Novel EBV LMP-2-affibody and affitoxin in molecular imaging and targeted therapy of nasopharyngeal carcinoma

Treatment of Epstein-Barr Virus infection in immunocompromised patients

Epstein-Barr Virus (EBV), is a ubiquitous γ-Herpesvirus that infects over 95% of the human population and can establish a life-long infection without causing any clinical symptoms in healthy individuals by residing in memory B-cells. Primary infection occurs in childhood and is mostly asymptomatic, however in some young adults it can result in infectious mononucleosis (IM). In immunocompromised individuals however, EBV infection has been associated with many different malignancies. Since EBV can infect both epithelial and B-cells and very rarely NK cells and T-cells, it is associated with both epithelial cancers like nasopharyngeal carcinoma (NPC) and gastric carcinoma (GC), with lymphomas including Burkitt Lymphoma (BL) or Post-transplant Lymphoproliferative Disorder (PTLD) and rarely with NK/T-cell lymphomas. Currently there are no approved antivirals active in PTLD nor in any other malignancy. Moreover, lytic phase disease almost never requires antiviral treatment. Although many novel therapies against EBV have been described, the management and/or prevention of EBV primary infections or reactivations remains difficult. In this review, we discuss EBV infection, therapies targeting EBV in both lytic and latent state with novel therapeutics developed that show anti-EBV activity as well as EBV-associated malignancies both, epithelial and lymphoproliferative malignancies and emerging therapies targeting the EBV-infected cells.

Research progress and application of single-cell sequencing in head and neck malignant tumors

Single-cell sequencing (SCS) is a technology that separates thousands of cells from the organism and accurately analyzes the genetic material expressed in each cell using high-throughput sequencing technology. Unlike the traditional bulk sequencing approach, which can only provide the average value of a cell population and cannot obtain specific single-cell data, single-cell sequencing can identify the gene sequence and expression changes of a single cell, and reflects the differences between genetic material and protein between cells, and ultimately the role played by the tumor microenvironment. single-cell sequencing can further explore the pathogenesis of head and neck malignancies from the single-cell biological level and provides a theoretical basis for the clinical diagnosis and treatment of head and neck malignancies. This article will systematically introduce the latest progress and application of single-cell sequencing in malignant head and neck tumors.

Targeting EBV-encoded products: Implications for drug development in EBV-associated diseases

Epstein-Barr virus, a human gamma-herpesvirus, has a close connection to the pathogenesis of cancers and other diseases, which are a burden for public health worldwide. So far, several drugs or biomolecules have been discovered that can target EBV-encoded products for treatment, such as Silvestrol, affinity toxin, roscovitine, H20, H31, curcumin, thymoquinone, and ribosomal protein L22. These drugs activate or inhibit the function of some biomolecules, affecting subsequent signalling pathways by acting on the products of EBV. These drugs usually target LMP1, LMP2; EBNA1, EBNA2, EBNA3; EBER1, EBER2; Bam-HI A rightward transcript and BHRF1. Additionally, some promising findings in the fields of vaccines, immunological, and cellular therapies have been established. In this review, we mainly summarise the function of drugs mentioned above and unique mechanisms, hoping that we can help giving insight to the design of drugs for the treatment of EBV-associated diseases.

A lipid-based LMP2-mRNA vaccine to treat nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a serious and highly invasive epithelial malignancy that is closely associated with Epstein-Barr virus (EBV). Due to the lack of therapeutic vaccines for NPC, we selected EBV latent membrane protein 2 (LMP2) as a preferable targeting antigen to develop a lipid-based LMP2-mRNA (mLMP2) vaccine. Full-length mLMP2 expressing LMP2 was first synthesized using an in vitro transcription method and then encapsulated into (2,3-dioleacyl propyl) trimethylammonium chloride (DOTAP)-based cationic liposomes to obtain the mRNA vaccine (LPX-mLMP2). The cell assays showed that the antigen-presenting cells were capable of highly efficient uptake of LPX-mLMP2 and expression of LMP2. LMP2 could subsequently be presented to form the peptide-major histocompatibility complex (pMHC). Furthermore, LPX-mLMP2 could accumulate in the spleen, express antigens, promote the maturation of dendritic cells and stimulate antigen-specific T-cell responses in vivo. It dramatically inhibited the tumor growth of the LMP2-expressing tumor model after three doses of vaccination. Additionally, the proliferation of antigen-specific T cells in the tumor site made a good sign for the promise of mRNA vaccines in virus-induced cancer. Overall, we provided a newly developed antigen-encoding mRNA vaccine with advantages against NPC. We also demonstrated that mRNA vaccines are attractive candidates for cancer immunotherapy.

