Facilitating T Cell Infiltration in Tumor Microenvironment Overcomes Resistance to PD-L1 Blockade

Multistage-responsive nanovehicle to improve tumor penetration for dual-modality imaging-guided photodynamic-immunotherapy

The exploration of an intelligent multifunctional imaging-guided therapeutic platform is of great significance because of its ideal delivery efficiency and controlled release. In this work, a tumor microenvironment (TME)-responsive nanocarrier (denoted as MB@MSP) is designed for on-demand, sequentially release of a short D-peptide antagonist of programmed cell death-ligand 1 (named as P^DPPA-1) and a photosensitizer methylene blue (MB). Fe₃O₄-Au located in the core of MB@MSP is used as a magnetic resonance imaging and micro-computed tomography imaging contrast agent for noninvasive diagnosis of solid tumors and simultaneous monitoring of drug delivery. The P^DPPA-1 coated on MB@MSP can be shed due to the cleavage of the peptide substrate by matrix metalloproteinase-2 (MMP-2) that is highly expressed in the tumor stroma, and disulfide bonding is further broken when it encounters high levels of glutathione (GSH) in TME, which finally leads to significant size reduction and charge-reversal. These transitions facilitate penetration and uptake of nanocarriers against tumors. Noticeably, the released P^DPPA-1 can block the immune checkpoint to create an environment that favors the activation of cytotoxic T lymphocytes and augment the antitumor immune response elicited by photodynamic therapy, thus significantly improving therapeutic outcomes. Studies of the underlying mechanisms suggest that the designed MMP-2 and GSH-sensitive delivery system not only induce apoptosis of tumor cells but also modulate the immunosuppressive tumor microenvironment to eventually augment the suppression tumor metastasis effect of CD8⁺ cytotoxic T cells. Overall, the visualization of the therapeutic processes with comprehensive information renders MB@MSP an intriguing platform to realize the combined treatment of metastatic tumors.

Multi-omics profiling of primary small cell carcinoma of the esophagus reveals RB1 disruption and additional molecular subtypes

Primary small cell carcinoma of the esophagus (PSCCE) is a lethal neuroendocrine carcinoma. Previous studies proposed a genetic similarity between PSCCE and esophageal squamous cell carcinoma (ESCC) but provided little evidence for differences in clinical course and neuroendocrine differentiation. We perform whole-exome sequencing, RNA sequencing and immunohistochemistry profiling on 46 PSCCE cases. Integrated analyses enable the discovery of multiple mechanisms of RB1 disruption in 98% (45/46) of cases. The transcriptomic landscape of PSCCE closely resembles small cell lung cancer (SCLC) but differs from ESCC or esophageal adenocarcinoma (EAC). Distinct gene expression patterns regulated by ASCL1 and NEUROD1 define two molecular subtypes, PSCCE-A and PSCCE-N, which are highly similar to SCLC subtypes. A T cell excluded phenotype is widely observed in PSCCE. In conclusion, PSCCE has genomic alterations, transcriptome features and molecular subtyping highly similar to SCLC but distinct from ESCC or EAC. These observations are relevant to oncogenesis mechanisms and therapeutic vulnerability.

Primary small cell carcinoma of the oesophagus has a poor prognosis, and has not been fully characterised molecularly. Here, the authors study the disease using multi-omics technology and find frequent RB1 disruptions and similarities to small cell lung cancer, opening potential therapeutic avenues.

Disruption of Wnt/β-catenin Pathway Elevates the Sensitivity of Gastric Cancer Cells to PD-1 Antibody

BACKGROUND

Gastric cancer (GC) is the fifth most common malignancy tumor and the third cause of cancer-related death around the world. Immune checkpoint inhibitors (ICIs) such as programmed cell death-1 (PD-1) antibodies play an active role in tumor therapy. A recent study reveals that the Wnt/β-catenin signaling pathway is negatively correlated with T-cell infiltration in the tumor microenvironment (TME), thereby influencing the therapeutic efficacy of the PD-1 antibody.

OBJECTIVE

In this study, we aimed to uncover the relationship of the Wnt/β-catenin pathway to CD8+ T cell activity as well as its effect on anti-PD-1 therapeutic efficacy in GC.

METHODS

We first collected clinical samples and went through an immunohistochemical analysis and found that a high β-catenin expression in GC tissues was often associated with a significant absence of CD8+ T-cell infiltration.

RESULTS

In addition, our data further indicated that disruption of the Wnt/β-catenin pathway in GC cells inhibited their migratory and invasive ability. Meanwhile, enhanced sensitivity of GC cells to PD-1 blockade therapy was evident by decreased Jurkat cell apoptosis rate and increased GC cell apoptosis rate in a tumor and Jurkat cells co-culture system with the presence of Wnt/β-catenin pathway inhibition.

CONCLUSION

Collectively, these findings indicated that the Wnt/β-catenin pathway might play a significant role in modulating the activity of Jurkat cells, and downregulation of Wnt/β-catenin may enhance the sensitivity of GC cells to PD-1 antibody in vitro. This result further indicated that β-catenin and PD-1 targeted inhibition might become a potential and effective therapy for GC patients.

B16 melanomas evade antitumor immunity by the loss of epitope presentation and the acquisition of tumor resistance to granzyme B

Melanomas exhibit the highest rate of heterogeneity among cancer cell types. In this study, we tested the two types of B16 melanoma cells (B16-S0-1 and B16-S1-1) showing resistance to antitumor immunity. These cells expressed Trp2 protein. Contrary to B16 and B16-S0-1 cells, B16-S1-1 cells failed to stimulate IFN-γ responses in Trp2-specific CD8+ T cells, suggesting that B16-S1-1 cells may have lost the ability to present antigen to Ag-specific CTLs in the context of MHC class I molecules. However, B16-S0-1 cells exhibited active Stat3 and decreased Bcl-2 expression, which were found to be not associated with immune escape. B16-S0-1 cells were more resistant to granzyme B-mediated caspase activation and apoptosis than B16 cells. Thus, these data show that B16 cells escape antitumor immune responses through the loss of epitope presentation to CTLs and the acquisition of tumor cell resistance to granzyme B-mediated caspase activation.

Inflammation-Induced Tumorigenesis and Metastasis

Inflammation, especially chronic inflammation, plays a pivotal role in tumorigenesis and metastasis through various mechanisms and is now recognized as a hallmark of cancer and an attractive therapeutic target in cancer. In this review, we discuss recent advances in molecular mechanisms of how inflammation promotes tumorigenesis and metastasis and suppresses anti-tumor immunity in various types of solid tumors, including esophageal, gastric, colorectal, liver, and pancreatic cancer as well as hematopoietic malignancies.

Targeting KDM4A epigenetically activates tumor-cell-intrinsic immunity by inducing DNA replication stress

Developing strategies to activate tumor-cell-intrinsic immune response is critical for improving tumor immunotherapy by exploiting tumor vulnerability. KDM4A, as a histone H3 lysine 9 trimethylation (H3K9me3) demethylase, has been found to play a critical role in squamous cell carcinoma (SCC) growth and metastasis. Here we report that KDM4A inhibition promoted heterochromatin compaction and induced DNA replication stress, which elicited antitumor immunity in SCC. Mechanistically, KDM4A inhibition promoted the formation of liquid-like HP1γ puncta on heterochromatin and stall DNA replication, which activated tumor-cell-intrinsic cGAS-STING signaling through replication-stress-induced cytosolic DNA accumulation. Moreover, KDM4A inhibition collaborated with PD1 blockade to inhibit SCC growth and metastasis by recruiting and activating CD8+ T cells. In vivo lineage tracing demonstrated that KDM4A inhibition plus PD1 blockade efficiently eliminated cancer stem cells. Altogether, our results demonstrate that targeting KDM4A can activate anti-tumor immunity and enable PD1 blockade immunotherapy by aggravating replication stress in SCC cells.

