The B7 family and cancer therapy: costimulation and coinhibition

Associations of PD-1 and PD-L1 gene polymorphisms with cancer risk: a meta-analysis based on 50 studies

Programmed death-1 and its ligand-1 (PD-1/PD-L1), immune checkpoints proteins, play a crucial role in anti-tumor responses. A large number of studies have evaluated the relationships of PD-1/PD-L1 polymorphisms with risk of cancer, but evidence for the associations remains inconsistent. Therefore, we performed a meta-analysis to examine the associations between PD-1/PD-L1 single nucleotide polymorphisms (SNPs) and cancer predisposition. Results showed that PD-1.3 and PD-L1 rs17718883 were significantly correlated with overall cancer risk. PD-1.5 was prominently linked with cervical cancer (CC), non-small cell lung cancer (NSCLC), TC (thyroid cancer), brain tumor, AML (acute myelocytic leukemia) and UCC (urothelial cell carcinoma) risk, PD-1.9 with breast cancer (BC), AML, esophageal cancer (EC) and ovarian cancer (OC) risk, and PD-1.3 with colorectal cancer (CRC) and BCC (basal cell carcinoma) risk. PD-1.1 polymorphism slightly elevated BC and OC susceptibility, whereas the rs4143815 variant notably decreased the risk of gastric cancer (GC), hepatocellular carcinoma (HCC) and OC, but increased the risk of BC. PD-1.6 was closely linked with AML risk, PD-L1 rs2890658 with NSCLC, HCC and BC risk, rs17718883 with HCC and GC risk, rs10815225 with GC risk, and rs2297136 with NSCLC and HCC risk. Interestingly, the rs7421861, rs10815225, and rs10815225 markedly reduced cancer susceptibility among Asians. The rs7421861 polymrophism decreased cancer risk among Caucasians, rather than the rs10815225 elevated cancer risk. Our results supported that PD-1 and PD-L1 SNPs were dramatically correlated with cancer risk.

CD80-Fc fusion protein as a potential cancer immunotherapy strategy

The activation of T lymphocytes is a crucial component of the immune response, and the presence of CD80, a membrane antigen, is necessary for T-cell activation. CD80 is usually expressed on antigen-presenting cells (APCs), which can interact with cluster of differentiation 28 (CD28) or programmed cell death ligand 1 (PD-L1) to promote T-cell proliferation, differentiation and function by activating costimulatory signal or blocking inhibitory signal. Simultaneously, CD80 on the APCs also interacts with cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) on the surface of T cells to suppress the response of specific effector T cells, particularly in the context of persistent antigenic stimulation. Due to the pivotal role of CD80 in the immune response, the CD80-Fc fusion protein has emerged as a promising approach for cancer immunotherapy. This review primarily focused on the crucial role of CD80 in the cancer immunotherapy. We also reviewed the current advancements in the research of CD80-Fc fusion proteins. Finally, we deliberated on the challenges encountered by CD80-Fc fusion proteins and proposed the potential strategies that could yield the benefits for patients.

Development of anti-PD-L1 antibody based on structure prediction of AlphaFold2

Accurate structural information plays a crucial role in comprehending biological processes and designing drugs. Indeed, the remarkable precision of the AlphaFold2 has facilitated significant advancements in predicting molecular structures, encompassing antibodies and antigens. This breakthrough has paved the way for rational drug design, ushering in new possibilities in the field of pharmaceutical development. Within this study, performing analysis and humanization guided by the structures predicted by AlphaFold2. Notably, the resulting humanized antibody, h3D5-hIgG1, demonstrated exceptional binding affinity to the PD-L1 protein. The KD value of parental antibody 3D5-hIgG1 was increased by nearly 7 times after humanization. Both h3D5-hIgG1 and 3D5-hIgG1 bound to cells expressing human PD-L1 with EC50 values of 5.13 and 9.92nM, respectively. Humanization resulted in a twofold increase in the binding capacity of the antibody, with h3D5-hIgG1 exhibiting superior performance compared to the parental antibody 3D5-hIgG1. Furthermore, h3D5-hIgG1 promoted cytokine secretion of T cells, and significantly suppressed MC38-hPD-L1 tumor growth. This study highlights the potential for artificial intelligence-assisted drug development, which is poised to become a prominent trend in the future.

Neuroblastoma in the Era of Precision Medicine: A Clinical Review

The latest advances in treatment for patients with neuroblastoma are constantly being incorporated into clinical trials and clinical practice standards, resulting in incremental improvements in the survival of patients over time. Survivors of high-risk neuroblastoma (HRNBL), however, continue to develop treatment-related late effects. Additionally, for the majority of the nearly 50% of patients with HRNBL who experience relapse, no curative therapy currently exists. As technologies in diagnostic and molecular profiling techniques rapidly advance, so does the discovery of potential treatment targets. Here, we discuss the current clinical landscape of therapies for neuroblastoma in the era of precision medicine.

Antitumor activity of the investigational B7-H3 antibody-drug conjugate, vobramitamab duocarmazine, in preclinical models of neuroblastoma

INTRODUCTION

B7-H3 is a potential target for pediatric cancers, including neuroblastoma (NB). Vobramitamab duocarmazine (also referred to as MGC018 and herein referred to as vobra duo) is an investigational duocarmycin-based antibody-drug conjugate (ADC) directed against the B7-H3 antigen. It is composed of an anti-B7-H3 humanized IgG1/kappa monoclonal antibody chemically conjugated through a cleavable valine-citrulline linker to a duocarmycin-hydroxybenzamide azaindole (vc-seco-DUBA). Vobra duo has shown preliminary clinical activity in B7-H3-expressing tumors.

METHODS

B7-H3 expression was evaluated by flow-cytometry in a panel of human NB cell lines. Cytotoxicity was evaluated in monolayer and in multicellular tumor spheroid (MCTS) models by the water-soluble tetrazolium salt,MTS, proliferation assay and Cell Titer Glo 3D cell viability assay, respectively. Apoptotic cell death was investigated by annexin V staining. Orthotopic, pseudometastatic, and resected mouse NB models were developed to mimic disease conditions related to primary tumor growth, metastases, and circulating tumor cells with minimal residual disease, respectively.

RESULTS

All human NB cell lines expressed cell surface B7-H3 in a unimodal fashion. Vobra duo was cytotoxic in a dose-dependent and time-dependent manner against all cell lines (IC50 range 5.1-53.9 ng/mL) and NB MCTS (IC50 range 17.8-364 ng/mL). Vobra duo was inactive against a murine NB cell line (NX-S2) that did not express human B7-H3; however, NX-S2 cells were killed in the presence of vobra duo when co-cultured with human B7-H3-expressing cells, demonstrating bystander activity. In orthotopic and pseudometastatic mouse models, weekly intravenous treatments with 1 mg/kg vobra duo for 3 weeks delayed tumor growth compared with animals treated with an irrelevant (anti-CD20) duocarmycin-ADC. Vobra duo treatment for 4 weeks further increased survival in both orthotopic and resected NB models. Vobra duo compared favorably to TOpotecan-TEMozolomide (TOTEM), the standard-of-care therapy for NB relapsed disease, with tumor relapse delayed or arrested by two or three repeated 4-week vobra duo treatments, respectively. Further increased survival was observed in mice treated with vobra duo in combination with TOTEM. Vobra duo treatment was not associated with body weight loss, hematological toxicity, or clinical chemistry abnormalities.

CONCLUSION

Vobra duo exerts relevant antitumor activity in preclinical B7-H3-expressing NB models and represents a potential candidate for clinical translation.

Microbiota-dependent regulation of costimulatory and coinhibitory pathways via innate immune sensors and implications for immunotherapy

Our bodies are inhabited by trillions of microorganisms. The host immune system constantly interacts with the microbiota in barrier organs, including the intestines. Over decades, numerous studies have shown that our mucosal immune system is dynamically shaped by a variety of microbiota-derived signals. Elucidating the mediators of these interactions is an important step for understanding how the microbiota is linked to mucosal immune homeostasis and gut-associated diseases. Interestingly, the efficacy of cancer immunotherapies that manipulate costimulatory and coinhibitory pathways has been correlated with the gut microbiota. Moreover, adverse effects of these therapies in the gut are linked to dysregulation of the intestinal immune system. These findings suggest that costimulatory pathways in the immune system might serve as a bridge between the host immune system and the gut microbiota. Here, we review mechanisms by which commensal microorganisms signal immune cells and their potential impact on costimulation. We highlight how costimulatory pathways modulate the mucosal immune system through not only classical antigen-presenting cells but also innate lymphocytes, which are highly enriched in barrier organs. Finally, we discuss the adverse effects of immune checkpoint inhibitors in the gut and the possible relationship with the gut microbiota.

