined that CRNDE was upregulated in HCC samples and that CRNDE-positive cells were predominantly enriched in malignant tumor cells. In vivo functional assays revealed that CRNDE-induced tumor cells supported HCC progression, recruited abundant granulocyte myeloid-derived suppressor cells (G-MDSCs) and restricted the infiltration of T cells. In terms of mechanisms, CRNDE bound with Toll-like receptor 3 (TLR3) and activated NF-κB signaling to increase the secretion of c-x-c motif chemokine ligand 3 (CXCL3). CRNDE knockdown could significantly suppress the accumulation of G-MDSCs and enhance the infiltration of T cells in the TME of HCC in vivo. Taken together, our study reveals the CRNDE-NF-κB-CXCL3 axis plays a crucial role in driving the immunosuppressive niche to facilitate HCC progression by recruiting G-MDSCs.

Mapping inherited genetic variation with opposite effects on autoimmune disease and cancer identifies candidate drug targets associated with the anti-tumor immune response

Background

Germline alleles near genes that encode certain immune checkpoints (CTLA4, CD200) are associated with autoimmune/autoinflammatory disease and cancer but in opposite directions. This motivates a systematic search for additional germline alleles which demonstrate this pattern with the aim of identifying potential cancer immunotherapeutic targets using human genetic evidence.

Methods

Pairwise fixed effect cross-disorder meta-analyses combining genome-wide association studies (GWAS) for breast, prostate, ovarian and endometrial cancers (240,540 cases/317,000 controls) and seven autoimmune/autoinflammatory diseases (112,631 cases/895,386 controls) coupled with in silico follow-up. To ensure detection of alleles with opposite effects on cancer and autoimmune/autoinflammatory disease, the signs on the beta coefficients in the autoimmune/autoinflammatory GWAS were reversed prior to meta-analyses.

Results

Meta-analyses followed by linkage disequilibrium clumping identified 312 unique, independent lead variants with Pmeta<5x10-8 associated with at least one of the cancer types at Pcancer<10-3 and one of the autoimmune/autoinflammatory diseases at Pauto<10-3. At each lead variant, the allele that conferred autoimmune/autoinflammatory disease risk was protective for cancer. Mapping each lead variant to its nearest gene as its putative functional target and focusing on genes with established immunological effects implicated 32 of the nearest genes. Tumor bulk RNA-Seq data highlighted that the tumor expression of 5/32 genes (IRF1, IKZF1, SPI1, SH2B3, LAT) were each strongly correlated (Spearman's ρ>0.5) with at least one intra-tumor T/myeloid cell infiltration marker (CD4, CD8A, CD11B, CD45) in every one of the cancer types. Tumor single-cell RNA-Seq data from all cancer types showed that the five genes were more likely to be expressed in intra-tumor immune versus malignant cells. The five lead SNPs corresponding to these genes were linked to them via expression quantitative trait locus mechanisms and at least one additional line of functional evidence. Proteins encoded by the genes were predicted to be druggable.

Conclusion

We provide population-scale germline genetic and functional genomic evidence to support further evaluation of the proteins encoded by IRF1, IKZF1, SPI1, SH2B3, and LAT as possible targets for cancer immunotherapy.

DJ-1: A Potential Biomarker Related to Prognosis, Chemoresistance, and Expression of Microenvironmental Chemokine in HR-Positive Breast Cancer

DJ-1 is significantly elevated in various malignancies. However, the clinical significance of DJ-1 in hormone receptor (HR)-positive (HR+) breast cancer remains unclear. We evaluated DJ-1 expression in different databases and validated in vitro assay by RT-PCR and western blot among HR+ breast cancer. The correlations between DJ-1 level and tumor-immune were calculated. Mutational landscape, enriched signaling pathways, and drug sensitivity analyses were also assessed between DJ-1 high and low-expression groups. DJ-1 was upregulated in HR+ breast cancer, and high DJ-1 expression was significantly linked with poor prognosis. DJ-1 was correlated with the expression and function of different immune cells. The low DJ-1 group showed sensitivity to paclitaxel and docetaxel, while the high-expression group showed sensitivity to doxorubicin. CTLA4 and PD-L1 were more sensitive in high-DJ-1 group. It is involved in a range of pathways and might behave as a novel biomarker of prognostic value for the immune environment and drug sensitivity in HR+ breast cancer.

Tumor cell-intrinsic SETD2 inactivation sensitizes cancer cells to immune checkpoint blockade through the NR2F1-STAT1 pathway

BACKGROUND

Cancer immunotherapies can induce durable tumor regression, but most patients do not respond. SETD2 mutation has been linked to the efficacy of immune checkpoint inhibitors (ICIs) immunotherapy. The functional importance of the SETD2 inactivation and how to modulate immunotherapy response remains unclear.

METHODS

To explore the function of SETD2 in immunotherapy, knockout and subsequent functional experiments were conducted. Bulk RNA-seq, ATAC-seq, Chip-seq and single-cell RNA-seq were performed to dissect the mechanism and explore the immune microenvironment of mouse tumor. Flow cytometry was used to assess cell surface antigen and intratumoral T cell levels.

RESULTS

We comprehensively determine the effect of SETD2 inactivation in ICIs therapy and elucidate the mechanistic impact on tumor immunity. Murine syngeneic tumors harboring Setd2 inactivation are sensitive to ICIs. By bulk and single-cell RNA-seq, we further reveal that SETD2 inactivation reprograms intratumoral immune cells and inflames the tumor microenvironment, which is characterized by high infiltration of T cells and enhanced antigen presentation to activate CD8+ T cell-mediated killing. Mechanistically, via an integrated multiomics analysis using ATAC-seq, ChIP-seq and RNA-seq, we demonstrate that SETD2 inactivation reduces NR2F1 transcription by impairing H3K36me3 deposition and chromatin accessibility, which activates the STAT1 signaling pathway to promote chemokines and programmed cell death protein-1 (PD-1) expression and enhance antigen presentation. All these regulatory mechanisms synergistically promote the effects of anti-programmed cell death ligand 1 immunotherapy in Setd2-knockout syngeneic mouse models. The SETD2-NR2F1-STAT1 regulatory axis is conserved in human and murine cancers. Finally, cancer patients harboring SETD2 mutations who received ICIs show increased durable clinical benefits and survival.

CONCLUSIONS

These findings provide novel insights into the biology of SETD2 inactivation regulation and reveal a new potential therapeutic biomarker for ICIs immunotherapy in various refractory cancers.

Targeting the epigenome to reinvigorate T cells for cancer immunotherapy

Cancer immunotherapy using immune-checkpoint inhibitors (ICIs) has revolutionized the field of cancer treatment; however, ICI efficacy is constrained by progressive dysfunction of CD8+ tumor-infiltrating lymphocytes (TILs), which is termed T cell exhaustion. This process is driven by diverse extrinsic factors across heterogeneous tumor immune microenvironment (TIME). Simultaneously, tumorigenesis entails robust reshaping of the epigenetic landscape, potentially instigating T cell exhaustion. In this review, we summarize the epigenetic mechanisms governing tumor microenvironmental cues leading to T cell exhaustion, and discuss therapeutic potential of targeting epigenetic regulators for immunotherapies. Finally, we outline conceptual and technical advances in developing potential treatment paradigms involving immunostimulatory agents and epigenetic therapies.

Engineering strategies to optimise adoptive cell therapy in ovarian cancer

Ovarian cancer is amongst the ten most common cancer types in women, and it is one of the leading causes of death. Despite the promising results of targeted therapies, including anti-angiogenic agents and poly (ADP-ribose) polymerase inhibitors (PARPi), the majority of patients will relapse and develop treatment resistance, implying that novel therapeutic strategies are required. Adoptive cell therapy (ACT) refers to the process by which autologous immune cells are used to eliminate cancer. Examples include tumour infiltrating lymphocytes (TILs), T cells genetically engineered with T cell receptors (TCR), or chimeric antigen receptor (CAR)-T cells. Recently, ACT has revealed promising results in the treatment of haematological malignancies, however, its application to solid tumours is still limited due to lack of functionality and persistence of T cells, prevalence of an exhausted phenotype and impaired trafficking towards the tumour microenvironment (TME). In this review we explore the potential of ACT for the treatment of ovarian cancer and strategies to overcome its principal limitations.

CXCL6: A potential therapeutic target for inflammation and cancer

Chemokines were originally defined as cytokines that affect the movement of immune cells. In recent years, due to the increasing importance of immune cells in the tumor microenvironment (TME), the role of chemokines has changed from a single "chemotactic agent" to a key factor that can regulate TME and affect the tumor phenotype. CXCL6, also known as granulocyte chemoattractant protein-2 (GCP-2), can recruit neutrophils to complete non-specific immunity in the process of inflammation. Cancer-related genes and interleukin family can promote the abnormal secretion of CXCL6, which promotes tumor growth, metastasis, epithelial mesenchymal transformation (EMT) and angiogenesis in the TME. CXCL6 also has a role in promoting fibrosis and tissue damage repair. In this review, we focus on the regulatory network affecting CXCL6 expression, its role in the progress of inflammation and how it affects tumorigenesis and progression based on the TME, in an attempt to provide a potential target for the treatment of diseases such as inflammation and cancer.

