Interleukin-10 expressed at early tumour sites induces subsequent generation of CD4(+) T-regulatory cells and systemic collapse of antitumour immunity

Prognostic value of Maspin protein level in patients with triple negative breast cancer

The search for prognostic markers in breast cancer has bumped into a typical feature of these tumors, intra and intertumoral heterogeneity. Changes in the expression profile, localization of these proteins or shedding to the surrounding stroma can be useful in the search for new markers. In this context, classification by molecular subtypes can bring perspectives for both diagnosis and screening for appropriate treatments. However, the Triple Negative (TN) subtype, which is already the one with the worst prognosis, lacks appropriate and consistent molecular markers. In this work, we analyzed 346 human breast cancer samples in tissue microarrays (TMA) from cases diagnosed with invasive breast carcinoma to assess the expression and localization pattern of Maspin and their correlation with clinical parameters. To complement our findings, we also used TCGA data to analyze the mRNA levels of these respective genes. Our data suggests that the TN subtype demonstrates a higher level of cytoplasmic Maspin compared to the other subtypes. Maspin transcript levels follow the same trend. However, TN patients with lower Maspin expression tend to have worse overall survival and free-survival metastasis rates. Finally, we used Maspin expression data to verify possible relationships with the clinicopathological information of our cohort. Our univariate analyses indicate that Maspin is related to the expression of estrogen receptor (ER) and progesterone receptor (PR). Furthermore, Maspin expression levels also showed correlation with Scarff-Bloom-Richardson (SBR) parameter, and stromal Maspin showed a relationship with lymph node involvement. Our data is not consistently robust enough to categorize Maspin as a prognostic marker. However, it does indicate a change in the expression profile within the TN subtype.

Liquid biopsy approach to monitor the efficacy and response to CAR-T cell therapy

BACKGROUND

Chimeric antigen receptor (CAR)-T cells are approved for use in the treatment of hematological malignancies. Axicabtagene ciloleucel (YESCARTA) and brexucabtagene autoleucel (TECARTUS) genetically modified autologous T cells expressing an anti-CD19 scFv based on the FMC63 clone have shown impressive response rates for the treatment of CD19+B cell malignancies, but there remain challenges in monitoring long-term persistence as well as the functional characterization of low-level persisting CAR-T cells in patients. Furthermore, due to CD19-negative driven relapse, having the capability to monitor patients with simultaneous detection of the B cell malignancy and persisting CAR-T cells in patient peripheral blood is important for ensuring timely treatment optionality and understanding relapse.

METHODS

This study demonstrates the development and technical validation of a comprehensive liquid biopsy, high-definition single cell assay (HDSCA)-HemeCAR for (1) KTE-X19 CAR-T cell identification and analysis and (2) simultaneously monitoring the CD19-epitope landscape on neoplastic B cells in cryopreserved or fresh peripheral blood. Proprietary anti-CD19 CAR reagents, healthy donor transduced CAR-T cells, and patient samples consisting of malignant B cell fractions from manufacturing were used for assay development.

RESULTS

The CAR-T assay showed an approximate limit of detection at 1 cell in 3 million with a sensitivity of 91%. Genomic analysis was additionally used to confirm the presence of the CAR transgene. This study additionally reports the successful completion of two B cell assays with multiple CD19 variants (FMC63 and LE-CD19) and a unique fourth channel biomarker (CD20 or CD22). In patient samples, we observed that CD19 isoforms were highly heterogeneous both intrapatient and interpatient.

CONCLUSIONS

With the simultaneous detection of the CAR-T cells and the B cell malignancy in patient peripheral blood, the HDSCA-HemeCAR workflow may be considered for risk monitoring and patient management.

The Role of CD4 T Cell Help in CD8 T Cell Differentiation and Function During Chronic Infection and Cancer

CD4 and CD8 T cells are key players in the immune response against both pathogenic infections and cancer. CD4 T cells provide help to CD8 T cells via multiple mechanisms, including licensing dendritic cells (DCs), co-stimulation, and cytokine production. During acute infection and vaccination, CD4 T cell help is important for the development of CD8 T cell memory. However, during chronic viral infection and cancer, CD4 helper T cells are critical for the sustained effector CD8 T cell response, through a variety of mechanisms. In this review, we focus on T cell responses in conditions of chronic Ag stimulation, such as chronic viral infection and cancer. In particular, we address the significant role of CD4 T cell help in promoting effector CD8 T cell responses, emerging techniques that can be utilized to further our understanding of how these interactions may take place in the context of tertiary lymphoid structures, and how this key information can be harnessed for therapeutic utility against cancer.

Hypoxia drives CD39-dependent suppressor function in exhausted T cells to limit antitumor immunity

CD8+ T cells are critical for elimination of cancer cells. Factors within the tumor microenvironment (TME) can drive these cells to a hypofunctional state known as exhaustion. The most terminally exhausted T (tTex) cells are resistant to checkpoint blockade immunotherapy and might instead limit immunotherapeutic efficacy. Here we show that intratumoral CD8+ tTex cells possess transcriptional features of CD4+Foxp3+ regulatory T cells and are similarly capable of directly suppressing T cell proliferation ex vivo. tTex cell suppression requires CD39, which generates immunosuppressive adenosine. Restricted deletion of CD39 in endogenous CD8+ T cells resulted in slowed tumor progression, improved immunotherapy responsiveness and enhanced infiltration of transferred tumor-specific T cells. CD39 is induced on tTex cells by tumor hypoxia, thus mitigation of hypoxia limits tTex suppression. Together, these data suggest tTex cells are an important regulatory population in cancer and strategies to limit their generation, reprogram their immunosuppressive state or remove them from the TME might potentiate immunotherapy.

Characteristics of tumor microenvironment and novel immunotherapeutic strategies for non-small cell lung cancer

Immune checkpoint inhibitor-based immunotherapy has revolutionized the treatment approach of non-small cell lung cancer (NSCLC). Monoclonal antibodies against programmed cell death-1 (PD-1) and PD-ligand 1 (PD-L1) are widely used in clinical practice, but other antibodies that can circumvent innate and acquired resistance are bound to undergo preclinical and clinical studies. However, tumor cells can develop and facilitate the tolerogenic nature of the tumor microenvironment (TME), resulting in tumor progression. Therefore, the immune escape mechanisms exploited by growing lung cancer involve a fine interplay between all actors in the TME. A better understanding of the molecular biology of lung cancer and the cellular/molecular mechanisms involved in the crosstalk between lung cancer cells and immune cells in the TME could identify novel therapeutic weapons in the old war against lung cancer. This article discusses the role of TME in the progression of lung cancer and pinpoints possible advances and challenges of immunotherapy for NSCLC.

IL-10 in cancer: an essential thermostatic regulator between homeostatic immunity and inflammation - a comprehensive review

Cytokines are soluble proteins that mediate intercellular signaling regulating immune and inflammatory responses. Cytokine modulation represents a promising cancer immunotherapy approach for immune-mediated tumor regression. However, redundancy in cytokine signaling and cytokines' pleiotropy, narrow therapeutic window, systemic toxicity, short half-life and limited efficacy represent outstanding challenges for cytokine-based cancer immunotherapies. Recently, there has been interest in the paradoxical role of IL-10 in cancer, its controversial prognostic utility and novel strategies to enhance its therapeutic profile. Here, the authors review the literature surrounding the role of IL-10 within the tumor microenvironment, its prognostic correlates to cancer patient outcomes and its pro- and antitumor effects, and they assess the legitimacy of potential therapeutic strategies harnessing IL-10 by outlining the notable preclinical and clinical evidence to date.

