Tackling Cancer Resistance by Immunotherapy: Updated Clinical Impact and Safety of PD-1/PD-L1 Inhibitors. Cancers (Basel). 2018;10. [PMID: 29370105 PMCID: PMC5836064 DOI: 10.3390/cancers10020032]

Pan-cancer analysis identifies the IRF family as a biomarker for survival prognosis and immunotherapy

IRF family genes have been shown to be crucial in tumorigenesis and tumour immunity. However, information about the role of IRF in the systematic assessment of pan-cancer and in predicting the efficacy of tumour therapy is still unknown. In this work, we performed a systematic analysis of IRF family genes in 33 tumour samples, including expression profiles, genomics and clinical characteristics. We then applied Single-Sample Gene-Set Enrichment Analysis (ssGSEA) to calculate IRF-scores and analysed the impact of IRF-scores on tumour progression, immune infiltration and treatment efficacy. Our results showed that genomic alterations, including SNPs, CNVs and DNA methylation, can lead to dysregulation of IRFs expression in tumours and participate in regulating multiple tumorigenesis. IRF-score expression differed significantly between 12 normal and tumour samples and the impact on tumour prognosis and immune infiltration depended on tumour type. IRF expression was correlated to drug sensitivity and to the expression of immune checkpoints and immune cell infiltration, suggesting that dysregulation of IRF family expression may be a critical factor affecting tumour drug response. Our study comprehensively characterizes the genomic and clinical profile of IRFs in pan-cancer and highlights their reliability and potential value as predictive markers of oncology drug efficacy. This may provide new ideas for future personalized oncology treatment.

β-Glucan-conjugated anti-PD-L1 antibody enhances antitumor efficacy in preclinical mouse models

The use of immune checkpoint blockade (ICB) is a promising approach for clinical cancer treatment. However, most of cancer patients do not respond to anti-PD-1/PD-L1 antibody. In this study, we proposed a novel strategy of antibody-β-glucan conjugates (AGC) to enhance the antitumor immune response to ICB therapy. The AGC were constructed by conjugating an anti-PD-L1 antibody with a β-glucan via click chemistry. This design facilitates the delivery of β-glucan into the tumor microenvironment (TME). Furthermore, the bridging effect mediated by AGC can promote the interaction between tumor cells and dendritic cells (DCs), thereby enhancing immunotherapeutic benefits. In the MC38 tumor-bearing mouse model, AGC demonstrated powerful tumor suppression, achieving a tumor suppression rate of 86.7 %. Immunophenotyping, cytokine analysis, RNA sequencing, and FTY720-treated models were combined to elucidate the mechanism underlying AGC function. Compared with anti-PD-L1 antibody, AGC induced an earlier immune response, infiltration of DCs, and activation of preexisting T cells in the TME, with T cells predominantly proliferating locally rather than migrating from other organs. In conclusion, these data suggest that AGC could serve as a promising strategy to improve ICB therapy with prospects for clinical utilization.

The Effectiveness of Cancer Immune Checkpoint Inhibitor Retreatment and Rechallenge-A Systematic Review

Despite a great success of immunotherapy in cancer treatment, a great number of patients will become resistant. This review summarizes recent reports on immune checkpoint inhibitor retreatment or rechallenge in order to overcome primary resistance. The systematic review was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The search was performed using PubMed, Web of Science and Scopus. In total, 31 articles were included with a total of 812 patients. There were 16 retreatment studies and 13 rechallenge studies. We identified 15 studies in which at least one parameter (overall response rate or disease control rate) improved or was stable at secondary treatment. Interval treatment, primary response to and the cause of cessation for the first immune checkpoint inhibitors seem to be promising predictors of secondary response. However, high heterogeneity of investigated cohorts and lack of reporting guidelines are limiting factors for current in-depth analysis.

Current status of N-, O-, S-heterocycles as potential alkaline phosphatase inhibitors: a medicinal chemistry overview

Heterocycles are a class of compounds that have been found to be potent inhibitors of alkaline phosphatase (AP), an enzyme that plays a critical role in various physiological processes such as bone metabolism, cell growth and differentiation, and has been linked to several diseases such as cancer and osteoporosis. AP is a widely distributed enzyme, and its inhibition has been considered as a therapeutic strategy for the treatment of these diseases. Heterocyclic compounds have been found to inhibit AP by binding to the active site of the enzyme, thereby inhibiting its activity. Heterocyclic compounds such as imidazoles, pyrazoles, and pyridines have been found to be potent AP inhibitors and have been studied as potential therapeutics for the treatment of cancer, osteoporosis, and other diseases. However, the development of more potent and selective inhibitors that can be used as therapeutics for the treatment of various diseases is an ongoing area of research. Additionally, the study of the mechanism of action of heterocyclic AP inhibitors is an ongoing area of research, which could lead to the identification of new targets and new therapeutic strategies. The enzyme known as AP has various physiological functions and is present in multiple tissues and organs throughout the body. This article presents an overview of the different types of AP isoforms, their distribution, and physiological roles. It also discusses the structure and mechanism of AP, including the hydrolysis of phosphate groups. Furthermore, the importance of AP as a clinical marker for liver disease, bone disorders, and cancer is emphasized, as well as its use in the diagnosis of rare inherited disorders such as hypophosphatasia. The potential therapeutic applications of AP inhibitors for different diseases are also explored. The objective of this literature review is to examine the function of alkaline phosphatase in various physiological conditions and diseases, as well as analyze the structure-activity relationships of recently reported inhibitors. The present review summarizes the structure-activity relationship (SAR) of various heterocyclic compounds as AP inhibitors. The SAR studies of these compounds have revealed that the presence of a heterocyclic ring, particularly a pyridine, pyrimidine, or pyrazole ring, in the molecule is essential for inhibitory activity. Additionally, the substitution pattern and stereochemistry of the heterocyclic ring also play a crucial role in determining the potency of the inhibitor.

Emerging biomaterials for tumor immunotherapy

BACKGROUND

The immune system interacts with cancer cells in various intricate ways that can protect the individual from overproliferation of cancer cells; however, these interactions can also lead to malignancy. There has been a dramatic increase in the application of cancer immunotherapy in the last decade. However, low immunogenicity, poor specificity, weak presentation efficiency, and off-target side effects still limit its widespread application. Fortunately, advanced biomaterials effectively contribute immunotherapy and play an important role in cancer treatment, making it a research hotspot in the biomedical field.