Identification of genetic variations associated with drug resistance in non-small cell lung cancer patients undergoing systemic treatment

Non-small cell lung cancer (NSCLC) is characterized by relatively rapid response to systemic treatments yet inevitable resistance and predisposed to distant metastasis. We thus aimed at performing sequencing analysis to determine genomic events and underlying mechanisms concerning drug resistance in NSCLC. We performed targeted sequencing of 40 medication-relevant genes on plasma samples from 98 NSCLC patients and analyzed impact of genetic alterations on clinical presentation as well as response to systemic treatments. Profiling of multi-omics data from 1024 NSCLC tissues in public datasets was carried out for comparison and validation of identified molecular events implicated in resistance. A genetic association of CYP2D6 deletion with drug resistance was identified through circulating tumor DNA (ctDNA) profiling and response assessment. FCGR3A amplification was potentially involved in resistance to EGFR inhibitors. We further verified our findings in tissue samples and focused on potential resistance mechanisms, which uncovered that depleted CYP2D6 affected a set of genes involved in EMT, oncogenic signaling as well as inflammatory pathways. Tumor microenvironment analysis revealed that NSCLC with CYP2D6 loss manifested increased levels of immunomodulatory gene expressions, PD-L1 expression, relatively high mutational burden and lymphocyte infiltration. DNA methylation alterations were also found to be correlated with mRNA expressions and copy numbers of CYP2D6. Finally, MEK inhibitors were identified by CMap as the prospective therapeutic drugs for CYP2D6 deletion. These analyses identified novel resistance mechanisms to systemic NSCLC treatments and had significant implications for the development of new treatment strategies.

Inducible Tertiary Lymphoid Structures: Promise and Challenges for Translating a New Class of Immunotherapy

Tertiary lymphoid structures (TLS) are ectopically formed aggregates of organized lymphocytes and antigen-presenting cells that occur in solid tissues as part of a chronic inflammation response. Sharing structural and functional characteristics with conventional secondary lymphoid organs (SLO) including discrete T cell zones, B cell zones, marginal zones with antigen presenting cells, reticular stromal networks, and high endothelial venues (HEV), TLS are prominent centers of antigen presentation and adaptive immune activation within the periphery. TLS share many signaling axes and leukocyte recruitment schemes with SLO regarding their formation and function. In cancer, their presence confers positive prognostic value across a wide spectrum of indications, spurring interest in their artificial induction as either a new form of immunotherapy, or as a means to augment other cell or immunotherapies. Here, we review approaches for inducible (iTLS) that utilize chemokines, inflammatory factors, or cellular analogues vital to TLS formation and that often mirror conventional SLO organogenesis. This review also addresses biomaterials that have been or might be suitable for iTLS, and discusses remaining challenges facing iTLS manufacturing approaches for clinical translation.

Chemokines and the immune response to cancer

Chemokines are chemotactic cytokines that regulate the migration of immune cells. Chemokines function as cues for the coordinated recruitment of immune cells into and out of tissue and also guide the spatial organization and cellular interactions of immune cells within tissues. Chemokines are critical in directing immune cell migration necessary to mount and then deliver an effective anti-tumor immune response; however, chemokines also participate in the generation and recruitment of immune cells that contribute to a pro-tumorigenic microenvironment. Here, we review the role of the chemokine system in anti-tumor and pro-tumor immune responses and discuss how malignant cells and the tumor microenvironment regulate the overall chemokine landscape to shape the type and outcome of immune responses to cancer and cancer treatment.

Development and Validation of a CD8+ T Cell Infiltration-Related Signature for Melanoma Patients

Aim

Immunotherapy shows efficacy in only a subset of melanoma patients. Here, we intended to construct a risk score model to predict melanoma patients’ sensitivity to immunotherapy.

Methods

Integration analyses were performed on melanoma patients from high-dimensional public datasets. The CD8+ T cell infiltration related genes (TIRGs) were selected via TIMER and CIBERSORT algorithm. LASSO Cox regression was performed to screen for the crucial TIRGs. Single sample gene set enrichment analysis (ssGSEA) and ESTIMATE algorithm were used to evaluate the immune activity. The prognostic value of the risk score was determined by univariate and multivariate Cox regression analysis.

Results

184 candidate TIRGs were identified in melanoma patients. Based on the candidate TIRGs, melanoma patients were classified into three clusters which were characterized by different immune activity. Six signature genes were further screened out of 184 TIRGs and a representative risk score for patient survival was constructed based on these six signature genes. The risk score served as an indicator for the level of CD8+ T cell infiltration and acted as an independent prognostic factor for the survival of melanoma patients. By using the risk score, we achieved a good predicting result for the response of cancer patients to immunotherapy. Moreover, pan-cancer analysis revealed the risk score could be used in a wide range of non-hematologic tumors.

Conclusions

Our results showed the potential of using signature gene-based risk score as an indicator to predict melanoma patients’ sensitivity to immunotherapy.

High endothelial venules (HEVs) in immunity, inflammation and cancer

High endothelial venules (HEVs) are specialized blood vessels mediating lymphocyte trafficking to lymph nodes (LNs) and other secondary lymphoid organs. By supporting high levels of lymphocyte extravasation from the blood, HEVs play an essential role in lymphocyte recirculation and immune surveillance for foreign invaders (bacterial and viral infections) and alterations in the body’s own cells (neoantigens in cancer). The HEV network expands during inflammation in immune-stimulated LNs and is profoundly remodeled in metastatic and tumor-draining LNs. HEV-like blood vessels expressing high levels of the HEV-specific sulfated MECA-79 antigens are induced in non-lymphoid tissues at sites of chronic inflammation in many human inflammatory and allergic diseases, including rheumatoid arthritis, Crohn’s disease, allergic rhinitis and asthma. Such vessels are believed to contribute to the amplification and maintenance of chronic inflammation. MECA-79⁺ tumor-associated HEVs (TA-HEVs) are frequently found in human tumors in CD3⁺ T cell-rich areas or CD20⁺ B-cell rich tertiary lymphoid structures (TLSs). TA-HEVs have been proposed to play important roles in lymphocyte entry into tumors, a process essential for successful antitumor immunity and lymphocyte-mediated cancer immunotherapy with immune checkpoint inhibitors, vaccines or adoptive T cell therapy. In this review, we highlight the phenotype and function of HEVs in homeostatic, inflamed and tumor-draining lymph nodes, and those of HEV-like blood vessels in chronic inflammatory diseases. Furthermore, we discuss the role and regulation of TA-HEVs in human cancer and mouse tumor models.

Window-of-opportunity clinical trial of pembrolizumab in patients with recurrent glioblastoma reveals predominance of immune-suppressive macrophages

BACKGROUND

We sought to ascertain the immune effector function of pembrolizumab within the glioblastoma (GBM) microenvironment during the therapeutic window.

METHODS

In an open-label, single-center, single-arm phase II "window-of-opportunity" trial in 15 patients with recurrent (operable) GBM receiving up to 2 pembrolizumab doses before surgery and every 3 weeks afterward until disease progression or unacceptable toxicities occurred, immune responses were evaluated within the tumor.

RESULTS

No treatment-related deaths occurred. Overall median follow-up time was 50 months. Of 14 patients monitored, 10 had progressive disease, 3 had a partial response, and 1 had stable disease. Median progression-free survival (PFS) was 4.5 months (95% CI: 2.27, 6.83), and the 6-month PFS rate was 40%. Median overall survival (OS) was 20 months, with an estimated 1-year OS rate of 63%. GBM patients' recurrent tumors contained few T cells that demonstrated a paucity of immune activation markers, but the tumor microenvironment was markedly enriched for CD68+ macrophages.

CONCLUSIONS

Immune analyses indicated that pembrolizumab anti-programmed cell death 1 (PD-1) monotherapy alone can't induce effector immunologic response in most GBM patients, probably owing to a scarcity of T cells within the tumor microenvironment and a CD68+ macrophage preponderance.

Design of an Injectable Polypeptide Hydrogel Depot Containing the Immune Checkpoint Blocker Anti-PD-L1 and Doxorubicin to Enhance Antitumor Combination Therapy

Combination therapy can be used to enhance the therapeutic response and decrease side effects during cancer treatment. In this study, a system is developed to locally deliver the immune checkpoint blockade antibody targeting programmed death-ligand 1 (anti-PD-L1 or aPD-L1) and doxorubicin (Dox), by an injectable, biocompatible polypeptide hydrogel as a drug depot. The localized and sustained release of Dox after the intratumoral injection of the co-loaded hydrogel induces immunogenic tumor cell death, thus promoting an antitumor immunological response. The tumor inhibitory effect is significantly enhanced by the simultaneous release of aPD-L1 at the tumor site thanks to its action on the inhibition of the PD-1/PD-L1 pathway and restoration of the tumor-killing effect of cytotoxic T cells. Treatment of the B16F10 melanoma model with the aPD-L1 and Dox co-loaded hydrogel leads to a remarkable inhibition of tumor progression and prolongation of animal survival.