Targeting glycans for CAR therapy: The advent of sweet CARs

Chimeric antigen receptor (CAR) T cell therapy has created a paradigm shift in the treatment of hematologic malignancies but has not been as effective toward solid tumors. For such tumors, the primary obstacles facing CAR T cells are scarcity of tumor-specific antigens and the hostile and complex tumor microenvironment. Glycosylation, the process by which sugars are post-translationally added to proteins or lipids, is profoundly dysregulated in cancer. Abnormally glycosylated glycoproteins expressed on cancer cells offer unique targets for CAR T therapy as they are specific to tumor cells. Tumor stromal cells also express abnormal glycoproteins and thus also have the potential to be targeted by glycan-binding CAR T cells. This review will discuss the state of CAR T cells in the therapy of solid tumors, the cancer glycoproteome and its potential for use as a therapeutic target, and the landscape and future of glycan-binding CAR T cell therapy.

Effects of prolonged treatment of TGF-βR inhibitor SB431542 on radiation-induced signaling in breast cancer cells

PURPOSE

We have earlier characterized increased TGF-β signaling in radioresistant breast cancer cells. In this study, we wanted to determine the effect of prolonged treatment of TGF-βR inhibitor SB431542 on radiation-induced signaling, viz., genes regulating apoptosis, EMT, anti and pro-inflammatory cytokines.

MATERIALS AND METHODS

Breast cancer cells were pretreated with TGF-βR inhibitor (SB 431542) followed by exposure to 6 Gy and recovery period of 7 days (D7-6G). We assessed cell survival by MTT assay, cytokines by ELISA and expression analysis by RT-PCR, flow cytometry, and western blot. We carried out migration assays using trans well inserts. We performed bioinformatics analyses of human cancer database through cBioportal.

RESULTS

There was an upregulation of TGF-β1 and 3 and downregulation of TGF-β2, TGF-βR1, and TGF-βR2 in invasive breast carcinoma samples compared to normal tissue. TGF-β1 and TNF-α was higher in radioresistant D7-6G cells with upregulation of pSMAD3, pNF-kB, and ERK signaling. Pretreatment of D7-6G cells with TGF-βR inhibitor SB431542 abrogated pSMAD3, increased proliferation, and migration along with an increase in apoptosis and pro-apoptotic genes. This was associated with hybrid E/M phenotype and downregulation of TGF-β downstream genes, HMGA2 and Snail. There was complete agreement in the expression of mRNA and protein data in genes like vimentin, Snail and HMGA2 in different treatment groups. However, there was disagreement in expression of mRNA and protein in genes like Bax, Bcl-2, E-cadherin, Zeb-1 among the different treatment groups indicating post-transcriptional and post-translational processing of these proteins. Treatment of cells with only SB431542 also increased expression of some E/M genes indicating TGF-β independent effects. Increased IL-6 and IL-10 secretion by SB431542 along with increase in pSTAT3 and pCREB1 could probably explain these TGF-β/Smad3 independent effects.

CONCLUSION

These results highlight that TGF-β-pSMAD3 and TNF-α-pNF-kB are the predominant signaling pathways in radioresistant cells and possibility of some TGF-β/Smad3 independent effects on prolonged treatment with the drug SB431542.

Perspectives for Combining Viral Oncolysis With Additional Immunotherapies for the Treatment of Melanoma

Melanoma is the deadliest type of skin cancer with steadily increasing incidence worldwide during the last few decades. In addition to its tumor associated antigens (TAAs), melanoma has a high mutation rate compared to other tumors, which promotes the appearance of tumor specific antigens (TSAs) as well as increased lymphocytic infiltration, inviting the use of therapeutic tools that evoke new or restore pre-existing immune responses. Innovative therapeutic proposals, such as immune checkpoint inhibitors (ICIs), have emerged as effective options for melanoma. However, a significant portion of these patients relapse and become refractory to treatment. Likewise, strategies using viral vectors, replicative or not, have garnered confidence and approval by different regulatory agencies around the world. It is possible that further success of immune therapies against melanoma will come from synergistic combinations of different approaches. In this review we outline molecular features inherent to melanoma and how this supports the use of viral oncolysis and immunotherapies when used as monotherapies or in combination.

Monitoring Immune Cell Function Through Optical Imaging: a Review Highlighting Transgenic Mouse Models

Transgenic mouse models have facilitated research of human diseases and validation of therapeutic approaches. Inclusion of optical reporter genes (fluorescent or bioluminescent genes) in the targeting vectors used to develop such models makes in vivo imaging of cellular and molecular events possible, from the microscale to the macroscale. In particular, transgenic mouse models expressing optical reporter genes allowed accurately distinguishing immune cell types from trafficking in vivo using intravital microscopy or whole-body optical imaging. Besides lineage tracing and trafficking of different subsets of immune cells, the ability to monitor the function of immune cells is of pivotal importance for investigating the effects of immunotherapies against cancer. Here, we introduce the reader to state-of-the-art approaches to develop transgenics, optical imaging techniques, and several notable examples of transgenic mouse models developed for immunology research by critically highlighting the models that allow the following of immune cell function.

Clinical Application of Cytokines in Cancer Immunotherapy

Cytokines are key components of the immune system and play pivotal roles in anticancer immune response. Cytokines as either therapeutic agents or targets hold clinical promise for cancer precise treatment. Here, we provide an overview of the various roles of cytokines in the cancer immunity cycle, with a particular focus on the clinical researches of cytokine-based drugs in cancer therapy. We review 27 cytokines in 2630 cancer clinical trials registered with ClinicalTrials.gov that had completed recruitment up to January 2021 while summarizing important cases for each cytokine. We also discuss recent progress in methods for improving the delivery efficiency, stability, biocompatibility, and availability of cytokines in therapeutic applications.

Harnessing the IL-21-BATF Pathway in the CD8+ T Cell Anti-Tumor Response

Simple Summary

In cancer, CD8⁺ T cells enter a state of dysfunction within the tumor that prevents them from targeting and killing tumor cells. Our study aims to uncover how CD8⁺ T cells can be helped by CD4⁺ T cells or modified in order to improve their effector function against cancer. Thus, allowing them to better fight and control tumors. Our work shows that the protein Basic Leucine Zipper ATF-Like Transcription Factor (BATF) may be a key regulator of CD8⁺ T cells and their anti-tumor function. These findings can provide further insight for the development of novel therapeutic treatments for cancer patients.

Abstract

In cancer, CD8⁺ T cells enter a dysfunctional state which prevents them from effectively targeting and killing tumor cells. Tumor-infiltrating CD8⁺ T cells consist of a heterogeneous population of memory-like progenitor, effector, and terminally exhausted cells that exhibit differing functional and self-renewal capacities. Our recently published work has shown that interleukin (IL)-21-producing CD4⁺ T cells help to generate effector CD8⁺ T cells within the tumor, which results in enhanced tumor control. However, the molecular mechanisms by which CD4⁺ helper T cells regulate the differentiation of effector CD8⁺ T cells are not well understood. In this study, we found that Basic Leucine Zipper ATF-Like Transcription Factor (BATF), a transcription factor downstream of IL-21 signaling, is critical to maintain CD8⁺ T cell effector function within the tumor. Using mixed bone marrow chimeras, we demonstrated that CD8⁺ T cell-specific deletion of BATF resulted in impaired tumor control. In contrast, overexpressing BATF in CD8⁺ T cells enhanced effector function and resulted in improved tumor control, bypassing the need for CD4⁺ helper T cells. Transcriptomic analyses revealed that BATF-overexpressing CD8⁺ T cells had increased expression of costimulatory receptors, effector molecules, and transcriptional regulators, which may contribute to their enhanced activation and effector function. Taken together, our study unravels a previously unappreciated CD4⁺ T cell-derived IL-21–BATF axis that could provide therapeutic insights to enhance effector CD8⁺ T cell function to fight cancer.