Albendazole induces an anti-tumor effect and potentiates PD-L1 blockade immunotherapy

BACKGROUND

Previously, albendazole (ABZ) has been reported as an anti-parasitic drug rather than anti-tumor drug. Our study aim to investigate whether ABZ also has a potential anti-tumor effect by shaping the tumor immune microenvironment and interrogate whether ABZ could synergize with the PD-L1 blockade.

METHODS

C57BL/6 mice (C57) were intravenously injected with B16F10-luciferase (B16-luc) cells to establish a lung metastatic melanoma model and subcutaneously inoculated with B16-luc cells to establish a subcutaneous tumor model. The tumor volume and tumor metastasis loci of the mice were measured by a vernier caliper and in vivo imaging. RNA sequencing was performed to analyze the different genes and pathways of immune cells in the tumors. Flow cytometry and immunofluorescence were used to analyze the different subsets of tumor-infiltrating immune cells.

RESULTS

The results suggested that ABZ significantly inhibited lung melanoma metastasis with decreased fluorescence intensity and nodule score and mediated the regression of subcutaneous melanoma in mice with decreased tumor volume. Moreover, RNA sequencing results showed that ABZ regulated the gene expression levels and pathways of immune cells in the tumor microenvironment (TME). Meanwhile, flow cytometry and immunofluorescence showed that the number and percentage of CD8+ T cells, CD4+ T cells, and TH1 cells were enhanced in tumors after ABZ treatment. Furthermore, the combination of ABZ and anti-PD-L1 treatment significantly potentiated anti-tumor efficacy in both lung metastasis and subcutaneous melanoma models and mediated an increase in the percentage of CD8+ T cells, CD4+ T cells, and TH1 cells as compared to the control group.

CONCLUSION

ABZ inhibits melanoma growth and metastasis. Moreover, ABZ synergized with PD-L1 blockade mediates tumor regression.

Elevated expression of CXCL3 in colon cancer promotes malignant behaviors of tumor cells in an ERK-dependent manner

BACKGROUND

CXC chemokine ligand 3 (CXCL3) is a member of CXC-type chemokine family that is identified as a major regulator in immune and inflammation responses. Recently, numerous evidence indicated that CXCL3 is broadly expressed in various human tumor types, and it is also known to play a critical role in mediating tumor development and progression. However, the expression profile of CXCL3 and the exact molecular mechanism behind the role of CXCL3 in colon adenocarcinoma (COAD) has not been fully elucidated.

METHODS

The expression and clinical significance of CXCL3 mRNA and protein in the tissues from COAD patients were estimated using bioinformatics and immunohistochemistry assays. The expression and roles of exogenous administration or overexpression of CXCL3 in HT-29 and SW480 COAD cells were determined using enzyme-linked immunosorbent assay(ELISA), Cell Counting Kit-8 (CCK-8) and Transwell assays. Mechanically, CXCL3-induced malignant behaviors were elucidated using western blotting assay and extracellular signal-regulated protein kinase 1/2 (ERk1/2) inhibitor PD98059.

RESULTS

The cancer genome atlas (TCGA)-COAD data analysis revealed that CXCL3 mRNA is highly expressed and has high clinical diagnostic accuracy in COAD. Increased expression of CXCL3 mRNA was associated with patient's clinical stage, race, gender, age, histological subtype, nodal mestastasis and tumor protein 53 (TP53) mutation status. Similarly, immunohistochemistry assay also exhibited that CXCL3 protein in COAD tissues was significantly up-regulated. Gene expression associated assay implied that CXC chemokine ligand 1 (CXCL1) and CXC chemokine ligand 2 (CXCL2) were markedly correlated with CXCL3 in COAD. Protein-protein interaction (PPI) analysis revealed that cyclin B1 (CCNB1), mitotic arrest deficient 2 like 1 (MAD2L1), H2A family member Z (H2AFZ) and CXCL2 may be the important protein molecules involved in CXCL3-related tumor biology. Gene set enrichment analysis (GSEA) analysis revealed that CXCL3 was mainly enriched in the cell cycle, DNA replication, NOD-like receptors, NOTCH and transforming growth factor-β (TGF-β) Signal pathways. In vitro, exogenous administration or overexpression of CXCL3 resulted in increased malignant behaviors of HT-29 and SW480 cells, and down-regulation of CXCL3 expression inhibited the malignant behaviors of these tumor cells. In addition, overexpression of CXCL3 affected the expression of genes related to extracellular signal regulated kinase (ERK) pathway, including ERK1/2, p-ERK, B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax) and Cyclin D1. Finally, CXCL3-induced malignant behaviors in HT-29 and SW480 cells were obviously attenuated following treatment with ERK inhibitor PD98059.

CONCLUSION

CXCL3 is upregulated in COAD and plays a crucial role in the control of malignant behaviors of tumor cells, which indicated its involvement in the pathogenesis of COAD.

Low-dose radiotherapy combined with dual PD-L1 and VEGFA blockade elicits antitumor response in hepatocellular carcinoma mediated by activated intratumoral CD8+ exhausted-like T cells

Atezolizumab (anti-PD-L1) combined with bevacizumab (anti-VEGFA) is the first-line immunotherapy for advanced hepatocellular carcinoma (HCC), but the number of patients who benefit from this regimen remains limited. Here, we combine dual PD-L1 and VEGFA blockade (DPVB) with low-dose radiotherapy (LDRT), which rapidly inflames tumors, rendering them vulnerable to immunotherapy. The combinatorial therapy exhibits superior antitumor efficacy mediated by CD8+ T cells in various preclinical HCC models. Treatment efficacy relies upon mobilizing exhausted-like CD8+ T cells (CD8+ Tex) with effector function and cytolytic capacity. Mechanistically, LDRT sensitizes tumors to DPVB by recruiting stem-like CD8+ Tpex, the progenitor exhausted CD8+ T cells, from draining lymph nodes (dLNs) into the tumor via the CXCL10/CXCR3 axis. Together, these results further support the rationale for combining LDRT with atezolizumab and bevacizumab, and its clinical translation.

CRIP1 fosters MDSC trafficking and resets tumour microenvironment via facilitating NF-κB/p65 nuclear translocation in pancreatic ductal adenocarcinoma

OBJECTIVE

Pancreatic ductal adenocarcinoma (PDAC) is among the most immunosuppressive tumour types. The tumour immune microenvironment (TIME) is largely driven by interactions between immune cells and heterogeneous tumour cells. Here, we aimed to investigate the mechanism of tumour cells in TIME formation and provide potential combination treatment strategies for PDAC patients based on genotypic heterogeneity.

DESIGN

Highly multiplexed imaging mass cytometry, RNA sequencing, mass cytometry by time of flight and multiplex immunofluorescence staining were performed to identify the pro-oncogenic proteins associated with low immune activation in PDAC. An in vitro coculture system, an orthotopic PDAC allograft tumour model, flow cytometry and immunohistochemistry were used to explore the biological functions of cysteine-rich intestinal protein 1 (CRIP1) in tumour progression and TIME formation. RNA sequencing, mass spectrometry and chromatin immunoprecipitation were subsequently conducted to investigate the underlying mechanisms of CRIP1.

RESULTS

Our results showed that CRIP1 was frequently upregulated in PDAC tissues with low immune activation. Elevated CRIP1 expression induced high levels of myeloid-derived suppressor cell (MDSC) infiltration and fostered an immunosuppressive tumour microenvironment. Mechanistically, we primarily showed that CRIP1 bound to nuclear factor kappa-B (NF-κB)/p65 and facilitated its nuclear translocation in an importin-dependent manner, leading to the transcriptional activation of CXCL1/5. PDAC-derived CXCL1/5 facilitated the chemotactic migration of MDSCs to drive immunosuppression. SX-682, an inhibitor of CXCR1/2, blocked tumour MDSC recruitment and enhanced T-cell activation. The combination of anti-PD-L1 therapy with SX-682 elicited increased CD8+T cell infiltration and potent antitumor activity in tumour-bearing mice with high CRIP1 expression.

CONCLUSIONS

The CRIP1/NF-κB/CXCL axis is critical for triggering immune evasion and TIME formation in PDAC. Blockade of this signalling pathway prevents MDSC trafficking and thereby sensitises PDAC to immunotherapy.