Breaking down the tumor immune infiltration within pediatric sarcomas

Immunotherapies are a promising therapeutic option, yet for a variety of reasons, these treatments have achieved limited success against sarcomas. The immunosuppressive tumor microenvironment (TME) of sarcomas as well as lack of predictive biomarkers, decreased T-cell clonal frequency, and high expression of immunosuppressive infiltrating cells has thus far prevented major success using immunotherapies. By breaking down the TME into its individual components and understanding how the various cell types interact with each other as well as in the context of the complex immune microenvironment, can lead to effective therapeutic immunotherapy treatments, potentially improving outcomes for those with metastatic disease.

Serum immune mediators as novel predictors of response to anti-PD-1/PD-L1 therapy in non-small cell lung cancer patients with high tissue-PD-L1 expression

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related morbidity and mortality worldwide. Immune checkpoint inhibitors (ICIs) including anti-PD-1 and anti-PD-L1 antibodies, have significantly changed the treatment outcomes with better overall survival, but only 15-40% of the patients respond to ICIs therapy. The search for predictive biomarkers of responses is warranted for better clinical outcomes. We aim here to identify pre-treatment soluble immune molecules as surrogate biomarkers for tissue PD-L1 (TPD-L1) status and as predictors of response to anti-PD-1/PD-L1 therapy in NSCLC patients. Sera from 31 metastatic NSCLC patients, eligible for anti-PD-1/PD-L1 or combined chemoimmunotherapy, were collected prior to treatment. Analysis of soluble biomarkers with TPD-L1 status showed significant up/down regulation of the immune inhibitory checkpoint markers (sSiglec7, sSiglec9, sULBP4 and sPD-L2) in patients with higher TPD-L1 (TPD-L1 >50%) expression. Moreover, correlation analysis showed significant positive linear correlation of soluble PD-L1 (sPD-L1) with higher TPD-L1 expression. Interestingly, only responders in the TPD-L1 >50% group showed significant down regulation of the immune inhibitory markers (sPD-L2, sTIMD4, sNectin2 and CEA). When responders vs. non-responders were compared, significant down regulation of other immune inhibitory biomarkers (sCD80, sTIMD4 and CEA) was recorded only in responding patients. In this, the optimal cut-off values of CD80 <91.7 pg/ml and CEA <1614 pg/ml were found to be significantly associated with better progression free survival (PFS). Indeed, multivariate analysis identified the cutoff-value of CEA <1614 pg/ml as an independent predictor of response in our patients. We identified here novel immune inhibitory/stimulatory soluble mediators as potential surrogate/predictive biomarkers for TPD-L1 status, treatment response and PFS in NSCLC patients treated with anti-PD-1/PD-L1 therapy.

cis-B7:CD28 interactions at invaginated synaptic membranes provide CD28 co-stimulation and promote CD8+ T cell function and anti-tumor immunity

B7 ligands (CD80 and CD86), expressed by professional antigen-presenting cells (APCs), activate the main co-stimulatory receptor CD28 on T cells in trans. However, in peripheral tissues, APCs expressing B7 ligands are relatively scarce. This raises the questions of whether and how CD28 co-stimulation occurs in peripheral tissues. Here, we report that CD8⁺ T cells displayed B7 ligands that interacted with CD28 in cis at membrane invaginations of the immunological synapse as a result of membrane remodeling driven by phosphoinositide-3-kinase (PI3K) and sorting-nexin-9 (SNX9). cis-B7:CD28 interactions triggered CD28 signaling through protein kinase C theta (PKCθ) and promoted CD8⁺ T cell survival, migration, and cytokine production. In mouse tumor models, loss of T cell-intrinsic cis-B7:CD28 interactions decreased intratumoral T cells and accelerated tumor growth. Thus, B7 ligands on CD8⁺ T cells can evoke cell-autonomous CD28 co-stimulation in cis in peripheral tissues, suggesting cis-signaling as a general mechanism for boosting T cell functionality.

Interleukin-2 family cytokines: An overview of genes, expression, signaling and functional roles in teleost

The interleukin-2 (IL-2) family cytokines include IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21, which share γ chain (γc) subunit in receptors. The IL-2 family cytokines have unique biological effects that regulate differentiation, survival and activation of multiple lymphocyte lineages. Deficiency of IL-2 family signaling pathway in mammals prevents CD4⁺ T cells from developing effector functions and CD8⁺ T cells from developing immunological memory. In the present review, we addressed available information from teleost IL-2 family cytokines and discussed implications in teleost immunity. Also, we described and discussed their expression profiles, receptors, signaling transductions and functions. In teleost, IL-2 family has 5 members (IL-2, IL-4/13, IL-7, IL-15, IL-21) without IL-9, and their receptors share a common γc subunit and include other 6 subunits (IL-2Rβ1/2, IL-4Rα1/2, IL-13Rα1/2, IL-7Rα, IL-15Rα, and IL-21Rα1/2). Some paralogues have changes in domain structure and show differential expression, modulation, functions. IL-2 family cytokines constitutively express in many immune associated tissues and are largely induced after pathogenic microbial stimulation. In general, there are relatively conserved functions in the IL-2 family throughout vertebrates, and many of the key IL-2 family members are important in lymphocyte proliferation and differentiation, development, inflammation from fishes to mammals. This review will give an update on the effective information of teleost IL-2 family cytokines. Thus, it will provide a source of reference for other researchers/readers and inspire further interest.

B7-H3 expression is associated with high PD-L1 expression in clear cell renal cell carcinoma and predicts poor prognosis

BACKGROUND

Clear cell Renal cell carcinoma (ccRCC) is an immunogenic tumor. B7 family members, such as CTLA-4, PD-1, and PD-L1, are the main components of immune checkpoints that regulate various immune responses. Specifically, B7-H3 regulates T cell-mediated immune responses against cancer. This study aimed to analyze the association between B7-H3 and CTLA-4 expression and the prognostic factors of ccRCC to provide a basis for their potential use as predictive factors and in immunotherapy.

METHODS

Formalin-fixed paraffin-embedded specimens were obtained from 244 ccRCC patients, and B7-H3, CTLA-4, and PD-L1 expressions were evaluated using immunohistochemical staining.

RESULTS

B7-H3 and CTLA-4 were positive in 73 (29.9%) and 57 (23.4%) of the 244 patients, respectively. B7-H3 expression was significantly associated with PD-L1 expression (P <  0.0001); however, CTLA-4 expression was not (P = 0.842). Kaplan-Meier analysis showed that positive B7-H3 expression was associated with poor progression-free survival (PFS) (P <  0.0001), whereas CTLA-4 expression was not (P = 0.457). Multivariate analysis revealed that B7-H3 was correlated with poor PFS (P = 0.031), whereas CTLA-4 was not (P = 0.173).

CONCLUSIONS

To the best of our knowledge, this study is the first to investigate B7-H3 and PD-L1 expression and survival in ccRCC. B7-H3 expression is an independent prognostic factor for ccRCC. Furthermore, multiple immune cell inhibitory targets, such as B7-H3 and PD-L1, can be used for therapeutic tumor regression in a clinical setting.

The Importance of the Immune System and Molecular Cell Signaling Pathways in the Pathogenesis and Progression of Lung Cancer

Lung cancer is a disease that in recent years has become one of the greatest threats to modern society. Every year there are more and more new cases and the percentage of deaths caused by this type of cancer increases. Despite many studies, scientists are still looking for answers regarding the mechanisms of lung cancer development and progression, with particular emphasis on the role of the immune system. The aim of this literature review was to present the importance of disorders of the immune system and the accompanying changes at the level of cell signaling in the pathogenesis of lung cancer. The collected results showed that in the process of immunopathogenesis of almost all subtypes of lung cancer, changes in the tumor microenvironment, deregulation of immune checkpoints and abnormalities in cell signaling pathways are involved, which contribute to the multistage and multifaceted carcinogenesis of this type of cancer. We, therefore, suggest that in future studies, researchers should focus on a detailed analysis of tumor microenvironmental immune checkpoints, and to validate their validity, perform genetic polymorphism analyses in a wide range of patients and healthy individuals to determine the genetic susceptibility to lung cancer development. In addition, further research related to the analysis of the tumor microenvironment; immune system disorders, with a particular emphasis on immunological checkpoints and genetic differences may contribute to the development of new personalized therapies that improve the prognosis of patients.