MAIN BODY

This review discusses immunotherapies and the development of related biomaterials for application in the field. The review first summarizes the various types of tumor immunotherapy applicable in clinical practice as well as their underlying mechanisms. Further, it focuses on the types of biomaterials applied in immunotherapy and related research on metal nanomaterials, silicon nanoparticles, carbon nanotubes, polymer nanoparticles, and cell membrane nanocarriers. Moreover, we introduce the preparation and processing technologies of these biomaterials (liposomes, microspheres, microneedles, and hydrogels) and summarize their mechanisms when applied to tumor immunotherapy. Finally, we discuss future advancements and shortcomings related to the application of biomaterials in tumor immunotherapy.

CONCLUSION

Research on biomaterial-based tumor immunotherapy is booming; however, several challenges remain to be overcome to transition from experimental research to clinical application. Biomaterials have been optimized continuously and nanotechnology has achieved continuous progression, ensuring the development of more efficient biomaterials, thereby providing a platform and opportunity for breakthroughs in tumor immunotherapy.

Immune-related adverse events are associated with therapeutic efficacy of immunotherapy in patients with melanoma brain metastases

Immunotherapy with T-cell checkpoint inhibitors have changed the treatment landscape for patients with melanoma brain metastases (MBMs), offering increased survival compared with historical outcomes. We sought to identify clinical features associated with intracranial tumour responses or progression-free survival (PFS) in patients with MBMs treated with immunotherapy. Patients with MBMs treated with immunotherapy from August 2013 to March 2020 were identified through local databases. Melanoma disease burdens and immune-related adverse events (irAEs) were assessed retrospectively by review of patient medical records. Efficacy was evaluated by determining objective response rates (ORRs) in brain metastases using immune-Response Evaluation Criteria in Solid Tumours criteria, MBM-specific survival and overall PFS. Twenty-six patients were identified as eligible for this study. The presence and volume of extracranial metastases (ECM) were associated with a non-significant trend of reduced intracranial ORRs and PFS. Patients with irAEs, on the other hand, had significantly increased intracranial ORRs and PFS compared to those without irAEs. Severe, grade ≥3 irAEs and co-occurrence of ≥2 irAEs were also significantly associated with longer PFS. The presence and volume of ECM correlated inversely with development and severity of irAEs. We report a strong association between the development of irAEs and favourable melanoma-specific outcomes in patients with MBMs receiving immunotherapy. Contrary to previous studies, we found that co-occurrence of ECM in these patients was associated with fewer irAEs and reduced treatment efficacy.

IP-score correlated to endogenous tumour antigen peptide processing: A candidate clinical response score algorithm of immune checkpoint inhibitors therapy in multiple cohorts

The processing of endogenous tumour antigen peptides was essential for anti-tumour immunity in the tumour microenvironment. A high degree of Endogenous tumour antigen peptide processing has been demonstrated to improve the prognosis of carcinoma patients. However, there is insufficient evidence to prove its effect on the clinical response to immune checkpoint inhibitor therapy. To undertake a more in-depth analysis of the effects of the aforementioned genes on immunotherapy, we constructed a gene set evaluation score system relevant to tumour endogenous antigen peptide therapy using the GSVA approach. This rating mechanism is known as IP score (IPs). Immediately afterwards, we used the TCGA pan-cancer cohorts to conduct a comprehensive analysis of 6 genes in the IPs, and the analysis results showed that these six genes were related to the proportion of CD8⁺ T lymphocytes in a variety of solid tumours. As a prognostic protective factor for solid tumours, patients had better prognosis outcomes in the group with high expression levels of the above genes. We analysed the differential expression of six genes between immune checkpoint inhibitor treatment response and disease progression groups using several treatment cohorts. The results revealed that after treatment with PD-1 or CTLA4 inhibitors, the expression levels of the above six genes were comparatively high in the effective group, but the expression of the signature genes was dramatically downregulated in the ICI-insensitive groups. This indicates that the 6 genes are related to the clinical response to ICI treatment. Finally, we used the GSVA method to evaluate the above signatures, and the results showed that PDCD1, CTAL4, CD274 and LAG3 were significantly higher expressed in the IPs high-expression group; therefore, based on the processing of endogenous antigenic peptides in tumours, a predictive score of clinical response to immune checkpoint inhibitor therapy composed of 6 genes(PSMB8/PSMB9/PSMB10/PSME1/PSME2/IRF1) was constructed, and the role of each independent variable in the signature in the solid tumour microenvironment and the impact on ICI treatment were comprehensively analysed. This study provides a candidate evaluation score for predicting clinical response to immune checkpoint inhibitor therapy.

Advancements in Cancer Immunotherapies

Recent work has suggested involvement of the immune system in biological therapies specifically targeting tumor microenvironment. Substantial advancement in the treatment of malignant tumors utilizing immune cells, most importantly T cells that play a key role in cell-mediated immunity, have led to success in clinical trials. Therefore, this article focuses on the therapeutic approaches and developmental strategies to treat cancer. This review emphasizes the immunomodulatory response, the involvement of key tumor-infiltrating cells, the mechanistic aspects, and prognostic biomarkers. We also cover recent advancements in therapeutic strategies.

Stress hormones are associated with inflammatory cytokines and attenuation of T-cell function in the ascites from patients with high grade serous ovarian cancer

Mounting evidence suggests that chronic stress and subsequent distress can promote ovarian cancer progression. These altered psychological states have been linked to sustained release of stress hormones, activation of the β-adrenergic receptors in ovarian cancer cells, and induction of pro-tumoral signaling pathways. In addition, data suggest that chronic stress promotes an inflammatory landscape highlighted by increased infiltration of tumor-associated macrophages into the ovarian tumor microenvironment (TME). In ovarian cancer, ascites is a unique TME comprised of tumor, and immune cells, which secrete pro-tumoral cytokines and chemokines that modulate tumor-associated immunity. However, our knowledge about how stress hormones impact the ascites TME remains limited. We hypothesized that the ascites harbors measurable levels of stress hormones, and accumulation of these in the ascites generates a pro-tumorigenic, inflammatory, and immunosuppressive TME. We evaluated ascites samples from 49 patients with high grade serous ovarian cancer (HGSOC) and quantified cortisol and stress hormones metabolites, metanephrine (MN), and normetanephrine (NMN) in all samples. We also measured 38 individual cytokines in the ascites, including several pro-inflammatory cytokines, such as IL-6, which were positively correlated to MN or NMN levels of those samples. Conversely, we found cortisol levels were negatively correlated to several pro-inflammatory cytokines. As T-cells are integral to the TME and our analyses identified cytokines in the ascites known to modulate T-cell function, we characterized ascites-derived T-cells and assessed the impact of stress hormones on the T-cell phenotype. Our data show an altered CD4+/CD8+ T-cell ratio and a heterogeneous expression of exhaustion markers in T-cells from the ascites, while ascites-derived CD8+ T-cells exposed to epinephrine had decreased co-expression CD38 and Granzyme B. To extend these findings to animal models, we subjected ovarian cancer-bearing mice to daily restraint stress, which resulted in increased tumor growth in two models. Congruent with our human analyses, we detected corticosterone, MN, and NMN in the ascites from tumor-bearing mice, and these stress hormones correlated with several inflammatory cytokines. Moreover, daily restraint stress leads to increased CD4+PD-1+/CD8+PD-1+ T-cell ratio in the ovarian tumor microenvironment. Overall, these data highlight a role of stress hormones in the ascites TME as a driver of tumor-associated inflammation, T-cell suppression, and disease progression.