Metabolic reprogramming of T regulatory cells in the hypoxic tumor microenvironment

Metabolic dysregulation in the hypoxic tumor microenvironment (TME) is considered as a hallmark of solid tumors, leading to changes in biosynthetic pathways favoring onset, survival and proliferation of malignant cells. Within the TME, hypoxic milieu favors metabolic reprogramming of tumor cells, which subsequently affects biological properties of tumor-infiltrating immune cells. T regulatory cells (Tregs), including both circulating and tissue-resident cells, are particularly susceptible to hypoxic metabolic signaling that can reprogram their biological and physicochemical properties. Furthermore, metabolic reprogramming modifies Tregs to utilize alternative substrates and undergo a plethora of metabolic events to meet their energy demands. Major impact of this metabolic reprogramming can result in differentiation, survival, excessive secretion of immunosuppressive cytokines and proliferation of Tregs within the TME, which in turn dampen anti-tumor immune responses. Studies on fine-tuning of Treg metabolism are challenging due to heterogenicity of tissue-resident Tregs and their dynamic functions. In this review, we highlight tumor intrinsic and extrinsic factors, which can influence Treg metabolism in the hypoxic TME. Moreover, we focus on metabolic reprogramming of Tregs that could unveil potential regulatory networks favoring tumorigenesis/progression, and provide novel insights, including inhibitors against acetyl-coA carboxylase 1 and transforming growth factor beta into targeting Treg metabolism for therapeutic benefits.

Strategies to Improve Chimeric Antigen Receptor Therapies for Neuroblastoma

Chimeric antigen receptors (CARs) are among the curative immunotherapeutic approaches that exploit the antigen specificity and cytotoxicity function of potent immune cells against cancers. Neuroblastomas, the most common extracranial pediatric solid tumors with diverse characteristics, could be a promising candidate for using CAR therapies. Several methods harness CAR-modified cells in neuroblastoma to increase therapeutic efficiency, although the assessment has been less successful. Regarding the improvement of CARs, various trials have been launched to overcome insufficient capacity. However, the reasons behind the inadequate response against neuroblastoma of CAR-modified cells are still not well understood. It is essential to update the present state of comprehension of CARs to improve the efficiency of CAR therapies. This review summarizes the crucial features of CARs and their design for neuroblastoma, discusses challenges that impact the outcomes of the immunotherapeutic competence, and focuses on devising strategies currently being investigated to improve the efficacy of CARs for neuroblastoma immunotherapy.

Egr2 regulation in T cells is mediated through IFNγ/STAT1 and IL-6/STAT3 signalling pathway

The immune system is a host defence system to protect the body against foreign invaders. T cells are one of the major components of the immune cells and they are essential for immune responses. Early growth response gene (Egr2) in T cells is important for maintaining immune functions of T cells by promoting adaptive immune responses while controlling inflammation and preventing the development of autoimmune diseases. A study by our group demonstrated the function of Egr2 as a checkpoint regulator controlling the proliferation and differentiation of the T cells. In association, Egr2 and 3 play indispensable role in T cell immune response, but the mechanism regulating Egr2 expression in T cells is still unclear. In this study, we analysed the Egr2 expression mechanism in CD4 T cells under antigen stimulation. We found that Egr2 expression is regulated by different cytokines including IL-2 and IL-4, which increased Egr2 induction in activated T cells. However, inflammatory cytokines, including INFγ and IL-6, suppressed Egr2 expression through STAT1 and STAT3 signalling pathway respectively, highlighting a mechanism for tolergenic immune response on T cells.

The Role of Immunological Synapse in Predicting the Efficacy of Chimeric Antigen Receptor (CAR) Immunotherapy

Abstract

Chimeric Antigen Receptor (CAR) immunotherapy utilizes genetically-engineered immune cells that express a unique cell surface receptor that combines tumor antigen specificity with immune cell activation. In recent clinical trials, the adoptive transfer of CAR-modified immune cells (including CAR-T and CAR-NK cells) into patients has been remarkably successful in treating multiple refractory blood cancers. To improve safety and efficacy, and expand potential applicability to other cancer types, CARs with different target specificities and sequence modifications are being developed and tested by many laboratories. Despite the overall progress in CAR immunotherapy, conventional tools to design and evaluate the efficacy and safety of CAR immunotherapies can be inaccurate, time-consuming, costly, and labor-intensive. Furthermore, existing tools cannot always determine how responsive individual patients will be to a particular CAR immunotherapy. Recent work in our laboratory suggests that the quality of the immunological synapse (IS) can accurately predict CAR-modified cell efficacy (and toxicity) that can correlate with clinical outcomes. Here we review current efforts to develop a Synapse Predicts Efficacy (SPE) system for easy, rapid and cost-effective evaluation of CAR-modified immune cell immunotherapy. Ultimately, we hypothesize the conceptual basis and clinical application of SPE will serve as an important parameter in evaluating CAR immunotherapy and significantly advance precision cancer immunotherapy.

FoxP3+ T regulatory cells in cancer: Prognostic biomarkers and therapeutic targets

T Regulatory cells (Tregs) can have both protective and pathological roles. They maintain immune homeostasis and inhibit immune responses in various diseases, including cancer. Proportions of Tregs in the peripheral blood of some cancer patients increase by approximately two-fold, compared to those in healthy individuals. Tregs contribute to cancer development and progression by suppressing T effector cell functions, thereby compromising tumor killing and promoting tumor growth. Highly immunosuppressive Tregs express upregulated levels of the transcription factor, Forkhead box protein P3 (FoxP3). Elevated levels of FoxP3⁺ Tregs within the tumor microenvironment (TME) showed a positive correlation with poor prognosis in various cancer patients. Despite the success of immunotherapy, including the use of immune checkpoint inhibitors, a significant proportion of patients show low response rates as a result of primary or acquired resistance against therapy. Some of the mechanisms which underlie the development of therapy resistance are associated with Treg suppressive function. In this review, we describe Treg contribution to cancer development/progression, and the mechanisms of Treg-mediated immunosuppression. We discuss the prognostic significance of FoxP3⁺ Tregs in different cancers and their potential use as prognostic biomarkers. We also describe potential therapeutic strategies to target Tregs in combination with other types of immunotherapies aiming to overcome tumor resistance and improve clinical outcomes in cancer patients. Overall, understanding the prognostic significance of FoxP3⁺ Tregs in various cancers and their contribution to therapy resistance could help in the development of more effective targeted therapeutic strategies to enhance the clinical outcomes in cancer patients.

An Open-Label Study of the Safety and Efficacy of Tag-7 Gene-Modified Tumor Cells-Based Vaccine in Patients with Locally Advanced or Metastatic Malignant Melanoma or Renal Cell Cancer

LESSONS LEARNED

This study showed that carefully selected patients with locally advanced and metastatic forms of malignant melanoma and renal cell carcinoma could potentially have long-term disease control with a tag-7 gene-modified tumor cells-based vaccine. Randomized clinical trials in patients whose tumors produce low amounts of immunosuppressive factors are needed to confirm this hypothesis in both the adjuvant and metastatic settings.

BACKGROUND

Immunotherapy may produce long-lasting effects on survival and toxicity. The magnitude of efficacy may be dependent on immune factors. We analyzed the results of a phase I/II study of a tag-7 gene-modified tumor cells-based vaccine (GMV) in patients with malignant melanoma (MM) or renal cell carcinoma (RCC) with biomarker analysis of immunosuppressive factors (ISFs) production by their tumor cells.

METHODS

From 2001 to 2014, 80 patients received GMV: 68 with MM and 12 with RCC. Treatment in the metastatic setting included 61 patients (MM, 51; RCC, 10), and treatment in the adjuvant setting (after complete cytoreduction) included 19 patients (MM, 17; RCC, 2). Twenty-six patients were stage III (33%), and 54 (67%) were stage IV. The patients' tumor samples were transferred to culture, transfected with tag-7 gene, and inactivated by radiation. The produced product was injected subcutaneously every 3 weeks until progression or 2 years of therapy. ISFs were measured in the supernatants of the tumor cell cultures and used as predictive factors.

