Effector CD4 and CD8 T cells and their role in the tumor microenvironment

Regulatory and effector T cell subsets in tumor-draining lymph nodes of patients with squamous cell carcinoma of head and neck

Background

A crucial role for the immune system has been proposed in the establishment and progression of head and neck squamous cell carcinoma (HNSCC). In this study, we investigated the cytokine and regulatory profiles of T cells in tumor draining lymph nodes (TDLNs) of patients with HNSCC.

Results

The frequencies of CD4+TNF-α+ and CD4+TNF-αhi negatively were associated with poor prognostic factors such as LN involvement (P = 0.015 and P = 0.019, respectively), stage of the disease (P = 0.032 and P = 0.010, respectively) and tumor size (P = 0.026 and P = 0.032, respectively). Frequencies of CD8+IFN-γ+ and CD8+IFN-γ+ TNF-α+ T cells showed negative relationship with tumor grade (P = 0.035 and P = 0.043, respectively). While, the frequencies of CD4+IL-4+, CD8+IL-10+, CD8+IL-4+T cells were higher in advanced stages of the disease (P = 0.042, P = 0.041 and P = 0.030, respectively) and CD4+IFN-γ+TNF-α−, CD8+IL-4+ and CD8+IFN-γ+TNF-α− T cells were higher in patients with larger tumor size (P = 0.026 and P = 0.032, respectively). Negative associations were found between the frequencies of CD4+CD25+Foxp3+ and CD4+CD25+Foxp3+CD127low/− Treg cells and cancer stage (P = 0.015 and P = 0.059).

Conclusion

This study shed more lights on the changes in immune profile of T cells in TDLNs of HNSCC. Larger tumor size and/or LN involvement were associated with lower frequencies of CD4+TNF-α+, CD8+IFN-γ+ and CD8+IFN-γ+TNF-α+ but higher frequency of CD4+IL-4+ T cells. Moreover, Foxp3+Tregs correlated with good prognostic indicators.

Targeted drug delivery system for ovarian cancer microenvironment: Improving the effects of immunotherapy

Immunotherapies have shown modest benefits in the current clinical trials for ovarian cancer. The tumor microenvironment (TME) in an immunosuppressive phenotype contributes to this “failure” of immunotherapy in ovarian cancer. Many stromal cell types in the TME (e.g., tumor-associated macrophages and fibroblasts) have been identified as having plasticity in pro- and antitumor activities and are responsible for suppressing the antitumor immune response. Thus, the TME is an extremely valuable target for adjuvant interventions to improve the effects of immunotherapy. The current strategies targeting the TME include: 1) eliminating immunosuppressive cells or transforming them into immunostimulatory phenotypes and 2) inhibiting their immunosuppressive or pro-tumor production. Most of the effective agents used in the above strategies are genetic materials (e.g., cDNA, mRNA, or miRNA), proteins, or other small molecules (e.g., peptides), which are limited in their target and instability. Various formulations of drug delivery system (DDS) have been designed to realize the controlled release and targeting delivery of these agents to the tumor sites. Nanoparticles and liposomes are the most frequently exploited materials. Based on current evidence from preclinical and clinical studies, the future of the DDS is promising in cancer immunotherapy since the combination of agents with a DDS has shown increased efficacy and decreased toxicities compared with free agents. In the future, more efforts are needed to further identify the hallmarks and biomarkers in the ovarian TME, which is crucial for the development of more effective, safe, and personalized DDSs.

90Y-Labeled Gold Nanoparticle Depot (NPD) Combined with Anti-PD-L1 Antibodies Strongly Inhibits the Growth of 4T1 Tumors in Immunocompetent Mice and Induces an Abscopal Effect on a Distant Non-Irradiated Tumor

The effectiveness and normal tissue toxicity of a novel nanoparticle depot (NPD) brachytherapy seed incorporating gold nanoparticles (AuNPs) labeled with β-particle emitting, ⁹⁰Y (termed a "radiation nanomedicine"), were studied for the treatment of 4T1 triple-negative murine mammary carcinoma tumors in Balb/c mice and for inducing an abscopal effect on a distant non-irradiated tumor alone or combined with anti-PD-L1 immune checkpoint antibodies. Balb/c mice with two subcutaneous 4T1 tumors─a primary tumor and a distant secondary tumor were implanted intratumorally (i.t.) in the primary tumor with NPD incorporating 3.5 MBq of ⁹⁰Y-AuNPs (1 × 10¹⁴ AuNPs) or unlabeled AuNPs, alone or combined with systemically administered anti-PD-L1 antibodies (200 μg i.p. three times/week for 2 weeks) or received anti-PD-L1 antibodies alone or no treatment. The primary tumor was strongly growth-inhibited over 14 d by NPD incorporating ⁹⁰Y-AuNPs but only very modestly inhibited by NPD incorporating unlabeled AuNPs. Anti-PD-L1 antibodies alone were ineffective, and combining anti-PD-L1 antibodies with NPD incorporating ⁹⁰Y-AuNPs did not further inhibit the growth of the primary tumor. Secondary tumor growth was inhibited by treatment of the primary tumor with NPD incorporating ⁹⁰Y-AuNPs, and growth inhibition was enhanced by anti-PD-L1 antibodies. Treatment of the primary tumor with NPD incorporating unlabeled AuNPs or anti-PD-L1 antibodies alone had no effect on secondary tumor growth. Biodistribution studies showed high uptake of ⁹⁰Y in the primary tumor [516-810% implanted dose/g (%ID/g)] but very low uptake in the secondary tumor (0.033-0.16% ID/g) and in normal tissues (<0.5% ID/g) except for kidneys (5-8% ID/g). Very high radiation absorbed doses were estimated for the primary tumor (472 Gy) but very low doses in the secondary tumor (0.13 Gy). There was highdose-heterogeneity in the primary tumor with doses as high as 9964 Gy in close proximity to the NPD, decreasing rapidly with distance from the NPD. Normal organ doses were low (<1 Gy) except for kidneys (4 Gy). No normal tissue toxicity was observed, but white blood cell counts (WBC) decreased in tumor-bearing mice treated with NPD incorporating ⁹⁰Y-AuNPs. Decreased WBC counts were interpreted as tumor response and not toxicity since these were higher than that in healthy non-tumor-bearing mice, and there was a direct association between WBC counts and 4T1 tumor burden. We conclude that implantation of NPD incorporating ⁹⁰Y-AuNPs into a primary 4T1 tumor in Balb/c mice strongly inhibited tumor growth and combined with anti-PD-L1 antibodies induced an abscopal effect on a distant secondary tumor. This radiation nanomedicine is promising for the local treatment of triple-negative breast cancer tumors in patients, and these therapeutic effects may extend to non-irradiated lesions, especially when combined with checkpoint immunotherapy.

Breast cancer liver metastasis: Pathogenesis and clinical implications

Breast cancer is the most common malignant disease in female patients worldwide and can spread to almost every place in the human body, most frequently metastasizing to lymph nodes, bones, lungs, liver and brain. The liver is a common metastatic location for solid cancers as a whole, and it is also the third most common metastatic site for breast cancer. Breast cancer liver metastasis (BCLM) is a complex process. Although the hepatic microenvironment and liver sinusoidal structure are crucial factors for the initial arrest of breast cancer and progression within the liver, the biological basis of BCLM remains to be elucidated. Importantly, further understanding of the interaction between breast cancer cells and hepatic microenvironment in the liver metastasis of breast cancer will suggest ways for the development of effective therapy and prevention strategies for BCLM. In this review, we provide an overview of the recent advances in the understanding of the molecular mechanisms of the hepatic microenvironment in BCLM formation and discuss current systemic therapies for treating patients with BCLM as well as potential therapeutic development based on the liver microenvironment-associated signaling proteins governing BCLM.

Pancancer analysis of a potential gene mutation model in the prediction of immunotherapy outcomes

Background: Immune checkpoint blockade (ICB) represents a promising treatment for cancer, but predictive biomarkers are needed. We aimed to develop a cost-effective signature to predict immunotherapy benefits across cancers.