KCNN4 is a Potential Biomarker for Predicting Cancer Prognosis and an Essential Molecule that Remodels Various Components in the Tumor Microenvironment: A Pan-Cancer Study

Objectives: Potassium Calcium-Activated Channel Subfamily N Member 4 (KCNN4) is a member of the KCNN family. Studies have revealed that KCNN4 is implicated in various physiological processes as well as promotes the malignant phenotypes of cancer cells. However, little is known about its associations with survival outcomes across varying cancer types.

Methods: Herein, we systematically explored the prognostic value of KCNN4 in the pan-cancer dataset retrieved from multiple databases. Next, we performed correlation analysis of KCNN4 expression with tumor mutational burden (TMB) and microsatellite instability (MSI), and immune checkpoint genes (ICGs) to assess its potential as a predictor of immunotherapy efficacy. Afterwards, patients were divided into increased-risk group and decreased-risk group based on the contrasting survival outcomes in various cancer types. Furthermore, the underlying mechanisms of the distinctive effects were analyzed using ESTIMATE, CIBERSORT algorithms, and Gene Set Enrichment Analysis (GSEA) analysis.

Results: KCNN4 expression levels were aberrant in transcriptomic and proteomic levels between cancer and normal control tissues in pan-cancer datasets, further survival analysis elucidated that KCNN4 expression was correlated to multiple survival data, and clinical annotations. Besides, KCNN4 expression was correlated to TMB and MSI levels in 14 types and 12 types of pan-cancers, respectively. Meanwhile, different types of cancer have specific tumor-infiltrating immune cell (TICs) profiles.

Conclusions: Our results revealed that KCNN4 could be an essential biomarker for remodeling components in the tumor microenvironment (TME), and a robust indicator for predicting prognosis as well as immunotherapy response in pan-cancer patients.

Impact of Diets on Response to Immune Checkpoint Inhibitors (ICIs) Therapy against Tumors

Immunotherapy has revolutionized the established therapeutics against tumors. As the major immunotherapy approach, immune checkpoint inhibitors (ICIs) achieved remarkable success in the treatment of malignancies. However, the clinical gains are far from universal and durable, because of the primary and secondary resistance of tumors to the therapy, or side effects induced by ICIs. There is an urgent need to find safe combinatorial strategies that enhance the response of ICIs for tumor treatment. Diets have an excellent safety profile and have been shown to play pleiotropic roles in tumor prevention, growth, invasion, and metastasis. Accumulating evidence suggests that dietary regimens bolster not only the tolerability but also the efficacy of tumor immunotherapy. In this review, we discussed the mechanisms by which tumor cells evade immune surveillance, focusing on describing the intrinsic and extrinsic mechanisms of resistance to ICIs. We also summarized the impacts of different diets and/or nutrients on the response to ICIs therapy. Combinatory treatments of ICIs therapy with optimized diet regimens own great potential to enhance the efficacy and durable response of ICIs against tumors, which should be routinely considered in clinical settings.

An evidence mapping and scientometric analysis of the top-100 most cited clinical trials of anti-PD-1/PD-L1 drugs to treat cancers

OBJECTIVE

To gain a deeper understanding of the hot topics and future prospects of programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) inhibitors treatment of cancer through scientometric analysis of the top-100 most cited clinical trials.

MATERIALS AND METHODS

We searched the Web of Science Core Collection database from 1980 to June 2019. Two reviewers independently screened the top-100 most cited clinical trials that defined by the National Institutes of Health starting from the most cited article. Title, year of publication, citations, type of cancer, and focused aspects of outcomes were extracted from included clinical trials. VOSviewer software (version 1.6.9) and Excel 2016 were used to do statistical analysis. The evidence mapping was used to present the relationship between cancers, drugs, citations, and outcomes, etc. RESULTS: The top-100 most cited clinical trials published from 2010 to 2018 in nine journals with high impact factor (IF) (IF₂₀₁₈:6.68-70.67), and Lancet Oncology (USA) published the most clinical trials (n = 29, IF₂₀₁₈ = 35.3856). The total number of citations of the top-100 most cited clinical trials was from 59 to 5606. 920 authors from 34 countries and 458 organizations participated in publishing the top-100 most cited clinical trials. The USA (n = 95) and Memorial Sloan-Kettering Cancer Center (n = 31) contributed the most publications. Based on the evidence mapping, there are 25 different types of cancers (e.g. lung cancer, melanoma, and renal cell cancer) and five focused aspects of outcomes (e.g. safety and efficacy).

CONCLUSION

The USA was the dominant country. Anti-PD-1/PD-L1 drugs were widely used to treat lung cancer, melanoma, renal cell cancer, and Hodgkin lymphoma. More exploration should be done to explore the use of anti-PD-1/PD-L1 drugs to treat more type of cancers in future research.

CARs and beyond: tailoring macrophage-based cell therapeutics to combat solid malignancies

Recent understanding of the role and contribution of immune cells in disease onset and progression has pioneered the field of immunotherapies. Use of genetic engineering to deliver, correct or enhance immune cells has been clinically successful, especially in the field of cancer immunotherapy. Indeed, one of the most attractive approaches is the introduction of chimeric antigen receptors (CARs) to immune cells, such as T cells. Recent studies revealed that adapting this platform for use in macrophages may widen the spectrum of CAR applications for better control of solid tumors and, thus, extend this treatment strategy to more patients with cancer. Given the novel insights into tumor-associated macrophages and new targeting strategies to boost anticancer therapy, this review aims to provide an overview of the current status of the role of macrophages in cancer therapy. The various genetic engineering approaches that can be used to optimize macrophages for use in oncology are discussed, with special attention dedicated to the implication of the CAR platform on macrophages for anticancer therapy. The current clinical status, challenges and future perspective of macrophage-based drugs are highlighted.

Therapeutic efficacy of dendritic cell vaccine combined with programmed death 1 inhibitor for hepatocellular carcinoma

BACKGROUND AND AIM

Hepatocellular carcinoma (HCC) remains a serious cause of cancer-related deaths worldwide. Developing new therapeutic strategies is urgently needed to improve the outcomes of HCC patients. Dendritic cell (DC)-based vaccines and programmed death 1 (PD-1) immune checkpoint inhibitors have been regarded as potential immunotherapeutics for HCC. However, the therapeutic efficacy of combining these two treatments for HCC remains to be evaluated.