Analysis of Tumor Microenvironment Characteristics in Bladder Cancer: Implications for Immune Checkpoint Inhibitor Therapy

The tumor microenvironment (TME) plays a crucial role in cancer progression and recent evidence has clarified its clinical significance in predicting outcomes and efficacy. However, there are no studies on the systematic analysis of TME characteristics in bladder cancer. In this study, we comprehensively evaluated the TME invasion pattern of bladder cancer in 1,889 patients, defined three different TME phenotypes, and found that different subtypes were associated with the clinical prognosis and pathological characteristics of bladder cancer. We further explored the signaling pathways, cancer-immunity cycle, copy number, and somatic mutation differences among the different subtypes and used the principal component analysis algorithm to calculate the immune cell (IC) score, a tool for comprehensive evaluation of TME. Univariate and multivariate Cox regression analyses showed that ICscore is a reliable and independent prognostic biomarker. In addition, the use of anti-programmed death-ligand (PD-L1) treatment cohort, receiver operating characteristic (ROC) curve, Tumor Immune Dysfunction and Exclusion (TIDE), Subnetwork Mappings in Alignment of Pathways (SubMAP), and other algorithms confirmed that ICscore is a reliable prognostic biomarker for immune checkpoint inhibitor response. Patients with higher ICscore showed a significant therapeutic advantage in immunotherapy. In conclusion, this study improves our understanding of the characteristics of TME infiltration in bladder cancer and provides guidance for more effective personalized immunotherapy strategies.

Sequence of αPD-1 relative to local tumor irradiation determines the induction of abscopal antitumor immune responses

Although radiotherapy has been used for over a century to locally control tumor growth, alone it rarely induces an abscopal response or systemic antitumor immunity capable of inhibiting distal tumors outside of the irradiation field. Results from recent studies suggest that combining immune checkpoint blockades to radiotherapy may enhance abscopal activity. However, the treatment conditions and underlying immune mechanisms that consistently drive an abscopal response during radiation therapy combinations remain unknown. Here, we analyzed the antitumor responses at primary and distal tumor sites, demonstrating that the timing of αPD-1 antibody administration relative to radiotherapy determined the potency of the induced abscopal response. Blockade of the PD-1 pathway after local tumor irradiation resulted in the expansion of polyfunctional intratumoral CD8⁺ T cells, a decrease in intratumoral dysfunctional CD8⁺ T cells, expansion of reprogrammable CD8⁺ T cells, and induction of potent abscopal responses. However, administration of αPD-1 before irradiation almost completely abrogated systemic immunity, which associated with increased radiosensitivity and death of CD8⁺ T cells. The subsequent reduction of polyfunctional effector CD8⁺ T cells at the irradiated tumor site generated a suboptimal systemic antitumor response and the loss of abscopal responses. Therefore, this report maximizes the potential synergy between radiotherapy and αPD-1 immunotherapy, information that will benefit clinical combinations of radiotherapy and immune checkpoint blockade.

Identification and validation of significant gene mutations to predict clinical benefit of immune checkpoint inhibitors in lung adenocarcinoma

OBJECTIVE

Immune checkpoint inhibitors (ICI) has achieved remarkable clinical benefit in advanced lung adenocarcinoma (LUAD). However, effective clinical use of ICI agents is encumbered by the high rate of innate resistance. The aim of our research is to identify significant gene mutations which can predict clinical benefit of immune checkpoint inhibitors in LUAD.

METHODS

The "mafComapre" function of "MafTools" package was used to screen the differentially mutated genes between durable clinical benefit (DCB) group and no durable clinical benefit (NDB) group based on the somatic mutation data from NSCLc_PD1_mSK_2018. Machine learning was performed to select significantly mutated genes to accurately classify patients into DCB group and NDB group. A nomogram model was constructed based on the significantly mutated genes to predict the susceptibility of patients to ICI. Finally, we explored the correlation between two classifications of immune cell infiltration, PD-1 and PD-L1 expression, tumor mutational burden (TMB) and prognosis.

RESULTS

Through utilize machine learning, 6 significantly mutated genes were obtained from 8 differentially mutated genes and used to accurately classify patients into DCB group and NDB group. The DCA curve and clinical impact curve revealed that the patients can benefit from the decisions made based on the nomogram model. Patients highly sensitive to ICI have elevated immune activity, higher expression of PD-1 and PD-L1, increased TMB, and well prognosis if they accept ICI treatment.

CONCLUSIONS

Our research selected 6 significantly mutated genes that can predict clinical benefit of ICI in LUAD patients.

Distinct prognostic values of programmed death-ligand 1 and programmed cell death protein 1 in lung adenocarcinoma and squamous cell carcinoma patients

Background

Although immunotherapy has demonstrated similar clinical activities in the treatment of lung adenocarcinoma (ADC) and squamous cell carcinoma (SCC), several studies have shown programmed death-ligand 1 (PD-L1) to have different predictive roles in ADC and SCC. This study was conducted to compare the different functions of PD-L1/programmed cell death protein 1 (PD-1) pathway in these malignancies.

Methods

A multi-dimensional analysis based on public databases and 2 independent cohorts including 262 patients with lung cancer was performed. Immunohistochemistry (IHC) and fluorescence-based multiplexed staining were used to detect the immune factors.

Results

PD-L1 was observed to have different expressions and regulatory mechanisms between SCC and ADC. PD-L1 was significantly increased from the messenger RNA (mRNA) to protein levels in the SCC group compared with the ADC group. Also, PD-L1 on tumor cells (TCs) was positively correlated with CD8⁺ tumor lymphocyte infiltrates in ADC, but not in SCC. More importantly, PD-L1 was considered to be an independent predictor of overall survival (OS) for ADC patients. In contrast, in SCC patients, PD-1⁺ tumor-infiltrating lymphocytes (TILs) were considered a poor prognostic predictor.

Conclusions

These findings showed that PD-L1 in ADC and PD-1⁺ TILs in SCC respectively indicates T-cell function, which plays a crucial role in determining prognosis. The distinct functions of the biomarkers between ADC and SCC might provide potential avenues for guiding anti-PD-1/PD-L1 immunotherapy.

History of Extensive Disease Small Cell Lung Cancer Treatment: Time to Raise the Bar? A Review of the Literature

Simple Summary

Small cell lung cancer (SCLC) remains the most aggressive form of neuroendocrine tumor of the lung, for which treatment options remain limited. The introduction of immune checkpoint inhibitors has modified for the first time the therapeutic strategies in patients with extensive disease after decades. New therapeutic approaches are required. Deeper knowledge of tumor biology is required to gain new insights into this complex disease.

Abstract

Several trials have tried for decades to improve the outcome of extensive disease small cell lung cancer (ED-SCLC) through attempts to modify the standard treatments. Nevertheless, platinum/etoposide combination and topotecan have remained respectively the first and the second line standard treatments for the last 40 years. With the advent of immunotherapy, this scenario has finally changed. Our review aims to provide an overview of the primary studies on the actual therapeutic strategies available for ED-SCLC patients, and to highlight emerging evidence supporting the use of immunotherapy in SCLC patients.

Bilberry anthocyanin extracts enhance anti-PD-L1 efficiency by modulating gut microbiota

The undesirable low response rate is a major hurdle to garnering the maximum potential of immune checkpoint inhibitors in cancer treatments. Recent advances in exploring the effects of intestinal flora on the medical efficacy of immune checkpoint blockade have shed new light on the application of immune checkpoint inhibitors. Inspired by the prebiotic role of anthocyanin-rich extracts, we propose using bilberry anthocyanin extracts to modulate the composition of gut microbiota and eventually, promote the efficiency of immune checkpoint inhibitors. This study demonstrates the effectiveness of orally administered bilberry anthocyanin extracts in enhancing the anti-tumor efficiency of the PD-L1 antibody in the experimental mouse MC38 tumor model. We observed an increase in the fecal abundance of Clostridia and Lactobacillus johnsonii and improved effective community diversity. These findings reinforce the importance of intestinal flora composition and open up unprecedented opportunities in using natural compounds to enhance the efficacy of immune checkpoint inhibitors.