Methods: We proposed a study framework to construct the signature. Specifically, we built a multivariate Cox proportional hazards regression model with LASSO using 80% of an ICB-treated cohort (n = 1661) from MSKCC. The desired signature named SIGP was the risk score of the model and was validated in the remaining 20% of patients and an external ICB-treated cohort (n = 249) from DFCI.

Results: SIGP was based on 18 candidate genes (NOTCH3, CREBBP, RNF43, PTPRD, FAM46C, SETD2, PTPRT, TERT, TET1, ROS1, NTRK3, PAK7, BRAF, LATS1, IL7R, VHL, TP53, and STK11), and we classified patients into SIGP high (SIGP-H), SIGP low (SIGP-L) and SIGP wild type (SIGP-WT) groups according to the SIGP score. A multicohort validation demonstrated that patients in SIGP-L had significantly longer overall survival (OS) in the context of ICB therapy than those in SIGP-WT and SIGP-H (44.00 months versus 13.00 months and 14.00 months, p &lt; 0.001 in the test set). The survival of patients grouped by SIGP in non-ICB-treated cohorts was different, and SIGP-WT performed better than the other groups. In addition, SIGP-L + TMB-L (approximately 15% of patients) had similar survivals to TMB-H, and patients with both SIGP-L and TMB-H had better survival. Further analysis on tumor-infiltrating lymphocytes demonstrated that the SIGP-L group had significantly increased abundances of CD8+ T cells.

Conclusion: Our proposed model of the SIGP signature based on 18-gene mutations has good predictive value for the clinical benefit of ICB in pancancer patients. Additional patients without TMB-H were identified by SIGP as potential candidates for ICB, and the combination of both signatures showed better performance than the single signature.

Glutamine is essential for overcoming the immunosuppressive microenvironment in malignant salivary gland tumors

Rationale: Immunosuppression in the tumor microenvironment (TME) is key to the pathogenesis of solid tumors. Tumor cell-intrinsic autophagy is critical for sustaining both tumor cell metabolism and survival. However, the role of autophagy in the host immune system that allows cancer cells to escape immune destruction remains poorly understood. Here, we determined if attenuated host autophagy is sufficient to induce tumor rejection through reinforced adaptive immunity. Furthermore, we determined whether dietary glutamine supplementation, mimicking attenuated host autophagy, is capable of promoting antitumor immunity. Methods: A syngeneic orthotopic tumor model in Atg5+/+ and Atg5flox/flox mice was established to determine the impact of host autophagy on the antitumor effects against mouse malignant salivary gland tumors (MSTs). Multiple cohorts of immunocompetent mice were used for oncoimmunology studies, including inflammatory cytokine levels, macrophage, CD4+, and CD8+ cells tumor infiltration at 14 days and 28 days after MST inoculation. In vitro differentiation and in vivo dietary glutamine supplementation were used to assess the effects of glutamine on Treg differentiation and tumor expansion. Results: We showed that mice deficient in the essential autophagy gene, Atg5, rejected orthotopic allografts of isogenic MST cells. An enhanced antitumor immune response evidenced by reduction of both M1 and M2 macrophages, increased infiltration of CD8+ T cells, elevated IFN-γ production, as well as decreased inhibitory Tregs within TME and spleens of tumor-bearing Atg5flox/flox mice. Mechanistically, ATG5 deficiency increased glutamine level in tumors. We further demonstrated that dietary glutamine supplementation partially increased glutamine levels and restored potent antitumor responses in Atg5+/+ mice. Conclusions: Dietary glutamine supplementation exposes a previously undefined difference in plasticity between cancer cells, cytotoxic CD8+ T cells and Tregs.

A Graph Based Neural Network Approach to Immune Profiling of Multiplexed Tissue Samples

Multiplexed immunofluorescence provides an un-precedented opportunity for studying specific cell-to-cell and cell microenvironment interactions. We employ graph neural networks to combine features obtained from tissue morphology with measurements of protein expression to profile the tumour microenvironment associated with different tumour stages. Our framework presents a new approach to analysing and processing these complex multi-dimensional datasets that overcomes some of the key challenges in analysing these data and opens up the opportunity to abstract biologically meaningful interactions.

Challenges and the Evolving Landscape of Assessing Blood-Based PD-L1 Expression as a Biomarker for Anti-PD-(L)1 Immunotherapy

While promising, PD-L1 expression on tumor tissues as assessed by immunohistochemistry has been shown to be an imperfect biomarker that only applies to a limited number of cancers, whereas many patients with PD-L1-negative tumors still respond to anti-PD-(L)1 immunotherapy. Recent studies using patient blood samples to assess immunotherapeutic responsiveness suggests a promising approach to the identification of novel and/or improved biomarkers for anti-PD-(L)1 immunotherapy. In this review, we discuss the advances in our evolving understanding of the regulation and function of PD-L1 expression, which is the foundation for developing blood-based PD-L1 as a biomarker for anti-PD-(L)1 immunotherapy. We further discuss current knowledge and clinical study results for biomarker identification using PD-L1 expression on tumor and immune cells, exosomes, and soluble forms of PD-L1 in the peripheral blood. Finally, we discuss key challenges for the successful development of the potential use of blood-based PD-L1 as a biomarker for anti-PD-(L)1 immunotherapy.

Melanopsin (Opn4) is an oncogene in cutaneous melanoma

The search for new therapeutical targets for cutaneous melanoma and other cancers is an ongoing task. We expanded this knowledge by evaluating whether opsins, light- and thermo-sensing proteins, could display tumor-modulatory effects on melanoma cancer. Using different experimental approaches, we show that melanoma cell proliferation is slower in the absence of Opn4, compared to Opn4WT due to an impaired cell cycle progression and reduced melanocyte inducing transcription factor (Mitf) expression. In vivo tumor progression of Opn4KO cells is remarkably reduced due to slower proliferation, and higher immune system response in Opn4KO tumors. Using pharmacological assays, we demonstrate that guanylyl cyclase activity is impaired in Opn4KO cells. Evaluation of Tumor Cancer Genome Atlas (TCGA) database confirms our experimental data as reduced MITF and OPN4 expression in human melanoma correlates with slower cell cycle progression and presence of immune cells in the tumor microenvironment (TME). Proteomic analyses of tumor bulk show that the reduced growth of Opn4KO tumors is associated with reduced Mitf signaling, higher translation of G2/M proteins, and impaired guanylyl cyclase activity. Conversely, in Opn4WT tumors increased small GTPase and an immune-suppressive TME are found. Such evidence points to OPN4 as an oncogene in melanoma, which could be pharmacologically targeted.

Factors related to the suppression of the antitumour immune response in female dogs with inflammatory mammary carcinoma

Inflammatory mammary carcinoma (IMC), a neoplasia affecting women and female dogs, is considered an aggressive cancer with high metastatic potential and a low survival rate. Studies focused on the tumour microenvironment indicate that the aggressive behaviour of this tumour is primarily correlated with immunological factors as well as inflammation. The objective of this study was to analyse the possible strategies used by the tumour cells to suppress the immune response in female dogs with IMC. Forty-six female dogs were divided into three groups: control (C, n = 10), IMC (n = 14) and mammary carcinoma (MC, n = 22). Clinical-pathological evaluations, survival at follow-up, immunophenotyping of leukocytes in peripheral blood and tumours, and immunohistochemical evaluation of CD4⁺, granzyme B, perforin and FAS-L were performed. Clinical and pathological results showed a higher frequency of the primary form of neoplasia, solid arrays of tumor cells and a lower survival rate in the IMC group (30 days). Morphometric analysis of inflammatory infiltrate revealed more lymphocytes and macrophages in the IMC group. Immunophenotyping analysis of peripheral blood revealed a higher frequency of CD8⁺ T-cells (p = 0.0017), a lower frequency of CD4⁺ T-cells (p <0.0001), and significantly higher mean MHCI and MHCII CD14⁺ fluorescence intensity in the IMC group (p = 0.038 and p = 0.0117, respectively). The immunohistochemical evaluation of tumour sections showed fewer FAS-L-positive inflammatory cells in the IMC group. These results suggest the important contribution of CD8⁺ T-cells, macrophages and FAS-L in the aggressiveness of IMC.