METHODS

In this study, DCs were derived from mouse bone marrow and pulsed with mouse HCC cell lysates to generate a DC vaccine. A monoclonal antibody that blocks the interaction of mouse PD-1 with its ligands was used as a PD-1 inhibitor. An orthotopic HCC mouse model was established to assess the effect of a DC vaccine in combination with a PD-1 inhibitor on overall survival and tumor volume.

RESULTS

Compared with the untreated control, single treatment with a DC vaccine or PD-1 inhibitor prolonged the overall survival and reduced the tumor volume of HCC mice. Further, compared with the single treatment with the DC vaccine or the PD-1 inhibitor, a combination treatment using both agents elicited a higher cytotoxicity of T cells against HCC cells and resulted in a better overall survival, smaller tumor volume, and greater tumor cell apoptosis in HCC mice.

CONCLUSIONS

Our results suggest that a combination treatment with DC vaccine and PD-1 inhibitor may be a promising therapeutic strategy for HCC.

Distinct Biomarker Profiles and TCR Sequence Diversity Characterize the Response to PD-L1 Blockade in a Mouse Melanoma Model

Only a subset of patients responds to immune checkpoint blockade (ICB) in melanoma. A preclinical model recapitulating the clinical activity of ICB would provide a valuable platform for mechanistic studies. We used melanoma tumors arising from an Hgf^tg;Cdk4^R24C/R24C genetically engineered mouse (GEM) model to evaluate the efficacy of an anti-mouse PD-L1 antibody similar to the anti-human PD-L1 antibodies durvalumab and atezolizumab. Consistent with clinical observations for ICB in melanoma, anti-PD-L1 treatment elicited complete and durable response in a subset of melanoma-bearing mice. We also observed tumor growth delay or regression followed by recurrence. For early treatment assessment, we analyzed gene expression profiles, T-cell infiltration, and T-cell receptor (TCR) signatures in regressing tumors compared with tumors exhibiting no response to anti-PD-L1 treatment. We found that CD8⁺ T-cell tumor infiltration corresponded to response to treatment, and that anti-PD-L1 gene signature response indicated an increase in antigen processing and presentation, cytokine-cytokine receptor interaction, and natural killer cell-mediated cytotoxicity. TCR sequence data suggest that an anti-PD-L1-mediated melanoma regression response requires not only an expansion of the TCR repertoire that is unique to individual mice, but also tumor access to the appropriate TCRs. Thus, this melanoma model recapitulated the variable response to ICB observed in patients and exhibited biomarkers that differentiate between early response and resistance to treatment, providing a valuable platform for prediction of successful immunotherapy. IMPLICATIONS: Our melanoma model recapitulates the variable response to anti-PD-L1 observed in patients and exhibits biomarkers that characterize early antibody response, including expansion of the TCR repertoire.

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.

The emerging role of miRNA in the perturbation of tumor immune microenvironment in chemoresistance: Therapeutic implications

Chemoresistance is a major hindrance in cancer chemotherapies, a leading cause of tumor recurrence and cancer-related deaths. Cancer cells develop numerous strategies to elude immune attacks and are regulated by immunological factors. Cancer cells can alter the expression of several immune modulators to upregulate the activities of immune checkpoint pathways. Targeting the immune checkpoint inhibitors is a part of the cancer immunotherapy altered during carcinogenesis. These immune modulators have the capability to reprogram the tumor microenvironment, thereby change the efficacy of chemotherapeutics. In general, the sensitivity of drugs is reduced in the immunosuppressive tumor microenvironment, resulting in chemoresistance and tumor relapse. The regulation of microRNAs (miRNAs) is well established in cancer initiation, progression, and therapy. Intriguingly, miRNA affects cancer immune surveillance and immune response by targeting immune checkpoint inhibitors in the tumor microenvironment. miRNAs alter the gene expression at the post-transcriptional level, which modulates both innate and adaptive immune systems. Alteration of tumor immune microenvironment influences drug sensitivity towards cancer cells. Besides, the expression profile of immune-modulatory miRNAs can be used as a potential biomarker to predict the response and clinical outcomes in cancer immunotherapy and chemotherapy. Recent evidences have revealed that cancer-derived immune-modulatory miRNAs might be promising targets to counteract cancer immune escape, thereby increasing drug efficacy. In this review, we have compiled the role of miRNAs in overcoming the chemoresistance by modulating tumor microenvironment and discussed their preclinical and clinical implications.

Engineering Oxaliplatin Prodrug Nanoparticles for Second Near-Infrared Fluorescence Imaging-Guided Immunotherapy of Colorectal Cancer

Colorectal cancer (CRC) ranks as the third common and the fourth lethal cancer type worldwide. Immune checkpoint blockade therapy demonstrates great efficacy in a subset of metastatic CRC patients, but precise activation of the antitumor immune response at the tumor site is still challenging. Here a versatile prodrug nanoparticle for second near-infrared (NIR-II) fluorescence imaging-guided combinatory immunotherapy of CRC is reported. The prodrug nanoparticles are constructed with a polymeric oxaliplatin prodrug (PBOXA) and a donor-spacer-acceptor-spacer-donor type small molecular fluorophore TQTCD. The later displays large Stokes shift (>300 nm), fluorescence emission over 1000 nm, and excellent photothermal conversion performance for NIR-II fluorescence imaging-guided photothermal therapy (PTT). The prodrug nanoparticles show seven times higher intratumoral OXA accumulation than free oxaliplatin. TQTCD-based PTT and PBOXA-induced chemotherapy trigger immunogenic cell death of the tumor cells and elicit antitumor immune response in a spatiotemporally controllable manner. Further combination of the prodrug nanoparticle-based PTT/chemotherapy with programmed death ligand 1 blockade significantly promotes intratumoral infiltration of the cytotoxic T lymphocytes and eradicates the CRC tumors. The NIR-II fluorescence imaging-guided immunotherapy may provide a promising approach for CRC treatment.

A Novel Bispecific Antibody with PD-L1-assisted OX40 Activation for Cancer Treatment

Immunotherapy using OX40 agonist antibodies shows great preclinical efficacy in mouse tumor models. But in a clinical setting, OX40 agonist antibody alone or in combination with checkpoint blockade exhibits only modest efficacy due to lack of sufficient activation. We hypothesized that the limited antitumor activity in patients may due to insufficient clustering of OX40 antibody in the tumor. To test this hypothesis, we generated a tetravalent programmed death ligand-1 (PD-L1)/OX40 BsAb by fusing two PD-L1 VHH fragments to the C-terminus of a nonblocking agonistic anti-OX40 antibody. The resulting BsAb had intact function of each parental antibody, including efficiently blocking PD1/PD-L1 interaction and inducing OX40 activation. In addition, this BsAb showed significantly enhanced potency in activation of OX40-expressing T cells when PD-L1-expressing tumor cells or dendrite cells were present, through PD-L1-mediated cross-linking of OX40. Moreover, the BsAb exhibited superior antitumor activities over the parental monospecific antibodies alone or in combination in multiple in vivo tumor models. These results demonstrated a great potential for further clinical development of the potent immunostimulatory PD-L1/OX40 bispecific antibody.