Electronic Supplementary Material

Supplementary material (methods of cytotoxicity assay, LMP2 expression, hemolysis test, the results of purity and maturity of BMDCs, LMP2 expression, and evaluation of T cells in lymph nodes and gating strategy for CTLs) is available in the online version of this article at 10.1007/s12274-022-5254-x.

Epstein-Barr Virus (EBV) Epithelial Associated Malignancies: Exploring Pathologies and Current Treatments

Epstein-Barr virus (EBV) is one of eight known herpesviruses with the potential to infect humans. Globally, it is estimated that between 90-95% of the population has been infected with EBV. EBV is an oncogenic virus that has been strongly linked to various epithelial malignancies such as nasopharyngeal and gastric cancer. Recent evidence suggests a link between EBV and breast cancer. Additionally, there are other, rarer cancers with weaker evidence linking them to EBV. In this review, we discuss the currently known epithelial malignancies associated with EBV. Additionally, we discuss and establish which treatments and therapies are most recommended for each cancer associated with EBV.

Protein scaffolds: Antibody alternative for cancer diagnosis and therapy

Although antibodies are well developed and widely used in cancer therapy and diagnostic fields, some defects remain, such as poor tissue penetration, long in vivo metabolic retention, potential cytotoxicity, patent limitation, and high production cost. These issues have led scientists to explore and develop novel antibody alternatives. Protein scaffolds are small monomeric proteins with stable tertiary structures and mutable residues, which emerged in the 1990s. By combining robust gene engineering and phage display techniques, libraries with sufficient diversity could be established for target binding scaffold selection. Given the properties of small size, high affinity, and excellent specificity and stability, protein scaffolds have been applied in basic research, and preclinical and clinical fields over the past two decades. To date, more than 20 types of protein scaffolds have been developed, with the most frequently used being affibody, adnectin, ANTICALIN®, DARPins, and knottin. In this review, we focus on the protein scaffold applications in cancer therapy and diagnosis in the last 5 years, and discuss the pros and cons, and strategies of optimization and design.

Although antibodies are well developed and widely used in cancer therapy and diagnostic fields, some defects remain, such as poor tissue penetration, long in vivo metabolic retention, potential cytotoxicity, patent limitation, and high production cost.

Novel EBV LMP1 C-terminal domain binding affibody molecules as potential agents for in vivo molecular imaging diagnosis of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is consistently associated with Epstein-Barr virus (EBV) latent infection and is common in Southern China and Southeast Asia. The viral latent membrane proteins LMP1 and LMP2 are persistently expressed in NPC tissues; the cytoplasmic domain of LMP1 (LMP1 C-terminal) and LMP2A (LMP2A N-terminal) proteins is essential for maintenance of latency and can alter host cell signaling to facilitate tumor growth and progression. Thus, targeting LMP1 or LMP2 oncoprotein has been an increasing interest for diagnosis and targeted therapy of NPC. Affibody molecules, a new class of small-affinity engineered scaffold proteins, have demonstrated high potential for therapeutics, diagnostics, and biotechnological applications. More recently, radiolabelled HER2-specific affibody molecules have demonstrated to be useful in imaging of HER2 expressing tumor. In this study, we report three novel EBV LMP1 C-terminal (EBV LMP1-C) domain affibody molecules (Z_LMP1-C15, Z_LMP1-C114, and Z_LMP1-C277) were selected by biopanning from a random-peptide displayed phage library and used for molecular imaging in tumor-bearing nude mice. Surface plasmon resonance (SPR), indirect immunofluorescence, and immunohistochemistry (IHC) clearly showed that all three selected affibody molecules have high affinity and specificity in binding to EBV LMP1 protein. Moreover, in vivo tumor imaging revealed that Dylight-755-labeled affibody molecules accumulated rapidly in tumor site after injection (1 h) and then were continuously maintained for 24 h in EBV-positive NPC xenograft mice model. In conclusion, our findings highlight the potential use of Z_LMP1-C affibody molecules as tumor-specific molecular imaging agents of EBV-associated NPC.Key points• We screened three novel affibody molecules (Z_LMP1-C15, Z_LMP1-C114, and Z_LMP1-C277) targeting EBV LMP1-C terminal domain• Z_LMP1-C recognize the recombinant and native LMP1-C with high affinity and specificity• Z_LMP1-C can be used for molecular imaging.