Identification of lncRNA Signature of Tumor-Infiltrating T Lymphocytes With Potential Implications for Prognosis and Chemotherapy of Head and Neck Squamous Cell Carcinoma

Purpose: We systematically analyzed HNSCC-infiltrating T lymphocytes lncRNAs (HILTlncRNAs) to assess their predictive value for the survival outcome and immunotherapy response of patients with anti-programmed death-1 (PD-1) therapy and to evaluate their predictive power to chemotherapeutic agents. Methods: HNSCC transcriptome and clinical information was obtained from The Cancer Genome Atlas (TCGA) database. Immunocell microarray data were obtained from the Gene Expression Omnibus (GEO) database. T-cell-specific lncRNAs were identified by differential expression analysis. Prognostic paired HILTlncRNAs (PHILTlncRNAs) were filtered and modeled by univariate cox, lasso and multivariate cox regression analysis. To construct lncRNA-miRNA-mRNA competitive endogenous RNA (ceRNA) regulatory networks, differentially expressed mRNAs in HNSCC patients were incorporated, microRNAs and differentially expressed mRNAs interacting with T-cell-specific lncRNAs were filtered out based on miRcode, miRDB, miRTarBase, and TargetScan databases. Results: 75 T-cell-specific lncRNAs and 9 prognostic PHILTlncRNAs were identified. Low-risk HNSCC patients had a better prognosis and significant immune cell infiltration, driving the immune response. Differential expression of RNA-binding proteins (RBPs), PD-1 and programmed cell death 1 ligand 1 (PD-L1) was demonstrated in the high and low risk groups of HNSCC patients. In the high risk group, high expression of PD-1 improved patient prognosis, whereas the opposite was observed in the low-risk group. The promoter methylation levels of two RBPs (DNMT1 and ZC3H12D) were decreased in HNSCC patients compared with normal samples, their expression levels were positively correlated with PD-1 and PD-L1 levels and T-cell infiltration. Finally, we screened the sensitivity of HNSCC patients to chemotherapeutic agents and found it differed between high and low risk groups. Conclusion: HILTlncRNAs provided a theoretical basis for immune targeted therapy and drug development.

Clinical significance of CD8-positive lymphocytes on tumor cell clusters of ascites cell block in ovarian high-grade serous carcinoma

Background

The clinical significance of CD8‐positive (CD8⁺) lymphocytes on tumor cell clusters of ascites cell blocks in patients with ovarian high‐grade serous carcinoma (HGSC) was investigated.

Methods

Among HGSC patients who underwent surgery from January 2014 to December 2019, 38 patients with ascites cell block were selected. Using these cell blocks and primary ovarian tumor tissue, the presence of CD8⁺ lymphocytes and the expression of PD‐L1 were examined immunohistochemically. Tumor cell clusters were defined as cell clumps consisting of more than 10 malignant cells in cell block. Cases with at least one CD8⁺ lymphocyte in tumor cell cluster were defined as positive CD8⁺ lymphocytes (Group A); others were defined as negative CD8⁺ lymphocytes (Group B). The tumor tissue CD8⁺ lymphocytes were counted mechanically. Clinicopathological features were retrospectively compared between the two groups.

Results

In total, 38 cases were identified: 25 (65.8%) in Group A and 13 (34.2%) in Group B. More cases in Group A were positive for CD4 (p < 0.01), PD‐L1 (p = 0.02), FoxP3 (p = 0.02) and had a higher number of CD8⁺ lymphocytes in the tissue (p = 0.03). Patients in Group A had better progression‐free survival (p < 0.01) and overall survival (p = 0.04). In multivariate analysis, Group A was an independent prognostic factor for both progression‐free survival (hazard ratio, 0.24; p < 0.01) and overall survival (hazard ratio, 0.21; p = 0.03).

Conclusion

The presence of CD8⁺ lymphocytes in tumor cell clusters of ascites was associated with the status of immune reaction in the tissue and prognosis in patients with HGSC and might be useful information of the immune‐associated therapy.

Immune System in Action

Tumor exists as a complex network of structures with an ability to evolve and evade the host immune surveillance mechanism. The immune milieu which includes macrophages, dendritic cells, natural killer cells, neutrophils, mast cells, B cells, and T cells is found in the core, the invasive margin, or the adjacent stromal or lymphoid component of the tumor. The immune infiltrate is heterogeneous and varies within a patient and between patients of the same tumor histology. The location, density, functionality, and the crosstalk between the immune cells in the tumor microenvironment influence the nature of immune response, prognosis, and treatment outcomes in cancer patients. Therefore, an understanding of the characteristics of the immune cells and their role in tumor immune surveillance is of paramount importance to identify immune targets and to develop novel immune therapeutics in the war against cancer. In this chapter, we provide an overview of the individual components of the human immune system and the translational relevance of predictive biomarkers.

DFMO Improves Survival and Increases Immune Cell Infiltration in Association with MYC Downregulation in the Pancreatic Tumor Microenvironment

Pancreatic ductal adenocarcinoma (PDAC) has an extremely poor five-year survival rate of less than 10%. Immune suppression along with chemoresistance are obstacles for PDAC therapeutic treatment. Innate immune cells, such as tumor-associated macrophages, are recruited to the inflammatory environment of PDAC and adversely suppress cytotoxic T lymphocytes. KRAS and MYC are important oncogenes associated with immune suppression and pose a challenge to successful therapies. Here, we targeted KRAS, through inhibition of downstream c-RAF with GW5074, and MYC expression via difluoromethylornithine (DFMO). DFMO alone and with GW5074 reduced in vitro PDAC cell viability. Both DFMO and GW5074 showed efficacy in reducing in vivo PDAC growth in an immunocompromised model. Results in immunocompetent syngeneic tumor-bearing mice showed that DFMO and combination treatment markedly decreased tumor size, but only DFMO increased survival in mice. To further investigate, immunohistochemical staining showed DFMO diminished MYC expression and increased tumor infiltration of macrophages, CD86+ cells, CD4+ and CD8+ T lymphocytes. GW5074 was not as effective in modulating the tumor infiltration of total CD3+ lymphocytes or tumor progression and maintained MYC expression. Collectively, this study highlights that in contrast to GW5074, the inhibition of MYC through DFMO may be an effective treatment modality to modulate PDAC immunosuppression.

Radiogenomics: Hunting Down Liver Metastasis in Colorectal Cancer Patients

Radiomics is a developing new discipline that analyzes conventional medical images to extract quantifiable data that can be mined for new biomarkers that show the biology of pathological processes at microscopic levels. These data can be converted into image-based signatures to improve diagnostic, prognostic and predictive accuracy in cancer patients. The combination of radiomics and molecular data, called radiogenomics, has clear implications for cancer patients' management. Though some studies have focused on radiogenomics signatures in hepatocellular carcinoma patients, only a few have examined colorectal cancer metastatic lesions in the liver. Moreover, the need to differentiate between liver lesions is fundamental for accurate diagnosis and treatment. In this review, we summarize the knowledge gained from radiomics and radiogenomics studies in hepatic metastatic colorectal cancer patients and their use in early diagnosis, response assessment and treatment decisions. We also investigate their value as possible prognostic biomarkers. In addition, the great potential of image mining to provide a comprehensive view of liver niche formation is examined thoroughly. Finally, new challenges and current limitations for the early detection of the liver premetastatic niche, based on radiomics and radiogenomics, are also discussed.