B7-H3-targeting Fc-optimized antibody for induction of NK cell reactivity against sarcoma

Natural killer (NK) cells largely contribute to antibody-dependent cellular cytotoxicity (ADCC), a central factor for success of monoclonal antibodies (mAbs) treatment of cancer. The B7 family member B7-H3 (CD276) recently receives intense interest as a novel promising target antigen for immunotherapy. B7-H3 is highly expressed in many tumor entities, whereas expression on healthy tissues is rather limited. We here studied expression of B7-H3 in sarcoma, and found substantial levels to be expressed in various bone and soft-tissue sarcoma subtypes. To date, only few immunotherapeutic options for treatment of sarcomas that are limited to a minority of patients are available. We here used a B7-H3 mAb to generate chimeric mAbs containing either a wildtype Fc-part (8H8_WT) or a variant Fc part with amino-acid substitutions (S239D/I332E) to increase affinity for CD16 expressing NK cells (8H8_SDIE). In comparative studies we found that 8H8_SDIE triggers profound NK cell functions such as activation, degranulation, secretion of IFNγ and release of NK effector molecules, resulting in potent lysis of different sarcoma cells and primary sarcoma cells derived from patients. Our findings emphasize the potential of 8H8_SDIE as novel compound for treatment of sarcomas, particularly since B7-H3 is expressed in bone and soft-tissue sarcoma independent of their subtype.

The immunological role of b7-h4 in pregnant women with sars-cov2 infection

Problem

T‐cells are key players in fighting the coronavirus disease 2019 (COVID‐19). The checkpoint molecule B7‐H4, a member of the B7 family, can inhibit T‐cell activation and proliferation by inhibiting NF‐kb expression. We aimed to elucidate the immunological role of soluble B7‐H4 (sB7‐H4) and B7‐H4 in pregnant women suffered from an acute Sars‐Cov2 infection.

Methods

Expression levels of sB7‐H4 and cytokines were detected by enzyme linked immunosorbent assay. B7‐H4 and cytokines mRNA expression was analyzed by qPCR, and B7‐H4 and NF‐κb (p65) protein levels were investigated by western blot and immunofluorescence staining in placenta chorionic villous and decidual basalis tissues of COVID‐19 affected women and healthy controls.

Results

Fibrinoid necrosis in the periphery of placental villi was increased in the COVID‐19‐affected patients. sB7‐H4 protein in maternal and cord blood serum and IL‐6/IL‐10 were increased while leukocytes were decreased during SARS‐CoV‐2 infection. Serum sB7‐H4 level was increased according to the severity of SARS‐Cov‐2 infection. Cytokines (IL‐6, IL‐18, IL‐1β, TNF‐α), B7‐H4 mRNA and protein in the decidual basalis tissues of COVID‐19‐infected pregnant women were significantly increased compared to healthy controls. IL‐18 and IL‐1β were significantly increased in the placenta chorionic villous samples of COVID‐19 affected patients, while NF‐κb (p65) expression was decreased.

Conclusions

The expression of the immunological marker sB7‐H4 correlated with the severity of COVID‐19 disease in pregnant women. sB7‐H4 and B7‐H4 can be used to monitor the progression of COVID‐19 infection during pregnancy, and for evaluating of the maternal immune status.

Crosstalk between the B7/CD28 and EGFR pathways: Mechanisms and therapeutic opportunities

Somatic activating mutations in the epidermal growth factor receptor (EGFR) are one of the most common oncogenic drivers in cancers such as non-small-cell lung cancer (NSCLC), metastatic colorectal cancer, glioblastoma, head and neck cancer, pancreatic cancer, and breast cancer. Molecular-targeted agents against EGFR signaling pathways have shown robust clinical efficacy, but patients inevitably experience acquired resistance. Although immune checkpoint inhibitors (ICIs) targeting PD-1/PD-L1 have exhibited durable anti-tumor responses in a subset of patients across multiple cancer types, their efficacy is limited in cancers harboring activating gene alterations of EGFR. Increasing studies have demonstrated that upregulation of new B7/CD28 family members such as B7-H3, B7x and HHLA2, is associated with EGFR signaling and may contribute to resistance to EGFR-targeted therapies by creating an immunosuppressive tumor microenvironment (TME). In this review, we discuss the regulatory effect of EGFR signaling on the PD-1/PD-L1 pathway and new B7/CD28 family member pathways. Understanding these interactions may inform combination therapeutic strategies and potentially overcome the current challenge of resistance to EGFR-targeted therapies. We also summarize clinical data of anti-PD-1/PD-L1 therapies in EGFR-mutated cancers, as well as ongoing clinical trials of combination of EGFR-targeted therapies and anti-PD-1/PD-L1 immunotherapies.

Immunotherapy-induced Colitis: A Comprehensive Review of Epidemiology, Clinical Presentation, Diagnostic Workup, and Management Plan

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of a variety of malignancies including advanced melanoma, non-small cell lung cancer, renal cell carcinoma, head and neck cancers among others. Since their introduction, there has been significant improvement in survival and prognosis in patients with advanced malignancies. Unfortunately, improved outcomes have come at a price of significant immune-related adverse events, with those of the gastrointestinal tract being the most common. Gastrointestinal immune-related adverse events frequently present as diarrhea and colitis, the severity of which can range from mild diarrhea to fulminant colitis with intestinal perforation. Currently, management of ICI-induced colitis is primarily guided by retrospective studies and expert opinion. A significant number of ICI-induced colitis responds to high-dose corticosteroids; however, some patients require further therapy with biologics. There is limited information on the factors which may predispose patients to ICI-induced colitis. Future research elucidating these risk factors along with development of a scoring system could allow for risk-stratification of patients before initiation of ICI therapy. Such a system may help clinicians and patients keep a high index of suspicion regarding ICI-induced colitis and could hopefully reduce the incidence of severe cases. Similarly, future studies should investigate protective factors against ICI-induced colitis, which could potentially allow more patients to safely benefit from ICI therapy.

Engaging Pattern Recognition Receptors in Solid Tumors to Generate Systemic Antitumor Immunity

Malignant tumors frequently exploit innate immunity to evade immune surveillance. The priming, function, and polarization of antitumor immunity fundamentally depends upon context provided by the innate immune system, particularly antigen presenting cells. Such context is determined in large part by sensing of pathogen specific and damage associated features by pathogen recognition receptors (PRRs). PRR activation induces the delivery of T cell priming cues (e.g. chemokines, co-stimulatory ligands, and cytokines) from antigen presenting cells, playing a decisive role in the cancer immunity cycle. Indeed, endogenous PRR activation within the tumor microenvironment (TME) has been shown to generate spontaneous antitumor T cell immunity, e.g., cGAS-STING mediated activation of antigen presenting cells after release of DNA from dying tumor cells. Thus, instigating intratumor PRR activation, particularly with the goal of generating Th1-promoting inflammation that stokes endogenous priming of antitumor CD8⁺ T cells, is a growing area of clinical investigation. This approach is analogous to in situ vaccination, ultimately providing a personalized antitumor response against relevant tumor associated antigens. Here I discuss clinical stage intratumor modalities that function via activation of PRRs. These approaches are being tested in various solid tumor contexts including melanoma, colorectal cancer, glioblastoma, head and neck squamous cell carcinoma, bladder cancer, and pancreatic cancer. Their mechanism (s) of action relative to other immunotherapy approaches (e.g., antigen-defined cancer vaccines, CAR T cells, dendritic cell vaccines, and immune checkpoint blockade), as well as their potential to complement these approaches are also discussed. Examples to be reviewed include TLR agonists, STING agonists, RIG-I agonists, and attenuated or engineered viruses and bacterium. I also review common key requirements for effective in situ immune activation, discuss differences between various strategies inclusive of mechanisms that may ultimately limit or preclude antitumor efficacy, and provide a summary of relevant clinical data.

Comprehensive Analysis of HOX Family Members as Novel Diagnostic and Prognostic Markers for Hepatocellular Carcinoma

Background. The homeobox (HOX) gene family has been found to be involved in human cancers. However, its involvement in hepatocellular carcinoma (HCC) has not been well documented. Here, we comprehensively evaluated the role of HOXs in HCC. Methods. RNA sequencing profile of TCGA-LIHC and LIRI-JP were obtained from the Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium (ICGC), respectively. Data of TCGA-LIHC methylation were downloaded from UCSC Xena. Genetic alteration data for the TCGA samples was obtained from cBioPortal and GSCA. The diagnostic efficiency was assessed using ROC curves. The prognostic significance was evaluated by the Kaplan–Meier method and Cox regression analysis. Subsequent functional analysis was performed through the clusterProfiler package. ssGSEA, ESTIMATE, and TIDE algorithms were employed to explore the relationship between HOXs and the HCC microenvironment. Finally, pRRophetic package and NCI-60 cancerous cell lines were applied to estimate anticancer drug sensitivity. Results. The mRNA levels of HOXs in HCC tissues were higher than those of noncancerous tissues and were correlated with poor overall survival (OS). HOXA6, C6, D9, D10, and D13 could serve as independent risk factors for OS. Further functional analysis revealed that these five HOXs regulate the cell proliferation, cell cycle, immune response, and microenvironment composition of HCC. In addition, the aberrant expression and methylation of HOXs is of great value in the diagnosis of HCC. Conclusion. HOXs play crucial roles in HCC and could serve as potential markers for HCC diagnosis and prognosis.