Emerging nanotechnological strategies to reshape tumor microenvironment for enhanced therapeutic outcomes of cancer immunotherapy

Immunotherapy was emerged as a novel cancer treatment in the last decade, however, efficacious responses to mono-immunotherapy have only been achieved in a relatively small portion of patients whereas combinational immunotherapies often lead to concurrent side effects. It has been proved that the tumor microenvironment (TME) is responsible for tumor immune escape and the ultimate treatment failure. Recently, both the understanding of the TME and the applications of nanotechnological strategies have achieved remarkable progresses, and reviewing the emerging immune-regulatory nanosystems may provide valuable information for specifically modulating the TME at different immune stages. In this review, we focus on comprehending the recently proposed T-cell-based tumor classification and identifying the most promising targets for different tumor phenotypes, and then summarizing the nanotechnological strategies to best target corresponding immune-related factors. For future precise personalized immunotherapy, the tailor-made TME modulation strategies conducted by well-designed nanosystems to alleviate the suppressive TME and then promote anti-tumor immune responses will significantly benefit the clinical outcomes of cancer patients.

DNA scaffolds enable efficient and tunable functionalization of biomaterials for immune cell modulation

Biomaterials can improve the safety and presentation of therapeutic agents for effective immunotherapy, and a high level of control over surface functionalization is essential for immune cell modulation. Here, we developed biocompatible immune cell-engaging particles (ICEp) that use synthetic short DNA as scaffolds for efficient and tunable protein loading. To improve the safety of chimeric antigen receptor (CAR) T cell therapies, micrometre-sized ICEp were injected intratumorally to present a priming signal for systemically administered AND-gate CAR-T cells. Locally retained ICEp presenting a high density of priming antigens activated CAR T cells, driving local tumour clearance while sparing uninjected tumours in immunodeficient mice. The ratiometric control of costimulatory ligands (anti-CD3 and anti-CD28 antibodies) and the surface presentation of a cytokine (IL-2) on ICEp were shown to substantially impact human primary T cell activation phenotypes. This modular and versatile biomaterial functionalization platform can provide new opportunities for immunotherapies.

Immune landscape and therapeutic strategies: new insights into PD-L1 in tumors

PD-1/PD-L1 axis represents an important target for renormalizing and resetting anti-tumor immunity in cancer patients. Currently, anti-PD-1/PD-L1 therapy has been applied in a broad spectrum of tumors and has yielded durable remission in patients. However, how to further broaden the application, guide personalized therapeutic strategies, and improve clinical responses remains a vital task. At present, PD-L1 expression is an important parameter of clinical indications for immune checkpoint blockade in many types of cancers, a strategy based on the supposition that positive PD-L1 expression reflects local T cell response. Recent studies have revealed that PD-L1 expression is regulated by multiple layers of complicated factors, during which the host immune microenvironment exerts a pivotal role and determines the clinical efficacy of the therapy. In this review, we will summarize recent findings on PD-1/PD-L1 in cancer, focusing on how local immune landscape participates in the regulation of PD-L1 expression and modification. Importantly, we will also discuss these topics in the context of clinical treatment and analyze how these fundamental principles might inspire our efforts to develop more precise and effective immune therapeutics for cancer.

B16 melanoma control by anti-PD-L1 requires CD8+ T cells and NK cells: application of anti-PD-L1 Abs and Trp2 peptide vaccines

Anti-programmed death ligand 1 (PD-L1) therapy has been beneficial in treating patients with certain cancers. Here, we tested whether anti-PD-L1 therapy is effective for controlling different types of tumors using animal models of TC-1, MC38 and B16. We found that, despite PD-L1 expression, anti-PD-L1 therapy showed little and some antitumor activity in the TC-1 and MC38 models. However, anti-PD-L1 therapy exhibited a more dramatic antitumor effect in the B16 model. This difference in antitumor responses was likely associated with the CD8 + T cell infiltration status of tumor tissues. In the B16 model, CD8 + T cells and to a lesser degree NK cells were found to be responsible for the antitumor response of anti-PD-L1 therapy, as determined by immune cell subset depletion. In particular, CD8 + T cells from B16-bearing mice produced an IFN-γ in response to B16 cells and citrate phosphate buffer-treated B16 cell peptide elutes but not to an immunodominant class I epitope, Trp2_180-188, suggesting that CD8 + T cells that recognize neoantigens were induced in B16 tumor-bearing mice and then reactivated by anti-PD-L1 for tumor control. When B16 tumor-bearing mice were treated with anti-PD-L1 in combination with Trp2_180-188 peptide vaccines, they displayed significantly more tumor control than either single therapy. Taken together, these studies show that B16 melanomas are more effectively controlled through reactivation of tumor-infiltrating lymphocytes by anti-PD-L1 therapy. Moreover, combined therapy using anti-PD-L1 and Trp2 peptide vaccines is more beneficial for controlling B16 melanomas through reactivation of neoantigen-specific CD8 + T cells and induction of Trp2-specific CD8 + T cells.

Optimal combination treatment regimens of vaccine and radiotherapy augment tumor-bearing host immunity

A major obstacle to immunotherapy is insufficient infiltration of effector immune cells into the tumor microenvironment. Radiotherapy greatly reduces tumor burden but relapses often occur. Here we show that the immunosuppressive tumor microenvironment was gradually established by recruiting Tregs after radiation. Despite tumors being controlled after depletion of Tregs in the irradiated area, improvement of mice survival remained poor. A much better antitumor effect was achieved with vaccination followed by radiation than other treatments. Vaccination followed by radiation recruited more effector T cells in tumor regions, which responded to high levels of chemokines. Sequential combination of vaccination and radiotherapy could elicit distinct host immune responses. Our study demonstrated that optimal combination of irradiation and vaccination is required to achieve effective antitumor immune responses. We propose a combination regimen that could be easily translated into the clinic and offer an opportunity for rational combination therapies design in cancer treatment.

Development of DNA Vaccine Targeting E6 and E7 Proteins of Human Papillomavirus 16 (HPV16) and HPV18 for Immunotherapy in Combination with Recombinant Vaccinia Boost and PD-1 Antibody

Immunotherapy for cervical cancer should target high-risk human papillomavirus types 16 and 18, which cause 50% and 20% of cervical cancers, respectively. Here, we describe the construction and characterization of the pBI-11 DNA vaccine via the addition of codon-optimized human papillomavirus 18 (HPV18) E7 and HPV16 and 18 E6 genes to the HPV16 E7-targeted DNA vaccine pNGVL4a-SigE7(detox)HSP70 (DNA vaccine pBI-1). Codon optimization of the HPV16/18 E6/E7 genes in pBI-11 improved fusion protein expression compared to that in DNA vaccine pBI-10.1 that utilized the native viral sequences fused 3' to a signal sequence and 5' to the HSP70 gene of Mycobacterium tuberculosis Intramuscular vaccination of mice with pBI-11 DNA better induced HPV antigen-specific CD8+ T cell immune responses than pBI-10.1 DNA. Furthermore, intramuscular vaccination with pBI-11 DNA generated stronger therapeutic responses for C57BL/6 mice bearing HPV16 E6/E7-expressing TC-1 tumors. The HPV16/18 antigen-specific T cell-mediated immune responses generated by pBI-11 DNA vaccination were further enhanced by boosting with tissue-antigen HPV vaccine (TA-HPV). Combination of the pBI-11 DNA and TA-HPV boost vaccination with PD-1 antibody blockade significantly improved the control of TC-1 tumors and extended the survival of the mice. Finally, repeat vaccination with clinical-grade pBI-11 with or without clinical-grade TA-HPV was well tolerated in vaccinated mice. These preclinical studies suggest that the pBI-11 DNA vaccine may be used with TA-HPV in a heterologous prime-boost strategy to enhance HPV 16/18 E6/E7-specific CD8+ T cell responses, either alone or in combination with immune checkpoint blockade, to control HPV16/18-associated tumors. Our data serve as an important foundation for future clinical translation.IMPORTANCE Persistent expression of high-risk human papillomavirus (HPV) E6 and E7 is an obligate driver for several human malignancies, including cervical cancer, wherein HPV16 and HPV18 are the most common types. PD-1 antibody immunotherapy helps a subset of cervical cancer patients, and its efficacy might be improved by combination with active vaccination against E6 and/or E7. For patients with HPV16+ cervical intraepithelial neoplasia grade 2/3 (CIN2/3), the precursor of cervical cancer, intramuscular vaccination with a DNA vaccine targeting HPV16 E7 and then a recombinant vaccinia virus expressing HPV16/18 E6-E7 fusion proteins (TA-HPV) was safe, and half of the patients cleared their lesions in a small study (NCT00788164). Here, we sought to improve upon this therapeutic approach by developing a new DNA vaccine that targets E6 and E7 of HPV16 and HPV18 for administration prior to a TA-HPV booster vaccination and for application against cervical cancer in combination with a PD-1-blocking antibody.