RESULTS

No major safety issues or grade 5 adverse events (AEs) were seen. One grade 4 and two grade 3 AEs were registered. No AEs were registered in 89.4% of treatment cycles. No delayed AE was found. The 5-year overall survival (OS) in the intention-to-treat population was 25.1%. There were no differences between MM OS and RCC OS (log rank, p = .44). Median OS in the metastatic setting was 0.7 years and in the adjuvant setting was 3.1 years. Classification trees were built on the basis of ISF production (Fig. 1). The median OS was 6.6 years in the favorable prognosis (FP) group (major histocompatibility complex class I polypeptide-related sequence A [MICA] level ≤582 pg/mL, n = 15) and 4.6 months in the unfavorable (UF) group (MICA level >582 pg/mL, n = 12; p < .0001). No significant differences were found between classification trees based on ISFs (transforming growth factor β1 [TGF-β1], interleukin-10 [IL-10], and vascular endothelial growth factor [VEGF]). In patients with stage III-IV MM with FP, median OS was 2.3 years, with 31% patients alive at 10 years (Fig. 2) in the UF group (0.4 years; log rank, p = 1.94E-5). No FP patients received modern immunotherapy.

CONCLUSION

GMV showed high results in carefully selected patients with low ISF (TGF-β1, IL-10, and VEGF) production. The method should be further investigated in patients with FP.

Transversus abdominis plane block with general anesthesia blunts the perioperative stress response in patients undergoing radical gastrectomy

Background

Surgical stress induces the release of neuroendocrine mediators and cytokines during perioperative period, which may have adverse effects on cancer patients. While the surgical stress responsse can be affected by anesthetic technique. Therefore, we designed this study to assess whether subcostal transversus abdominis plane (TAP) block can affect perioperative neuroendocrine stress response, postoperative analgesia and postoperative recovery in patients undergoing radical gastrectomy under general anesthesia.

Methods

Sixty-five patients were recruited. Patients randomly received general anesthesia (control group), or general anesthesia combined with TAP block (40 mL of 0.375% ropivacaine) (TAP group). The primary outcome was neuroendocrine levels including norepinephrine (NE), epinephrine (E), cortisol (Cor), glucose (Glu), interleukin (IL)-6 and IL-10 during 48 h after surgery. Secondary outcomes included pain score, hemodynamic variables and recovery characteristics.

Results

Data from 61 of 65 patients were analyzed. The levels of NE, E, Cor, and Glu were blunt by TAP block during perioperative period. The levels of IL-6 and IL-10 were significantly lower in TAP group than in control group. TAP block efficiently relieved postoperative acute pain up to 12 h postoperatively with more stable perioperative hemodynamics compared with control group.

Conclusions

Subcostal TAP block blunts perioperative stress response and provides efficient analgesia, with good hemodynamic stability and minimal adverse effects.

CAR-T cell therapy in melanoma: A future success story?

Chimeric antigen receptor (CAR)-T cells are one of the impressive recent success stories of anti-cancer immunotherapy. Especially in haematological malignancies, this treatment strategy has shown promising results leading to the recent approval of two CAR-T cell constructs targeting CD19 in the United States and the European Union. After the huge success in haematological cancers, the next step will be the evaluation of its efficacy in different solid tumors, which is currently investigated in preclinical as well as clinical settings. A commonly examined tumor model in the context of immunotherapy is melanoma, since it is known for its immunogenic features. However, the first results of CAR-T cell therapy in solid tumors did not reveal the same impressive outcomes that were observed in haematological malignancies, as engineered cells need to cope with several challenges. Obstacles include the lack of migration of CAR-T cells from blood vessels to the tumor site as well as the immunosuppressive tumor microenvironment within solid tumors. Another hurdle is posed by the identification of an ideal target antigen to avoid on-target/off-tumor toxicities. Regarding immune escape mechanisms, which can be developed by tumor cells to bypass immune recognition, the observation of antigen loss should also be considered. This article gives an overview of the challenges displayed in CAR-T cell therapy for the use in solid tumors and discusses different new strategies and approaches that deal with these problems in order to improve CAR-T cell therapy, particularly for its use in melanoma.

Clinical Efficacy and Tumor Microenvironment Influence in a Dose-Escalation Study of Anti-CD19 Chimeric Antigen Receptor T Cells in Refractory B-Cell Non-Hodgkin's Lymphoma

PURPOSE

Anti-CD19 chimeric antigen receptor (CAR) T cells represent a novel immunotherapy and are highly effective in treating relapsed/refractory B-cell non-Hodgkin's lymphoma (B-NHL). How tumor microenvironment influences clinical response to CAR T therapy remains of great interest.

PATIENTS AND METHODS

A phase I, first-in-human, dose-escalation study of anti-CD19 JWCAR029 was conducted in refractory B-NHL (NCT03355859) and 10 patients received CAR T cells at an escalating dose of 2.5 × 10⁷(n = 3), 5 × 10⁷(n = 4), and 1 × 10⁸(n = 3) cells. Core needle biopsy was performed on tumor samples collected from diffuse large B-cell lymphoma patients on Day -6 (1 day before lymphodepletion) and on Day 11 after CAR T-cell infusion when adequate CAR T-cell expansion was detected.

RESULTS

The overall response rate was 100%, with 6 of 9 (66.7%) evaluable patients achieving complete remission. The most common adverse events of grade 3 or higher were neutropenia (10/10, 100%), anemia (3/10, 30%), thrombocytopenia (3/10, 30%), and hypofibrinogenemia (2/10, 20%). Grade 1 cytokine release syndrome occurred in all patients and grade 3 neurotoxicity in 1 patient. The average peak levels of peripheral blood CAR T cells and cytokines were similar in 3 different dose levels, but CAR T cells were significantly higher in patients achieved complete remission on Day 29. Meanwhile, RNA sequencing identified gene expression signatures differentially enriched in complete and partial remission patients. Increased tumor-associated macrophage infiltration was negatively associated with remission status.

CONCLUSIONS

JWCAR029 was effective and safe in treating refractory B-NHL. The composition of the tumor microenvironment has a potential impact in CAR T therapy response.

Context-Dependent Effect of Glucocorticoids on the Proliferation, Differentiation, and Apoptosis of Regulatory T Cells: A Review of the Empirical Evidence and Clinical Applications

Glucocorticoids (GCs) are widely used to treat several diseases because of their powerful anti-inflammatory and immunomodulatory effects on immune cells and non-lymphoid tissues. The effects of GCs on T cells are the most relevant in this regard. In this review, we analyze how GCs modulate the survival, maturation, and differentiation of regulatory T (Treg) cell subsets into both murine models and humans. In this way, GCs change the Treg cell number with an impact on the mid-term and long-term efficacy of GC treatment. In vitro studies suggest that the GC-dependent expansion of Treg cells is relevant when they are activated. In agreement with this observation, the GC treatment of patients with established autoimmune, allergic, or (auto)inflammatory diseases causes an expansion of Treg cells. An exception to this appears to be the local GC treatment of psoriatic lesions. Moreover, the effects on Treg number in patients with multiple sclerosis are uncertain. The effects of GCs on Treg cell number in healthy/diseased subjects treated with or exposed to allergens/antigens appear to be context-dependent. Considering the relevance of this effect in the maturation of the immune system (tolerogenic response to antigens), the success of vaccination (including desensitization), and the tolerance to xenografts, the findings must be considered when planning GC treatment.

microRNA-142-mediated repression of phosphodiesterase 3B critically regulates peripheral immune tolerance

Tregs play a fundamental role in immune tolerance via control of self-reactive effector T cells (Teffs). This function is dependent on maintenance of a high intracellular cAMP concentration. A number of microRNAs are implicated in the maintenance of Tregs. In this study, we demonstrate that peripheral immune tolerance is critically dependent on posttranscriptional repression of the cAMP-hydrolyzing enzyme phosphodiesterase-3b (Pde3b) by microRNA-142-5p (miR-142-5p). In this manner, miR-142-5p acts as an immunometabolic regulator of intracellular cAMP, controlling Treg suppressive function. Mir142 was associated with a super enhancer bound by the Treg lineage–determining transcription factor forkhead box P3 (FOXP3), and Treg-specific deletion of miR-142 in mice (Treg^Δ142) resulted in spontaneous, lethal, multisystem autoimmunity, despite preserved numbers of phenotypically normal Tregs. Pharmacological inhibition and genetic ablation of PDE3B prevented autoimmune disease and reversed the impaired suppressive function of Tregs in Treg^Δ142 animals. These findings reveal a critical molecular switch, specifying Treg function through the modulation of a highly conserved, cell-intrinsic metabolic pathway. Modulation of this pathway has direct relevance to the pathogenesis and treatment of autoimmunity and cancer.