TROP-2, Nectin-4, GPNMB, and B7-H3 Are Potentially Therapeutic Targets for Anaplastic Thyroid Carcinoma

Simple Summary

Anaplastic thyroid carcinoma is a highly aggressive thyroid tumor with a poor prognosis. There are limited choices for the effective treatment of this type of carcinoma. Whether the targets of antibody–drug conjugates are expressed in anaplastic thyroid carcinoma remains unclear. Therefore, we examined expression rates of the following antibody–drug conjugate targets using the tissue microarrays of anaplastic thyroid carcinomas: human epidermal growth factor receptor 2, nectin-4, trophoblast cell surface antigen 2, glycoprotein non-metastatic B, and B7-H3. We found that glycoprotein non-metastatic B and B7-H3 were expressed in most anaplastic thyroid carcinoma tissues. Trophoblast cell surface antigen 2 and nectin-4 were expressed in 65% and 59% of anaplastic thyroid carcinoma tissues, respectively. Trophoblast cell surface antigen 2 was high expressed in anaplastic thyroid carcinoma undifferentiated from papillary thyroid carcinoma. In contrast, nectin-4 expression was high in patients with de novo anaplastic thyroid carcinoma. These cell membrane proteins are potential therapeutic targets for anaplastic thyroid carcinoma.

Abstract

Background: Anaplastic thyroid carcinoma (ATC) is a highly aggressive thyroid tumor with a poor prognosis. However, there are limited choices for ATC treatment. Recently, the effectiveness of antibody–drug conjugates has been demonstrated in various carcinomas. Whether the targets of antibody–drug conjugates are expressed in anaplastic thyroid carcinoma remains unclear. Methods: Fifty-four patients with ATC were enrolled in this study. Tissue microarrays were constructed using the archives of formalin-fixed paraffin-embedded tissue blocks. All sections were stained with the following antibody–drug conjugate targets: human epidermal growth factor receptor 2 (HER2), nectin-4, trophoblast cell surface antigen 2 (TROP-2), glycoprotein non-metastatic B (GPNMB), and B7-H3. Results: HER2 was negative in all tissues, whereas GPNMB and B7-H3 were expressed in most ATC tissues. TROP-2 and nectin-4 were expressed in 65% and 59% of ATC tissues, respectively. TROP-2 was expressed at significantly higher levels in ATC undifferentiated from papillary thyroid carcinoma than in ATC undifferentiated from follicular thyroid carcinoma and de novo ATC. In contrast, nectin-4 expression was markedly higher in patients with de novo ATC than in those with papillary and follicular thyroid carcinoma. Conclusions: TROP-2 and nectin-4 are potential therapeutic targets for ATC undifferentiated from papillary thyroid carcinoma and de novo ATC, respectively. GPNMB and B7-H3 potential for treating all types of ATC.

Expression of Tim-3 drives phenotypic and functional changes in Treg cells in secondary lymphoid organs and the tumor microenvironment

Regulatory T cells (Treg cells) are critical mediators of self-tolerance, but they can also limit effective anti-tumor immunity. Although under homeostasis a small fraction of Treg cells in lymphoid organs express the putative checkpoint molecule Tim-3, this protein is expressed by a much larger proportion of tumor-infiltrating Treg cells. Using a mouse model that drives cell-type-specific inducible Tim-3 expression, we show that expression of Tim-3 by Treg cells is sufficient to drive Treg cells to a more effector-like phenotype, resulting in increases in suppressive activity, effector T cell exhaustion, and tumor growth. We also show that T-reg-cell-specific inducible deletion of Tim-3 enhances anti-tumor immunity. Enhancement of Treg cell function by Tim-3 is strongly correlated with increased expression of interleukin-10 (IL-10) and a shift to a more glycolytic metabolic phenotype. Our data demonstrate that Tim-3⁺ Treg cells may be a relevant therapeutic target cell type for the treatment of cancer.

Regulatory T cells (Treg cells) limit the immune response to tumors, and tumor-infiltrating Treg cells are especially suppressive. However, the mechanisms underlying enhanced Treg cell function are poorly understood. Banerjee et al. show that Tim-3 expression is linked to increased Treg cell suppressive activity, possibly through the cytokine IL-10, in mouse models and people with cancer.

Immune checkpoint B7-H3 protein expression is associated with poor outcome and androgen receptor status in prostate cancer

BACKGROUND

Novel immune checkpoint-based immunotherapies may benefit specific groups of prostate cancer patients who are resistant to other treatments.

METHODS

We analyzed by immunohistochemistry the expression of B7-H3, PD-L1/B7-H1, and androgen receptor (AR) in tissue samples from 120 prostate adenocarcinoma patients treated with radical prostatectomy in Spain, and from 206 prostate adenocarcinoma patients treated with radical prostatectomy in Norway.

RESULTS

B7-H3 expression correlated positively with AR expression and was associated with biochemical recurrence in the Spanish cohort, but PD-L1 expression correlated with neither of them. Findings for B7-H3 were validated in the Norwegian cohort, where B7-H3 expression correlated positively with Gleason grade, surgical margins, seminal vesicle invasion, and CAPRA-S risk group, and was associated with clinical recurrence. High B7-H3 expression in the Norwegian cohort was also consistent with positive AR expression.

CONCLUSION

These results suggest distinct clinical relevance of the two immune checkpoint proteins PD-L1 and B7-H3 in prostate cancer. Our findings highlight B7-H3 as an actionable novel immune checkpoint protein in prostate cancer.

Poliovirus receptor (PVR)-like protein cosignaling network: new opportunities for cancer immunotherapy

Immune checkpoint molecules, also known as cosignaling molecules, are pivotal cell-surface molecules that control immune cell responses by either promoting (costimulatory molecules) or inhibiting (coinhibitory molecules) a signal. These molecules have been studied for many years. The application of immune checkpoint drugs in the clinic provides hope for cancer patients. Recently, the poliovirus receptor (PVR)-like protein cosignaling network, which involves several immune checkpoint receptors, i.e., DNAM-1 (DNAX accessory molecule-1, CD226), TIGIT (T-cell immunoglobulin (Ig) and immunoreceptor tyrosine-based inhibitory motif (ITIM)), CD96 (T cell activation, increased late expression (TACLILE)), and CD112R (PVRIG), which interact with their ligands CD155 (PVR/Necl-5), CD112 (PVRL2/nectin-2), CD111 (PVRL1/nectin-1), CD113 (PVRL3/nectin-3), and Nectin4, was discovered. As important components of the immune system, natural killer (NK) and T cells play a vital role in eliminating and killing foreign pathogens and abnormal cells in the body. Recently, increasing evidence has suggested that this novel cosignaling network axis costimulates and coinhibits NK and T cell activation to eliminate cancer cells after engaging with ligands, and this activity may be effectively targeted for cancer immunotherapy. In this article, we review recent advances in research on this novel cosignaling network. We also briefly outline the structure of this cosignaling network, the signaling cascades and mechanisms involved after receptors engage with ligands, and how this novel cosignaling network costimulates and coinhibits NK cell and T cell activation for cancer immunotherapy. Additionally, this review comprehensively summarizes the application of this new network in preclinical trials and clinical trials. This review provides a new immunotherapeutic strategy for cancer treatment.

Residue-specific binding mechanisms of PD-L1 to its monoclonal antibodies by computational alanine scanning

Programmed cell death 1 receptor (PD-1) on the surface of T cells and its ligand 1 (PD-L1) are immune checkpoint proteins. Treating cancer patients with inhibitors blocking this checkpoint has significantly prolonged the survival rate of patients. In this study, we examined several monoclonal antibodies (mAbs) of PD-L1 and studied their detailed binding mechanism to PD-L1. An efficient computational alanine scanning method was used to perform quantitative analysis of hotspot residues that are important for PD-1/PD-L1 binding. A total of five PD-L1/mAb complexes were investigated and hotspots on both PD-L1 and mAbs were predicted. Our result shows that PD-L1M115 and PD-L1Y123 are two relatively important hotspots in all the five PD-L1/mAb binding complexes. It is also found that the important residues of mAbs binding to PD-L1M115 and PD-L1Y123 are similar to each other. The computational alanine scanning result is compared to the experimental measurements that are available for two of the mAbs (KN035 and atezolizumab). The calculated alanine scanning result is in good agreement with the experimental data with a correlation coefficient of 0.87 for PD-L1/KN035 and 0.6 for PD-L1/atezolizumab. Our computation found more hotspots on PD-L1 in the PD-L1/KN035 complex than those in the PD-L1/atezolizumab system, indicating stronger binding affinity in the former than the latter, which is in good agreement with the experimental finding. The present work provides important insights for the design of new mAbs targeting PD-L1.