ICBcomb: a comprehensive expression database for immune checkpoint blockade combination therapy

The success of immune checkpoint blockade (ICB) promotes the immunotherapy to be a new pillar in cancer treatment. However, the low response rate of the ICB therapy limits its application. To increase the response rate and enhance efficacy, the ICB combination therapy has emerged and its clinical trials are increasing. Nevertheless, the gene expression profile and its pattern of ICB combination were not comprehensively studied, which limits the understanding of the ICB combination therapy and the identification of new drugs. Here, we constructed ICBcomb (http://bioinfo.life.hust.edu.cn/ICBcomb/), a comprehensive database, by analyzing the human and mouse expression data of the ICB combination therapy and comparing them between groups treated with ICB, other drugs or their combinations. ICBcomb contains 1399 samples across 29 cancer types involving 52 drugs. It provides a user-friendly web interface for demonstrating the results of the available comparisons in the ICB combination therapy datasets with five functional modules: [1, 2] the 'Dataset/Disease' modules for browsing the expression, enrichment and comparison results in each dataset or disease; [3] the 'Gene' module for inputting a gene symbol and displaying its expression and comparison results across datasets/diseases; [4] the 'Gene Set' module for GSVA/GSEA enrichment analysis on the built-in gene sets and the user-input gene sets in different comparisons; [5] the 'Immune Cell' module for immune cell infiltration comparison between different groups by immune cell abundance analysis. The ICBcomb database provides the first resource for gene expression profile and comparison in ICB combination therapy, which may provide clues for discovering the mechanism of effective combination strategies and new combinatory drugs.

γδ T cells: origin and fate, subsets, diseases and immunotherapy

The intricacy of diseases, shaped by intrinsic processes like immune system exhaustion and hyperactivation, highlights the potential of immune renormalization as a promising strategy in disease treatment. In recent years, our primary focus has centered on γδ T cell-based immunotherapy, particularly pioneering the use of allogeneic Vδ2+ γδ T cells for treating late-stage solid tumors and tuberculosis patients. However, we recognize untapped potential and optimization opportunities to fully harness γδ T cell effector functions in immunotherapy. This review aims to thoroughly examine γδ T cell immunology and its role in diseases. Initially, we elucidate functional differences between γδ T cells and their αβ T cell counterparts. We also provide an overview of major milestones in γδ T cell research since their discovery in 1984. Furthermore, we delve into the intricate biological processes governing their origin, development, fate decisions, and T cell receptor (TCR) rearrangement within the thymus. By examining the mechanisms underlying the anti-tumor functions of distinct γδ T cell subtypes based on γδTCR structure or cytokine release, we emphasize the importance of accurate subtyping in understanding γδ T cell function. We also explore the microenvironment-dependent functions of γδ T cell subsets, particularly in infectious diseases, autoimmune conditions, hematological malignancies, and solid tumors. Finally, we propose future strategies for utilizing allogeneic γδ T cells in tumor immunotherapy. Through this comprehensive review, we aim to provide readers with a holistic understanding of the molecular fundamentals and translational research frontiers of γδ T cells, ultimately contributing to further advancements in harnessing the therapeutic potential of γδ T cells.

Chemokines: A key driver for inflammation in protozoan infection

Chemokines belong to the group of small proteins within the cytokine family having strong chemo-attractant properties. In most cases, the strong immuno-modulatory role of chemokines is crucial for generating the immune response against pathogens in various protozoan diseases. In this review, we have given a brief update on the classification, characterization, homeostasis, transcellular migration, and immuno-modulatory role of chemokines. Here we will evaluate the potential role of chemokines and their regulation in various protozoan diseases. There is a significant direct relationship between parasitic infection and the recruitment of effector cells of the immune response. Chemokines play an indispensable role in mediating several defense mechanisms against infection, such as leukocyte recruitment and the generation of innate and cell-mediated immunity that aids in controlling/eliminating the pathogen. This process is controlled by the chemotactic movement of chemokines induced as a primary host immune response. We have also addressed that chemokine expressions during infection are time-dependent and orchestrated in a systematic pattern that ultimately assists in generating a protective immune response. Taken together, this review provides a systematic understanding of the complexity of chemokines profiles during protozoan disease conditions and the rationale of targeting chemokines for the development of therapeutic strategies.

Identification of Immune Subtypes and Candidate mRNA Vaccine Antigens in Small Cell Lung Cancer

BACKGROUND

Immune checkpoint inhibitors (ICIs) have demonstrated promising outcomes in small cell lung cancer (SCLC), but not all patients benefit from it. Thus, developing precise treatments for SCLC is a particularly urgent need. In our study, we constructed a novel phenotype for SCLC based on immune signatures.

METHODS

We clustered patients with SCLC hierarchically in 3 publicly available datasets according to the immune signatures. ESTIMATE and CIBERSORT algorithm were used to evaluate the components of the tumor microenvironment. Moreover, we identified potential mRNA vaccine antigens for patients with SCLC, and qRT-PCR were performed to detect the gene expression.

RESULTS

We identified 2 SCLC subtypes and named Immunity High (Immunity_H) and Immunity Low (Immunity_L). Meanwhile, we obtained generally consistent results by analyzing different datasets, suggesting that this classification was reliable. Immunity_H contained the higher number of immune cells and a better prognosis compared to Immunity_L. Gene-set enrichment analysis revealed that several immune-related pathways such as cytokine-cytokine receptor interaction, programmed cell death-Ligand 1 expression and programmed cell death-1 checkpoint pathway in cancer were hyperactivated in the Immunity_H. However, most of the pathways enriched in the Immunity_L were not associated with immunity. Furthermore, we identified 5 potential mRNA vaccine antigens of SCLC (NEK2, NOL4, RALYL, SH3GL2, and ZIC2), and they were expressed higher in Immunity_L, it indicated that Immunity_L maybe more suitable for tumor vaccine development.

CONCLUSIONS

SCLC can be divided into Immunity_H and Immunity_L subtypes. Immunity_H may be more suitable for treatment with ICIs. NEK2, NOL4, RALYL, SH3GL2, and ZIC2 may be act as potential antigens for SCLC.

Down-regulation of stimulator of interferon genes (STING) expression and CD8+ T-cell infiltration depending on HER2 heterogeneity in HER2-positive gastric cancer

BACKGROUND

HER2 signaling might be involved in the regulation of immune cell activation in the tumor microenvironment (TME) of gastric cancer (GC). However, the relationship between HER2 status and immune cell condition in the HER2-positive GC TME is not clearly understood.

METHODS

To investigate the effect of HER2 signaling on the activation of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, which contributes to immune cell activation in the GC TME, we evaluated the associations among the expressions of HER2, cGAS-STING, and the number of CD8+ tumor-infiltrating lymphocytes (TIL) by considering HER2 heterogeneity in HER2-positive GC tissues. We also examined the effect of HER2 signaling on the activation of STING signaling in vitro using human HER2-positive GC cell lines.

RESULTS

The expression of HER2 is highly heterogeneous in HER2-positive GC tissues, and we found that the number of CD8+ TIL in HER2 high areas was significantly lower than that in HER2 low areas in HER2-positive GC tissues. Intriguingly, the tumor cell-intrinsic expression of STING, but not cGAS, was also significantly lower in the HER2 high areas than the HER2 low areas in HER2-positive GC tissues. Moreover, in vitro experiments, we demonstrated that the blockade of HER2 signaling increased the expression of STING and its target genes, including IFNB1, CXCL9/10/11, and CCL5, in HER2-positive GC cell lines.

CONCLUSIONS

Our results suggest that HER2 signaling might suppress immune cell activation in the GC TME by inhibiting STING signaling in tumor cells in HER2-positive GC.

Critical Roles of SRC-3 in the Development and Progression of Breast Cancer, Rendering It a Prospective Clinical Target

Breast cancer (BCa) is the most frequently diagnosed malignant tumor in women and is also one of the leading causes of cancer-related death. Most breast tumors are hormone-dependent and estrogen signaling plays a critical role in promoting the survival and malignant behaviors of these cells. Estrogen signaling involves ligand-activated cytoplasmic estrogen receptors that translocate to the nucleus with various co-regulators, such as steroid receptor co-activator (SRC) family members, and bind to the promoters of target genes and regulate their expression. SRC-3 is a member of this family that interacts with, and enhances, the transcriptional activity of the ligand activated estrogen receptor. Although SRC-3 has important roles in normal homeostasis and developmental processes, it has been shown to be amplified and overexpressed in breast cancer and to promote malignancy. The malignancy-promoting potential of SRC-3 is diverse and involves both promoting malignant behavior of tumor cells and creating a tumor microenvironment that has an immunosuppressive phenotype. SRC-3 also inhibits the recruitment of tumor-infiltrating lymphocytes with effector function and promotes stemness. Furthermore, SRC-3 is also involved in the development of resistance to hormone therapy and immunotherapy during breast cancer treatment. The versatility of SRC-3 in promoting breast cancer malignancy in this way makes it a good target, and methodical targeting of SRC-3 probably will be important for the success of breast cancer treatment.