Predictive Biomarkers of Response to Immunotherapy in Metastatic Renal Cell Cancer

Introduction

In the last decades, the therapeutic decision-making approach to metastatic renal cell cancer (mRCC) has dramatically changed thanks to the introduction in the treatment scenario of, first, anti-angiogenic agents and, afterward, immune-checkpoint inhibitors (ICIs). Immunotherapy is now the standard of care in pretreated mRCC patients and has recently entered even the first line setting. Nevertheless, in mRCC as well as in other tumor settings, a durable and clinically meaningful benefit from treatment with ICIs is not obtained for all patients treated. Therefore, the necessity to identify and validate predictive biomarkers of response to immunotherapy has emerged, in order to design the optimal treatment strategy for mRCC patients.

Discussion

In this review, we present and discuss the most promising predictive biomarkers of response to ICIs in mRCC with the recent data available. In details, the first marker that was investigated is the immunohistochemical expression of programmed death receptor ligand 1 (PD-L1), showing a negative prognostic role in mRCC, but the debate about its potential predictive value is still open. Additionally, the high heterogeneity in PD-L1 determination methods adds complexity to this issue. Second, the tumor mutational or neoantigen burden is an emerging biomarker of increased response to immunotherapy, hypothesizing that the higher the TMB, the higher is the production of neoantigens, and thus the stimulation of anti-tumor immune response, even though controversial results have been obtained. Third, the tumor microenvironment, namely the different populations of the immune infiltrate, plays a key role in tumor progression and in the response to immunotherapy. Finally, several studies have collected evidence on the potential association of the occurrence of immune-related adverse events (irAEs) with the benefit from ICIs, first in non-small cell lung cancer (NSCLC) and melanoma, and recently even in mRCC.

Conclusion

Several promising biomarkers of response to immunotherapy with ICIs have been identified, though without conclusive results upon their potential predictive value in mRCC. Therefore, the results of the exploratory analyses of the recently presented first-line trials and hopefully of future prospective, biomarker-driven studies could provide useful tools to be applied in the everyday clinical practice.

Monoclonal Antibodies in Cancer Therapy

Monoclonal antibody-based immunotherapy is now considered to be a main component of cancer therapy, alongside surgery, radiation, and chemotherapy. Monoclonal antibodies possess a diverse set of clinically relevant mechanisms of action. In addition, antibodies can directly target tumor cells while simultaneously promoting the induction of long-lasting anti-tumor immune responses. The multifaceted properties of antibodies as a therapeutic platform have led to the development of new cancer treatment strategies that will have major impacts on cancer care. This review focuses on the known mechanisms of action, current clinical applications for the treatment of cancer, and mechanisms of resistance of monoclonal antibody therapy. We further discuss how monoclonal antibody-based strategies have moved towards enhancing anti-tumor immune responses by targeting immune cells instead of tumor antigens as well as some of the current combination therapies.

Responses of metastatic primary fallopian tube carcinoma to pembrolizumab and nab-paclitaxel: A case report

RATIONALE

Primary fallopian tube carcinoma (PFTC) is an extremely rare but invasive malignancy with a dismal prognosis. Very few data exist on the salvage treatment for patients with PFTC. Here we report a case showing an impressive response to immunotherapy combined with chemotherapy, which have never been reported before on patients with metastatic PFTC.

PATIENT CONCERNS

A 42-year-old woman, who was diagnosed with PFTC in 2010, had been failed of multiple systemic therapies and antiangiogenic therapy because of the disease recurrence and progression.

DIAGNOSIS

Metastatic primary fallopian tube carcinoma.

INTERVENTIONS

The patient underwent surgery in May 2010 and had multi-line chemotherapies plus an anti-vascular endothelial growth factor (anti-VEGF) monoclonal antibody for about 9 years. Due to treatment failure the patient accepted the immunotherapy with the checkpoint inhibitor, pembrolizumab, combined with nab-paclitaxel from December 2018 to April 2019.

OUTCOMES

The patient showed a complete response after 6 cycles treatment. Thus far, the patient is taking pembrolizumab as maintenance and remains in good health.

LESSONS

Pembrolizumab combined with chemotherapy for treatment of PFTC may provide a positive antitumor effect in multiple metastatic lesions, but more clinical evidence is needed to confirm the efficacy and safety.

Macrocyclic Peptide-Mediated Blockade of the CD47-SIRPα Interaction as a Potential Cancer Immunotherapy

Medium-sized macrocyclic peptides are an alternative to small compounds and large biomolecules as a class of pharmaceutics. The CD47-SIRPα signaling axis functions as an innate immune checkpoint that inhibits phagocytosis in phagocytes and has been implicated as a promising target for cancer immunotherapy. The potential of macrocyclic peptides that target this signaling axis as immunotherapeutic agents has remained unknown, however. Here we have developed a macrocyclic peptide consisting of 15 amino acids that binds to the ectodomain of mouse SIRPα and efficiently blocks its interaction with CD47 in an allosteric manner. The peptide markedly promoted the phagocytosis of antibody-opsonized tumor cells by macrophages in vitro as well as enhanced the inhibitory effect of anti-CD20 or anti-gp75 antibodies on tumor formation or metastasis in vivo. Our results suggest that allosteric inhibition of the CD47-SIRPα interaction by macrocyclic peptides is a potential approach to cancer immunotherapy.

Combination therapy with dendritic cell vaccine and programmed death ligand 1 immune checkpoint inhibitor for hepatocellular carcinoma in an orthotopic mouse model

Background

Hepatocellular carcinoma (HCC) is among the most common and lethal human cancers worldwide. Despite remarkable advances in treatment, high mortality in HCC patients remains a big challenge. To develop novel therapeutic strategies for HCC is thus urgently needed to improve patient survival. Dendritic cells (DC)-based vaccines can induce tumor-specific immunity and have emerged as a promising approach for treating HCC patients; however, its effectiveness needs to be improved. Recently, blockade of programmed death ligand 1 (PD-L1) immune checkpoint pathway has been shown to enhance anti-tumor immune responses and exhibited great potential in HCC therapy.