Reprogramming immunosuppressive myeloid cells by activated T cells promotes the response to anti-PD-1 therapy in colorectal cancer

Overcoming local immunosuppression is critical for immunotherapy to produce robust anti-tumor responses. Myeloid-derived suppressor cells (MDSCs) are key regulators of immunosuppressive networks and promote tumor progression. However, it remains unclear whether and how tumor-infiltrating MDSCs are shaped in response to anti-PD-1 treatment and what their impact on therapeutic efficacy is in colorectal cancer (CRC). In this study, the levels of infiltrating MDSCs were significantly higher in the non-responding organoids and were selectively reduced in the responding group, with MDSCs showing increased apoptosis and attenuated functional activity after anti-PD-1 treatment. A negative correlation between T-cell activation and MDSC function was also observed in fresh human CRC tissues. Mechanistic studies revealed that autocrine IFN-α/β upregulated TRAIL expression on activated T cells to elicit MDSC apoptosis via the TRAIL–DR5 interaction and acted synergistically with TNF-α to inhibit MDSC function of suppressing the T-cell response through the JNK-NMDAR-ARG-1 pathway. Moreover, blockade of IFN-α/β and TNF-α abolished the therapeutic efficacy of anti-PD-1 treatment by preserving the frequency and suppressive activity of infiltrating MDSCs in a CRC mouse model. This result suggested that reprogramming MDSCs by IFN-α/β and TNF-α from activated T cells was necessary for successful anti-PD-1 treatment and might serve as a novel strategy to improve the response and efficacy of anticancer therapy.

Epigenetic modulation of immunotherapy and implications in head and neck cancer

Cancer progression is facilitated by distinct mechanisms developed by cancer cells to avoid immune recognition and clearance. The clinical application of immune checkpoint blockade (ICB), via monoclonal antibodies blocking PD-1/PD-L1 and CTLA4, has achieved promising durable therapeutic response in various cancer types, including recurrent and metastatic head and neck squamous cell carcinomas (HNSCC). HNSCC represents a rational target of ICB treatment given its relatively high mutation burden and the presence of immune infiltrates. However, the limited response rates and recent negative clinical trials data identify an urgent need for new strategies to overcome immunotherapy resistance. Preclinical studies have revealed an important contribution of epigenetic regulators in the anti-tumor immune response. Multiple components of the tumor and host immune system interaction are under epigenetic regulation, including the cancer cells themselves, cytotoxic T lymphocytes, regulatory T lymphocytes, natural killer cells, and tumor-associated macrophages. Epigenetic targeting drugs such as DNA methyltransferase inhibitors, histone deacetylase, and methyltransferase inhibitors have demonstrated the potential to reverse immune suppression in various cancer models. The aim of this review is to summarize recent preclinical studies focused on investigating the function of epigenetic modulation in the host immune and cancer cell interface. We also provide a perspective on combining epigenetic modulation and immunotherapy in the management of HNSCC to improve outcomes—an area of great interest in future clinical studies.

Tumor-Associated Tertiary Lymphoid Structures: A Cancer Biomarker and a Target for Next-generation Immunotherapy

The different forms of lymphoid organization that coexist in our bodies appeared at distinct time points during the evolution of the animal kingdom. Some of these forms are constitutive, either in fully dedicated organs, such as lymph nodes, or in tissue interfacing with the external environment, such as mucosal-associated lymphoid tissues. Others, known as tertiary lymphoid structures (TLS), are selectively induced in response to inflammation in any peripheral tissues and organs. In this chapter, we discuss the functional interest of each of these lymphoid organizations under different physiopathological conditions. In the context of cancer, recent findings have identified TLS formation as a hallmark of active T- and B-cell immune responses against tumors. TLS are thus a powerful prognostic factor in nearly all solid cancers, which must be taken into account along with the tumor microenvironment. The presence of TLS also predicts the response to immunotherapy including immune checkpoint blockade. With tumor-associated TLS now a key target for the next generation of immunotherapy, this chapter discusses their potential therapeutic manipulations in oncology.

High intratumoral CD8+ T-cell infiltration is associated with improved survival in prostate cancer patients undergoing radical prostatectomy

BACKGROUND

A high density of CD8⁺ tumor infiltrating lymphocytes (TILs) is associated with improved survival in multiple cancers, but its prognostic role in prostate cancer remains controversial. The aim of our study was to evaluate the prognostic value of CD8⁺ TILs in prostate cancer patients undergoing radical prostatectomy (RP). We hypothesized that elevated density of CD8⁺ TILs in the RP specimen would correlate with improved clinical outcomes. This information may be helpful for future immunotherapy clinical trial design and treatment selection.

METHODS

Tumor microarrays constructed from 230 patients with localized prostate cancers who underwent RP from 2006 to 2012 at Roswell Park Comprehensive Cancer Center were analyzed retrospectively using immunohistochemistry. CD8⁺ cell density was evaluated using a computerized scoring system. The cohorts were separated by CD8⁺ TIL density at the 25th percentile (i.e., low <quartile 1 and high ≥quartile 1). The quartile 1 threshold was chosen through a "minimal p value approach" based on overall survival with correction of significance to adjust for multiple testing. Clinical outcomes were compared in the high versus low CD8⁺ TIL density groups.

RESULTS

One hundred and forty-nine (65%) patients had high risk diseases (Gleason >7 or pT3/4). The median follow-up time was 8.4 years. High CD8⁺ TIL density was associated with improved 5-year overall survival (98% vs. 91%, p = .01) and prostate cancer-specific survival (99% vs. 95%, p = .04) compared with patients with low CD8⁺ TIL density. There was a trend toward higher 5-year biochemical recurrence-free survival and metastasis-free survival in the cohort of patients with high CD8⁺ TIL density (52% vs. 38% and 86% vs. 73%, respectively), although the difference did not reach statistical significance (p = .18 and p = .05, respectively). In a multivariate analysis high CD8⁺ TIL density was an independent favorable prognostic factor for overall survival (hazards ratio = 0.38; 95% confidence interval: 0.17-0.87; p = .02). In contrast to the prognostic value of CD8⁺ TIL density, the CD8⁺ cell density in the matched normal prostate tissue was not associated with any clinical outcomes.

CONCLUSION

Intratumoral CD8⁺ T-cell infiltration in the RP specimen is independently associated with improved survival after RP in this high-risk prostate cancer cohort. Pre-RP immunomodulation that promotes intratumoral CD8⁺ cytotoxic T-cell infiltration may be beneficial for this population.

Roles of the Dynamic Tumor Immune Microenvironment in the Individualized Treatment of Advanced Clear Cell Renal Cell Carcinoma

Immune checkpoint inhibitors (ICIs) are currently a first-line treatment option for clear cell renal cell carcinoma (ccRCC). However, recent clinical studies have shown that a large number of patients do not respond to ICIs. Moreover, only a few patients achieve a stable and durable response even with combination therapy based on ICIs. Available studies have concluded that the response to immunotherapy and targeted therapy in patients with ccRCC is affected by the tumor immune microenvironment (TIME), which can be manipulated by targeted therapy and tumor genomic characteristics. Therefore, an in-depth understanding of the dynamic nature of the TIME is important for improving the efficacy of immunotherapy or combination therapy in patients with advanced ccRCC. Here, we explore the possible mechanisms by which the TIME affects the efficacy of immunotherapy and targeted therapy, as well as the factors that drive dynamic changes in the TIME in ccRCC, including the immunomodulatory effect of targeted therapy and genomic changes. We also describe the progress on novel therapeutic modalities for advanced ccRCC based on the TIME. Overall, this review provides valuable information on the optimization of combination therapy and development of individualized therapy for advanced ccRCC.