Changes of immune cells in patients with hepatocellular carcinoma treated by radiofrequency ablation and hepatectomy, a pilot study

In this pilot study, we compared the dynamic changes of circulating immune cells between patients with hepatocellular carcinoma (HCC) who underwent radiofrequency ablation (RFA) and hepatectomy. Seventy-three patients were enrolled in this study. Flow cytometry assay was performed to determine the immune cells in the peripheral blood mononuclear cells (PBMCs) before treatment and on days 7, 14, and 28 after treatment. We found that in the RFA group, the circulating cluster of differentiation (CD)4+ cells, the CD4+/CD8+ ratio, and natural killer (NK) cells continued to increase, and the circulating CD8+ cells continued to decrease after the treatment. In contrast, in the surgery group, the circulating CD4+ cells and CD4+/CD8+ ratio decreased over the first seven postoperative days and then began to increase, and CD8+ cells decreased on the first 7 postoperative days and began to increase thereafter. The changes of immune cells in tumor tissues consisted of an increase in the number of CD4+ cells, CD8+ cells, CD3+ cells, and NK cells immediately after RFA. Our results show that postoperative immune function continued to improve after RFA, but after surgery, it decreased in the first week and started to improve thereafter. These findings are important for clinicians when selecting the appropriate therapy for HCC.

CD4+ CD25+ regulatory T-cells role in tumor microenvironment of the squamous cell carcinoma

Introduction: Squamous cell carcinoma (SCC) is the most common skin cancer with a high rate of death. Different lymphocyte populations play an important role in modulating the immune response in the tumor microenvironment. The increase in the proportion of cluster of differentiation (CD)4+ CD25+ regulatory T-cell (Treg) lymphocytes is associated, in different studies, with the increase of the cell multiplication rate. Aim: To analyze the Treg lymphocyte subpopulations and to correlate the results with the presence of the CD8+ cytotoxic T-cell (Tc) lymphocyte population. Materials and Methods: Sixty primary skin SCC specimens were incubated with anti-CD8 (clone SP57) rabbit monoclonal antibody and anti-CD25 (clone 4C9) mouse monoclonal antibody. Results: The ratio of the intratumoral/peritumoral CD4+ CD25+ forkhead box protein p3 (Foxp3) lymphocytes was 0.46, emphasizing that at tumor margins, where tumor aggressiveness is higher, these lymphocytes subpopulations facilitate tumor progression. The comparative analysis of the tumor microenvironment profile revealed that in the case of intratumoral immune response, the number of Tc-type lymphocytes (CD8+) was 3.34 times higher compared to Treg lymphocytes (p<0001). In the peritumoral area, the number of Tc lymphocytes was 5.05 times higher compared to Treg lymphocytes (p<0001). Conclusions: Treg lymphocytes inhibition may cause the suppression of the antitumoral cell immune response in the tumor environment. We believe that Treg lymphocytes should represent a focus of interest for a new personalized therapy. New studies are needed to better understand the immune response in the tumor microenvironment.

TMB and Inflammatory Gene Expression Associated with Clinical Outcomes following Immunotherapy in Advanced Melanoma

Outcomes for patients with melanoma have improved over the past decade as a result of the development and FDA approval of immunotherapies targeting cytotoxic T lymphocyte antigen-4 (CTLA-4), programmed death-1 (PD-1), and programmed death ligand 1 (PD-L1). However, these therapies do not benefit all patients, and an area of intensive research investigation is identifying biomarkers that can predict which patients are most likely to benefit from them. Here, we report exploratory analyses of the associations of tumor mutational burden (TMB), a 4-gene inflammatory gene expression signature, and BRAF mutation status with tumor response, progression-free survival, and overall survival in patients with advanced melanoma treated as part of the CheckMate 066 and 067 phase III clinical trials evaluating immuno-oncology therapies. In patients enrolled in CheckMate 067 receiving the anti-PD-1 inhibitor nivolumab (NIVO) alone or in combination with the anti-CTLA-4 inhibitor ipilimumab (IPI) or IPI alone, longer survival appeared to associate with high (>median) versus low (≤median) TMB and with high versus low inflammatory signature scores. For NIVO-treated patients, the results regarding TMB association were confirmed in CheckMate 066. In addition, improved survival was observed with high TMB and absence of BRAF mutation. Weak correlations were observed between PD-L1, TMB, and the inflammatory signature. Combined assessment of TMB, inflammatory gene expression signature, and BRAF mutation status may be predictive for response to immune checkpoint blockade in advanced melanoma.

Histamine in cancer immunology and immunotherapy. Current status and new perspectives

Cancer is the second leading cause of death globally and its incidence and mortality are rapidly increasing worldwide. The dynamic interaction of immune cells and tumor cells determines the clinical outcome of cancer. Immunotherapy comes to the forefront of cancer treatments, resulting in impressive and durable responses but only in a fraction of patients. Thus, understanding the characteristics and profiles of immune cells in the tumor microenvironment (TME) is a necessary step to move forward in the design of new immunomodulatory strategies that can boost the immune system to fight cancer. Histamine produces a complex and fine-tuned regulation of the phenotype and functions of the different immune cells, participating in multiple regulatory responses of the innate and adaptive immunity. Considering the important actions of histamine-producing immune cells in the TME, in this review we first address the most important immunomodulatory roles of histamine and histamine receptors in the context of cancer development and progression. In addition, this review highlights the current progress and foundational developments in the field of cancer immunotherapy in combination with histamine and pharmacological compounds targeting histamine receptors.

MK-6, a novel not-α IL-2, elicits a potent antitumor activity by improving the effector to regulatory T cell balance

IL-2 is a pleiotropic cytokine that regulates immune cell homeostasis. Its immunomodulatory function has been used clinically as an active immunotherapy agent for metastatic cancers. However, severe adverse effects, including the vascular leak syndrome and the preferential stimulation of anti-immunogenic Treg rather than effector T cells, have been obstacles. We newly designed a mutein IL-2, Mutakine-6 (MK-6), with reduced IL-2Rα-binding capability. MK-6 induced comparable cell growth potential toward IL-2Rβγ-positive T cells but was far less efficient in in vitro Treg proliferation and STAT5 activation. Unlike IL-2, in vivo administration of MK-6 produced minimal adverse effects. Using CT26 and B16F10-syngeneic tumor models, we found MK-6 was highly efficacious on tumor regression. Serum albumin conjugation to MK-6 prolonged in vivo half-life and accumulated in CT26 tumors, showing enhanced antitumor effect. Tumor-infiltrating leukocytes analysis revealed that albumin-fused MK-6 increased the ratio of effector CD8⁺ T cells to CD4⁺ Treg cells. These results demonstrated that MK-6 is an efficient immunomodulator potentially used for improved immunotherapy with decreased adverse effects and attenuated Treg stimulation.

Proteomic Implications of Tumoral Infiltrating Lymphocytes in Melanoma: PD-L1, CD4 and CD8 - Short Review

Melanoma is a tumor developed by malignancy of melanocytes, being one of the most lethal cancers. Usually, it is associated with exposure to ultraviolet radiations, being most common in the skin, but can also be located extracutaneously as in the digestive tract, leptomeninges or uvea. Histopathologically it presents a phase of radial growth and a vertical one, often accompanied by an intra and peritumoral inflammatory infiltrate. Immunohistochemically, the confirmation of the diagnosis of melanoma should be accompanied by the assessment of proteomic markers of lymphocytic infiltrate such as PD-L1, CD4 and CD8. Those have a role in evaluating the prognosis and a possible prediction of the immunotherapeutic response.

Immunobiology of Melanoma

Despite the ability of immune-based interventions to dramatically increase the survival of patients with melanoma, a significant subset fail to benefit from this treatment, underscoring the need for accurate means to identify the patient population likely to respond to immunotherapy. Understanding how melanoma evades natural or manipulated immune responses could provide the information needed to identify such resistant individuals. Efforts to address this challenge are hampered by the vast immune diversity characterizing tumor microenvironments that remain largely understudied. It is thus important to more clearly elucidate the complex interactions that take place between the tumor microenvironment and host immune system.