CAR T Cell Therapy for Neuroblastoma

Patients with high risk neuroblastoma have a poor prognosis and survivors are often left with debilitating long term sequelae from treatment. Even after integration of anti-GD2 monoclonal antibody therapy into standard, upftont protocols, 5-year overall survival rates are only about 50%. The success of anti-GD2 therapy has proven that immunotherapy can be effective in neuroblastoma. Adoptive transfer of chimeric antigen receptor (CAR) T cells has the potential to build on this success. In early phase clinical trials, CAR T cell therapy for neuroblastoma has proven safe and feasible, but significant barriers to efficacy remain. These include lack of T cell persistence and potency, difficulty in target identification, and an immunosuppressive tumor microenvironment. With recent advances in CAR T cell engineering, many of these issues are being addressed in the laboratory. In this review, we summarize the clinical trials that have been completed or are underway for CAR T cell therapy in neuroblastoma, discuss the conclusions and open questions derived from these trials, and consider potential strategies to improve CAR T cell therapy for patients with neuroblastoma.

Perspectives on Chimeric Antigen Receptor T-Cell Immunotherapy for Solid Tumors

Chimeric antigen receptor (CAR) T-cell therapy entails the genetic engineering of a patient's T-cells to express membrane spanning fusion receptors with defined specificities for tumor-associated antigens. These CARs are capable of eliciting robust T-cell activation to initiate killing of the target tumor cells. This therapeutic approach has produced unprecedented clinical outcomes in the treatment of "liquid" hematologic cancers, but to date has not produced comparable responses in targeting solid malignancies. Advances in our understanding of the immunobiology of solid tumors have highlighted several hurdles which currently hinder the efficacy of this therapy. These barriers include the insufficient accumulation of CAR T-cells in the tumor due to poor trafficking or physical exclusion and the exposure of infiltrating CAR T-cells to a panoply of immune suppressive checkpoint molecules, cytokines, and metabolic stresses that are not conducive to efficient immune reactions and can thereby render these cells anergic, exhausted, or apoptotic. This mini-review summarizes these hurdles and describes some recent approaches and innovations to genetically re-engineer CAR T-cells to counter inhibitory influences found in the tumor microenvironment. Novel immunotherapy drug combinations to potentiate the activity of CAR T-cells are also discussed. As our understanding of the immune landscape of tumors improves and our repertoire of immunotherapeutic drugs expands, it is envisaged that the efficacy of CAR T-cells against solid tumors might be potentiated using combination therapies, which it is hoped may lead to meaningful improvements in clinical outcome for patients with refractory solid malignancies.

Immune checkpoint inhibitors in cancer therapy: a focus on T-regulatory cells

Regulatory T cells (Tregs) play essential roles in immune homeostasis; however, their role in tumor microenvironment (TME) is not completely evident. Several studies reported that infiltration of Tregs into various tumor tissues promotes tumor progression by limiting antitumor immunity and supporting tumor immune evasion. Furthermore, in TME, Tregs include heterogeneous subsets of cells expressing different immunosuppressive molecules favoring tumor progression. For an effective cancer therapy, it is critical to understand the Treg heterogeneity and biology in the TME. Recent studies have shown that immune checkpoint molecules promote cancer progression through various antitumor inhibitory mechanisms. Recent advances in cancer immunotherapy have shown the promising potentials of immune checkpoint inhibitors (ICIs) in inducing antitumor immune responses and clinical benefits in patients with cancer at late stages. Most studies revealed the effect of ICIs on T effector cells, and little is known about their effect on Tregs. In this review, we highlight the effects of the ICIs, including anti-CTLA-4, anti-PD-1/PD-L1, anti-LAG-3, anti-TIM-3, and anti-TIGIT, on tumor-infiltrating and peripheral Tregs to elicit effector T-cell functions against tumors. Additionally, we discuss how ICIs may target Tregs for cancer immunotherapy.

Potential effect of tumor-specific Treg-targeted antibodies in the treatment of human cancers: A bioinformatics analysis

One of the mechanisms of tumor rejection in immune-modulatory treatments is antibody-dependent cell-mediated cytotoxicity (ADCC) of regulatory T cells (Tregs) that infiltrate tumors in which cells expressing activating Fcγ receptors (FcγRs) are present. Our objective was to identify, through a bioinformatics analysis, Treg marker(s) expressed at the highest levels in nine types of human cancers, in order to determine the best targets for ADCC-inducing antitumor antibodies. We analyzed the mRNA levels of 24 surface Treg markers evaluated by the Affymetrix Human Genome U133 Plus 2.0 Array in 5728 cancer samples obtained via the Genevestigator v3 suite. Our analysis was based on overexpression of markers in tumors as compared to healthy tissues (HTs) and correlation between overexpression of the markers and the tumor suppressive microenvironment. Moreover, we evaluated tumoral infiltration of activating FcγR-expressing cells and calculated the ADCC index for each overexpressed marker, as an indicator of whether the marker was a good target for ADCC induction in tumor-infiltrating Tregs. The results demonstrated that the ADCC strategy is unlikely to succeed in colorectal, liver, prostate and ovarian cancers. Moreover, we identified nine Treg markers that could be targeted in the other tumors: 4-1BB, CD39, galectin-9, GITR, IL-21R, LAP, neuropilin-1, TIGIT and TNFR2. GITR and TIGIT were the only markers that could be potentially useful as targets for the treatment of three cancers: non-squamous and squamous NSCLC and breast infiltrating ductal carcinoma. LAP, neuropilin-1 and CD39 presented as good targets in the treatment of renal cell carcinoma. Our findings may have value for the development of new anti-tumor antibodies.

IL10 Release upon PD-1 Blockade Sustains Immunosuppression in Ovarian Cancer

Ligation of programmed cell death-1 (PD-1) in the tumor microenvironment is known to inhibit effective adaptive antitumor immunity. Blockade of PD-1 in humans has resulted in impressive, durable regression responses in select tumor types. However, durable responses have been elusive in ovarian cancer patients. PD-1 was recently shown to be expressed on and thereby impair the functions of tumor-infiltrating murine and human myeloid dendritic cells (TIDC) in ovarian cancer. In the present work, we characterize the regulation of PD-1 expression and the effects of PD-1 blockade on TIDC. Treatment of TIDC and bone marrow-derived dendritic cells (DC) with IL10 led to increased PD-1 expression. Both groups of DCs also responded to PD-1 blockade by increasing production of IL10. Similarly, treatment of ovarian tumor-bearing mice with PD-1 blocking antibody resulted in an increase in IL10 levels in both serum and ascites. While PD-1 blockade or IL10 neutralization as monotherapies were inefficient, combination of these two led to improved survival and delayed tumor growth; this was accompanied by augmented antitumor T- and B-cell responses and decreased infiltration of immunosuppressive MDSC. Taken together, our findings implicate compensatory release of IL10 as one of the adaptive resistance mechanisms that undermine the efficacy of anti-PD-1 (or anti-PD-L1) monotherapies and prompt further studies aimed at identifying such resistance mechanisms. Cancer Res; 77(23); 6667-78. ©2017 AACR.

Targeting macrophage anti-tumor activity to suppress melanoma progression

By phagocytosing cancer cells and their cellular debris, macrophages play a critical role in nonspecific defense (innate immunity) and, as antigen presenters, they help initiate specific defense mechanisms (adaptive immunity). Malignant melanoma is a lethal disease due to its aggressive capacity for metastasis and resistance to therapy. For decades, considerable effort has gone into development of an effective immunotherapy for treatment of metastatic melanoma. In this review, we focus on the anti-tumor activities of macrophages in melanoma and their potential as therapeutic targets in melanoma. Although macrophages can be re-educated through intercellular signaling to promote tumor survival owing to their plasticity, we expect that targeting the anti-tumor activity of macrophages remains a promising strategy for melanoma inhibition. The combination of tumoricidal macrophage activation and other treatments such as surgery, chemotherapy, and radiotherapy, may provide an effective and comprehensive anti-melanoma strategy.