Antibody-mediated delivery of LIGHT to the tumor boosts natural killer cells and delays tumor progression

LIGHT is a member of the tumor necrosis factor superfamily, which has been claimed to mediate anti-tumor activity on the basis of cancer cures observed in immunocompetent mice bearing transgenic LIGHT-expressing tumors. The preclinical development of a LIGHT-based therapeutic has been hindered by the lack of functional stability exhibited by this protein. Here, we describe the cloning, expression, and characterization of five antibody-LIGHT fusion proteins, directed against the alternatively spliced extra domain A of fibronectin, a conserved tumor-associated antigen. Among the five tested formats, only the sequential fusion of the F8 antibody in single-chain diabody format, followed by the LIGHT homotrimer expressed as a single polypeptide, yielded a protein (termed "F8-LIGHT") that was not prone to aggregation. A quantitative biodistribution analysis in tumor-bearing mice, using radio-iodinated protein preparations, confirmed that F8-LIGHT was able to preferentially accumulate at the tumor site, with a tumor-to-blood ratio of ca. five to one 24 hours after intravenous administration. Tumor therapy experiments, performed in two murine tumor models (CT26 and WEHI-164), featuring different levels of lymphocyte infiltration into the neoplastic mass, revealed that F8-LIGHT could significantly reduce tumor-cell growth and was more potent than a similar fusion protein (KSF-LIGHT), directed against hen egg lysozyme and serving as negative control of irrelevant specificity in the mouse. At a mechanistic level, the activity of F8-LIGHT was mainly due to an intratumoral expansion of natural killer cells, whereas there was no evidence of expansion of CD8 + T cells, neither in the tumor, nor in draining lymph nodes. Abbreviations: CTLA-4: Cytotoxic T-lymphocytes-associated protein 4; EGFR: Epidermal growth factor receptor; HVEM: Herpesvirus entry mediator; IFNγ: Interferon-gamma; LIGHT: Lymphotoxin, exhibits inducible expression and competes with HSV glycoprotein D for binding to herpesvirus entry mediator, a receptor expressed on T lymphocytes; LTβR: Lymphotoxin beta receptor; NF-κB: Nuclear factor "kappa-light-chain-enhancer" of activated B cells; NK: Natural killer cells; PD-1: Programmed cell death protein 1; PD-L1: Programmed death-ligand 1; TNF: Tumor necrosis factor.

Immune Modulation in Lung Cancer: Current Concepts and Future Strategies

Cancer immunotherapy represents the most dynamic field of biomedical research currently, with thoracic immuno-oncology as a forerunner. PD-(L)1 inhibitors are already part of standard first-line treatment for both non-small-cell and small-cell lung cancer, while unprecedented 5-year survival rates of 15-25% have been achieved in pretreated patients with metastatic disease. Evolving strategies are mainly aiming for improvement of T-cell function, increase of immune activation in the tumor microenvironment (TME), and supply of tumor-reactive lymphocytes. Several novel therapeutics have demonstrated preclinical efficacy and are increasingly used in rational combinations within clinical trials. Two overarching trends dominate: extension of immunotherapy to earlier disease stages, mainly as neoadjuvant treatment, and a shift of focus towards multivalent, individualized, mutatome-based antigen-specific modalities, mainly adoptive cell therapies and cancer vaccines. The former ensures ample availability of treated and untreated patient samples, the latter facilitates deeper mechanistic insights, and both in combination build an overwhelming force that is accelerating progress and driving the greatest revolution cancer medicine has seen so far. Today, immune modulation represents the most potent therapeutic modality in oncology, the most important topic in clinical and translational cancer research, and arguably our greatest, meanwhile justified hope for achieving cure of pulmonary neoplasms and other malignancies in the next future.

Injectable Liquid Crystal Formation System for Reshaping Tumor Immunosuppressive Microenvironment to Boost Antitumor Immunity: Postoperative Chemoimmunotherapy

Exploring optimal strategies to improve patient outcome postoperatively is still under challenge. Cancer immunotherapy has great potential to prevent the postoperative tumor recurrence and metastasis, which could be further strengthened by re-education of tumor microenvironment (TME). Herein, a local and sustained drug delivery system of liquid crystal formation system (LCFS) co-loaded with doxorubicin (DOX) and resiquimod (R848) (D/R@LCFS) is reported to confer effective chemoimmunotherapy with reduced systematic toxicity. After local administration, D/R@LCFS turns tumor into in situ vaccine via DOX-triggered immunogenic cell death effect accompanied with immunostimulatory effect of R848. Meanwhile, combination treatment of D/R@LCFS facilitates the recruitment of effector CD8⁺ T cells and the polarization of myeloid-derived suppressor cells and immunosuppressive type 2-polarized macrophages to tumoricidal antigen-presenting cells, favoring antigen-specific T cell immune response and inducing more immunogenic phenotypes in tumors. The generated in situ vaccine as well as reshaped TME by D/R@LCFS elicited systematic immune response and long term immune-memory effect in combination with immune checkpoint blockade to significantly prevent postoperative B16F10 or 4T1 tumor recurrence and metastasis. Therefore, this combination strategy of spatiotemporal TME modulation is expected to provide a clinical available option for effective postoperative chemoimmunotherapy.

Histone demethylase UTX/KDM6A enhances tumor immune cell recruitment, promotes differentiation and suppresses medulloblastoma

The deregulation of epigenetic pathways has been implicated as a critical step in tumorigenesis including in childhood brain tumor medulloblastoma. The H3K27me3 demethylase UTX/KDM6A plays important roles in development and is frequently mutated in various types of cancer. However, how UTX regulates tumor development remains largely unclear. Here, we report the generation of a UTX-deleted mouse model of SHH medulloblastoma that demonstrates the tumor suppressor functions of UTX, which could be antagonized by the deletion of another H3K27me3 demethylase JMJD3/KDM6B. Intriguingly, UTX deletion in cancerous cerebellar granule neuron precursors (CGNPs) resulted in the impaired recruitment of host CD8⁺ T cells to the tumor microenvironment through a non-cell autonomous mechanism. In both mouse medulloblastoma models and in human medulloblastoma cells, we showed that UTX activates Th1-type chemokines, which are responsible for T cell migration. Surprisingly, our results showed that the depletion of cytotoxic CD8⁺ T cells did not affect mouse medulloblastoma growth. Nevertheless, the UTX/chemokine/T cell recruitment pathway we identified may be applied to many other cancers and may be important for improving cancer immunotherapy. In addition, UTX is required for the expression of NeuroD2 in precancerous progenitors, which encodes a potent proneural transcription factor. Overexpression of NEUROD2 in CGNPs decreased cell proliferation and increased neuron differentiation. We showed that UTX deletion led to impaired neural differentiation, which could coordinate with active SHH signaling to accelerate medulloblastoma development. Thus, UTX regulates both cell-intrinsic oncogenic processes and the tumor microenvironment in medulloblastoma. Our study provides insights into both medulloblastoma development and context dependent functions of UTX in tumorigenesis.

Increased Production of LIGHT by T Cells in Eosinophilic Esophagitis Promotes Differentiation of Esophageal Fibroblasts Toward an Inflammatory Phenotype

BACKGROUND & AIMS

Eosinophilic esophagitis (EoE) is an antigen-mediated eosinophilic disease of the esophagus that involves fibroblast activation and progression to fibrostenosis. Cytokines produced by T-helper type 2 cells and transforming growth factor beta 1 (TGFβ1) contribute to the development of EoE, but other cytokines involved in pathogenesis are unknown. We investigate the effects of tumor necrosis factor superfamily member 14 (TNFSF14, also called LIGHT) on fibroblasts in EoE.

METHODS

We analyzed publicly available esophageal CD3+ T-cell single-cell sequencing data for expression of LIGHT. Esophageal tissues were obtained from pediatric patients with EoE or control individuals and analyzed by immunostaining. Human primary esophageal fibroblasts were isolated from esophageal biopsy samples of healthy donors or patients with active EoE. Fibroblasts were cultured; incubated with TGFβ1 and/or LIGHT; and analyzed by RNA sequencing, flow cytometry, immunoblots, immunofluorescence, or reverse transcription polymerase chain reaction. Eosinophils were purified from peripheral blood of healthy donors, incubated with interleukin 5, cocultured with fibroblasts, and analyzed by immunohistochemistry.