BRAF D594A mutation defines a unique biological and immuno-modulatory subgroup associated with functional CD8+ T cell infiltration in colorectal cancer

BACKGROUND

BRAF non-V600 mutation occupies a relatively small but critical subset in colorectal cancer (CRC). However, little is known about the biological functions and impacts of BRAF class III mutation in CRC. Here, we aim to explore how D594A mutation impacts on biological behaviors and immune related signatures in murine CRC cells.

METHODS

BRAF V600E (class I), G469V (class II) and D594A (class III) mutant cell lines were established based on MC38 cells. The biological behaviors of cells were evaluated in respect of cell growth, cell proliferation, cell apoptosis, cell migration and invasion by the methods of colony-forming assay, CCK-8 assay, Annexin V/PI staining and transwell assay. The concentrations of soluble cytokines were detected by ELISA. The membrane expression of immuno-modulatory molecules and the pattern of tumor infiltrating lymphocyte were evaluated by flow cytometry. The molecular mechanism was explored by RNA sequencing. Immunohistochemistry (IHC) staining was used for the detection of CD8α in tumor tissues. qRT-PCR and western blot were performed to assess the mRNA and protein expression. Anti-PD-L1 treatment and cytokines neutralization experiments were conducted in in vivo models.

RESULTS

D594A mutant cells displayed lower grade malignancy characteristics than V600E (class I) and G469V (class II) mutant cells. Meanwhile, D594A mutation led to evident immuno-modulatory features including upregulation of MHC Class I and PD-L1. In vivo experiments displayed that the frequency of infiltrated CD8+ T cells was significantly high within D594A mutant tumors, which may provide potential response to anti-PD-L1 therapy. RNA sequencing analysis showed that D594A mutation led to enhanced expression of ATF3 and THBS1, which thus facilitated CXCL9 and CXCL10 production upon IFN-γ treatment. In addition, CXCL9 or CXCL10 neutralization reduced the infiltration of CD8+ T cells into THBS1-overexpressing tumors.

CONCLUSIONS

D594A mutant CRC exhibited lower aggressiveness and immune-activated phenotype. ATF3-THBS1-CXCL9/CXCL10 axis mediated functional CD8+ T cells infiltration into the microenvironment of D594A mutant CRC. Our present study is helpful to define this mutation in CRC and provide important insights in designing effective immunotherapeutic strategies in clinic.

Angiopoietin-2 blockade suppresses growth of liver metastases from pancreatic neuroendocrine tumors by promoting T cell recruitment

Improving the management of metastasis in pancreatic neuroendocrine tumors (PanNETs) is critical, as nearly half of patients with PanNETs present with liver metastases, and this accounts for the majority of patient mortality. We identified angiopoietin-2 (ANGPT2) as one of the most upregulated angiogenic factors in RNA-Seq data from human PanNET liver metastases and found that higher ANGPT2 expression correlated with poor survival rates. Immunohistochemical staining revealed that ANGPT2 was localized to the endothelial cells of blood vessels in PanNET liver metastases. We observed an association between the upregulation of endothelial ANGPT2 and liver metastatic progression in both patients and transgenic mouse models of PanNETs. In human and mouse PanNET liver metastases, ANGPT2 upregulation coincided with poor T cell infiltration, indicative of an immunosuppressive tumor microenvironment. Notably, both pharmacologic inhibition and genetic deletion of ANGPT2 in PanNET mouse models slowed the growth of PanNET liver metastases. Furthermore, pharmacologic inhibition of ANGPT2 promoted T cell infiltration and activation in liver metastases, improving the survival of mice with metastatic PanNETs. These changes were accompanied by reduced plasma leakage and improved vascular integrity in metastases. Together, these findings suggest that ANGPT2 blockade may be an effective strategy for promoting T cell infiltration and immunostimulatory reprogramming to reduce the growth of liver metastases in PanNETs.

The landscape of cancer rewired GPCR signaling axes

We explored the dysregulation of GPCR ligand signaling systems in cancer transcriptomics datasets to uncover new therapeutics opportunities in oncology. We derived an interaction network of receptors with ligands and their biosynthetic enzymes, which revealed that multiple GPCRs are differentially regulated together with their upstream partners across cancer subtypes. We showed that biosynthetic pathway enrichment from enzyme expression recapitulated pathway activity signatures from metabolomics datasets, providing valuable surrogate information for GPCRs responding to organic ligands. We found that several GPCRs signaling components were significantly associated with patient survival in a cancer type-specific fashion. The expression of both receptor-ligand (or enzymes) partners improved patient stratification, suggesting a synergistic role for the activation of GPCR networks in modulating cancer phenotypes. Remarkably, we identified many such axes across several cancer molecular subtypes, including many pairs involving receptor-biosynthetic enzymes for neurotransmitters. We found that GPCRs from these actionable axes, including e.g., muscarinic, adenosine, 5-hydroxytryptamine and chemokine receptors, are the targets of multiple drugs displaying anti-growth effects in large-scale, cancer cell drug screens. We have made the results generated in this study freely available through a webapp (gpcrcanceraxes.bioinfolab.sns.it).

Chemokines and receptors in the development and progression of malignant tumors

Cancer cells, endothelial cells, inflammatory cells and various cytokines form a part of the tumor microenvironment (TME). Chemokines constitute the largest family of cytokines, and are mainly secreted by tumor cells and inflammatory cells in the TME. They play an important role in tumor development and progression by promoting tumor growth and metastasis, angiogenesis, and targeting the chemoattraction of inflammatory cells. Currently, some chemokine receptor antagonists are being used in clinical trials as targeted anti-tumor drugs. In this article, we review the roles of chemokines in the development and progression of malignant tumors based on recently published papers, taking into consideration of the new anti-tumor therapeutic strategies targeting chemokines and receptors.

Identification of an antigen-presenting cells/T/NK cells-related gene signature to predict prognosis and CTSL to predict immunotherapeutic response for lung adenocarcinoma: an integrated analysis of bulk and single-cell RNA sequencing

BACKGROUND

Antigen-presenting cells (APC)/T/NK cells are key immune cells that play crucial roles in fighting against malignancies including lung adenocarcinoma (LUAD). In this study, we aimed to identify an APC/T/NK cells-related gene signature (ATNKGS) and potential immune cell-related genes (IRGs) to realize risk stratification, prognosis, and immunotherapeutic response prediction for LUAD patients.

METHODS

Based on the univariate Cox regression and the LASSO Cox regression results of 196 APC/T/NK cells-related genes collected from three pathways in the KEGG database, we determined the final genes and established the ATNKGS-related risk model. The single-cell RNA sequencing data were applied for key IRGs identification and investigate their value in immunotherapeutic response prediction. Several GEO datasets and an external immunotherapy cohort from Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, were applied for validation.

RESULTS

In this study, nine independent public datasets including 1108 patients were enrolled. An ATNKGS containing 16 genes for predicting overall survival of LUAD patients was constructed with robust prognostic capability. The ATNKGS high risk group was related to significantly worse OS outcomes than those in the low-risk group, which were verified in TCGA and four GEO datatsets. A nomogram combining the ATNKGS risk score with clinical TNM stage achieved the optimal prediction performance. The single-cell RNA sequencing analysis revealed CTSL as an IRG of macrophage and monocyte. Moreover, though CTSL was an indicator for poor prognosis of LUAD patients, CTSL high expression group was associated with higher ESTIMATEScore, immune checkpoints expression, and lower TIDE score. Several immunotherapeutic cohorts have confirmed the response-predicting significance of CTSL in patients receiving immune checkpoint inhibitor (ICI) treatment.

CONCLUSIONS

Our study provided an insight into the significant role of APC/T/NK cells-related genes in survival risk stratification and CTSL in response prediction of immunotherapy in patients with LUAD.

Neutrophil-Mediated Tumor-Targeting Delivery System of Oncolytic Bacteria Combined with ICB for Melanoma Lung Metastasis Therapy

Oncolytic bacteria are the most promising tumor target vector. Questions also remain regarding finding a balance between the therapeutic efficacy and safety of oncolytic bacteria. The critical measure of how this balance is maintained is the improvement in tumor colonization. Attenuated Salmonella typhimurium (VNP20009) as the only Salmonella strain to be evaluated in a clinical trial is a potential tumor therapeutic bacterium. A delivery system with controlled release of VNP after being loaded into neutrophils, which significantly increases the tumor-targeting of VNP and enhances its therapeutic efficacy in a melanoma lung metastasis model is constructed. To improve the synergistic therapeutic effect, a PD1 nanobody is applied to this system (NE(PD1nb)). NE(PD1nb) activate dendritic cells (DCs) differentiation and stimulate the M1-like differentiation of macrophages, and induce CD4+ T-cells maturity and cytotoxic CD8+ T-cells activation through DCs tumor antigen presentation.