The Role of Natural Killer Cells in Soft Tissue Sarcoma: Prospects for Immunotherapy

Simple Summary

Soft-tissue sarcomas (STS) represent about 80% of sarcomas, and are a heterogeneous group of rare and malignant tumors. Morphological evaluation has been the standard model for the diagnosis of sarcomas, and even in samples with similar characteristics, they present genetic differences, which further increases the diversity of sarcomas. This variety is one of the main challenges for the classification and understanding of STS patterns, as well as for the respective treatments, which further decreases patient survival (<5 years). Natural Killer (NK) cells have a fundamental role in the control and immune surveillance of cancer development, progression and metastases. Notwithstanding the scarcity of studies to characterize NK cells in STS, it is noteworthy that the progression of these malignancies is associated with altered NK cells. These findings support the additional need to explore NK cell-based immunotherapy in STS; some clinical trials, although very tentatively, are already underway.

Abstract

Soft-tissue sarcomas (STS) represent about 80% of sarcomas, and are a heterogeneous group of rare and malignant tumors. STS arise from mesenchymal tissues and can grow into structures such as adipose tissue, muscles, nervous tissue and blood vessels. Morphological evaluation has been the standard model for the diagnosis of sarcomas, and even in samples with similar characteristics, they present a diversity in cytogenetic and genetic sequence alterations, which further increases the diversity of sarcomas. This variety is one of the main challenges for the classification and understanding of STS patterns, as well as for their respective treatments, which further decreases patient survival (<5 years). Despite some studies, little is known about the immunological profile of STS. As for the immunological profile of STS in relation to NK cells, there is also a shortage of studies. Observations made in solid tumors show that the infiltration of NK cells in tumors is associated with a good prognosis of the disease. Notwithstanding the scarcity of studies to characterize NK cells, their receptors, and ligands in STS, it is noteworthy that the progression of these malignancies is associated with altered NK phenotypes. Despite the scarcity of information on the function of NK cells, their phenotypes and their regulatory pathways in STS, the findings of this study support the additional need to explore NK cell-based immunotherapy in STS further. Some clinical trials, very tentatively, are already underway. STS clinical trials are still the basis for adoptive NK-cell and cytokine-based therapy.

B7-H3/CD276: An Emerging Cancer Immunotherapy

Immunotherapy aiming at suppressing tumor development by relying on modifying or strengthening the immune system prevails among cancer treatments and points out a new direction for cancer therapy. B7 homolog 3 protein (B7-H3, also known as CD276), a newly identified immunoregulatory protein member of the B7 family, is an attractive and promising target for cancer immunotherapy because it is overexpressed in tumor tissues while showing limited expression in normal tissues and participating in tumor microenvironment (TME) shaping and development. Thus far, numerous B7-H3-based immunotherapy strategies have demonstrated potent antitumor activity and acceptable safety profiles in preclinical models. Herein, we present the expression and biological function of B7-H3 in distinct cancer and normal cells, as well as B7-H3-mediated signal pathways in cancer cells and B7-H3-based tumor immunotherapy strategies. This review provides a comprehensive overview that encompasses B7-H3’s role in TME to its potential as a target in cancer immunotherapy.

The role of immunotherapy and molecular‑targeted therapy in the treatment of melanoma (Review)

Skin melanomas are malignant neoplasms originating from neuroectodermal melanocytes. Compared to other neoplasms, melanomas have a high rate of growth. Their incidence is highest in Australia and New Zealand, in high‑income European countries (Switzerland, Norway, Sweden) and in the US. In Poland, the standardized incidence rate is approximately 5/100,000. Melanomas are typically highly radioresistant and chemoresistant. Before the era of immunotherapy, inoperable lesions were treated using chemotherapy based mainly on dacarbazine, temozolomide or fotemustine, which did not yield the expected results in terms of extending survival time or improving patient comfort. Therefore, there has emerged a need to seek other solutions. In most cases, the use of immunological treatment or targeted therapy has had a positive impact on survival time and relapse‑free survival. However, these periods are still relatively short, hence the need for further research and improvement of treatment. The most promising strategies appear to be antibodies that block programmed death receptor‑1 (PD‑1) and programmed death receptor ligand‑1 (PD‑L1) molecules, anti‑CTLA4 antibodies (cytotoxic T‑lymphocyte antigen 4) and therapy with BRAF and MEK inhibitors.

Immunomodulatory mAbs as Tools to Investigate on Cis-Interaction of PD-1/PD-L1 on Tumor Cells and to Set Up Methods for Early Screening of Safe and Potent Combinatorial Treatments

Simple Summary

A novel challenge in cancer immunotherapy is the identification of the most potent combinations of immunomodulatory mAbs that are capable of maximizing therapeutic benefits while minimizing irAEs. We set up an in vitro system to quickly predict the efficacy and eventual cardiotoxic side effects of combinatorial treatments, thus allowing for the early screening of most potent and safe combinatorial therapeutic regimens for both validated and emerging immunomodulatory mAbs against different immune checkpoints (ICs). Furthermore, we provide for the first time evidence on cis-interactions of ICs in tumor cells.

Abstract

Antibodies targeting Immune Checkpoints (IC) on tumor infiltrating lymphocytes improve immune responses against cancer. Recently, the expression of some ICs has also been reported on cancer cells. We used the clinically validated Ipilimumab and Nivolumab and other novel human antibodies targeting Cytotoxic T- lymphocyte-antigen 4 (CTLA-4), Programmed Death receptor-1 (PD-1) and Programmed Death Ligand 1 (PD-L1) to shed light on the functions of these ICs in cancer cells. We show here for the first time that all these antagonistic mAbs are able to reduce Erk phosphorylation and, unexpectedly, to induce a significant increase of ICs expression on tumor cells, involving a hyperphosphorylation of NF-kB. On the contrary, agonistic PD-L1 and PD-1 recombinant proteins showed opposite effects by leading to a significant reduction of PD-1 and PD-L1, thus also suggesting the existence of a crosstalk in tumor cells between multiple ICs. Since the immunomodulatory mAbs show their higher anti-tumor efficacy by activating lymphocytes against cancer cells, we also investigated whether it was possible to identify the most efficient combinations of immunomodulatory mAbs for achieving potent anti-tumor efficacy associated with the lowest adverse side effects by setting up novel simple and predictive in vitro models based on co-cultures of tumor cells or human fetal cardiomyocytes with lymphocytes. We demonstrate here that novel combinations of immunomodulatory mAbs with more potent anti-cancer activity than Ipilimumab and Nivolumab combination can be identified with no or lower cardiotoxic side effects. Thus, we propose these co-cultures-based assays as useful tools to test also other combinatorial treatments of emerging immunomodulatory mAbs against different ICs for the early screening of most potent and safe combinatorial therapeutic regimens.

Role of CD8+ T lymphocyte cells: Interplay with stromal cells in tumor microenvironment

CD8⁺ T lymphocytes are pivotal cells in the host response to antitumor immunity. Tumor-driven microenvironments provide the conditions necessary for regulating infiltrating CD8⁺ T cells in favor of tumor survival, including weakening CD8⁺ T cell activation, driving tumor cells to impair immune attack, and recruiting other cells to reprogram the immune milieu. Also in tumor microenvironment, stromal cells exert immunosuppressive skills to avoid CD8⁺ T cell cytotoxicity. In this review, we explore the universal function and fate decision of infiltrated CD8⁺ T cells and highlight their antitumor response within various stromal architectures in the process of confronting neoantigen-specific tumor cells. Thus, this review provides a foundation for the development of antitumor therapy based on CD8⁺ T lymphocyte manipulation.

Antibody-Functionalized Nanowires: A Tuner for the Activation of T Cells

T cells sense both chemical cues delivered by antigen molecules and physical cues delivered by the environmental elasticity and topography; yet, it is still largely unclear how these cues cumulatively regulate the immune activity of T cells. Here, we engineered a nanoscale platform for ex vivo stimulation of T cells based on antigen-functionalized nanowires. The nanowire topography and elasticity, as well as the immobilized antigens, deliver the physical and chemical cues, respectively, enabling the systematic study of the integrated effect of these cues on a T cell's immune response. We found that T cells sense both the topography and bending modulus of the nanowires and modulate their signaling, degranulation, and cytotoxicity with the variation in these physical features. Our study provides an important insight into the physical mechanism of T cell activation and paves the way to novel nanomaterials for the controlled ex vivo activation of T cells in immunotherapy.