RESULTS

LIGHT was up-regulated in the esophageal tissues from patients with EoE, compared with control individuals, and expressed by several T-cell populations, including T-helper type 2 cells. TNF receptor superfamily member 14 (TNFRSF14, also called HVEM) and lymphotoxin beta receptor are receptors for LIGHT that were expressed by fibroblasts from healthy donors or patients with active EoE. Stimulation of esophageal fibroblasts with LIGHT induced inflammatory gene transcription, whereas stimulation with TGFβ1 induced transcription of genes associated with a myofibroblast phenotype. Stimulation of fibroblasts with TGFβ1 increased expression of HVEM; subsequent stimulation with LIGHT resulted in their differentiation into cells that express markers of myofibroblasts and inflammatory chemokines and cytokines. Eosinophils tethered to esophageal fibroblasts after LIGHT stimulation via intercellular adhesion molecule-1.

CONCLUSIONS

T cells in esophageal tissues from patients with EoE express increased levels of LIGHT compared with control individuals, which induces differentiation of fibroblasts into cells with inflammatory characteristics. TGFβ1 increases fibroblast expression of HVEM, a receptor for LIGHT. LIGHT mediates interactions between esophageal fibroblasts and eosinophils via ICAM1. This pathway might be targeted for the treatment of EoE.

Stromal reaction inhibitor and immune-checkpoint inhibitor combination therapy attenuates excluded-type colorectal cancer in a mouse model

Despite recent advances in cancer immunotherapy, the efficacy of colorectal cancer (CRC) immunotherapy regimens is limited. This study evaluated the combined effect of an anti-PD-1 antibody and a platelet-derived growth factor receptor inhibitor (imatinib) on CRC progression using an orthotopic transplanted mouse model that reproduced the three histological phenotypes of CRC (inflamed-, excluded-, and desert-type). The frequency of each of these phenotypes in 196 human CRC tissue samples was also evaluated. Excluded-type CRC had the highest frequency in human tissue samples. In the mouse model, imatinib suppressed stromal reaction and increased sensitivity to anti-PD-1 treatment in excluded-type CRC. Antitumor effect was observed in mice with excluded-type tumors only after concomitant administration of anti-PD-1 antibody and imatinib. Immunohistological analysis revealed a reduction in stromal volume and an increase in the number of CD8-positive T cells in the tumor nest following combination therapy. RNA sequencing revealed significant activation of immune-related pathways and suppression of stromal-related pathways in transplanted tumors treated with combination therapy compared with tumors treated with anti-PD-1 antibody monotherapy. This combination therapy may prove effective for CRC cases that are unresponsive to anti-PD-1 antibody monotherapy.

PD-1 blockade synergizes with intratumoral vaccination of a therapeutic HPV protein vaccine and elicits regression of tumor in a preclinical model

INTRODUCTION

The human papillomavirus (HPV) encoded oncoproteins E6 and E7 are constitutively expressed in HPV-associated cancers, making them logical therapeutic targets. Intramuscular immunization of patients with HPV16 L2E7E6 fusion protein vaccine (TA-CIN) is well tolerated and induces HPV-specific cellular immune responses. Efficacy of PD-1 immune checkpoint blockade correlates with the level of tumor-infiltrating CD8 + T cells, yet most patients lack significant tumor infiltration of immune cells making immune checkpoint blockade suboptimal. We hypothesized that intratumoral vaccination with TA-CIN could increase the number of tumor-infiltrating CD8 + T cells, synergize with PD-1 blockade and result in better control of tumors compared with either PD-1 blockade or vaccination alone.

METHODS

We examined the immunogenicity and antitumor effects of intratumoral vaccination with TA-CIN alone or in combination with PD-1 blockade in the TC-1 syngeneic murine tumor model expressing HPV16 E6/E7.

RESULTS

Intratumoral vaccination with TA-CIN induced stronger antigen-specific CD8 + T cell responses and antitumor effects. Intratumoral TA-CIN vaccination generated a systemic immune response that was able to control distal TC-1 tumors. Furthermore, intratumoral TA-CIN vaccination induced tumor infiltration of antigen-specific CD8 + T cells. Knockout of Batf3 abolished antigen-specific CD8 + T cell responses and antitumor effects of intratumoral TA-CIN vaccination. Finally, PD-1 blockade synergizes with intratumoral TA-CIN vaccination resulting in significantly enhanced antigen-specific CD8 + T cell responses and complete regression of tumors, whereas either alone failed to control established TC-1 tumor.

CONCLUSIONS

Our results provide rationale for future clinical testing of intratumoral TA-CIN vaccination in combination with PD-1 blockade for the control of HPV16-associated tumors.

CTNNB1 mutation suppresses infiltration of immune cells in hepatocellular carcinoma through miRNA-mediated regulation of chemokine expression

Mutations in the CTNNB1 gene in hepatocellular carcinoma (HCC) are related to immune exclusion, and HCC patients with CTNNB1 mutations tend to be primarily resistant to anti-PD1 therapy. However, systemic evaluation of immune cell infiltration in HCC with mutant CTNNB1 is lacking, and the mechanism of immune exclusion resulting from CTNNB1 mutations remains unclear. Based on CTNNB1 mutation status in HCC, we investigated RNA and miRNA expression and infiltration of immune cells. Data downloaded from TCGA showed that HCC with CTNNB1 mutation had an increased expression of CTNNB1. HCC with CTNNB1 mutation showed a reduction in infiltration score as well as in abundance of certain kinds of immune cells, including CD4 naïve T cells, CD4+ T cells, Tex cells, Th2 cells, Tfh cells, B cells, macrophages, and NK cells. Furthermore, there were 13 chemokines downregulated among all the 14 differentially expressed chemokines (DE-CKs) in CTNNB1 mutants compared to those in the wild type. A positive correlation was found between the expression of DE-CKs and infiltration score, as well as infiltration level of 6 types of immune cells, namely B cells, CD8+ cells, CD4+ cells, macrophages, neutrophils, and dendritic cells. Additionally, 302 differentially expressed immune-related genes (DE-IRGs) were involved mainly in the human immune response and cytokine-cytokine receptor interaction. The target DE-IRGs of differentially expressed miRNAs (DE-miRNAs) were identified and used to construct a network with DE-miRNAs and DE-CKs. Overall, CTNNB1 mutation in HCC led to a decrease in chemokine expression and subsequent suppression of immune cell infiltration partly through regulating specific miRNA-IRG-CK axes, pointing to a potential combination of interference of Wnt/β-catenin signaling with immunotherapy in HCC with CTNNB1 mutation.

PD-L1 on dendritic cells attenuates T cell activation and regulates response to immune checkpoint blockade

Immune checkpoint blockade therapies have shown clinical promise in a variety of cancers, but how tumor-infiltrating T cells are activated remains unclear. In this study, we explore the functions of PD-L1 on dendritic cells (DCs), which highly express PD-L1. We observe that PD-L1 on DC plays a critical role in limiting T cell responses. Type 1 conventional DCs are essential for PD-L1 blockade and they upregulate PD-L1 upon antigen uptake. Upregulation of PD-L1 on DC is mediated by type II interferon. While DCs are the major antigen presenting cells for cross-presenting tumor antigens to T cells, subsequent PD-L1 upregulation protects them from killing by cytotoxic T lymphocytes, yet dampens the antitumor responses. Blocking PD-L1 in established tumors promotes re-activation of tumor-infiltrating T cells for tumor control. Our study identifies a critical and dynamic role of PD-L1 on DC, which needs to be harnessed for better invigoration of antitumor immune responses.

Enhancing KDM5A and TLR activity improves the response to immune checkpoint blockade

The bifunctional compound D18 improves checkpoint blockade efficacy by increasing KDM5A and PD-L1 abundance and inducing TLR7/8 activation.