Relationship Between Interleukin-10 Gene C-819T Polymorphism and Gastric Cancer Risk: Insights From a Meta-Analysis

BACKGROUND As a pleiotropic cytokine, interleukin-10 (IL-10) plays a regulatory role in carcinogenesis and tumor growth. The aim of this meta-analysis was to assess the susceptibility of the IL-10 gene C-819T polymorphism to gastric cancer. MATERIAL AND METHODS Study identification and data extraction were independently completed by 2 authors. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated and summarized. RESULTS In total, 11 articles including 1960 gastric cancer patients and 3705 controls were qualified. Overall analyses revealed a 13% reduced risk of gastric cancer conferred by the -819T allele relative to the -819C allele (OR=0.87; 95% CI: 0.77-0.97; P=0.016), without heterogeneity (I2=35.1%). In subgroup analyses, a significant difference was identified in East Asian populations (OR=0.85; 95% CI: 0.73-0.98; P=0.029, I2=43.6%), for gastric adenocarcinoma (OR=0.80; 95% CI: 0.66-0.96; P=0.017, I2=0.0%), and in population-based studies (OR=0.81; 95% CI: 0.70-0.93; P=0.003, I2=0.0%). The visual funnel plots and Egger's tests suggested no evidence of publication bias. CONCLUSIONS Extending previous findings, we demonstrate a protective role of the IL-10 gene -819T allele in susceptibility to gastric cancer, and this role was more evident for gastric adenocarcinoma.

Mutant KRAS Conversion of Conventional T Cells into Regulatory T Cells

Constitutive activation of the KRAS oncogene in human malignancies is associated with aggressive tumor growth and poor prognosis. Similar to other oncogenes, KRAS acts in a cell-intrinsic manner to affect tumor growth or survival. However, we describe here a different, cell-extrinsic mechanism through which mutant KRAS contributes to tumor development. Tumor cells carrying mutated KRAS induced highly suppressive T cells, and silencing KRAS reversed this effect. Overexpression of the mutant KRAS(G12V)gene in wild-type KRAS tumor cells led to regulatory T-cell (Treg) induction. We also demonstrate that mutant KRAS induces the secretion of IL10 and transforming growth factor-β1 (both required for Treg induction) by tumor cells through the activation of the MEK-ERK-AP1 pathway. Finally, we report that inhibition of KRAS reduces the infiltration of Tregs in KRAS-driven lung tumorigenesis even before tumor formation. This cell-extrinsic mechanism allows tumor cells harboring a mutant KRAS oncogene to escape immune recognition. Thus, an oncogene can promote tumor progression independent of its transforming activity by increasing the number and function of Tregs. This has a significant clinical potential, in which targeting KRAS and its downstream signaling pathways could be used as powerful immune modulators in cancer immunotherapy.

The diverse roles of the TNF axis in cancer progression and metastasis

Metastasis is a multi-step process that ultimately depends on the ability of disseminating cancer cells to establish favorable communications with their microenvironment. The tumor microenvironment consists of multiple and continuously changing cellular and molecular components. One of the factors regulating the tumor microenvironment is TNF-α, a pleiotropic cytokine that plays key roles in apoptosis, angiogenesis, inflammation and immunity. TNF-α can have both pro- and anti-tumoral effects and these are transmitted via two major receptors, the 55 kDa TNFR1 and the 75 kDa TNFR2 that have distinct, as well as overlapping functions. TNFR1 is ubiquitously expressed while the expression of TNFR2 is more restricted, mainly to immune cells. While TNFR1 can transmit pro-apoptotic or pro-survival signals through a complex network of downstream mediators, the role of TNFR2 is less well understood. One of its main functions is to act as a survival factor and moderate the pro-apoptotic effects of TNFR1, particularly in immune cells. In this review, we summarize the evidence for the involvement of the TNF system in the progression of the metastatic process from its contribution to the early steps of tumor cell invasion to its role in the colonization of distant sites, particularly the liver. We show how the TNF receptors each contribute to these processes by regulating and shaping the tumor microenvironment. Current evidence and concepts on the potential use of TNF targeting agents for cancer prevention and therapy are discussed.

The lymphatic system and pancreatic cancer

This review summarizes current knowledge of the biology, pathology and clinical understanding of lymphatic invasion and metastasis in pancreatic cancer. We discuss the clinical and biological consequences of lymphatic invasion and metastasis, including paraneoplastic effects on immune responses and consider the possible benefit of therapies to treat tumors that are localized to lymphatics. A review of current techniques and methods to study interactions between tumors and lymphatics is presented.

Cancer immunotherapy via nucleic acid aptamers

Over the past decade, immune therapy has become a standard treatment for a variety of cancers. Monoclonal antibodies, immune adjuvants and vaccines against oncogenic viruses are now well-established cancer therapies. Immune modulation is a principal element of supportive care for many high-dose chemotherapy regimens. Aptamers are short nucleic acids that bind to defined targets with high affinity and specificity. The first aptamers have been selected around two decades ago by an in vitro process named SELEX (systematic evolution of ligands by exponential enrichment). Since then, numerous aptamers with specificities for a variety of targets from small molecules to proteins or even whole cells have been selected. Targeting immunomodulatory ligands in the progressive tumor lesions of the patients would be prophylactic or therapeutic and may reduce drug-associated toxicities. A new class of inhibitory and agonistic ligands composed of short oligonucleotide (ODN) aptamers was developed recently that exhibited bioactivities comparable or superior to that of antibodies. This paper addressed progress in cancer immunotherapy with nucleic acid aptamers and highlighted recent developments either in immune system targeting or in immunotherapy methods involved aptamers. We discussed aptamer limitations when used as therapeutic agents for cancer treatment and suggested ways to overcome those limitations.

Is sentinel node susceptibility to metastases related to nodal immune modulation?

Sentinel lymph nodes (SLNs), the initial site of regional metastases, directly receive lymph containing immune-modulatory cytokines and tumor cells from primary melanomas. Immune-suppressed SLNs are ideal for studies of tissue susceptibility to metastases. They show reduced antigen-presenting dendritic cells, activated T cells, high endothelial venules, and transvenular immigration of T cells. Tumor-induced immune suppression contributes to establishment of nodal metastases. SLNs may serve as an effective model to study reversal of tumor-induced immune suppression. We reviewed this topic in Nature Reviews of Immunology in 2006. We here summarize the Nature paper and provide additional results from ongoing studies and the recent literature.

Vaccine-induced but not tumor-derived Interleukin-10 dictates the efficacy of Interleukin-10 blockade in therapeutic vaccination

Blocking antibodies against immunosuppressive molecules have shown promising results in cancer patients. However, there are not enough data to define those conditions dictating treatment efficacy. In this scenario, IL-10 is a cytokine with controversial effects on tumor growth. Thus, our aim was to characterize in which setting IL-10 blockade may potentiate the beneficial effects of a therapeutic vaccine In the IL-10-expressing B16-OVA and TC-1 P3 (A15) tumor models, therapeutic vaccination with tumor antigens plus the TLR7 ligand Imiquimod increased IL-10 production. Although blockade of IL-10 signal with anti-IL-10R antibodies did not inhibit tumor growth, when combined with vaccination it enhanced tumor rejection, associated with stronger innate and adaptive immune responses. Interestingly, a similar enhancement on immune responses was observed after simultaneous vaccination and IL-10 blockade in naive mice. However, when using vaccines containing as adjuvants the TLR3 ligand poly(I:C) or anti-CD40 agonistic antibodies, despite tumor IL-10 expression, anti-IL-10R antibodies did not provide any beneficial effect on tumor growth and antitumor immune responses. Of note, as opposed to Imiquimod, vaccination with this type of adjuvants did not induce IL-10 and correlated with a lack of in vitro IL-10 production by dendritic cells (DC). Finally, in B16-OVA-bearing mice, blockade of IL-10 during therapeutic vaccination with a multiple adjuvant combination (MAC) with potent immunostimulatory properties but still inducing IL-10 led to superior antitumor immunity and complete tumor rejection. These results suggest that for therapeutic antitumor vaccination, blockade of vaccine-induced IL-10 is more relevant than tumor-associated IL-10.