PLEKHA4 is a novel prognostic biomarker that reshapes the tumor microenvironment in lower-grade glioma

Background

Lower-grade glioma (LGG) is a primary intracranial tumor that carry a high risk of malignant transformation and limited therapeutic options. Emerging evidence indicates that the tumor microenvironment (TME) is a superior predictor for tumor progression and therapy response. PLEKHA4 has been demonstrated to be a biomarker for LGG that correlate with immune infiltration. However, the fundamental mechanism by which PLEKHA4 contributes to LGG is still poorly understood.

Methods

Multiple bioinformatic tools, including Tumor Immune Estimation Resource (TIMER), Gene Expression Profiling Interactive Analysis (GEPIA2), Shiny Methylation Analysis Resource Tool (SMART), etc., were incorporated to analyze the PLEKHA4. ESTIMATE, ssGSEA, CIBERSORT, TIDE and CellMiner algorithms were employed to determine the association of PLEKHA4 with TME, immunotherapy response and drug sensitivities. Immunohistochemistry (IHC)-based tissue microarrays and M2 macrophage infiltration assay were conducted to verify their associations.

Results

PLEKHA4 expression was found to be dramatically upregulated and strongly associated with unfavorable overall survival (OS) and disease-specific survival (DSS) in LGG patients, as well as their poor clinicopathological characteristics. Cox regression analysis identified that PLEKHA4 was an independent prognostic factor. Methylation analysis revealed that DNA methylation correlates with PLEKHA4 expression and indicates a better outcome in LGG. Moreover, PLEKHA4 was remarkably correlated with immune responses and TME remodeling, as evidenced by its positive correlation with particular immune marker subsets and the putative infiltration of immune cells. Surprisingly, the proportion of M2 macrophages in TME was strikingly higher than others, inferring that PLEKHA4 may regulate the infiltration and polarization of M2 macrophages. Evidence provided by IHC-based tissue microarrays and M2 macrophage infiltration assay further validated our findings. Moreover, PLEKHA4 expression was found to be significantly correlated with chemokines, interleukins, and their receptors, further supporting the critical role of PLEKHA4 in reshaping the TME. Additionally, we found that PLEKHA4 expression was closely associated with drug sensitivities and immunotherapy responses, indicating that PLEKHA4 expression also had potential clinical significance in guiding immunotherapy and chemotherapy in LGG.

Conclusion

PLEKHA4 plays a pivotal role in reshaping the TME of LGG patients, and may serve as a potential predictor for LGG prognosis and therapy.

Deactivation of ligand-receptor interactions enhancing lymphocyte infiltration drives melanoma resistance to Immune Checkpoint Blockade

Immune checkpoint blockade (ICB) is a promising cancer therapy; however, resistance often develops. To learn more about ICB resistance mechanisms, we developed IRIS (Immunotherapy Resistance cell-cell Interaction Scanner), a machine learning model aimed at identifying candidate ligand-receptor interactions (LRI) that are likely to mediate ICB resistance in the tumor microenvironment (TME). We developed and applied IRIS to identify resistance-mediating cell-type-specific ligand-receptor interactions by analyzing deconvolved transcriptomics data of the five largest melanoma ICB therapy cohorts. This analysis identifies a set of specific ligand-receptor pairs that are deactivated as tumors develop resistance, which we refer to as resistance deactivated interactions (RDI). Quite strikingly, the activity of these RDIs in pre-treatment samples offers a markedly stronger predictive signal for ICB therapy response compared to those that are activated as tumors develop resistance. Their predictive accuracy surpasses the state-of-the-art published transcriptomics biomarker signatures across an array of melanoma ICB datasets. Many of these RDIs are involved in chemokine signaling. Indeed, we further validate on an independent large melanoma patient cohort that their activity is associated with CD8+ T cell infiltration and enriched in hot/brisk tumors. Taken together, this study presents a new strongly predictive ICB response biomarker signature, showing that following ICB treatment resistant tumors turn inhibit lymphocyte infiltration by deactivating specific key ligand-receptor interactions.

CYFIP2 serves as a prognostic biomarker and correlates with tumor immune microenvironment in human cancers

BACKGROUND

The mechanisms whereby CYFIP2 acts in tumor development and drives immune infiltration have been poorly explored. Thus, this study aimed to identifying the role of CYFIP2 in tumors and immune response.

METHODS

In this study, we first explored expression patterns, diagnostic role and prognostic value of CYFIP2 in cancers, particularly in lung adenocarcinoma (LUAD). Then, we performed functional enrichment, genetic alterations, DNA methylation analysis, and immune cell infiltration analysis of CYFIP2 to uncover its potential mechanisms involved in immune microenvironment.

RESULTS

We found that CYFIP2 significantly differentially expressed in different tumors including LUAD compared with normal tissues. Furthermore, CYFIP2 was found to be significantly correlated with clinical parameters in LUAD. According to the diagnostic and survival analysis, CYFIP2 may be employed as a potential diagnostic and prognostic biomarker. Moreover, genetic alterations revealed that mutation of CYFIP2 was the main types of alterations in different cancers. DNA methylation analysis indicated that CYFIP2 mRNA expression correlated with hypomethylation. Afterwards, functional enrichment analysis uncovered that CYFIP2 was involved in tumor-associated and immune-related pathways. Immune infiltration analysis indicated that CYFIP2 was significantly correlated with immune cells infiltration. In particular, CYFIP2 was strongly linked with immune microenvironment scores. Additionally, CYFIP2 exhibited a significant relationship with immune regulators and immune-related genes including chemokines, chemokines receptors, and MHC genes.

CONCLUSION

Our results suggested that CYFIP2 may serve as a prognostic cancer biomarker for determining prognosis and might be a promising therapeutic strategy for tumor immunotherapy.

Role of chemokines in the crosstalk between tumor and tumor-associated macrophages

Tumor microenvironment (TME) consists of a dynamic network of non-tumoral stromal cells, including cancer-associated fibroblasts, endothelial cells, tumor-associated macrophages (TAMs), B and T cells. In the TME, TAMs support tumor initiation, progression, invasion and metastasis by promoting angiogenesis and immunosuppression of the tumor cells. There is close crosstalk between TAMs and tumor cells. Notably, chemokines are a significant messenger mediating the crosstalk between tumor cells and TAMs. TAMs can promote tumor progression via secretion of chemokines. Various chemokines secreted by tumors are involved in the generation and polarization of TAMs, the infiltration of TAMs in tumors, and the development of TAMs' suppressive function. This paper reviews CCL2-CCR2, CCL3/5-CCR5, CCL15-CCR1, CCL18-CCR8, CX3CL1/CCL26-CX3CR1, CXCL8-CXCR1/2, CXCL12-CXCR4/CXCR7 signaling pathways, their role in the recruitment, polarization and exertion of TAMs, and their correlation with tumor development, metastasis and prognosis. Furthermore, we present the current research progress on modulating the effects of TAMs with chemokine antagonists and discuss the prospects and potential challenges of using chemokine antagonists as therapeutic tools for cancer treatment. The TAMs targeting by chemokine receptor antagonists in combination with chemotherapy drugs, immune checkpoint inhibitors or radiotherapy appears to be a promising approach.

Impaired secretion of C-X-C motif chemokine ligand 10 by stimulation with a Toll-like receptor 4 ligand in endometrial epithelium of infertile patients with minimal-to-mild endometriosis

Successful embryo implantation requires transient, well-controlled inflammation in decidualizing cells. In mice, Toll-like receptor (TLR) 4 signaling in endometrial epithelial cells (EECs) by stimulation with factors present in seminal fluids has been shown to be a key upstream driver of a controlled inflammatory response. Clinical evidence supports that exposure of the female reproductive tract to seminal plasma promotes implantation success. We investigated the response of EECs to TLR2 (Pam3Csk4), TLR 3 (Poly I:C), and TLR4 (lipopolysaccharides [LPS]) ligands with respect to secretion of C-X-C motif chemokine ligand (CXCL) 10 (CXCL10) and interleukin-6 (IL-6) in infertile patients with minimal-to-mild endometriosis (EECs-endo) (n = 38) and those of healthy, fertile women (EECs-healthy) (n = 30). Stimulation with either Pam3Csk4, Poly I:C or LPS, significantly induced CXCL10 and IL-6 in EECs-healthy (p < 0.05). In EECs-endo, either Pam3Csk4 or Poly I:C significantly induced CXCL10 (p < 0.05), whereas no significant response was observed after stimulation with LPS. Neither LPS, Poly I:C, nor Pam3Csk4 significantly induced IL-6 secretion in EECs-endo. Secretion of CXCL10 in EECs-healthy after stimulation with LPS was significantly higher (p < 0.05) than that in EECs-endo. CXCL10 decreased cell proliferation of EECs from both groups. Activation of nuclear factor kappa light chain enhancer of activated B cells and signal transducer and activator of transcription 3 signalings was not impaired, but activation of p38 mitogen-activated protein kinases signaling by LPS stimulation was impaired in EECs-endo. The present findings suggested that an insufficient response of EECs to a TLR4 ligand may be involved in molecular mechanisms of endometriosis-associated infertility.