Colonic epithelial cathelicidin (LL-37) expression intensity is associated with progression of colorectal cancer and presence of CD8+ T cell infiltrate

Colorectal cancer (CRC) remains a leading cause of cancer mortality. Here, we define the colonic epithelial expression of cathelicidin (LL-37) in CRC. Cathelicidin exerts pleotropic effects including anti-microbial and immunoregulatory functions. Genetic knockout of cathelicidin led to increased size and number of colorectal tumours in the azoxymethane-induced murine model of CRC. We aimed to translate this to human disease. The expression of LL-37 in a large (n = 650) fully characterised cohort of treatment-naïve primary human colorectal tumours and 50 matched normal mucosa samples with associated clinical and pathological data (patient age, gender, tumour site, tumour stage [UICC], presence or absence of extra-mural vascular invasion, tumour differentiation, mismatch repair protein status, and survival to 18 years) was assessed by immunohistochemistry. The biological consequences of LL-37 expression on the epithelial barrier and immune cell phenotype were assessed using targeted quantitative PCR gene expression of epithelial permeability (CLDN2, CLDN4, OCLN, CDH1, and TJP1) and cytokine (IL-1β, IL-18, IL-33, IL-10, IL-22, and IL-27) genes in a human colon organoid model, and CD3+ , CD4+ , and CD8+ lymphocyte phenotyping by immunohistochemistry, respectively. Our data reveal that loss of cathelicidin is associated with human CRC progression, with a switch in expression intensity an early feature of CRC. LL-37 expression intensity is associated with CD8+ T cell infiltrate, influenced by tumour characteristics including mismatch repair protein status. There was no effect on epithelial barrier gene expression. These data offer novel insights into the contribution of LL-37 to the pathogenesis of CRC and as a therapeutic molecule.

Key sunitinib-related biomarkers for renal cell carcinoma

Background

Renal cell carcinoma (RCC) contributed to 403,262 new cases worldwide in 2018, which constitutes 2.2% of global cancer, nevertheless, sunitinib, one of the major targeted therapeutic agent for RCC, often developed invalid due to resistance. Emerging evidences suggested sunitinib can impact tumor environment which has been proven to be a vital factor for tumor progression.

Methods

In the present study, we used ssGSEA to extract the immune infiltrating abundance of clear cell RCC (ccRCC) and normal control samples from GSE65615, TCGA, and GTEx; key immune cells were determined by Student's t‐test and univariable Cox analysis. Co‐expression network combined with differentially expressed analysis was then applied to derive key immune‐related genes for ccRCC, followed by the identification of hub genes using differential expression analysis. Subsequently, explorations and validations of the biological function and the immune‐related and sunitinib‐related characteristics were conducted in KEGG, TISIDB, Oncomine, ICGC, and GEO databases.

Results

We refined immature dendritic cells and central memory CD4 T cells which showed associations with sunitinib and ccRCC. Following, five hub genes (CRYBB1, RIMBP3C, CEACAM4, HAMP, and LYL1) were identified for their strong relationships with sunitinib and immune infiltration in ccRCC. Further validations in external data refined CRYBB1, CEACAM4, and HAMP which play a vital role in sunitinib resistance, immune infiltrations in ccRCC, and the development and progression of ccRCC. In conclusion, our findings could shed light on the resistance of sunitinib in ccRCC and provide novel biomarkers or drug targets for ccRCC.

Biguanides drugs: Past success stories and promising future for drug discovery

Biguanides have attracted much attention a century ago and showed resurgent interest in recent years after a long period of dormancy. They constitute an important class of therapeutic agents suitable for the treatment of a wide spectrum of diseases. Therapeutic indications of biguanides include antidiabetic, antimalarial, antiviral, antiplaque, and bactericidal applications. This review presents an extensive overview of the biological activity of biguanides and different mechanisms of action of currently marketed biguanide-containing drugs, as well as their pharmacological properties when applicable. We highlight the recent developments in research on biguanide compounds, with a primary focus on studies on metformin in the field of oncology. We aim to provide a critical overview of all main bioactive biguanide compounds and discuss future perspectives for the design of new drugs based on the biguanide fragment.

Analyses of PD-L1 and Inflammatory Gene Expression Association with Efficacy of Nivolumab ± Ipilimumab in Gastric Cancer/Gastroesophageal Junction Cancer

PURPOSE

In advanced gastric cancer/gastroesophageal junction cancer (GC/GEJC), there is a need to identify biomarkers of response to therapies, such as immune checkpoint inhibitors.

PATIENTS AND METHODS

In post hoc exploratory analyses from CheckMate 032 (GC/GEJC cohort), we evaluated associations between nivolumab ± ipilimumab (NIVO ± IPI) efficacy and programmed death ligand 1 (PD-L1) expression, defined by tumor cells (% TC) or combined positive score (CPS; sum of PD-L1-staining TCs + immune cells, divided by total viable TCs, × 100) using the Dako PD-L1 IHC 28-8 pharmDx assay, or inflammatory gene expression.

RESULTS

There was a trend toward increased efficacy (objective response and overall survival) when PD-L1 expression was determined by CPS compared with % TC at higher cutoffs of ≥5 and ≥10 in the pooled analysis of all treatment regimens. In this analysis, 19% and 26% of patients with PD-L1-positive tumors at a CPS cutoff of ≥5 and ≥10, respectively, had an objective response compared with 8% and 9% of patients at the equivalent % TC cutoffs. Longer survival was demonstrated in patients with PD-L1-positive (defined by CPS cutoffs of ≥5 and ≥10) versus PD-L1-negative status. Similar results were observed in the NIVO 1 mg/kg + IPI 3 mg/kg subgroup. Multiple inflammatory gene signatures/transcripts, including a signature consisting of four genes (CD274, CD8A, LAG3, and STAT1), showed associations with response to NIVO ± IPI.

CONCLUSIONS

This study suggests a greater association of PD-L1 expression by CPS with NIVO ± IPI efficacy compared with % TC PD-L1 expression in patients with GC/GEJC. Inflammatory signatures were also associated with NIVO ± IPI response, warranting further investigation.See related commentary by Moutafi and Rimm, p. 3812.

Endothelial cell-derived Apelin inhibits tumor growth by altering immune cell localization

The Apelin/APJ signalling pathway, involved in multiple physiological and pathological processes, has been attracting increasing interest recently. In our previous study, Apelin overexpression in colon26 tumor cells suppressed tumor growth by inducing vascular maturation. Here, we found that MC38 and LLC tumor growth were greater in the absence of Apelin than in wild-type (WT) mice, suggesting that Apelin acts as a tumor suppressor. Consistent with this, treating WT mice with [Pyr¹]Apelin-13 inhibited tumor growth. In MC38 tumors, only endothelial cells (ECs) strongly express APJ, a cognate receptor for Apelin, indicating that EC-derived Apelin might regulate tumor formation in an autocrine manner. Comparing with WT mice, larger numbers of vessels with narrower diameters were observed in tumors of Apelin knockout mice and lack of Apelin enhanced tumor hypoxia. Investigating immune cells in the tumor revealed that [Pyr¹]Apelin-13 infusion induced the accumulation of CD8⁺ and CD4⁺ T cells in central areas. Moreover, RNA-sequencing analysis showed that Apelin induces chemokine CCL8 expression in ECs. Thus, enhancing anti-tumor immunity might be one of the mechanisms by which Apelin is involved in tumor growth. Our result indicated that increased CCL8 expression might induce CD8⁺  T cells infiltration into tumor and tumor inhibition.

Macrophage Polarization States in the Tumor Microenvironment

The M1/M2 macrophage paradigm plays a key role in tumor progression. M1 macrophages are historically regarded as anti-tumor, while M2-polarized macrophages, commonly deemed tumor-associated macrophages (TAMs), are contributors to many pro-tumorigenic outcomes in cancer through angiogenic and lymphangiogenic regulation, immune suppression, hypoxia induction, tumor cell proliferation, and metastasis. The tumor microenvironment (TME) can influence macrophage recruitment and polarization, giving way to these pro-tumorigenic outcomes. Investigating TME-induced macrophage polarization is critical for further understanding of TAM-related pro-tumor outcomes and potential development of new therapeutic approaches. This review explores the current understanding of TME-induced macrophage polarization and the role of M2-polarized macrophages in promoting tumor progression.