Molecular Properties and Therapeutic Targeting of the EBV-Encoded Receptor BILF1

The γ-herpesvirus Epstein-Barr Virus (EBV) establishes lifelong infections in approximately 90% of adults worldwide. Up to 1,000,000 people yearly are estimated to suffer from health conditions attributed to the infection with this virus, such as nasopharyngeal and gastric carcinomas as well as several forms of B, T and NK cell lymphoma. To date, no EBV-specific therapeutic option has reached the market, greatly reducing the survival prognoses of affected patients. Similar to other herpesviruses, EBV encodes for a G protein-coupled receptor (GPCR), BILF1, affecting a multitude of cellular signaling pathways. BILF1 has been identified to promote immune evasion and tumorigenesis, effectively ensuring a life-long persistence of EBV in, and driving detrimental health conditions to its host. This review summarizes the epidemiology of EBV-associated malignancies, their current standard-of-care, EBV-specific therapeutics in development, GPCRs and their druggability, and most importantly consolidates the findings of over 15 years of research on BILF1 in the context of EBV-specific drug development. Taken together, BILF1 constitutes a promising target for the development of novel EBV-specific therapeutics.

Gemcitabine and APG-1252, a novel small molecule inhibitor of BCL-2/BCL-XL, display a synergistic antitumor effect in nasopharyngeal carcinoma through the JAK-2/STAT3/MCL-1 signaling pathway

Advanced nasopharyngeal carcinoma (NPC) has a poor prognosis, with an unfavorable response to palliative chemotherapy. Unfortunately, there are few effective therapeutic regimens. Therefore, we require novel treatment strategies with enhanced efficacy. The present study aimed to investigate the antitumor efficacy of APG-1252-M1, a dual inhibitor of BCL-2/BCL-XL, as a single agent and combined with gemcitabine. We applied various apoptotic assays and used subcutaneous transplanted NPC model to assess the in vitro and in vivo antitumor activity. Moreover, phospho-tyrosine kinase array was used to investigate the combined therapy’s potential synergistic mechanism. In addition, further validation was performed using immunohistochemistry and western blotting. In vitro, we observed that APG-1252-M1 had moderate antitumor activity toward NPC cells; however, it markedly improved gemcitabine’s ability to promote NPC cell apoptosis and suppress invasion, migration, and proliferation. Specifically, APG-1252 plus gemcitabine exhibited even remarkable antitumor activity in vivo. Mechanistically, the drug combination synergistically suppressed NPC by activating caspase-dependent pathways, blocking the phospho (p)-JAK-2/STAT3/MCL-1 signaling pathway, and inhibiting epithelial-mesenchymal transition. In conclusion, the results indicated that the combination of APG-1252 and gemcitabine has synergistic anticancer activities against NPC, providing a promising treatment modality for patients with NPC.

Novel Affibody Molecules Targeting the HPV16 E6 Oncoprotein Inhibited the Proliferation of Cervical Cancer Cells

Despite prophylactic vaccination campaigns, high-risk human papillomavirus (HPV)-induced cervical cancer remains a significant health threat among women, especially in developing countries. The initial occurrence and consequent progression of this cancer type primarily rely on, E6 and E7, two key viral oncogenes expressed constitutively, inducing carcinogenesis. Thus, E6/E7 have been proposed as ideal targets for HPV-related cancer diagnosis and treatment. In this study, three novel HPV16 E6-binding affibody molecules (Z_HPV16E61115, Z_HPV16E61171, and Z_HPV16E61235) were isolated from a randomized phage display library and cloned for bacterial production. These affibody molecules showed high binding affinity and specificity for recombinant and native HPV16 E6 as determined by surface plasmon resonance, indirect immunofluorescence, immunohistochemistry, and near-infrared small animal optical imaging in vitro and in vivo. Moreover, by binding to HPV16 E6 protein, Z_HPV16E61235 blocked E6-mediated p53 degradation, which increased the expression of some key p53 target genes, including BAX, PUMA and p21, and thereby selectively reduced the viability and proliferation of HPV16-positive cells. Importantly, Z_HPV16E61235 was applied in combination with HPV16 E7-binding affibody Z_HPV16E7384 to simultaneously target the HPV16 E6/E7 oncoproteins, and this combination inhibited cell proliferation more potently than either modality alone. Mechanistic studies revealed that the synergistic antiproliferative activity depends primarily on the induction of cell apoptosis and senescence but not cell cycle arrest. Our findings provide strong evidence that three novel HPV16 E6-binding affibody molecules could form a novel basis for the development of rational strategies for molecular imaging and targeted therapy in HPV16-positive preneoplastic and neoplastic lesions.