Methods

In this study, we generated DC vaccine by pulsing the C57BL/6J mouse bone marrow-derived DC with mouse hepatoma Hep-55.1C cell lysate. We developed a therapeutic strategy combining DC vaccine and PD-L1 inhibitor for HCC and evaluated its efficacy in an orthotopic HCC mouse model in which Hep-55.1C cells were directly injected into left liver lobe of C57BL/6J mouse.

Results

Compared with a control group of mice, groups of mice treated with DC vaccine or PD-L1 inhibitor had significantly improved overall survival, reduced tumor volume, and increased tumor cell apoptosis. Remarkably, combination treatment with DC vaccine and PD-L1 inhibitor led to considerably longer overall survival, smaller tumor volume, and higher tumor cell apoptosis of mice than either treatment alone in a dose-dependent manner through inducing a stronger anti-tumor cytotoxic T cell response.

Conclusion

Our data suggested that combination therapy with DC vaccine and PD-L1 inhibitor might have great promise as a novel treatment strategy for HCC.

Radiofrequency combined with immunomodulation for hepatocellular carcinoma: State of the art and innovations

Hepatocellular carcinoma (HCC) is the most common primary liver tumor and has been considered a very immunogenic tumor. The treatment with radiofrequency ablation (RFA) has been established as the standard ablative therapy for early HCC, and is currently recognized as the main ablative tool for HCC tumors < 5 cm in size; however, progression and local recurrence remain the main disadvantages of this approach. To solve this clinical problem, recent efforts were concentrated on multimodal treatment, combining different strategies, including the combination of RFA and immunotherapy. This article reviewed the combination treatment of RFA with immunotherapy and found that this treatment strategy leads to an increased response of anti-tumor T cells, significantly reduces the risk of recurrence and improves survival rates compared to RFA alone. This review highlighted scientific evidence that supports the current recommendations for pre-clinical studies, and discuss the need for further research on this topic.

Value assessment of immuno-oncology in the treatment of rare tumors in the era of accelerated conditional approvals

Aim: To conduct a value assessment of an immuno-oncology (IO) therapy for a rare cancer and evaluate whether existing frameworks consider challenges associated with valuing IOs for rare cancers. Materials & methods: Value frameworks developed by American Society of Clinical Oncologists, Memorial Sloan Kettering Cancer Center and National Comprehensive Cancer Network were used to estimate the value of an IO therapy in a rare cancer based on single-arm trial data and retrospective studies. Results: Paucity of direct evidence comparing rare cancer treatments and lack of acceptance of indirect comparisons hinder appropriate value assessment. Measurement of value based on short-term outcomes may not capture the value of IOs, where survival is often characterized by a plateau. Conclusion: Further work is required to factor in nuances associated with rare cancers and guide end users of the frameworks. To capture true value, multiple or more holistic value assessments are required.

MHC class-I downregulation in PD-1/PD-L1 inhibitor refractory Merkel cell carcinoma and its potential reversal by histone deacetylase inhibition: a case series

BACKGROUND

Merkel cell carcinoma (MCC) is an aggressive skin cancer in which PD-1/PD-L1 blockade has shown remarkable response rates. However, a significant proportion of patients shows primary or secondary resistance against PD-1/PD-L1 inhibition, with HLA class-I downregulation and insufficient influx of CD8+ T cells into the tumor as possible immune escape mechanisms. Histone deacetylase inhibitors (HDACi) have been demonstrated to reverse low HLA class-I expression caused by epigenetic downregulation of the antigen machinery (APM) in vitro and in pre-clinical models in vivo.

CASE PRESENTATIONS

We report four cases of patients with metastatic MCC who did not respond to immunotherapy by PD-1/PD-L1 blockade. Two of the patients received, subsequently, the HDACi panobinostat in combination with PD-1/PD-L1 blockade. Tumor biopsies of the patients were analyzed for cellular and molecular markers of antigen processing and presentation as well as the degree of T-cell infiltration.

RESULTS AND CONCLUSION

Low expression of APM-related genes associated with low HLA class-I surface expression was observed in all MCC patients, progressing on PD-1/PD-L1 blockade. In one evaluable patient, of the two treated with the combination therapy of the HDACi, panobinostat and PD-1/PD-L1 blockade, reintroduction of HLA class-I-related genes, enhanced HLA class-I surface expression, and elevated CD8+ T-cell infiltration into the MCC tumor tissue were observed; however, these changes did not translate into a clinical benefit. Our findings suggest that HDACi may be useful to overcome HLA class-I downregulation as a resistance mechanism against anti-PD-1/PD-L1 antibodies in MCC patients. Prospective clinical trials are needed to evaluate this notion.

Real-world efficacy and safety of nivolumab in previously-treated metastatic renal cell carcinoma, and association between immune-related adverse events and survival: the Italian expanded access program

Background

The Italian Renal Cell Cancer Early Access Program was an expanded access program that allowed access to nivolumab, for patients (pts) with metastatic renal cell carcinoma (mRCC) prior to regulatory approval.

Methods

Pts with previously treated advanced or mRCC were eligible to receive nivolumab 3 mg/kg every 2 weeks. Pts included in the analysis had received ≥1 dose of nivolumab and were monitored for drug-related adverse events (drAEs) using CTCAE v.4.0. Immune-related (ir) AEs were defined as AEs displaying a certain, likely or possible correlation with immunotherapy (cutaneous, endocrine, hepatic, gastro-intestinal and pulmonary). The association between overall survival (OS) and irAEs was assessed, and associations between variables were evaluated with a logistic regression model.

Results

A total of 389 pts were enrolled between July 2015 and April 2016. Overall, the objective response rate was 23.1%. At a median follow-up of 12 months, the median progression-free survival was 4.5 months (95% CI 3.7–6.2) and the 12-month overall survival rate was 63%. Any grade and grade 3–4 drAEs were reported in 124 (32%) and 27 (7%) of pts, respectively, and there were no treatment-related deaths. Any grade irAEs occurred in 76 (20%) of patients, 8% cutaneous, 4% endocrine, 2% hepatic, 5% gastro-intestinal and 1% pulmonary. Of the 22 drAEs inducing treatment discontinuation, 10 (45%) were irAEs. Pts with drAEs had a significantly longer survival than those without drAEs (median OS 22.5 versus 16.4 months, p = 0.01). Pts with irAEs versus without irAEs had a more significant survival benefit (median OS not reached versus 16.8 months, p = 0.002), confirmed at the landmark analysis at 6 weeks. The occurrence of irAEs displayed a strong association with OS in univariable (HR 0.48, p = 0.003) and multivariable (HR 0.57, p = 0.02) analysis.

Conclusions

The appearance of irAEs strongly correlates with survival benefit in a real-life population of mRCC pts treated with nivolumab.

Electronic supplementary material

The online version of this article (10.1186/s40425-019-0579-z) contains supplementary material, which is available to authorized users.