Analysis of Immune Landscape in Pancreatic and Ileal Neuroendocrine Tumours Demonstrates an Immune Cold Tumour Microenvironment

INTRODUCTION

Neuroendocrine tumours (NETs) are rare tumours with an increasing incidence. While low- and intermediate-grade pancreatic NET (PanNET) and small intestinal NET (siNET) are slow growing, they have a relatively high rate of metastasizing to the liver, leading to substantially worse outcomes. In many solid tumours, the outcome is determined by the quality of the antitumour immune response. However, the quality and significance of antitumour responses in NETs are incompletely understood. This study provides clinico-pathological analyses of the tumour immune microenvironment in PanNET and siNETs.

METHODS

Formalin-fixed paraffin-embedded tissue from consecutive resected PanNETs (61) and siNETs (131) was used to construct tissue microarrays (TMAs); 1-mm cores were taken from the tumour centre, stroma, tumour edge, and adjacent healthy tissue. TMAs were stained with antibodies against CD8, CD4, CD68, FoxP3, CD20, and NCR1. T-cell counts were compared with counts from lung cancers.

RESULTS

For PanNET, median counts were CD8+ 35.4 cells/mm2, CD4+ 7.6 cells/mm2, and CD68+ macrophages 117.7 cells/mm2. For siNET, there were CD8+ 39.2 cells/mm2, CD4+ 24.1 cells/mm2, and CD68+ 139.2 cells/mm2. The CD8+ cell density in the tumour and liver metastases were significantly lower than in the adjacent normal tissues, without evidence of a cell-rich area at the tumour edge that might have suggested immune exclusion. T-cell counts in lung cancer were significantly higher than those in PanNET and siNETs: CD8+ 541 cells/mm2 and CD4+ 861 cells/mm2 (p ≤ 0.0001).

CONCLUSION

PanNETs and siNETs are immune cold with no evidence of T cell exclusion; the low density of immune infiltrates indicates poor antitumour immune responses.

Generating CAR T cells from tumor-infiltrating lymphocytes

Background: Tumor-infiltrating lymphocytes (TILs) and chimeric antigen receptor (CAR) T-cell therapies have demonstrated promising, though limited, efficacy against melanoma. Methods: We designed a model system to explore the efficacy of dual specific T cells derived from melanoma patient TILs by transduction with a Her2-specific CAR. Results: Metastatic melanoma cells in our biobank constitutively expressed Her2 antigen. CAR-TIL produced greater amounts of IFN compared with parental TIL, when co-cultured with Her2 expressing tumor lines, including autologous melanoma tumor lines, although no consistent increase in cytotoxicity by TIL was afforded by expression of a CAR. Results of an in vivo study in NSG mice demonstrated tumor shrinkage when CAR-TILs were used in an adoptive cell therapy protocol. Conclusion: Potential limitations of transduced TIL in our study included limited proliferative potential and a terminally differentiated phenotype, which would need addressing in further work before consideration of clinical translation.

Identification of docetaxel-related biomarkers for prostate cancer

Prostate cancer (PCa) which was the second commonly diagnosed malignancy, contributed to the top fifth carcinoma death in men. Nevertheless, the main chemotherapeutic agent docetaxel came to failure due to chemoresistance. Recently, increasing evidence suggested the importance of tumour microenvironment (TME) in PCa. The present study aimed to explore the specific TME in PCa and find biomarkers related to both immune infiltration and docetaxel. The docetaxel-specific genes and differential expression genes comparing PCa with normal control samples were derived using DESeq2 and zinbwave with GSE140440, TCGA and GTEx datasets. Immune-infiltration-related genes were identified using CIBERSORT and co-expression network analysis. Key genes related to both docetaxel and immune infiltrating in PCa, including nine genes, namely ZNF486, IFI6, TMOD2, HSPA4L, ITPR1, LRRC37A7P, APOC1, APOBEC3G, and ITGA2, were determined by overlapping above three gene sets. ITGA2 was then defined as the hub gene for its significant prognostic implications. Further validations conducted on Oncomine, GEO, TISIDB, MSigDB, and The Human Protein Atlas confirmed the docetaxel-specific and immune infiltrating characteristics of ITGA2. To sum up, our findings could provide a better understanding of immune infiltrating and docetaxel-resistance in PCa, mostly, ITGA2 could serve as potential prognosis biomarkers and targets for the combination of docetaxel.

Chromatin accessibility governs the differential response of cancer and T cells to arginine starvation

Depleting the microenvironment of important nutrients such as arginine is a key strategy for immune evasion by cancer cells. Many tumors overexpress arginase, but it is unclear how these cancers, but not T cells, tolerate arginine depletion. In this study, we show that tumor cells synthesize arginine from citrulline by upregulating argininosuccinate synthetase 1 (ASS1). Under arginine starvation, ASS1 transcription is induced by ATF4 and CEBPβ binding to an enhancer within ASS1. T cells cannot induce ASS1, despite the presence of active ATF4 and CEBPβ, as the gene is repressed. Arginine starvation drives global chromatin compaction and repressive histone methylation, which disrupts ATF4/CEBPβ binding and target gene transcription. We find that T cell activation is impaired in arginine-depleted conditions, with significant metabolic perturbation linked to incomplete chromatin remodeling and misregulation of key genes. Our results highlight a T cell behavior mediated by nutritional stress, exploited by cancer cells to enable pathological immune evasion.

A prognostic value of CD45RA+, CD45RO+, CCL20+ and CCR6+ expressing cells as 'immunoscore' to predict cervical cancer induced by HPV

The interplay between cervical cancer (CC) and immune cells, mainly intratumoral lymphocytes, has a pivotal role in carcinogenesis. In this context, we evaluated the distribution of CD45RA⁺ and CD45RO⁺ cells as well as CCR6⁺ and CCL20⁺ cells in intraepithelial (IE) and marginal stroma (MS) areas from cervical intraepithelial neoplasia (CIN) I-III, and CC as 'immunoscore' for HPV-induced CC outcome. We observed increased CD45RA⁺ and CD45RO⁺ cells distribution in IE and MS areas in the CC group compared to CIN groups and healthy volunteers. Interestingly, there is a remarkable reduction of CCL20⁺ expressing cells distribution according to lesion severity. The CC group had a significant decrease in CCL20⁺ and CCR6⁺-expressing cells distribution in both IE and MS areas compared to all groups. Using the 'immunoscore' model, we observed an increased number of women presenting high CD45RA⁺/CD45RO⁺ and low CCL20⁺/CCR6⁺ 'immunoscore' in the CC group. Our results suggested a pattern in cervical inflammatory process with increasing CD45RA⁺/CD45RO⁺, and decreasing CCL20⁺/CCR6⁺ expression in accordance with CIN severity. Taken together, these markers could be evaluated as 'immunoscore' predictors to CC response. A more comprehensive analysis of longitudinal studies should be conducted to associate CD45RA⁺/CD45RO⁺ and CCL20⁺/CCR6⁺ 'immunoscore' to CC progression and validate its value as a prognosis method.

Modulation of the tumor micro-environment by CD8+ T cell-derived cytokines

Upon their activation, CD8⁺ T cells in the tumor micro-environment (TME) secrete cytokines such as IFNγ, TNFα, and IL-2. While over the past years a major interest has developed in the antigenic signals that induce such cytokine release, our understanding of the cells that subsequently sense these CD8⁺ T-cell secreted cytokines is modest. Here, we review the current insights into the spreading behavior of CD8⁺ T-cell-secreted cytokines in the TME. We argue for a model in which variation in the mode of cytokine secretion, cytokine half-life, receptor-mediated clearance, cytokine binding to extracellular components, and feedback or forward loops, between different cytokines or between individual tumors, sculpts the local tissue response to natural and therapy-induced T-cell activation in human cancer.