Induction of robust type-I CD8+ T-cell responses in WHO grade 2 low-grade glioma patients receiving peptide-based vaccines in combination with poly-ICLC

PURPOSE

WHO grade 2 low-grade gliomas (LGG) with high risk factors for recurrence are mostly lethal despite current treatments. We conducted a phase I study to evaluate the safety and immunogenicity of subcutaneous vaccinations with synthetic peptides for glioma-associated antigen (GAA) epitopes in HLA-A2(+) adults with high-risk LGGs in the following three cohorts: (i) patients without prior progression, chemotherapy, or radiotherapy (RT); (ii) patients without prior progression or chemotherapy but with prior RT; and (iii) recurrent patients.

EXPERIMENTAL DESIGN

GAAs were IL13Rα2, EphA2, WT1, and Survivin. Synthetic peptides were emulsified in Montanide-ISA-51 and given every 3 weeks for eight courses with intramuscular injections of poly-ICLC, followed by q12 week booster vaccines.

RESULTS

Cohorts 1, 2, and 3 enrolled 12, 1, and 10 patients, respectively. No regimen-limiting toxicity was encountered except for one case with grade 3 fever, fatigue, and mood disturbance (cohort 1). ELISPOT assays demonstrated robust IFNγ responses against at least three of the four GAA epitopes in 10 and 4 cases of cohorts 1 and 3, respectively. Cohort 1 patients demonstrated significantly higher IFNγ responses than cohort 3 patients. Median progression-free survival (PFS) periods since the first vaccine are 17 months in cohort 1 (range, 10-47+) and 12 months in cohort 3 (range, 3-41+). The only patient with large astrocytoma in cohort 2 has been progression-free for more than 67 months since diagnosis.

CONCLUSION

The current regimen is well tolerated and induces robust GAA-specific responses in WHO grade 2 glioma patients. These results warrant further evaluations of this approach. Clin Cancer Res; 21(2); 286-94. ©2014 AACR.

Cancer vaccines: Looking to the future

These are exciting times for the field of cancer immunotherapy. Although the clinical efficacy of monoclonal antibodies has been demonstrated since the early 1990s, the therapeutic profile of other immunotherapeutic approaches-especially vaccines-has not yet been formally clarified. However, the recent success of several immunotherapeutic regimens in cancer patients has boosted the development of this treatment modality. These achievements stemmed from recent scientific advances demonstrating the tolerogenic nature of cancer and the fundamental role of the tumor immune microenvironment in the suppression of antitumor immunity. New immunotherapeutic strategies against cancer attempt to promote protective antitumor immunity while disrupting the immunoregulatory circuits that contribute to tumor tolerance. Cancer vaccines differ from other anticancer immunotherapeutics in that they initiate the dynamic process of activating the immune system so as to successfully re-establish a state of equilibrium between tumor cells and the host. This article reviews recent clinical trials involving several different cancer vaccines and describes some of the most promising immunotherapeutic approaches that harness antitumor T-cell responses. In addition, we describe strategies whereby cancer vaccines can be exploited in combination with other therapeutic approach to overcome-in a synergistic fashion-tumor immunoevasion. Finally, we discuss prospects for the future development of broad spectrum prophylactic anticancer vaccines.

Temporary elimination of IL-10 enhanced the effectiveness of cyclophosphamide and BMDC-based therapy by decrease of the suppressor activity of MDSCs and activation of antitumour immune response

The antitumour activity of the dendritic cell (DC)-based cellular vaccines is greatly reduced in hostile tumour microenvironment. Therefore, there are many attempts to eliminate or neutralize both suppressor cells and cytokines. The aim of the investigation was to verify if temporary elimination of IL-10 just before injection of bone marrow-derived DCs (BMDCs) enhance the antitumour activity of applied vaccines and help to overcome the immunosuppressive tumour barrier. Mice bearing colon carcinoma MC38 were given single dose of cyclophosphamide (CY) followed by alternate injections of anti-IL-10 antibodies and BMDC-based vaccines consisted of BMDCs stimulated with MC38 tumour antigen (BMDC/TAg) or the combination of BMDC/TAg with BMDCs transduced with IL-12 genes (BMDC/IL-12). The high tumour growth inhibition was observed in mice treated with CY+anti-IL-10+BMDC/TAg as well as CY±anti-IL-10+BMDC/TAg+BMDC/IL-12. However, the mechanisms of action of particular treatment schemes were diversified. Generally, it was observed that application of anti-IL-10 Abs reduced suppressor activity of myeloid-derived suppressor cells (MDSCs). However, anti-IL-10 Abs in combination with diversely composed BMDC-based vaccines induced different components of an antitumour response. The high cytotoxic activity of spleen-derived NK cells and increased influx of these cells into tumours of mice treated with CY+anti-IL-10+BMDC/TAg indicate that mice from the group developed strong NK-dependent response. Whereas, application of anti-IL-10 Abs just before injection of BMDC/TAg+BMDC/IL-12 did not enhanced NK cell activity. Furthermore, it significantly impaired effectiveness of therapy composed of CY+BMDC/TAg+BMDC/IL-12 vaccine in induction of Th1 type immune response. Taken together, our results indicate that temporary elimination of IL-10 is an important and effective way to decrease the immune suppression associated with MDSCs activity and represents a useful strategy for successful enhancement of the antitumour activity of BMDC/TAg-based vaccines.

Anti-tumor effect of ribavirin in combination with interferon-α on renal cell carcinoma cell lines in vitro

BACKGROUND

Ribavirin is an anti-viral drug; however, recent data suggest that it may also be effective in cancer therapy. This study investigated the effect of ribavirin alone or in combination with IFN-α on biological processes: proliferation, apoptosis, and migration of murine (Renca) and human renal carcinoma (RCC) cells (786-0) in vitro.

METHODS

Renca and 786-0 cells were treated with IFN-α, ribavirin, or a combination of IFN-α and ribavirin at varying concentrations. Cell proliferation was evaluated using CCK-8 assay. Induction of apoptosis and distribution of cell cycle were determined by flow cytometry. The migratory capacity of cells was quantified using a transwell migration assay. The toxic effect of these drugs was examined using MTT assay in HEK-293 cells. ELISA was used to measure IL-10 and TGF-β content in the culture supernatants.

RESULTS

Our results showed that both ribavirin alone and in combination with IFN-α could significantly inhibit the cell proliferation and arrest the cell cycle progress at the G2/M phase. These treatments also inhibited cell migration and IL-10 production, in a concentration-dependent manner, in 786-0 and Renca cells. Moreover, they significantly induced apoptosis of RCC cells and increased TGF-β production in concentration-dependent manner. No significant toxic effect was observed in HEK-293 cells. We also found that the effect of combined treatment was more pronounced than that of ribavirin or IFN-α alone. However, the combined effect of the two drugs was not synergistic.

CONCLUSION

Our findings suggest that ribavirin can negatively affect biological processes of RCC cells. This agent might become a new candidate for the treatment of RCC in the clinical setting.

Induction of cytotoxic T cells as a novel independent survival factor in malignant melanoma with percutaneous peptide immunization

BACKGROUND

Malignant melanoma (MM) often shows multiple chemo-resistance, leading to poor prognosis of the patients. Therapeutic anti-cancer vaccination may be a feasible way to prolong the survival of patients. We have demonstrated that application of antigenic peptides via the tape-stripped, horny layer-removed skin, known as percutaneous peptide immunization (PPI), induces tumor cell-specific cytotoxic T lymphocytes (CTLs) in rodents and humans.

OBJECTIVE

To evaluate clinical significance of PPI in advanced MM patients.