Tumor microenvironment characterization in colorectal cancer to identify prognostic and immunotherapy genes signature

BACKGROUND

The tumor microenvironment (TME) plays a crucial role in tumorigenesis, progression, and therapeutic response in many cancers. This study aimed to comprehensively investigate the role of TME in colorectal cancer (CRC) by generating a TMEscore based on gene expression.

METHODS

The TME patterns of CRC datasets were investigated, and the TMEscores were calculated. An unsupervised clustering method was used to divide samples into clusters. The associations between TMEscores and clinical features, prognosis, immune score, gene mutations, and immune checkpoint inhibitors were analyzed. A TME signature was constructed using the TMEscore-related genes. The results were validated using external and clinical cohorts.

RESULTS

The TME pattern landscape was for CRC was examined using 960 samples, and then the TMEscore pattern of CRC datasets was evaluated. Two TMEscore clusters were identified, and the high TMEscore cluster was associated with early-stage CRC and better prognosis in patients with CRC when compared with the low TMEscore clusters. The high TMEscore cluster indicated elevated tumor cell scores and tumor gene mutation burden, and decreased tumor purity, when compared with the low TMEscore cluster. Patients with high TMEscore were more likely to respond to immune checkpoint therapy than those with low TMEscore. A TME signature was constructed using the TMEscore-related genes superimposing the results of two machine learning methods (LASSO and XGBoost algorithms), and a TMEscore-related four-gene signature was established, which had a high predictive value for discriminating patients from different TMEscore clusters. The prognostic value of the TMEscore was validated in two independent cohorts, and the expression of TME signature genes was verified in four external cohorts and clinical samples.

CONCLUSION

Our study provides a comprehensive description of TME characteristics in CRC and demonstrates that the TMEscore is a reliable prognostic biomarker and predictive indicator for patients with CRC undergoing immunotherapy.

Preoperative Systemic Immune-Inflammation Index is a Potential Biomarker in Adult Patients with High-Grade Gliomas Undergoing Radical Resection

Background

Increasing evidence has highlighted that systemic immune-inflammation index (SII), a recently developed prognostic biomarker that utilizes peripheral platelet, lymphocyte and neutrophil counts, is associated with unfavorable prognosis in various tumors. Nevertheless, the prognostic significance of SII in high-grade gliomas patients undergoing radical resection remains unclear. Therefore, the present study aimed to assess the potential of SII as a prognostic biomarker in this patient population.

Methods

A total of 111 adult patients with high-grade gliomas who underwent radical resection were consecutively enrolled in this investigation. The study involved the categorization of patients into high and low SII groups using predetermined cut-off values. Subsequently, forward stepwise logistic regression was employed to identify autonomous predictors for early gliomas recurrence. To mitigate the impact of confounding factors, a propensity score matching (PSM) analysis was performed between high and low SII patients. Finally, the Kaplan-Meier approach was utilized to compare the progression-free survival (PFS) and overall survival (OS) of the two groups.

Results

The study involved the categorization of patients into two groups based on their SII levels, namely high SII (> 604.8) and low SII (≤ 604.8) groups. Forward stepwise logistic regression revealed that high SII (p < 0.001) and tumor size ≥ 50 mm (p < 0.001) were significantly related to early recurrence of gliomas. Furthermore, the results indicate that PFS and OS were significantly shorter in the high SII group compared to the low SII group, both before and after PSM (p < 0.05).

Conclusion

Preoperative biomarker SII can serve as a prognostic biomarker for early recurrence and prognosis in patients with high-grade gliomas undergoing radical resection. Furthermore, the combination of tumor size and SII demonstrates a robust predictive capacity for early recurrence and prognosis in this patient population.

Mechanisms and regulation of defensins in host defense

As a family of cationic host defense peptides, defensins are mainly synthesized by Paneth cells, neutrophils, and epithelial cells, contributing to host defense. Their biological functions in innate immunity, as well as their structure and activity relationships, along with their mechanisms of action and therapeutic potential, have been of great interest in recent years. To highlight the key research into the role of defensins in human and animal health, we first describe their research history, structural features, evolution, and antimicrobial mechanisms. Next, we cover the role of defensins in immune homeostasis, chemotaxis, mucosal barrier function, gut microbiota regulation, intestinal development and regulation of cell death. Further, we discuss their clinical relevance and therapeutic potential in various diseases, including infectious disease, inflammatory bowel disease, diabetes and obesity, chronic inflammatory lung disease, periodontitis and cancer. Finally, we summarize the current knowledge regarding the nutrient-dependent regulation of defensins, including fatty acids, amino acids, microelements, plant extracts, and probiotics, while considering the clinical application of such regulation. Together, the review summarizes the various biological functions, mechanism of actions and potential clinical significance of defensins, along with the challenges in developing defensins-based therapy, thus providing crucial insights into their biology and potential clinical utility.

Deciphering the Tumor-Immune-Microbe Interactions in HPV-Negative Head and Neck Cancer

Patients with human papillomavirus-negative head and neck squamous cell carcinoma (HPV-negative HNSCC) have worse outcomes than HPV-positive HNSCC. In our study, we used a published dataset and investigated the microbes enriched in molecularly classified tumor groups. We showed that microbial signatures could distinguish Hypoxia/Immune phenotypes similar to the gene expression signatures. Furthermore, we identified three highly-correlated microbes with immune processes that are crucial for immunotherapy response. The survival of patients in a molecularly heterogenous group shows significant differences based on the co-abundance of the three microbes. Overall, we present evidence that tumor-associated microbiota are critical components of the tumor ecosystem that may impact tumor microenvironment and immunotherapy response. The results of our study warrant future investigation to experimentally validate the conclusions, which have significant impacts on clinical decision-making, such as treatment selection.

Construction and comprehensive analysis of a novel prognostic signature associated with immunogenic cell death molecular subtypes in patients with bladder cancer

Background

Immunogenic cell death (ICD) triggers adaptive immune responses that aid in anticancer therapy. However, the significance of ICD-associated genes (ICDAGs) in clinical applications and their potential impact on the tumor microenvironment (TME) remains unclear.

Methods

The TCGA cohort was divided into different ICD clusters using the method of Consensus clustering. We assessed the clinical results and TME features of various ICD clusters. GSVA quantified the activation of hallmark gene sets. To establish an ICD molecular subtypes-related prognostic model (ICDRPM), we performed LASSO Cox regression analysis on the differentially expressed genes (DEGs) among ICD subtypes. We evaluated the assessment of risk groups by analyzing the proportion of immune cells, the TME, differences in genomic mutation, the efficacy of immunotherapy, and drug sensitivity. To enhance the clinical effectiveness of the ICDRPM, a nomograph was developed.

Results

Two distinct molecular subtypes were identified, and changes in ICDRGs were associated with clinical outcomes and TME characteristics of patients. A total of 1162 differentially expressed genes (DEGs) were obtained from two ICD clusters, and an ICDRPS was then developed to predict overall survival (OS). During both internal and external validation, patients classified as high-risk exhibited significantly poorer overall survival compared to those classified as low-risk. Additionally, the ICDRPS (ICD_score) was identified as an independent prognostic indicator for patients with BC, demonstrating excellent predictive performance. Afterward, we constructed a dependable nomogram to improve the practicality of the ICD_score. Furthermore, low-risk individuals showed stronger immunocyte infiltration, higher immune checkpoint expression, and higher IPS-PD-1 combined IPS-CTLA4 scores, indicating a greater response to immune checkpoint inhibitors (ICIs). Moreover, individuals categorized as having low or high risk exhibited contrasting sensitivity to anticancer medications.

Conclusions

The model constructed for genes related to ICD provided meaningful clinical implications for immunotherapy, and facilitated individualized treatment for BC patients.

TP53 gain-of-function mutation modulates the immunosuppressive microenvironment in non-HPV-associated oral squamous cell carcinoma

BACKGROUND

TP53, the most mutated gene in solid cancers, has a profound impact on most hallmarks of cancer. Somatic TP53 mutations occur in high frequencies in head and neck cancers, including oral squamous cell carcinoma (OSCC). Our study aims to understand the role of TP53 gain-of-function mutation in modulating the tumor immune microenvironment (TIME) in OSCC.

METHODS

Short hairpin RNA knockdown of mutant p53R172H in syngeneic oral tumors demonstrated changes in tumor growth between immunocompetent and immunodeficient mice. HTG EdgeSeq targeted messenger RNA sequencing was used to analyze cytokine and immune cell markers in tumors with inactivated mutant p53R172H. Flow cytometry and multiplex immunofluorescence (mIF) confirmed the role of mutant p53R172H in the TIME. The gene expression of patients with OSCC was analyzed by CIBERSORT and mIF was used to validate the immune landscape at the protein level.