PD-1 inhibitor combined with apatinib for advanced gastric or esophagogastric junction cancer: a retrospective study

BACKGROUND

Nivolumab and pembrolizumab were approved as immune checkpoint inhibitors for third-line treatment of advanced gastric or esophagogastric junction cancer (GC/EGJC) in 2017. However, immunotherapy monotherapy has low efficacy. Apatinib has been proven effective in advanced GC/EGJC. Numerous studies have shown that immunotherapy has a synergistic effect when combined with targeted drug therapy. Based on these facts and to assess the efficacy and safety of programmed death 1 (PD-1) inhibitor and apatinib as combination therapy in patients (pts) with unresectable locally advanced or metastatic GC/EGJC, a retrospective clinical research study was carried out.

METHODS

Pts (n=24) received PD-1 inhibitor and apatinib (250 mg once daily) as second- or third-line therapy in this observational, retrospective study. The primary objectives were efficacy and safety.

RESULTS

At data cut-off (December 31, 2019), 24 pts were enrolled. Of the 19 pts who were evaluable, the objective response rate (ORR) was 26.3% (5/19), the median progression-free survival (PFS) was 3.0 (95% CI: 1.3 to 4.7) months, and the median overall survival (OS) was not reached. Grade 3 or 4 treatment-related adverse events (TRAEs) occurred in 3 (15.8%) of the 19 pts. These adverse events (AEs) included pruritus, rash, hand-foot syndrome, and increased aspartate aminotransferase (AST) or alanine aminotransferase (ALT). No treatment-related deaths occurred.

CONCLUSIONS

Combination therapy of PD-1 inhibitor and apatinib showed encouraging clinical activity and demonstrated tolerable toxicity in pts with advanced GC/EGJC. Hence, our work provide rationale for the combination of PD-1 inhibitor and apatinib in advanced GC/EGJC.

Tuberculosis-Cancer Parallels in Immune Response Regulation

Mycobacterium tuberculosis and cancer are two diseases with proclivity for the development of resistance to the host immune system. Mechanisms behind resistance can be host derived or disease mediated, but they usually depend on the balance of pro-inflammatory to anti-inflammatory immune signals. Immunotherapies have been the focus of efforts to shift that balance and drive the response required for diseases eradication. The immune response to tuberculosis has widely been thought to be T cell dependent, with the majority of research focused on T cell responses. However, the past decade has seen greater recognition of the importance of the innate immune response, highlighting factors such as trained innate immunity and macrophage polarization to mycobacterial clearance. At the same time, there has been a renaissance of immunotherapy treatments for cancer since the first checkpoint inhibitor passed clinical trials, in addition to work highlighting the importance of innate immune responses to cancer. However, there is still much to learn about host-derived responses and the development of resistance to new cancer therapies. This review examines the similarities between the immune responses to cancer and tuberculosis with the hope that their commonalities will facilitate research collaboration and discovery.

Overview of Current Progress in Immune Checkpoint Inhibitor Therapy for Advanced Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) remains to a common cause of tumor mortality worldwide and represents the most common type of lethal hepatic malignancy. The incidence of HCC is swiftly increasing in western countries and southeast Asia. Despite poor prognosis, traditional treatments for advanced HCC appear to be minimally effective or even useless since patients are usually diagnosed in the advanced stage of disease. In recent years, immune checkpoint blockade has shown promising results in multiple pre-clinical and clinical trials of different solid tumors, including advanced HCC. Novel drugs targeting immune checkpoints, such as nivolumab (anti-PD-1), durvalumab (anti-PD-L1), and tremelimumab (anti-CTLA-4) have been shown to be highly effective and relatively safe in monotherapy or in combination treatment of advanced liver cancer. Unlike other immunotherapies, this approach can rouse human anti-tumor immunity by relieving T-cell exhaustion and inhibiting the evasion of HCC by blocking co-inhibitory signaling transduction accurately. In this review, we will provide current knowledge of several major immune checkpoints and summarize recent data from clinical trials that applied immune checkpoint inhibitors alone or in combination. In addition, this review will discuss the limitations and future prospective of immune checkpoint-targeted therapy for advanced HCC.

Programming CAR T cells to enhance anti-tumor efficacy through remodeling of the immune system

Chimeric antigen receptor (CAR) T cells have been indicated effective in treating B cell acute lymphoblastic leukemia and non-Hodgkin lymphoma and have shown encouraging results in preclinical and clinical studies. However, CAR T cells have achieved minimal success against solid malignancies because of the additional obstacles of their insufficient migration into tumors and poor amplification and persistence, in addition to antigen-negative relapse and an immunosuppressive microenvironment. Various preclinical studies are exploring strategies to overcome the above challenges. Mobilization of endogenous immune cells is also necessary for CAR T cells to obtain their optimal therapeutic effect given the importance of the innate immune responses in the elimination of malignant tumors. In this review, we focus on the recent advances in the engineering of CAR T cell therapies to restore the immune response in solid malignancies, especially with CAR T cells acting as cellular carriers to deliver immunomodulators to tumors to mobilize the endogenous immune response. We also explored the sensitizing effects of conventional treatment approaches, such as chemotherapy and radiotherapy, on CAR T cell therapy. Finally, we discuss the combination of CAR T cells with biomaterials or oncolytic viruses to enhance the anti-tumor outcomes of CAR T cell therapies in solid tumors.

Adverse impact of bone metastases on clinical outcomes of patients with advanced non-small cell lung cancer treated with immune checkpoint inhibitors

Background

Bone metastasis (BoM) is common in patients with advanced non‐small cell lung cancer (NSCLC) and considered as one of the negative prognostic factors. However, the impact of BoM on clinical outcomes of patients with advanced NSCLC treated with immune checkpoint inhibitors (ICIs) remains unclear.

Methods

A total of 103 patients treated with ICI monotherapy and 101 patients treated with ICIs combined with chemotherapy or antiangiogenesis therapy were retrospectively analyzed. The differences in progression‐free survival (PFS), overall survival (OS) and objective response rate (ORR) between BoM+ and BoM− were investigated.

Results

Of those 101 patients who received combination therapy, no significant difference between BoM− and BoM+ in terms of both median PFS and median OS (median PFS, 10.1 vs. 12.1 months, P = 0.6; median OS, NR vs. 24.6 months, P = 0.713) was determined. In contrast, of the 103 patients who received ICI monotherapy, BoM+ patients had an inferior PFS (4.2 vs. 6.7 months, P = 0.0484) and OS (12.5 vs. 23.9 months, P = 0.0036) compared with BoM− patients. The univariate and multivariate analysis in the ICI monotherapy group also identified BoM as an independent factor attenuating the efficacy of ICI monotherapy. Of all BoM+ patients who received ICI monotherapy, neither palliative radiotherapy nor bisphosphonate drugs improved OS (palliative radiotherapy: 12.5 vs. 16.7 months, P = 0.487; bisphosphonate drugs: 12.5 vs. 9.7 months, P = 0.568).

Conclusions

BoM attenuated the efficacy of ICI monotherapy in patients with advanced NSCLC. Of BoM+ patients who received ICI monotherapy, neither palliative radiotherapy nor bisphosphonate drugs improved OS. Other therapeutic strategies are needed for patients with BoM.

EPHA5 mutation predicts the durable clinical benefit of immune checkpoint inhibitors in patients with lung adenocarcinoma

Immune checkpoint inhibitor (ICI) therapy has shown remarkable clinical benefit in lung adenocarcinoma (LUAD) patients. Genomic mutations may be applicable to predict the response to ICIs. Eph receptor A5 (EPHA5) is frequently mutated in breast cancer, lung cancer, and other tumors; however, its association with outcome in patients who receive immunotherapy remains unknown. In this study, we report that EPHA5 mutations were associated with increased tumor mutation burden (TMB), neoantigen load, levels of immune-related gene expression signatures, and enhanced tumor-infiltrating lymphocytes (TILs) in LUAD. LUAD patients with EPHA5 mutations in the immunotherapy cohort achieved a longer progression-free survival (PFS) time than patients with wild-type EPHA5. Immune response pathways were among the top enriched pathways in samples with EPHA5 mutations. In addition, patients with EPHA5 mutations tended to be more sensitive to certain targeted molecular inhibitors, including serdemetan, lox2, and PF1-1. Collectively, our results suggest that identifying mutations in the EPHA5 gene may provide insight into the genome-wide mutational burden and may serve as a biomarker to predict the immune response of patients with LUAD.