Generation of a novel affibody molecule targeting Chlamydia trachomatis MOMP

Abstract

Chlamydia trachomatis (C. trachomatis) is the leading cause of preventable blindness worldwide and the most prevalent cause of bacterial sexually transmitted diseases. At present, there is no available vaccine, and recurrences after antibiotics treatment are substantial problems. Major outer membrane protein (MOMP) accounts for 60% of the outer mass of C. trachomatis, functioning as trimeric porin, and it is highly antigenic. Therefore, MOMP is the most promising candidate for vaccine developing and target therapy of Chlamydia. Affibody, a new class of affinity ligands derived from the Z-domain in the binding region of Staphylococcus aureus protein A, has been the focus of researchers as a viable alternative to antibodies. In this study, the MOMP-targeted affibody molecule (Z_MOMP:461) was screened by phage-displayed peptide library. Further, the affinity and specificity were characterized by surface plasmon resonance (SPR) and Western blot. Immunofluorescence assay (IFA) indicated that the MOMP-binding affibody could recognize native MOMP in HeLa229 cells infected C. trachomatis. Immunoprecipitation assay confirmed further that Z_MOMP:461 molecule specifically recognizes the epitope on relaxed trimer MOMP. Our findings provide strong evidence that affibody molecule (Z_MOMP:461) serves as substitute for MOMP antibody for biological applications and has a great potential for delivering drugs for target therapy.

Key points

• We screened a novel affibody molecule Z_MOMP:461 targeting Chlamydia trachomatis MOMP.

• Z_MOMP:461 recognizes the recombinant and native MOMP with high affinity and specificity.

• Z_MOMP:461 could be internalized into live target cells.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00253-021-11128-x.

Chemotherapy and chemo-resistance in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is closely associated with Epstein-Barr virus (EBV) and occurs frequently in the south of China and Southeast Asian countries. Concurrent chemo-radiotherapy is one of the main treatments for NPC. Although, the combined treatment of chemo-radiotherapy produces a satisfying survival rate, the chemo-resistance arises as a big obstacle in curing recurrent NPC patients. The acquirement of chemo-resistance is usually along with a poor prognosis. So far, the mechanism of chemo-resistance in NPC has not been fully elucidated and there have not been a comprehensive review on this issue. Thus, it is of great significance to summarize the mechanisms involved in NPC chemo-resistance. In this review, the importance and limitations of chemotherapy and the mechanisms of chemo-resistances in NPC were discussed.

Emerging therapeutic targets for nasopharyngeal carcinoma: opportunities and challenges

Introduction: Nasopharyngeal carcinoma (NPC) is a major public health problem in several countries, especially those in Southeast Asia and North Africa. In its typical poorly differentiated form, the Epstein-Barr virus (EBV) genome is present in the nuclei of all malignant cells with restricted expression of a few viral genes. The malignant phenotype of NPC cells results from the influence of these viral products in combination with cellular genetic, epigenetic and functional alterations. With regard to host/tumor interactions, NPC is a remarkable example of immune escape in the context of a hot tumor.Areas covered: This article has an emphasis on emerging therapeutic targets that are considered upstream or at an early stage of clinical application. It examines targets related to cellular oncogenic alterations, latent EBV infection and tumor interactions with the immune system.Expert opinion: There is a remarkable emergence of new agents that target EBV products. The clinical application of these agents would benefit from a systematic and comprehensive molecular classification of NPCs and from easy access to pre-clinical models in public repositories. There is a strong rationale for more investigations on the potential of immune modulators, especially those related to NK cells.