Ganoderma lucidum polysaccharide (GLP) enhances antitumor immune response by regulating differentiation and inhibition of MDSCs via a CARD9-NF-κB-IDO pathway

A homogeneous polysaccharide (GLP), with an average molecular weight of 4.44 × 104 Da, was isolated and purified from the fruiting bodies of Ganoderma lucidum. In this work, we examined the antitumor activities of GLP using a mouse Lewis lung cancer (LLC) model and explored possible molecular pathways involved in its immunomodulatory mechanism on tumor-host interaction. GLP administration (25 and 100 mg/kg) significantly inhibited tumor growth, as evidenced by the decreased tumor volume and tumor weight, as well as histological features of tumor tissues with concomitant down-regulation of proliferating cell nuclear antigen (PCNA) proliferative marker. Less myeloid-derived suppressor cells (MDSCs) were accumulated in both spleen and tumor tissues from GLP-treated mice. In contrast, the percentage of CD4+ and CD8+ T cells together with the production of Th1-type cytokines (IFN-γ and IL-12) was increased in the spleen of LLC-bearing mice following GLP administration. Furthermore, GLP administration reversed the attenuated expression of CARD9, p-Syk and p-p65, and increased indoleamine 2,3-dioxygenase (IDO) protein expression in MDSCs of LLC-bearing mice. Collectively, our data demonstrated the first time that GLP induced the differentiation of MDSCs and inhibited the accumulation of MDSCs via CARD9-NF-κB-IDO pathway, thus prevented lung cancer development.

Biological Heterogeneity of Chondrosarcoma: From (Epi) Genetics through Stemness and Deregulated Signaling to Immunophenotype

Chondrosarcoma (ChS) is a primary malignant bone tumor. Due to its heterogeneity in clinical outcomes and resistance to chemo- and radiotherapies, there is a need to develop new potential therapies and molecular targets of drugs. Many genes and pathways are involved in in ChS progression. The most frequently mutated genes are isocitrate dehydrogenase ½ (IDH1/2), collagen type II alpha 1 chain (COL2A1), and TP53. Besides the point mutations in ChS, chromosomal aberrations, such as 12q13 (MDM2) amplification, the loss of 9p21 (CDKN21/p16/INK4A and INK4A-p14ARF), and several gene fusions, commonly occurring in sarcomas, have been found. ChS involves the hypermethylation of histone H3 and the decreased methylation of some transcription factors. In ChS progression, changes in the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K-AKT-mTOR) and hedgehog pathways are known to play a role in tumor growth and chondrocyte proliferation. Due to recent discoveries regarding the potential of immunotherapy in many cancers, in this review we summarize the current state of knowledge concerning cellular markers of ChS and tumor-associated immune cells. This review compares the latest discoveries in ChS biology from gene alterations to specific cellular markers, including advanced molecular pathways and tumor microenvironment, which can help in discovering new potential checkpoints in inhibitory therapy.

Bifidobacterium Strain-Specific Enhances the Efficacy of Cancer Therapeutics in Tumor-Bearing Mice

Colorectal cancer (CRC) is among the leading causes of cancer-related death in the world. The development of CRC is associated with smoking, diet, and microbial exposure. Previous studies have shown that dysbiosis of the gut microbiome affects cancer development, because it leads to inflammation and genotoxicity. Supplementation with specific microbiota induces anti-tumor effects by enhancing of anti-tumor immunity. Here, we observed that supplementation with either of two B. breve strains reduces tumor growth in MC38 colon carcinoma-bearing mice. Interestingly, only one B. breve strain boosted the efficacy of cancer therapeutics, including oxaliplatin and PD-1 blockade. Extensive immune profiling and transcriptomic analysis revealed that the boosting B. breve strain augments lymphocyte-mediated anti-cancer immunity. Our results suggest that supplementation with B. breve strains could potentially be used as a strategy to enhance the efficacy of CRC therapeutics.

Systemic immunity upon local oncolytic virotherapy armed with immunostimulatory genes may be supported by tumor-derived exosomes

Immunostimulatory gene therapy utilizing oncolytic viruses (OVs) as gene vehicles is a promising immunotherapy for cancer. Since viruses are immunogenic, systemic delivery can be troublesome due to neutralizing antibodies. Nevertheless, local delivery by intratumoral injection seems to induce systemic immune reactions. In this study, we demonstrate a novel mechanism of action of armed OV therapy suggesting that exosomes released by tumor cells infected with armed OV may participate to activate the immune system and this may also support systemic immunity. Tumor cell-derived exosomes commonly exert immunosuppressive functions. We hypothesized that exosomes derived from OV-infected tumor cells may instead be immunostimulatory. Human melanoma cells were infected by OVs armed with costimulatory molecules CD40 ligand (CD40L) and 4-1BB ligand (4-1BBL). Exosomes were purified and investigated for the presence of CD40L/4-1BBL mRNA and protein, and for their capacity to stimulate immune responses. The results show that the exosomes cargo transgenes. The exosomes from CD40L/4-1BBL-expressing tumor cells, or the viruses themselves, could stimulate robust dendritic cell (DC) activation with an enhanced level of major histocompatibility complex (MHC) and costimulatory molecules. Hence, exosomes after OV infection can locally activate immune responses at the tumor site and encounter immune cells such as DCs.

Overexpression of Interleukin-1α Suppresses Liver Metastasis of Lymphoma: Implications for Antitumor Effects of CD8+ T-cells

Interleukin (IL)-1 plays a key role in carcinogenesis, tumor progression, and metastasis. Although IL-1 may enhance the expansion of CD8+ T-cells, the pathological contribution of IL-1-activated CD8+ T-cells to tumor metastasis remains unclear. This study used a liver metastasis model of the EL4 T-cell lymphoma cells transplanted into human IL (hIL)-1α conditional transgenic (hIL-1α cTg) mice. Overproduction of hIL-1α suppressed both macroscopic and histological liver metastasis of EL4 T-cell lymphoma. The hIL-1α-induced inflammatory state increased the number of CD8+ T-cells both within and around metastatic tumors. Moreover, larger numbers of CD8+ T-cells showed greater infiltration of liver blood vessels in hIL-1α cTg mice than in control wild-type mice. Terminal deoxynucleotidyl transferase dUTP nick-end labeling staining of liver tissue from hIL-1α cTg mice indicated increased apoptosis of cells in the tumor. Localization of apoptosis cells resembled that of CD8+ T-cells. In addition, cytotoxicity assay showed that CD8+ T-cell counts from tumor-bearing hIL-1α cTg mice correlated with cytotoxicity against EL4. In summary, IL-1α suppresses lymphoma metastasis, and IL-1α-activated CD8+ T-cells may play important roles in inhibiting both tumor metastasis and metastatic tumor growth.

Microenvironmental Th9 and Th17 lymphocytes induce metastatic spreading in lung cancer

Immune microenvironment plays a critical role in lung cancer control versus progression and metastasis. In this investigation, we explored the effect of tumor-infiltrating lymphocyte subpopulations on lung cancer biology by studying in vitro cocultures, in vivo mouse models, and human lung cancer tissue. Lymphocyte conditioned media (CM) induced epithelial-mesenchymal transition (EMT) and migration in both primary human lung cancer cells and cell lines. Correspondingly, major accumulation of Th9 and Th17 cells was detected in human lung cancer tissue and correlated with poor survival. Coculturing lung cancer cells with Th9/Th17 cells or exposing them to the respective CM induced EMT in cancer cells and modulated the expression profile of genes implicated in EMT and metastasis. These features were reproduced by the signatory cytokines IL-9 and IL-17, with gene regulatory profiles evoked by these cytokines partly overlapping and partly complementary. Coinjection of Th9/Th17 cells with tumor cells in WT, Rag1-/-, Il9r-/-, and Il17ra-/- mice altered tumor growth and metastasis. Accordingly, inhibition of IL-9 or IL-17 cytokines by neutralizing antibodies decreased EMT and slowed lung cancer progression and metastasis. In conclusion, Th9 and Th17 lymphocytes induce lung cancer cell EMT, thereby promoting migration and metastatic spreading and offering potentially novel therapeutic strategies.