RESULTS

Mutant p53R172H contributes to a cytokine transcriptome network that inhibits the infiltration of cytotoxic CD8+ T cells and promotes intratumoral recruitment of regulatory T cells and M2 macrophages. Moreover, p53R172H also regulates the spatial distribution of immunocyte populations, and their distribution between central and peripheral intratumoral locations. Interestingly, p53R172H-mutated tumors are infiltrated with CD8+ and CD4+ T cells expressing programmed cell death protein 1, and these tumors responded to immune checkpoint inhibitor and stimulator of interferon gene 1 agonist therapy. CIBERSORT analysis of human OSCC samples revealed associations between immune cell populations and the TP53R175H mutation, which paralleled the findings from our syngeneic mouse tumor model.

CONCLUSIONS

These findings demonstrate that syngeneic tumors bearing the TP53R172H gain-of-function mutation modulate the TIME to evade tumor immunity, leading to tumor progression and decreased survival.

Biomarkers for Immune Checkpoint Inhibitors in Renal Cell Carcinoma

Immune checkpoint inhibitor (ICI) therapy has revolutionized renal cell carcinoma treatment. Patients previously thought to be palliative now occasionally achieve complete cures from ICI. However, since immunotherapies stimulate the immune system to induce anti-tumor immunity, they often lead to adverse autoimmunity. Furthermore, some patients receive no benefit from ICI, thereby unnecessarily risking adverse events. In many tumor types, PD-L1 expression levels, immune infiltration, and tumor mutation burden predict the response to ICI and help inform clinical decision making to better target ICI to patients most likely to experience benefits. Unfortunately, renal cell carcinoma is an outlier, as these biomarkers fail to discriminate between positive and negative responses to ICI therapy. Emerging biomarkers such as gene expression profiles and the loss of pro-angiogenic proteins VHL and PBRM-1 show promise for identifying renal cell carcinoma cases likely to respond to ICI. This review provides an overview of the mechanistic underpinnings of different biomarkers and describes the theoretical rationale for their use. We discuss the effectiveness of each biomarker in renal cell carcinoma and other cancer types, and we introduce novel biomarkers that have demonstrated some promise in clinical trials.

Comprehensive analysis and immune landscape of chemokines- and chemokine receptors-based signature in hepatocellular carcinoma

Background

Despite encouraging results from immunotherapy combined with targeted therapy for hepatocellular carcinoma (HCC), the prognosis remains poor. Chemokines and their receptors are an essential component in the development of HCC, but their significance in HCC have not yet been fully elucidated. We aimed to establish chemokine-related prognostic signature and investigate the association between the genes and tumor immune microenvironment (TIME).

Methods

342 HCC patients have screened from the TCGA cohort. A prognostic signature was developed using least absolute shrinkage and selection operator regression and Cox proportional risk regression analysis. External validation was performed using the LIHC-JP cohort deployed from the ICGC database. Single-cell RNA sequencing (scRNA-seq) data from the GEO database. Two nomograms were developed to estimate the outcome of HCC patients. RT-qPCR was used to validate the differences in the expression of genes contained in the signature.

Results

The prognostic signature containing two chemokines-(CCL14, CCL20) and one chemokine receptor-(CCR3) was successfully established. The HCC patients were stratified into high- and low-risk groups according to their median risk scores. We found that patients in the low-risk group had better outcomes than those in the high-risk group. The results of univariate and multivariate Cox regression analyses suggested that this prognostic signature could be considered an independent risk factor for the outcome of HCC patients. We discovered significant differences in the infiltration of various immune cell subtypes, tumor mutation burden, biological pathways, the expression of immune activation or suppression genes, and the sensitivity of different groups to chemotherapy agents and small molecule-targeted drugs in the high- and low-risk groups. Subsequently, single-cell analysis results showed that the higher expression of CCL20 was associated with HCC metastasis. The RT-qPCR results demonstrated remarkable discrepancies in the expression of CCL14, CCL20, and CCR3 between HCC and its paired adjacent non-tumor tissues.

Conclusion

In this study, a novel prognostic biomarker explored in depth the association between the prognostic model and TIME was developed and verified. These results may be applied in the future to improve the efficacy of immunotherapy or targeted therapy for HCC.

Molecular subtypes based on DNA sensors predict prognosis and tumor immunophenotype in hepatocellular carcinoma

DNA sensors play crucial roles in inflammation and have been indicated to be involved in antitumor or tumorigenesis, while it is still unclear whether DNA sensors have potential roles in the prognosis and immunotherapy of hepatocellular carcinoma (HCC). Herein, The Cancer Genome Atlas and Gene Expression Omnibus databases were used to analyze RNA sequencing data and clinical information. A total of 14 DNA sensors were collected and performed consensus clustering to determine their molecular mechanisms in HCC. Two distinct molecular subtypes (Clusters C1 and C2) were identified and were associated with different overall survival (OS). Immune subtype analysis revealed that C1 was mainly characterized by inflammation, while C2 was characterized by lymphocyte depletion. Immune scoring and immunomodulatory function analysis confirmed the different immune microenvironment of C1 and C2. Notably, significant differences in "Hot Tumor" Immunophenotype were observed between the two subtypes. Moreover, the prognostic model based on DNA sensors is capable of effectively predicting the OS of HCC patients. Besides, the chemotherapeutic drug analysis showed the different sensitivity of two subtypes. Taken together, our study shows that the proposed DNA sensors were a reliable signature to predict the prognosis and immunotherapy response with potential application in the clinical decision and treatment of HCC.

CXCR3 expression in regulatory T cells drives interactions with type I dendritic cells in tumors to restrict CD8+ T cell antitumor immunity

Infiltration of regulatory T (Treg) cells, an immunosuppressive population of CD4+ T cells, into solid cancers represents a barrier to cancer immunotherapy. Chemokine receptors are critical for Treg cell recruitment and cell-cell interactions in inflamed tissues, including cancer, and thus are an ideal therapeutic target. Here, we show in multiple cancer models that CXCR3+ Treg cells were increased in tumors compared with lymphoid tissues, exhibited an activated phenotype, and interacted preferentially with CXCL9-producing BATF3+ dendritic cells (DCs). Genetic ablation of CXCR3 in Treg cells disrupted DC1-Treg cell interactions and concomitantly increased DC-CD8+ T cell interactions. Mechanistically, CXCR3 ablation in Treg cells increased tumor antigen-specific cross-presentation by DC1s, increasing CD8+ T cell priming and reactivation in tumors. This ultimately impaired tumor progression, especially in combination with anti-PD-1 checkpoint blockade immunotherapy. Overall, CXCR3 is shown to be a critical chemokine receptor for Treg cell accumulation and immune suppression in tumors.

A network approach to define the predictive role of immune profile on tumor response and toxicity of anti PD-1 single agent immunotherapy in patients with solid tumors

Background

The immune profile of each patient could be considered as a portrait of the fitness of his/her own immune system. The predictive role of the immune profile in immune-related toxicities (irAEs) development and tumour response to treatment was investigated.

Methods

A prospective, multicenter study evaluating, through a multiplex assay, the soluble immune profile at the baseline of 53 patients with advanced cancer, treated with immunotherapy as single agent was performed. Four connectivity heat maps and networks were obtained by calculating the Spearman correlation coefficients for each group: responder patients who developed cumulative toxicity (R-T), responders who did not develop cumulative toxicity (R-NT), non-responders who developed cumulative toxicity (NR-T), non-responders who did not develop cumulative toxicity (NR-NT).

Results

A statistically significant up-regulation of IL-17A, sCTLA4, sCD80, I-CAM-1, sP-Selectin and sEselectin in NR-T was detected. A clear loss of connectivity of most of the soluble immune checkpoints and cytokines characterized the immune profile of patients with toxicity, while an inversion of the correlation for ICAM-1 and sP-selectin was observed in NR-T. Four connectivity networks were built for each group. The highest number of connections characterized the NR-T.

Conclusions

A connectivity network of immune dysregulation was defined for each subgroup of patients, regardless of tumor type. In patients with the worst prognosis (NR-T) the peculiar connectivity model could facilitate their early and timely identification, as well as the design of a personalized treatment approach to improve outcomes or prevent irAEs.

Tumor-associated myeloid cells in cancer immunotherapy

Tumor-associated myeloid cells (TAMCs) are among the most important immune cell populations in the tumor microenvironment, and play a significant role on the efficacy of immune checkpoint blockade. Understanding the origin of TAMCs was found to be the essential to determining their functional heterogeneity and, developing cancer immunotherapy strategies. While myeloid-biased differentiation in the bone marrow has been traditionally considered as the primary source of TAMCs, the abnormal differentiation of splenic hematopoietic stem and progenitor cells, erythroid progenitor cells, and B precursor cells in the spleen, as well as embryo-derived TAMCs, have been depicted as important origins of TAMCs. This review article provides an overview of the literature with a focus on the recent research progress evaluating the heterogeneity of TAMCs origins. Moreover, this review summarizes the major therapeutic strategies targeting TAMCs with heterogeneous sources, shedding light on their implications for cancer antitumor immunotherapies.