Immunotherapy Associated Pulmonary Toxicity: Biology Behind Clinical and Radiological Features

The broader use of immune checkpoint blockade in clinical routine challenges clinicians in the diagnosis and management of side effects which are caused by inflammation generated by the activation of the immune response. Nearly all organs can be affected by immune-related toxicities. However, the most frequently reported are: fatigue, rash, pruritus, diarrhea, nausea/vomiting, arthralgia, decreased appetite and abdominal pain. Although these adverse events are usually mild, reversible and not frequent, an early diagnosis is crucial. Immune-related pulmonary toxicity was most frequently observed in trials of lung cancer and of melanoma patients treated with the combination of the anti-cytotoxic T lymphocyte antigen (CTLA)-4 and the anti-programmed cell death-1 (PD-1) antibodies. The most frequent immune-related adverse event in the lung is represented by pneumonitis due to the development of infiltrates in the interstitium and in the alveoli. Clinical symptoms and radiological patterns are the key elements to be considered for an early diagnosis, rendering the differential diagnosis crucial. Diagnosis of immune-related pneumonitis may imply the temporary or definitive suspension of immunotherapy, along with the start of immuno-suppressive treatments. The aim of this work is to summarize the biological bases, clinical and radiological findings of lung toxicity under immune checkpoint blockade, underlining the importance of multidisciplinary teams for an optimal early diagnosis of this side effect, with the aim to reach an improved patient care.

The Risks and Benefits of Immune Checkpoint Blockade in Anti-AChR Antibody-Seropositive Non-Small Cell Lung Cancer Patients

Background: Anti-programmed cell death 1 (PD-1) monoclonal antibodies (Abs) unleash an immune response to cancer. However, a disruption of the immune checkpoint function by blocking PD-1/PD-ligand 1(PD-L1) signaling may trigger myasthenia gravis (MG) as a life-threatening immune-related adverse event. MG is a neuromuscular disease and is closely associated with being positive for anti-acetylcholine receptor (anti-AChR) Abs, which are high specific and diagnostic Abs for MG. Methods: A 72-year-old man was diagnosed with chemotherapy-refractory lung squamous cell carcinoma and nivolumab was selected as the third-line regimen. We describe the first report of an anti-AChR Ab-seropositive lung cancer patient achieving a durable complete response (CR) to an anti-PD-1 antibody therapy. To further explore this case, we performed multiplex immunofluorescence analysis on a pretreatment tumor. Results: The patient achieved a durable CR without developing MG. However, the levels of anti-AChR Abs were elevated during two years of anti-PD-1 antibody therapy. The tumor of the subclinical MG patient had high PD-L1 expression and an infiltrated–inflamed tumor immune microenvironment. Conclusions: This study suggests that immune checkpoint inhibitors can be safely used and provide the benefits for advanced cancer patients with immunologically ‘hot’ tumor even if anti-AChR Abs are positive. Although careful monitoring clinical manifestation in consultation with neurologist is needed, immune checkpoint inhibitors should be considered as a treatment option for asymptomatic anti-AChR Ab-seropositive cancer patients.

Tackling molecular targets beyond PD-1/PD-L1: Novel approaches to boost patients' response to cancer immunotherapy

In the new era of immunotherapy, which has changed the clinical oncology practice guidelines, there is a pressing need for finding novel approaches to tune up the clinical outcomes of immunotherapy and extend its benefits to a wider cohort of cancer patients. Several non-classical molecular immune targets beyond PD-1/PD-L1 signaling were shown to be engaged as feedback resistance circuits to shut down the antitumor immune response mediated by the classical immune checkpoint inhibitors. Those include T-cell inducible co-stimulator (ICOS), CD40, CD47, V-domain Ig suppressor of T-cell activation (VISTA), cyclin-dependent kinase (CDK)12, enhancer of Zeste homolog 2 (EZH2), toll-like receptors (TLRs) and OX-40 (CD134). Herein we critically discussed the latest studies concerned with understanding the mechanisms involved in the negative clinical response to classical immunotherapies and strategies to optimize the efficacy of cancer immunotherapy through novel combinatorial approaches.

Targeting Multiple Receptors to Increase Checkpoint Blockade Efficacy

Immune checkpoint blockade therapy is a powerful treatment strategy for many cancer types. Many patients will have limited responses to monotherapy targeted to a single immune checkpoint. Both inhibitory and stimulatory immune checkpoints continue to be discovered. Additionally, many receptors previously identified to play a role in tumor formation and progression are being found to have immunomodulatory components. The success of immunotherapy depends on maximizing pro-anti-tumor immunity while minimizing immunosuppressive signaling. Combining immune checkpoint targeted approaches with each other or with other receptor targets is a promising schema for future therapeutic regimen designs.

A comprehensive review on the role of co-signaling receptors and Treg homeostasis in autoimmunity and tumor immunity

The immune system ensures optimum T-effector (Teff) immune responses against invading microbes and tumor antigens while preventing inappropriate autoimmune responses against self-antigens with the help of T-regulatory (Treg) cells. Thus, Treg and Teff cells help maintain immune homeostasis through mutual regulation. While Tregs can contribute to tumor immune evasion by suppressing anti-tumor Teff response, loss of Treg function can result in Teff responses against self-antigens leading to autoimmune disease. Thus, loss of homeostatic balance between Teff/Treg cells is often associated with both cancer and autoimmunity. Co-stimulatory and co-inhibitory receptors, collectively known as co-signaling receptors, play an indispensable role in the regulation of Teff and Treg cell expansion and function and thus play critical roles in modulating autoimmune and anti-tumor immune responses. Over the past three decades, considerable efforts have been made to understand the biology of co-signaling receptors and their role in immune homeostasis. Mutations in co-inhibitory receptors such as CTLA4 and PD1 are associated with Treg dysfunction, and autoimmune diseases in mice and humans. On the other hand, growing tumors evade immune surveillance by exploiting co-inhibitory signaling through expression of CTLA4, PD1 and PDL-1. Immune checkpoint blockade (ICB) using anti-CTLA4 and anti-PD1 has drawn considerable attention towards co-signaling receptors in tumor immunology and created renewed interest in studying other co-signaling receptors, which until recently have not been as well studied. In addition to co-inhibitory receptors, co-stimulatory receptors like OX40, GITR and 4-1BB have also been widely implicated in immune homeostasis and T-cell stimulation, and use of agonistic antibodies against OX40, GITR and 4-1BB has been effective in causing tumor regression. Although ICB has seen unprecedented success in cancer treatment, autoimmune adverse events arising from ICB due to loss of Treg homeostasis poses a major obstacle. Herein, we comprehensively review the role of various co-stimulatory and co-inhibitory receptors in Treg biology and immune homeostasis, autoimmunity, and anti-tumor immunity. Furthermore, we discuss the autoimmune adverse events arising upon targeting these co-signaling receptors to augment anti-tumor immune responses.