An orally available PD-1/PD-L1 blocking peptide OPBP-1-loaded trimethyl chitosan hydrogel for cancer immunotherapy

Blockade of the immune checkpoint PD-1/PD-L1 with monoclonal antibodies demonstrated unprecedented clinical efficacies in many cancers. But the orally available low molecular weight inhibitors remain infancy. Compared to small molecules, peptide exhibits better selectivity and fewer side effects, but poor half-life and a big challenge to be orally administrated. Here, we developed a proteolysis-resistant D peptide OPBP-1 (Oral PD-L1 Binding Peptide 1) which could selectively bind PD-L1, significantly block PD-1/PD-L1 interaction and enhance IFN-γ (interferon γ) secretion from CD8⁺ T cells in human PBMCs (Peripheral blood mononuclear cells). OPBP-1 could significantly inhibit tumor growth in murine colorectal CT26 and melanoma B16-OVA models at a relatively low dose of 0.5 mg/kg, with enhancing the infiltration and function of CD8⁺ T cells. More interestingly, oral delivery of OPBP-1 loaded TMC (N, N, N-trimethyl chitosan) hydrogel (OPBP-1@TMC) showed promising OPBP-1 oral bioavailability (52.8%) and prolonged half-life (14.55 h) in rats, and also significantly inhibited tumor growth in CT26 model. In conclusion, we discovered and optimized a PD-1/PD-L1 blocking peptide OPBP-1, and subsequently loaded into a TMC based hydrogel oral delivery system, in order to maximally elevate the oral bioavailability of the peptide drug and effectively inhibit tumor growth. These results opened up a new prospect for oral drug development in cancer immunotherapy.

Checkpoint Inhibitor-Induced Colitis-A Clinical Overview of Incidence, Prognostic Implications and Extension of Current Treatment Options

In recent years, anti-tumor immunotherapies have witnessed a major breakthrough with the emergence of immune checkpoint inhibitors (ICIs). However, the use of ICIs has also brought an era of a certain class of adverse events that differ from those of classical chemotherapies and are more reminiscent of autoimmune diseases. This article focuses exclusively on colitis as an irAE with emphasis on vulnerable patient groups, the prognostic significance of colitis, treatment, and new therapeutic approaches that may be applicable. Colitis itself is associated with a favorable oncological outcome of the underlying disease but is as well the most common irAE leading to discontinuation of therapy. Especially in vulnerable patient groups such as IBD patients and elderly patients, colitis occurs more frequently as a side effect. It is precisely in these two patient groups that side effects more often lead to discontinuation of therapy. Therefore, in addition to the current therapy of colitis through immunosuppression, the focus should also be on new forms of therapy of severe colitis, such as fecal transplantation or ileostomy creation.

Genetic variations in the CTLA-4 immune checkpoint pathway are associated with colon cancer risk, prognosis, and immune infiltration via regulation of IQCB1 expression

The programmed cell death-1 (PD-1)/cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) immune checkpoint pathways serve as targets of immunotherapy for colorectal cancer. However, the associations between genetic variations in these pathways and colorectal cancer risk, prognosis, and immune status remain unclear. The associations between single-nucleotide polymorphisms (SNPs) and colorectal cancer risk and survival were evaluated in a case-control study comprising 1150 cases and 1342 controls along with 287 cases with overall survival information. We found that individuals with the A allele of B7-2 rs2681416 in CTLA-4 immune checkpoint pathway had a significantly increased risk of colorectal cancer [odds ratio (OR) = 1.37, P = 3.17 × 10^-4] than those with G allele under the dominant model, which had a predominant site-specific effect in colon cancer (OR = 1.55, P = 3.11 × 10^-5). In addition, rs2681416 significantly decreased the overall survival time of patients with colon cancer [hazard ratio (HR) = 1.96, P = 1.10 × 10^-2], but not of patients with rectal cancer (P = 0.271). Moreover, rs2681416 had an expression quantitative trait locus effect on the B7-2 flanking gene IQCB1 in colon tissues, which contributed to colon cancer risk by regulating genome organization and influenced the expression of IQCB1 in an allele-specific manner. IQCB1 expression was upregulated in colorectal cancer tissues compared with normal tissues, accounting for various critical carcinogenic states in colon cancer and promoting immune infiltration of Th17 cells in the tumor microenvironment. Our study highlights the important roles of genetic variations in immune checkpoint pathways and provides new insight into potential site-specific independent biomarkers for colorectal cancer susceptibility, prognosis, and tumor immune status.

Enhancing clinical and immunological effects of anti-PD-1 with belapectin, a galectin-3 inhibitor

BACKGROUND

PD-1/PD-L1 engagement and overexpression of galectin-3 (Gal-3) are critical mechanisms of tumor-induced immune suppression that contribute to immunotherapy resistance. We hypothesized that Gal-3 blockade with belapectin (GR-MD-02) plus anti-PD-1 (pembrolizumab) would enhance tumor response in patients with metastatic melanoma (MM) and head and neck squamous cell carcinoma (HNSCC).

METHODS

We performed a phase I dose escalation study of belapectin+pembrolizumab in patients with advanced MM or HNSCC (NCT02575404). Belapectin was administered at 2, 4, or 8 mg/kg IV 60 min before pembrolizumab (200 mg IV every 3 weeks for five cycles). Responding patients continued pembrolizumab monotherapy for up to 17 cycles. Main eligibility requirements were a functional Eastern Cooperative Oncology Group status of 0-2, measurable or assessable disease, and no active autoimmune disease. Prior T-cell checkpoint antibody therapy was permitted.

RESULTS

Objective response was observed in 50% of MM (7/14) and and 33% of HNSCC (2/6) patients. Belapectin+pembrolizumab was associated with fewer immune-mediated adverse events than anticipated with pembrolizumab monotherapy. There were no dose-limiting toxicities for belapectin within the dose range investigated. Significantly increased effector memory T-cell activation and reduced monocytic myeloid-derived suppressor cells (M-MDSCs) were observed in responders compared with non-responders. Increased baseline expression of Gal-3+ tumor cells and PD-1+CD8+ T cells in the periphery correlated with response as did higher serum trough levels of pembrolizumab.

CONCLUSIONS

Belapectin+pembrolizumab therapy has activity in MM and HNSCC. Increased Gal-3 expression, expansion of effector memory T cells, and decreased M-MDSCs correlated with clinical response. Further investigation is planned.

Immune checkpoint-related serum proteins and genetic variants predict outcomes of localized prostate cancer, a cohort study

BACKGROUND

The clinical predictors and biological mechanisms for localized prostate cancer (PCa) outcomes remain mostly unknown. We aim to evaluate the role of serum immune-checkpoint-related (ICK) proteins and genetic variations in predicting outcomes of localized PCa.

METHODS

We profiled the serum levels of 14 ICK-related proteins (BTLA, GITR, HVEM, IDO, LAG-3, PD-1, PD-L1, PD-L2, Tim-3, CD28, CD80, 4-1BB, CD27, and CTLA-4) in 190 patients with localized PCa. The genotypes of 97 single nucleotide polymorphisms (SNPs) from 19 ICK-related genes were analyzed in an extended population (N = 1762). Meta-data from ArrayExpress and TCGA was employed to validate and to probe functional data. Patients were enrolled and tumor aggressiveness, biochemical recurrence (BCR), and progression information were obtained. Statistical analyses were performed analyzing associations between serum biomarkers, genotypes, mRNA and outcomes.

RESULTS

We showed that serum (s)BTLA and sTIM3 levels were associated with PCa aggressiveness (P < 0.05). sCD28, sCD80, sCTLA4, sGITR, sHVEM and sIDO correlated with both BCR and progression risks (all P < 0.05). We further identified ICK variants were significantly associated with aggressiveness, BCR and progression. Among them, 4 SNPs located in CD80 (rs7628626, rs12695388, rs491407, rs6804441) were not only associated with BCR and progression risk, but also correlated with sCD80 level (P < 0.01). rs491407 was further validated in an independent cohort. The CD80 mRNA expression was associated with BCR (HR, 1.85, 95% CI 1.06-3.22, P = 0.03) in meta-analysis of validation cohorts.

CONCLUSION

We highlight the prognostic value of serum ICK-related proteins for predicting aggressiveness, BCR and progression of PCa. The genetic variations and mRNA expression in CD80 could be predictors and potential targets of localized PCa.