Clinical significance, tumor immune landscape and immunotherapy responses of ADAR in pan-cancer and its association with proliferation and metastasis of bladder cancer

BACKGROUND

ADAR is an enzyme involved in adenosine-inosine RNA editing. However, the role of ADAR in tumorigenesis, progression, and immunotherapy has not been fully elucidated.

METHODS

The TCGA, GTEx and GEO databases were extensively utilized to explore the expression level of ADAR across cancers. Combined with the clinical information of patients, the risk profile of ADAR in various cancers was delineated. We identified pathways enriched in ADAR and their related genes and explored the association between ADAR expression and the cancer immune microenvironment score and response to immunotherapy. Finally, we specifically explored the potential value of ADAR in the treatment of the bladder cancer immune response and verified the critical role of ADAR in the development and progression of bladder cancer through experiments.

RESULTS

ADAR is highly expressed in most cancers at both the RNA and protein level. ADAR is associated with the aggressiveness of some cancers, especially bladder cancer. In addition, ADAR is associated with immune-related genes, especially immune checkpoint genes, in the tumor immune microenvironment. Moreover, ADAR expression is positively correlated with tumor mutation burden and microsatellite instability in a variety of cancers, indicating that ADAR could be used as a biomarker of immunotherapy. Finally, we demonstrated that ADAR is a key pathogenic factor in bladder cancer. ADAR promoted proliferation and metastasis of bladder cancer cells.

CONCLUSION

ADAR regulates the tumor immune microenvironment and can be used as a biomarker of the tumor immunotherapy response, providing a novel strategy for the treatment of tumors, especially bladder cancer.

MDSCs in breast cancer: an important enabler of tumor progression and an emerging therapeutic target

Women worldwide are more likely to develop breast cancer (BC) than any other type of cancer. The treatment of BC depends on the subtype and stage of the cancer, such as surgery, radiotherapy, chemotherapy, and immunotherapy. Although significant progress has been made in recent years, advanced or metastatic BC presents a poor prognosis, due to drug resistance and recurrences. During embryonic development, myeloid-derived suppressor cells (MDSCs) develop that suppress the immune system. By inhibiting anti-immune effects and promoting non-immune mechanisms such as tumor cell stemness, epithelial-mesenchymal transformation (EMT) and angiogenesis, MDSCs effectively promote tumor growth and metastasis. In various BC models, peripheral tissues, and tumor microenvironments (TME), MDSCs have been found to amplification. Clinical progression or poor prognosis are strongly associated with increased MDSCs. In this review, we describe the activation, recruitment, and differentiation of MDSCs production in BC, the involvement of MDSCs in BC progression, and the clinical characteristics of MDSCs as a potential BC therapy target.

Sequential Chromogenic IHC: Spatial Analysis of Lymph Nodes Identifies Contact Interactions between Plasmacytoid Dendritic Cells and Plasmablasts

Recent clinical observations have emphasized the critical role that the spatial organization of immune cells in lymphoid structures plays in the success of cancer immunotherapy and patient survival. However, implementing sequential chromogenic IHC (scIHC) to analyze multiple biomarkers on a single tissue section has been limited because of a lack of a standardized, rigorous guide to the development of customized biomarker panels and a need for user-friendly analysis pipelines that can extract meaningful data. In this context, we provide a comprehensive guide for the development of novel biomarker panels for scIHC, using practical examples and illustrations to highlight the most common complications that can arise during the setup of a new biomarker panel, and provide detailed instructions on how to prevent and detect cross-reactivity between secondary reagents and carryover between detection antibodies. We also developed a novel analysis pipeline based on non-rigid tissue deformation correction, Cellpose-inspired automated cell segmentation, and computational network masking of low-quality data. We applied this biomarker panel and pipeline to study regional lymph nodes from patients with head and neck cancer, identifying novel contact interactions between plasmablasts and plasmacytoid dendritic cells in vivo. Given that Toll-like receptors, which are highly expressed in plasmacytoid dendritic cells, play a key role in vaccine efficacy, the significance of this cell-cell interaction decisively warrants further studies. In summary, this work provides a streamlined approach to the development of customized biomarker panels for scIHC that will ultimately improve our understanding of immune responses in cancer.

Significance

We present a comprehensive guide for developing customized biomarker panels to investigate cell-cell interactions in the context of immune responses in cancer. This approach revealed novel contact interactions between plasmablasts and plasmacytoid dendritic cells in lymph nodes from patients with head and neck cancer.

Analysis and validation of the potential of the MYO1E gene in pancreatic adenocarcinoma based on a bioinformatics approach

Pancreatic adenocarcinoma (PAAD) is a common digestive cancer, and its prognosis is poor. Myosin 1E (MYO1E) is a class I myosin family member whose expression and function have not been reported in PAAD. In the present study, bioinformatics analysis was used to explore the expression levels of MYO1E in PAAD and its prognostic value, and the immunological role of MYO1E in PAAD was analyzed. The study revealed that a variety of malignancies have substantially increased MYO1E expression. Further investigation demonstrated that PAAD tissues exhibited greater levels of MYO1E mRNA and protein expression than normal tissues. High MYO1E expression is associated with poor prognosis in patients with PAAD. MYO1E expression was also associated with pathological stage in patients with PAAD. Functional enrichment analysis demonstrated that MYO1E was linked to multiple tumor-related mechanisms in PAAD. The pancreatic adenocarcinoma tumor microenvironment (TME) was analyzed and it was revealed that MYO1E expression was positively associated with tumor immune cell infiltration. In addition, MYO1E was closely associated with some tumor chemokines/receptors and immune checkpoints. In vitro experiments revealed that the suppression of MYO1E expression could inhibit pancreatic adenocarcinoma cell proliferation, invasion and migration. Through preliminary analysis, the present study evaluated the potential function of MYO1E in PAAD and its function in TME, and MYO1E may become a potential biomarker for PAAD.

STING activation in macrophages by vanillic acid exhibits antineoplastic potential

The host stimulator of interferon genes (STING) signaling pathway is a major innate immune sensing pathway, and the stimulation of this pathway within antigen-presenting cells shows promise in targeting immune-suppressed tumors. Macrophages resident in tumors exhibit anti-inflammatory properties and enhance tumor growth and development. Polarizing such macrophages towards a pro-inflammatory phenotype is an effective strategy for tumor suppression. In the present study, we observed that the STING pathway was inactivated in breast and lung carcinomas, and a positive correlation existed between STING and macrophage markers in these tumors. We found that vanillic acid (VA) could stimulate the STING/TBK1/IRF3 pathway. VA mediated the production of type I IFN and promoted macrophage polarization into the M1 phenotype; this activity was dependent on STING activation. A direct-contact co-culture model and a transwell co-culture model revealed that macrophages with VA-induced STING activation exhibited anti-proliferative effects on SKBR3 and H1299 cells, although a STING antagonist and M2 macrophage-related cytokines alleviated this anti-proliferative effect. Further investigation indicated that phagocytosis and apoptosis-inducing effects were the major mediators of the anti-tumor effect of VA-treated macrophages. Mechanistically, VA promoted the polarization of macrophages to a M1 phenotype via IL-6R/JAK signaling, resulting in enhanced phagocytosis and apoptosis-induction effects. Additionally, STING activation-induced IFNβ production also participated in the apoptosis mediated by VA-treated macrophage in SKBR3 and H1299 cells. Mouse models with 4 T1 tumors confirmed the anti-tumor properties of VA in vivo and revealed the infiltration of VA-induced cytotoxic T cells into the tumors. These data suggest that VA is an effective agonist of STING and provides a new perspective for cancer immunotherapy.

RNF8 enhances the sensitivity of PD-L1 inhibitor against melanoma through ubiquitination of galectin-3 in stroma

The failure of melanoma immunotherapy can be mediated by immunosuppression in the tumor microenvironment (TME), and insufficient activation of effector T cells against the tumor. Here, we show that inhibition of galectin-3 (gal-3) enhances the infiltration of T cells in TME and improves the sensitivity of anti-PD-L1 therapy. We identify that RNF8 downregulated the expression of gal-3 by K48-polyubiquitination and promoted gal-3 degradation via the ubiquitin-proteasome system. RNF8 deficiency in the host but sufficiency in implanted melanoma results in immune exclusion and tumor progression due to the upregulation of gal-3. Upregulation of gal-3 decreased the immune cell infiltration by restricting IL-12 and IFN-γ. Inhibition of gal-3 reverses immunosuppression and induces immune cell infiltration in the tumor microenvironment. Moreover, gal-3 inhibitor treatment can increase the sensitivity of PD-L1 inhibitors via increasing immune cell infiltration and enhancing immune response in tumors. This study reveals a previously unrecognized immunoregulation function of RNF8 and provides a promising strategy for the therapy of "cold" tumors. Tremendous effects of melanoma treatment can be achieved by facilitating immune cell infiltration combined with anti-PD-L1 treatment.