Immunotherapy of alveolar echinococcosis via PD-1/PD-L1 immune checkpoint blockade in mice

The growth potential of the tumour‐like Echinococcus multilocularis metacestode (causing alveolar echinococcosis, AE) is directly dependent upon the nature/function of the periparasitic adaptive host immune‐mediated processes. PD‐1/PD‐L1 pathway (programmed cell death 1), which inhibits lymphocytic proliferation in tumour development, is over‐expressed at the chronic stage of AE. We tested the impact of a PD‐1/PD‐L1 pathway blockade on the outcome of both chronic AE (intraperitoneal metacestode inoculation, secondary AE and SAE) and acute AE (peroral egg infection, primary AE and PAE). To assess the parasite proliferation potential, we measured parasite mass weight for SAE and liver lesion number for PAE. In both models, the parasite load was significantly decreased in response to anti‐PD‐L1 antibody treatment. In SAE, anti‐PDL1 administration was associated with increased Th1 response parameters and decreased Treg responses, while in PAE anti‐PDL1 administration was associated with fewer lesions in the liver and decreased Treg/Th2 responses. Our findings highly suggested that a PD‐1/PD‐L1 pathway blockade triggered the host immune responses in favour of an immune‐mediated control of E. multilocularis proliferation. Based on this, future studies that combine PD‐1/PD‐L1 blockade with a parasitostatic albendazole medication may yield in a putatively curative therapeutic approach to control alveolar echinococcosis.

The roles of PD-1/PD-L1 and its signalling pathway in gastrointestinal tract cancers

Cancer immunotherapy has been increasingly applied in the treatment of advanced malignancies. Consequently, immune checkpoints have become a major concern. As PD-1 is an important immunomodulatory protein, the blockade of PD-1 and its ligand PD-L1 is a promising tumour immunotherapy for human carcinoma. In this review, we first discuss the role of the PD-1/PD-L1 interaction in gastrointestinal tract cancers. Targeting PD-1 and PD-L1 in immune cells and tumour cells may show remarkable efficiency in gastrointestinal tract cancers. Second, the PD-1/PD-L1-associated signalling pathway involved in cancer immunotherapy in gastrointestinal tract cancers is discussed. Most importantly, this review summarizes the PD-1/PD-L1-targeted immunotherapy combinations with relevant signalling pathways, which may result in a breakthrough for the treatment of gastrointestinal tract cancers, such as gastric cancer, colorectal cancer and liver cancer. Meanwhile, the review provides a deeper insight into the mechanism of checkpoint blockade immunotherapies.

PD1-CD28 Fusion Protein Enables CD4+ T Cell Help for Adoptive T Cell Therapy in Models of Pancreatic Cancer and Non-hodgkin Lymphoma

Background: Interaction of the programmed death receptor 1 (PD-1) and its ligand, PD-L1, suppresses T cell activity and permits tumors to evade T cell-mediated immune surveillance. We have recently demonstrated that antigen-specific CD8+ T cells transduced with a PD1-CD28 fusion protein are protected from PD-1-mediated inhibition. We have now investigated the potential of PD1-CD28 fusion protein-transduced CD4+ T cells alone or in combination with CD8+ T cells for immunotherapy of pancreatic cancer and non-Hodgkin lymphoma.

Methods: OVA-specific CD4+ and CD8+ were retrovirally transduced with the PD1-CD28 fusion protein. Cytokine release, proliferation, cytotoxic activity, and phenotype of transduced T cells were assessed in the context of Panc02-OVA (murine pancreatic cancer model) and E.G7-PD-L1 (murine T cell lymphoma model) cells.

Results: Stimulation of PD1-CD28 fusion protein-transduced CD4+ T cells with anti-CD3 and recombinant PD-L1 induced specific T cell activation, as measured by IFN-y release and T cell proliferation. Coculture with Panc02-OVA or E.G7-PD-L1 tumor cells also led to specific activation of CD4+ T cells. Cytokine release and T cell proliferation was most effective when tumor cells simultaneously encountered genetically engineered CD4+ and CD8+ T cells. Synergy between both cell populations was also observed for specific tumor cell lysis. T cell cytotoxicity was mediated via granzyme B release and mediated enhanced tumor control in vivo. Transduced CD4+ and CD8+ T cells in co-culture with tumor cells developed a predominant central memory phenotype over time. Different ratios of CD4+ and CD8+ transduced T cells led to a significant increase of IFN-y and IL-2 secretion positively correlating with CD4+ T cell numbers used. Mechanistically, IL-2 and MHC-I were central to the synergistic activity of CD4+ and CD8+ T cells, since neutralization of IL-2 prevented the crosstalk between these cell populations.

Conclusion: PD1-CD28 fusion protein-transduced CD4+ T cells significantly improved anti-tumoral effect of fusion protein-transduced CD8+ T cells. Thus, our results indicate that PD1-CD28 fusion protein-transduced CD4+ T cells have the potential to overcome the PD-1-PD-L1 immunosuppressive axis in pancreatic cancer and non-Hodgkin lymphoma.

Is high serum programmed death ligand 1 level a risk factor for poor survival in patients with gastric cancer?

BACKGROUND AND AIM

Although the clinicopathological significance of the expression of programmed death ligand 1(PD-L1) in various cancer tissues has been reported, serum PD-L1 level has not been evaluated in patients with surgically treated gastric cancer. Therefore, we evaluated the clinicopathological characteristics and prognostic significance of preoperative serum PD-L1 levels in patients with gastric cancer.

PATIENTS AND METHODS

Serum samples were obtained before surgery from 152 patients with gastric cancer, including 75 patients with stage I, 31 with stage II, 23 with stage III, and 23 with stage IV gastric cancer. The samples were analyzed using enzyme-linked immunosorbent assay to detect soluble PD-L1. Using the median serum PD-L1 level of 50 pg/mL, patients were divided into two groups, namely high serum and low serum PD-L1 level groups. Clinicopathological characteristics and prognosis were compared between these two groups using univariate and multivariate analysis.

RESULTS

Serum PD-L1 level was significantly associated with older age, positive cancer antigen 19-9 (CA19-9), C-reactive protein levels, and albumin levels but not with tumor stage. Patients in the high serum PD-L1 group showed significantly worse overall survival and recurrence-free survival than those in the low serum PD-L1 group (P < .05). Multivariate analysis showed that high serum PD-L1 level was an independent risk factor for poor overall survival (P = .02).

CONCLUSION

High serum PD-L1 level was a prognostic factor for reduced overall survival in patients with surgically treated gastric cancer.