Cell-Based Tracers as Trojan Horses for Image-Guided Surgery

Surgeons rely almost completely on their own vision and palpation to recognize affected tissues during surgery. Consequently, they are often unable to distinguish between different cells and tissue types. This makes accurate and complete resection cumbersome. Targeted image-guided surgery (IGS) provides a solution by enabling real-time tissue recognition. Most current targeting agents (tracers) consist of antibodies or peptides equipped with a radiolabel for Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT), magnetic resonance imaging (MRI) labels, or a near-infrared fluorescent (NIRF) dye. These tracers are preoperatively administered to patients, home in on targeted cells or tissues, and are visualized in the operating room via dedicated imaging systems. Instead of using these 'passive' tracers, there are other, more 'active' approaches of probe delivery conceivable by using living cells (macrophages/monocytes, neutrophils, T cells, mesenchymal stromal cells), cell(-derived) fragments (platelets, extracellular vesicles (exosomes)), and microorganisms (bacteria, viruses) or, alternatively, 'humanized' nanoparticles. Compared with current tracers, these active contrast agents might be more efficient for the specific targeting of tumors or other pathological tissues (e.g., atherosclerotic plaques). This review provides an overview of the arsenal of possibilities applicable for the concept of cell-based tracers for IGS.

The ITIM-Containing Receptor: Leukocyte-Associated Immunoglobulin-Like Receptor-1 (LAIR-1) Modulates Immune Response and Confers Poor Prognosis in Invasive Breast Carcinoma

BACKGROUND

The leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) plays a role in immune response homeostasis, extracellular matrix remodelling and it is overexpressed in many high-grade cancers. This study aimed to elucidate the biological and prognostic role of LAIR-1 in invasive breast cancer (BC).

METHODS

The biological and prognostic effect of LAIR-1 was evaluated at the mRNA and protein levels using well-characterised multiple BC cohorts. Related signalling pathways were evaluated using in silico differential gene expression and siRNA knockdown were used for functional analyses.

RESULTS

High LAIR-1 expression either in mRNA or protein levels were associated with high tumour grade, poor Nottingham Prognostic Index, hormone receptor negativity, immune cell infiltrates and extracellular matrix remodelling elements. High LAIR-1 protein expression was an independent predictor of shorter BC-specific survival and distant metastasis-free survival in the entire BC cohort and human epidermal growth factor receptor 2 (HER2)+ subtype. Pathway analysis highlights LAIR-1 association with extracellular matrix remodelling-receptor interaction, and cellular proliferation. Depletion of LAIR-1 using siRNA significantly reduced cell proliferation and invasion capability in HER2+ BC cell lines.

CONCLUSION

High expression of LAIR-1 is associated with poor clinical outcome in BC. Association with immune cells and immune checkpoint markers warrant further studies to assess the underlying mechanistic roles.

Beyond Blocking: Engineering RNAi-Mediated Targeted Immune Checkpoint Nanoblocker Enables T-Cell-Independent Cancer Treatment

The emergence of immune checkpoint blockade to activate host T cells to attack tumor cells has revolutionized the cancer treatment landscape over the past decade. However, sustained response has only been achieved in a small proportion of patients. This can be attributed to physiological barriers, such as T-cell heterogeneity and immunosuppressive tumor microenvironments. To this can be added obstacles intrinsic to traditional antibody-driven blockade methods, including the inability to inhibit checkpoint translocation from cytoplasm, systemic immune toxicity, and "bite back" effect on T cells. Using non-small cell lung cancer (NSCLC) as the cancer model, here we report an unconventional, yet powerful, tumor-targeted checkpoint blocking strategy by RNAi nanoengineering for T-cell-independent cancer therapy. Unlike antibodies, such nanoblocker silences both membranous and cytoplasmic PD-L1 in cancer cells, thus eliminating the binding step. Moreover, it is demonstrated that silencing of PD-L1 by the nanoblocker can cause the direct programmed cell death of NSCLC H460 cells, without the need of T-cell intervention. In vivo results from xenograft tumor models further demonstrate that tumor-homing peptide modification enables the nanoblocker to accumulate in the tumor tissue, downregulate the PD-L1 expression, and inhibit the tumor growth more efficiently than the nontargeted group. These findings may offer an effective means toward overcoming barriers against traditional checkpoint blockade and provide different insights into the molecular mechanism(s) underlying immunotherapy.

T-Box Transcription Factor 22 Is an Immune Microenvironment-Related Biomarker Associated With the BRAF V600E Mutation in Papillary Thyroid Carcinoma

Papillary thyroid cancer (PTC) is the most common malignant disease in endocrine systems. T-box transcription factor 22 (TBX22) is a phylogenetically conserved family member that has not been widely characterized in cancers. In this study, we explored the potential clinical significance and biological functions of TBX22 in PTC. Comprehensive analyses of TBX22 were based on the public databases and our local qRT-PCR cohort. We observed that TBX22 was significantly downregulated in PTC compared with normal tissues. TBX22 was associated with several clinicopathological factors in PTC. Low TBX22 expression correlated with BRAF ^V600E and TERT mutation. Functional enrichment analysis revealed that cancer-related pathways and immune progress were closely associated with TBX22 in PTC. In TBX22-low PTC, high immune infiltration levels with increased CD8⁺ T cells, natural killer, M1 macrophages, and T-regulatory cells were observed. TBX22 was negatively correlated with the activity of different steps of the anticancer immunity cycle. Functionally, overexpression of TBX22 inhibited the proliferation, invasion, and migration in PTC cells, while knocking down of TBX22 showed the opposite effects. The present findings disclose that TBX22, as an immune microenvironment-related biomarker, could be an important tumor suppresser gene and might inform the management of PTC patients better.

Osteoclast-expanded super-charged NK-cells preferentially select and expand CD8+ T cells

Osteoclasts (OCs) and much less dendritic cells (DCs) induce significant expansion and functional activation of NK cells, and furthermore, the OC-expanded NK cells preferentially increase the expansion and activation of CD8+ T cells by targeting CD4+ T cells. When autologous OCs were used to expand patient NK cells much lower percentages of expanded CD8+ T cells, decreased numbers of expanded NK cells and decreased functions of NK cells could be observed, and the addition of allogeneic healthy OCs increased the patients' NK function. Mechanistically, OC-expanded NK cells were found to lyse CD4+ T cells but not CD8+ T cells suggesting potential selection of CD8+ T cells before their expansion by OC activated NK cells. In agreement, Increased IFN-γ secretion, and NK cell-mediated cytotoxicity and higher percentages of CD8+ T cells, in various tissue compartments of oral tumor-bearing hu-BLT mice in response to immunotherapy by OC-expanded NK cells were observed. Thus, our results indicate an important relationship between NK and CD8+ T cells.

Evaluations of CRC2631 toxicity, tumor colonization, and genetic stability in the TRAMP prostate cancer model

Conventional cancer chemotherapies are not fully efficacious and do not target tumors, leading to significant treatment-related morbidities. A number of genetically attenuated cancer-targeting bacteria are being developed to safely target tumors in vivo. Here we report the toxicological, tumor-targeting, and efficacy profiles of Salmonella enterica serovar Typhimurium CRC2631 in a syngeneic and autochthonous TRAMP model of aggressive prostate cancer. CRC2631 preferentially colonize primary and metastatic tumors in the TRAMP animals. In addition, longitudinal whole genome sequencing studies of CRC2631 recovered from prostate tumor tissues demonstrate that CRC2631 is genetically stable. Moreover, tumor-targeted CRC2631 generates an anti-tumor immune response. Combination of CRC2631 with checkpoint blockade reduces metastasis burden. Collectively, these findings demonstrate a potential for CRC2631 in cancer immunotherapy strategies.