The clinical significance of HERV-H LTR -associating 2 expression in cervical adenocarcinoma

HERV-H LTR -associating 2 (HHLA2) is a recently discovered member of the B7-family of immune checkpoint molecules that is overexpressed in several types of cancer. The aim of the present study was to investigate the expression of HHLA2 in cervical adenocarcinoma (AC) and the relationship between its expression and clinicopathological factors to assess its use as a potential marker for AC prognosis.This study included 76 patients diagnosed with cervical AC. Their resected specimens were obtained and a tissue microarray was constructed. Expression of HHLA2 was detected by the immunohistochemistry. Based on the follow-up data, correlation of HHLA2 expression and clinicopathological features, including overall survival (OS) and disease-free survival, was evaluated. Furthermore, we investigated the correlation between the expression of HHLA2 and programmed death ligand 1 (PD-L1).A total of 76 cases of invasive cervical AC were evaluated. High HHLA2 expression was detected in 62 cases (81.6%) and low HHLA2 expression was presented in 14 cases (18.4%). HHLA2 expression showed a significant negative correlation with lymph node metastasis (P = .011). Disease free survival was 75.0% and 49.0% in high-expression and the low expression group, respectively (P = .057). Although there was no statistical significance, an improved OS was observed in the high expression group (83.1% vs 64.9%, P = .479). Further, the expression of HHLA2 and PD-L1 correlated positively (P = .005). Thus, an improved OS was observed in the PD-L1 expression group (90.7% vs 66.2%, P = .037).High expression of HHLA2 is related to tumor progression and prognosis in patients with cervical AC. Therefore, HHLA2 may be a potential biomarker for predicting prognosis of cervical AC.

B7-1 and GM-CSF enhance the anti-tumor immune effect of DC-tumor fusion vaccine in the treatment of prostate cancer

The treatment of castration-resistant prostate cancer (CRPC) is always a difficulty in the clinic. Most patients with localized tumor eventually develop CRPC, even if hormone therapy is initially effective. Increasing evidence shows immunotherapy has special advantages compared with traditional therapy in cancer treatment. In this study, we constructed the DC-PC-3 fusion vaccine with B7-1- and GM-CSF-specific modification, and studied its ability to stimulate specific immune response and anti-tumor effect in vitro. The results showed that fusion of DC and tumor cells can improve the expression of associated antigens of DCs. DC-tumor fusion vaccine can strongly promote T cell proliferation and IFN-γ secretion and induce a significant tumor-specific cytotoxic T lymphocyte response. In addition, the B7-1/GM-CSF-modified fusion vaccine showed a more significant anti-tumor effect and greater ability to stimulate the immune response than that without specific modification in vitro. Thus, GM-CSF/B7-1-modified fusion vaccine might be used as a potential therapy strategy for prostate cancer.

Molecular mechanisms of breast cancer chemoresistance by immune checkpoints

Progression of resistance to chemotherapy in breast cancer (BC) has been recognized as a main factor in decreasing the survival of patients with this malignancy. Recent investigations have described the involvement of immune checkpoint molecules in the progress of drug resistance in breast carcinoma patients. In the present study, the molecular participation of immune checkpoint factors in chemoresistance of BC both in-vitro and in-vivo is reviewed. Numerous immune checkpoints such as PD-1/PD-L1, CTLA-4, B7-H3, B7-H4, B7-1, and B7-2 have been specified as positive regulators of resistance to various drug types in BC. In several molecular pathways of drug resistance in BC, immune checkpoints affect the chemoresistance of this cancer in a drug- and cell-type-dependent manner. In addition, immune checkpoints promote chemoresistance in response to particular drugs in specific BC cell lines. Furthermore, several the immune checkpoint molecules have not been evaluated in the field of the chemoresistance in breast malignancy either in-vitro or in-vivo. Overall, investigations have indicated that targeting immune checkpoint molecules may be considered as a novel method to improve existing anti-BC treatments.

Understanding and Overcoming the Inflammatory Toxicities of Immunotherapy

Checkpoint blockade immunotherapy has led to impressive therapeutic responses in a wide variety of tumors, but also leads to a spectrum of inflammatory toxicities that can involve any organ system in the body. Although most inflammatory toxicities resolve with systemic immune suppression, fatal toxicities can occur, and interruption and discontinuation of immunotherapy because of toxicity are common. In addition to their clinical impact, these inflammatory toxicities also provide a window into immune regulation in humans. By studying the cellular and molecular mechanisms that drive this inflammation, we have an opportunity to learn how the immune checkpoints, cytotoxic T lymphocyte antigen-4 and programmed death-1 and its ligand, maintain immune homeostasis throughout the body. Although we have an increasingly detailed understanding of the mechanisms that drive effective antitumor immunity, we have a rudimentary picture of the mechanisms of toxicity. Most toxicities involve barrier organs, suggesting an important role for interactions with the environment, including the microbiome. Early analyses have implicated cytotoxic T cells, although the antigens recognized by these cells, and the pathways activated by and around them are still unknown. By gaining a detailed understanding of the immune mechanisms of toxicity, we have the potential to develop novel interventions for them. These treatments should take advantage of differences between effective antitumor immunity and the principal drivers of organ inflammation. By targeting these mechanistic differences, we can develop therapies that can be used alongside immunotherapy, blocking inflammatory toxicity while preserving or even enhancing the response to cancer.

Preclinical Development of MGC018, a Duocarmycin-based Antibody-drug Conjugate Targeting B7-H3 for Solid Cancer

B7-H3, also referred to as CD276, is a member of the B7 family of immune regulatory proteins. B7-H3 is overexpressed on many solid cancers, including prostate cancer, renal cell carcinoma, melanoma, squamous cell carcinoma of the head and neck, non-small cell lung cancer, and breast cancer. Overexpression of B7-H3 is associated with disease severity, risk of recurrence and reduced survival. In this article, we report the preclinical development of MGC018, an antibody-drug conjugate targeted against B7-H3. MGC018 is comprised of the cleavable linker-duocarmycin payload, valine-citrulline-seco duocarmycin hydroxybenzamide azaindole (vc-seco-DUBA), conjugated to an anti-B7-H3 humanized IgG1/kappa mAb through reduced interchain disulfides, with an average drug-to-antibody ratio of approximately 2.7. MGC018 exhibited cytotoxicity toward B7-H3-positive human tumor cell lines, and exhibited bystander killing of target-negative tumor cells when cocultured with B7-H3-positive tumor cells. MGC018 displayed potent antitumor activity in preclinical tumor models of breast, ovarian, and lung cancer, as well as melanoma. In addition, antitumor activity was observed toward patient-derived xenograft models of breast, prostate, and head and neck cancer displaying heterogeneous expression of B7-H3. Importantly, MGC018 exhibited a favorable pharmacokinetic and safety profile in cynomolgus monkeys following repeat-dose administration. The antitumor activity observed preclinically with MGC018, together with the positive safety profile, provides evidence of a potentially favorable therapeutic index and supports the continued development of MGC018 for the treatment of solid cancers. GRAPHICAL ABSTRACT: http://mct.aacrjournals.org/content/molcanther/19/11/2235/F1.large.jpg.

Isolation of Two Novel Human Anti-CTLA-4 mAbs with Intriguing Biological Properties on Tumor and NK Cells

The cytotoxic T lymphocyte-antigen 4 (CTLA-4) has been considered an IC exclusively expressed on T cells, where it counteracts the co-stimulatory CD28 receptor, by competing for its binding to CD-80 and CD-86. We recently found that it is expressed also on tumor and NK cells, suggesting other possible unknown roles of CTLA-4. To shed light on these novel aspects of CTLA-4, we used Ipilimumab, the first FDA approved human antibody targeting CTLA-4, in parallel studies with two novel human mAbs we isolated by using an efficient phage display selection strategy on live activated lymphocytes and purified mouse and human CTLA-4. The selection for cross-reactive mAbs was guaranteed by a high throughput sequencing to identify the sequences commonly enriched by two parallel pannings on human and mouse CTLA-4. Two isolated antibodies were found to bind with high affinity to both human and mouse CTLA-4 and lymphocytes, showing nanomolar or sub-nanomolar Kd values. They were able to kill Treg cells by ADCC, and to activate both human and mouse PBMCs, by strongly increasing cytokines secretion. Interestingly, they activated NK cells, exhibited cytotoxicity against cancer cells by inducing ADCC and inhibited tumor cell growth by affecting CTLA-4 downstream pathways in a similar fashion to CD-80 and CD-86 ligands and differently from Ipilimumab. Moreover, the novel mAbs showed a reduced ability to interfere in the binding of CD-80 ligands to CTLA-4 on T cells with respect to Ipilimumab, suggesting that they could allow for anti-tumor effects without the irAEs associated with the potent antagonistic activity of Ipilimumab.