METHODS

We performed PPI in 59 patients undergoing advanced MM with Melan-A, tyrosinase, MAGE-2, MAGE-3 and gp-100 peptides based on HLA typing in individuals. The induction of CTLs was assessed by the tetramer or pentamer flow cytometry in 35 patients. Patients showing positive CTL responses to all antigens were defined as complete responder (n=18), and those showing negative responses to at least one applied antigen were classified as incomplete responder (n=17). The primary endpoint of the study was overall survival (OS). For statistical analysis, log-rank test, univariate and multivariate Cox proportional hazard model were used.

RESULTS

OS of the complete responders was longer than that of the incomplete responders (median survival time: 55.8 vs 20.3 months, log rank P=0.089). A hazard ratio for the complete responders relative to the incomplete responders was 0.23 (95% confidence interval: 0.06-0.93, P=0.039) in a multivariate Cox proportional hazard model.

CONCLUSION

The induction of CTLs was a novel independent survival factor, and the induction of peptide-specific CTLs by PPI contributes to the prolonged survival and represents an impact on therapeutic approaches in MM. Unique trial number: UMIN000005706.

Intratumoral CD4+ T lymphodepletion sensitizes poorly immunogenic melanomas to immunotherapy with an OX40 agonist

Previous studies have shown that the antitumor effects of OX40 agonists depend on the immunogenicity of the tumor and that poorly immunogenic tumors such as B16F10 melanomas do not respond to OX40 agonist treatment. In this study, we have shown that intratumoral CD4+ T lymphodepletion sensitized poorly immunogenic B16F10 melanomas to immunotherapy with an OX40 agonist. CD4+ T lymphodepletion dramatically altered the tumor immune microenvironment, making it more susceptible to the antitumor effects of an OX40 agonist by enhancing the accumulation of CD8+ T cells and natural killer (NK) cells in tumor tissue. However, unexpectedly, the number of CD11b+ Gr-1(+) myeloid-derived suppressor cells (MDSCs) within tumor tissues also significantly increased as a result of CD4+ T lymphodepletion. As a countermeasure against CD8+ T-cell accumulation, CCR2-positive CD11b+ Gr-1(int) (monocytic) MDSCs predominantly increased. Treatment with an OX40 agonist under CD4+ T lymphodepletion neither reduced MDSCs nor increased CD8+ T cells and NK cells, but further enhanced the expression of cytotoxic molecules from tumor-infiltrating effector cells. Our results suggest that combined immunotherapy using both an OX40 agonist and CD4+ T lymphodepletion could be a promising therapeutic strategy for poorly immunogenic tumors and might be more effective if further combined with a therapeutic strategy targeting MDSCs.

Nonneuronal Cholinergic System in Breast Tumors and Dendritic Cells: Does It Improve or Worsen the Response to Tumor?

Besides being the main neurotransmitter in the parasympathetic nervous system, acetylcholine (ACh) can act as a signaling molecule in nonneuronal tissues. For this reason, ACh and the enzymes that synthesize and degrade it (choline acetyltransferase and acetylcholinesterase) as well as muscarinic (mAChRs) and nicotinic receptors conform the non-neuronal cholinergic system (nNCS). It has been reported that nNCS regulates basal cellular functions including survival, proliferation, adhesion, and migration. Moreover, nNCS is broadly expressed in tumors and in different components of the immune system. In this review, we summarize the role of nNCS in tumors and in different immune cell types focusing on the expression and function of mAChRs in breast tumors and dendritic cells (DCs) and discussing the role of DCs in breast cancer.

Cellular and molecular mechanisms in cancer immune escape: a comprehensive review

Immune escape is the final phase of cancer immunoediting process wherein cancer modulates our immune system to escape from being destroyed by it. Many cellular and molecular events govern the cancer's evasion of host immune response. The tumor undergoes continuous remodeling at the genetic, epigenetic and metabolic level to acquire resistance to apoptosis. At the same time, it effectively modifies all the components of the host's immunome so as to escape from its antitumor effects. Moreover, it induces accumulation of suppressive cells like Treg and myeloid derived suppressor cells and factors which also enable it to elude the immune system. Recent research in this area helps in defining the role of newer players like miRNAs and exosomes in immune escape. The immunotherapeutic approaches developed to target the escape phase appear quite promising; however, the quest for a perfect therapeutic agent that can achieve maximum cure with minimal toxicity continues.

Adoptive cell therapies for glioblastoma

Glioblastoma (GBM) is the most common and most aggressive primary brain malignancy and, as it stands, is virtually incurable. With the current standard of care, maximum feasible surgical resection followed by radical radiotherapy and adjuvant temozolomide, survival rates are at a median of 14.6 months from diagnosis in molecularly unselected patients (1). Collectively, the current knowledge suggests that the continued tumor growth and survival is in part due to failure to mount an effective immune response. While this tolerance is subtended by the tumor being utterly “self,” it is to a great extent due to local and systemic immune compromise mediated by the tumor. Different cell modalities including lymphokine-activated killer cells, natural killer cells, cytotoxic T lymphocytes, and transgenic chimeric antigen receptor or αβ T cell receptor grafted T cells are being explored to recover and or redirect the specificity of the cellular arm of the immune system toward the tumor complex. Promising phase I/II trials of such modalities have shown early indications of potential efficacy while maintaining a favorable toxicity profile. Efficacy will need to be formally tested in phase II/III clinical trials. Given the high morbidity and mortality of GBM, it is imperative to further investigate and possibly integrate such novel cell-based therapies into the current standards-of-care and herein we collectively assess and critique the state-of-the-knowledge pertaining to these efforts.

Genetic variations in cytotoxic T-lymphocyte antigen-4 and susceptibility to cervical cancer

Cytotoxic T-lymphocyte antigen-4 (CTLA-4), a molecule expressed predominantly on activated T cells, plays an important role in the down-regulation of T-cell activation. To evaluate the potential effects of CTLA-4 gene polymorphisms on susceptibility to cervical cancer, we genotyped polymorphisms in CTLA-4 (- 318 T/C, CT60 G/A,+49 G/A, - 658 T/C, and - 1661 G/A) and calculated odds ratios for the genotype and allele distributions between patients and controls. We then examined the functional relevance of the polymorphisms using enzyme-linked immunosorbent assays (ELISAs), in vitro lymphocyte proliferation assay, and cytotoxic assay. The CTLA-4 - 318 CC, CT60 AA, and+49 GG genotype frequencies were lower in patients than in controls (p <0.05). The frequencies of CTLA-4 - 318 T allele and CT60G allele carriers were significantly higher in patients than in controls (p <0.05). Upon stimulation, peripheral blood mononuclear cells (PBMCs) carrying the - 318TT and CT60GG genotypes exhibited significantly lower proliferation, IL-2, and IL-4 levels; fewer cytolytic activities; and higher TGF-β levels compared with PBMCs carrying the - 318 CC/CT or CT60 AA/AG genotypes. We also found that CTLA-4 - 318 T/C and CT60 G/A single nucleotide polymorphisms were associated with the severity of cervical cancer. These results indicate that CTLA-4 - 318 T/C and CT60 G/A can affect cervical cancer susceptibility by altering the immune status of an individual.

Deciphering and reversing tumor immune suppression

Generating an anti-tumor immune response is a multi-step process that is executed by effector T cells that can recognize and kill tumor targets. However, tumors employ multiple strategies to attenuate the effectiveness of T-cell-mediated attack. They achieve this by interfering with nearly every step required for effective immunity, from deregulation of antigen-presenting cells to establishment of a physical barrier at the vasculature that prevents homing of effector tumor-rejecting cells and the suppression of effector lymphocytes through the recruitment and activation of immunosuppressive cells such as myeloid-derived suppressor cells, tolerogenic monocytes, and T regulatory cells. Here, we review the ways in which tumors exert immune suppression and highlight the new therapies that seek to reverse this phenomenon and promote anti-tumor immunity. Understanding anti-tumor immunity, and how it becomes disabled by tumors, will ultimately lead to improved immune therapies and prolonged survival of patients.