Manipulation of the Immune System for Cancer Defeat: A Focus on the T Cell Inhibitory Checkpoint Molecules

The immune system actively counteracts the tumorigenesis process; a breakout of the immune system function, or its ability to recognize transformed cells, can favor cancer development. Cancer becomes able to escape from immune system control by using multiple mechanisms, which are only in part known at a cellular and molecular level. Among these mechanisms, in the last decade, the role played by the so-called "inhibitory immune checkpoints" is emerging as pivotal in preventing the tumor attack by the immune system. Physiologically, the inhibitory immune checkpoints work to maintain the self-tolerance and attenuate the tissue injury caused by pathogenic infections. Cancer cell exploits such immune-inhibitory molecules to contrast the immune intervention and induce tumor tolerance. Molecular agents that target these checkpoints represent the new frontier for cancer treatment. Despite the heterogeneity and multiplicity of molecular alterations among the tumors, the immune checkpoint targeted therapy has been shown to be helpful in selected and even histologically different types of cancer, and are currently being adopted against an increasing variety of tumors. The most frequently used is the moAb-based immunotherapy that targets the Programmed Cell Death 1 protein (PD-1), the PD-1 Ligand (PD-L1) or the cytotoxic T lymphocyte antigen-4 (CTLA4). However, new therapeutic approaches are currently in development, along with the discovery of new immune checkpoints exploited by the cancer cell. This article aims to review the inhibitory checkpoints, which are known up to now, along with the mechanisms of cancer immunoediting. An outline of the immune checkpoint targeting approaches, also including combined immunotherapies and the existing trials, is also provided. Notwithstanding the great efforts devoted by researchers in the field of biomarkers of response, to date, no validated FDA-approved immunological biomarkers exist for cancer patients. We highlight relevant studies on predictive biomarkers and attempt to discuss the challenges in this field, due to the complex and largely unknown dynamic mechanisms that drive the tumor immune tolerance.

Alpha-Fetoprotein Regulates the Expression of Immune-Related Proteins through the NF-κB (P65) Pathway in Hepatocellular Carcinoma Cells

Background

The prognosis of patients with hepatocellular carcinoma (HCC) is poor, with 60% to 70% of patients developing recurrence and metastasis within five years of radical resection. Alpha-fetoprotein (AFP) plays a significant role in predicting the recurrence and metastasis of HCC after surgery. However, its role in modulating tumor immunity has not been investigated. Our objective was to examine the effect of AFP on the expression of B7 family and activation of the NF-κB (P65) pathway in HCC.

Methods

We generated human hepatoma SMMC-7721 cell lines with or without recombinant AFP transfection (AFPup and control groups). Colony formation assay, Transwell invasion assay, and wound healing assay were used to detect the function of AFP. Liver cancer xenografts were made in BALB/c nude male mice (N = 6 per group). After 28 days of inoculation, the expression of immune genes in the HCC tissues, including PD-L (B7-H1), B7-H3, B7-H4, and P65, was evaluated by quantitative real-time PCR (qPCR) and western blot. In addition, immunofluorescence was used to determine the subcellular localization of the P65 protein, a key factor in the NF-κB pathway. An online HCC patients' dataset was also used to detect the connection between AFP and P65.

Results

Overexpression of AFP could enhance proliferation, invasion, and migration of HCC cells. Both qPCR and western blot results demonstrated that the expressions of PD-L1, B7-H4, and P65 were significantly higher in the AFP group compared to the controls (P < 0.05). Immunofluorescence results indicated that the majority of the P65 protein was located in the cytoplasm in the control group but was translocated to the nucleus in the AFPup group. The Spearman correlation coefficient confirms that AFP has a positive correlation with P65 in HCC patients (R = 0.33, P=0.05).

Conclusion

AFP could enhance proliferation, invasion, and migration in HCC cells. The upregulation of AFP would increase the PD-L1 and B7-H4 mRNA and protein expression in HCC tissues through the upregulation and activation of the P65 protein.

Mechanistic dissection of the PD-L1:B7-1 co-inhibitory immune complex

The B7 family represents one of the best-studied subgroups within the Ig superfamily, yet new interactions continue to be discovered. However, this binding promiscuity represents a major challenge for defining the biological contribution of each specific interaction. We developed a strategy for addressing these challenges by combining cell microarray and high-throughput FACS methods to screen for promiscuous binding events, map binding interfaces, and generate functionally selective reagents. Applying this approach to the interactions of mPD-L1 with its receptor mPD-1 and its ligand mB7-1, we identified the binding interface of mB7-1 on mPD-L1 and as a result generated mPD-L1 mutants with binding selectivity for mB7-1 or mPD-1. Next, using a panel of mB7-1 mutants, we mapped the binding sites of mCTLA-4, mCD28 and mPD-L1. Surprisingly, the mPD-L1 binding site mapped to the dimer interface surface of mB7-1, placing it distal from the CTLA-4/CD28 recognition surface. Using two independent approaches, we demonstrated that mPD-L1 and mB7-1 bind in cis, consistent with recent reports from Chaudhri A et al. and Sugiura D et al. We further provide evidence that while CTLA-4 and CD28 do not directly compete with PD-L1 for binding to B7-1, they can disrupt the cis PD-L1:B7-1 complex by reorganizing B7-1 on the cell surface. These observations offer new functional insights into the regulatory mechanisms associated with this group of B7 family proteins and provide new tools to elucidate their function in vitro and in vivo.

The Role of Immune Checkpoints after Cellular Therapy

Cellular therapies utilize the powerful force of the human immune system to target malignant cells. Allogeneic hematopoietic stem cell transplantation (allo-HCT) is the most established cellular therapy, but chimeric antigen receptor (CAR) T cell therapies have gained attention in recent years. While in allo-HCT an entirely novel allogeneic immune system facilitates a so-called Graft-versus-tumor, respectively, Graft-versus-leukemia (GvT/GvL) effect against high-risk hematologic malignancies, in CAR T cell therapies genetically modified autologous T cells specifically attack target molecules on malignant cells. These therapies have achieved high success rates, offering potential cures in otherwise detrimental diseases. However, relapse after cellular therapy remains a serious clinical obstacle. Checkpoint Inhibition (CI), which was recently designated as breakthrough in cancer treatment and consequently awarded with the Nobel prize in 2018, is a different way to increase anti-tumor immunity. Here, inhibitory immune checkpoints are blocked on immune cells in order to restore the immunological force against malignant diseases. Disease relapse after CAR T cell therapy or allo-HCT has been linked to up-regulation of immune checkpoints that render cancer cells resistant to the cell-mediated anti-cancer immune effects. Thus, enhancing immune cell function after cellular therapies using CI is an important treatment option that might re-activate the anti-cancer effect upon cell therapy. In this review, we will summarize current data on this topic with the focus on immune checkpoints after cellular therapy for malignant diseases and balance efficacy versus potential side effects.

B7-H3: A promising therapeutic target for autoimmune diseases

B7-H3 as a newly identified costimulatory molecule that belongs to B7 ligand family, is broadly expressed in both lymphoid and non-lymphoid tissues. The overexpression of B7-H3 has been verified to be correlated with the poor prognosis and poor clinical outcome of several human cancers. In recent years, researchers reveal that B7-H3 is involved in the pathogenesis of various autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), multiple sclerosis (MS), Sjögren's syndrome (SS), ankylosing spondylitis (AS), etc. In this review, we will discuss the biological function of B7-H3 and summarize the progress made over past years regarding its role in the occurrence and development of autoimmune diseases. The insights gained from these findings could serve as the foundation for future therapies of these diseases.

B7-H4 is a potential prognostic biomarker of prostate cancer

B7-H4 is a member of B7 family which regulates immune responses by delivering costimulatory signals. However, it negatively regulates T cell-mediated immunity and may play an important role in tumor immune evasion. Although several studies have been reported that expression of B7-H4 is elevated in the several types of human cancer with a poor clinical outcome, its clinical significance in the prostate cancer (PCa) has not been well studied. In this study, we investigated the clinical significance of B7-H4 in human PCa and determined if B7-H4 expression is associated with the cancer cell stemness in PCa. Our studies show that expression of B7-H4 is correlated with the pathologic tumor (pT) stage and the clinical stage of PCa. The Kaplan-Meier survival analysis revealed that PCa patients with high expression of B7-H4 exhibits a shorter overall survival (OS) rate. Univariate and multivariate Cox regression analysis indicated that B7-H4 is an independent poor prognostic factor of PCa. In addition, the expression of B7-H4 is correlated with the cancer cell stemness associated genes expression in PCa. Further, our studies show that B7-H4 regulates cancer cell stemness associated genes expression and effects on the cell cycle and PI3K/Akt signaling related genes expression in PCa. These results indicate that B7-H4 expression is associated with cancer cell stemness, and B7-H4 is a potential prognostic biomarker and a therapeutic target of PCa.