Latent membrane protein 1 (LMP1) expression in Hodgkin lymphoma and its correlation with clinical and histologic parameters

Epigenetic Mechanisms in Latent Epstein-Barr Virus Infection and Associated Cancers

The Epstein-Barr Virus (EBV) is a double-stranded DNA-based human tumor virus that was first isolated in 1964 from lymphoma biopsies. Since its initial discovery, EBV has been identified as a major contributor to numerous cancers and chronic autoimmune disorders. The virus is particularly efficient at infecting B-cells but can also infect epithelial cells, utilizing an array of epigenetic strategies to establish long-term latent infection. The association with histone modifications, alteration of DNA methylation patterns in host and viral genomes, and microRNA targeting of host cell factors are core epigenetic strategies that drive interactions between host and virus, which are necessary for viral persistence and progression of EBV-associated diseases. Therefore, understanding epigenetic regulation and its role in post-entry viral dynamics is an elusive area of EBV research. Here, we present current outlooks of EBV epigenetic regulation as it pertains to viral interactions with its host during latent infection and its propensity to induce tumorigenesis. We review the important epigenetic regulators of EBV latency and explore how the strategies involved during latent infection drive differential epigenetic profiles and host-virus interactions in EBV-associated cancers.

CAR-T Cell Therapy for Classical Hodgkin Lymphoma

Classical Hodgkin lymphoma (cHL) is a malignancy characterized by the presence of Hodgkin and Reed-Sternberg (HRS) cells within a complex tumor microenvironment (TME). Despite advances in conventional therapies, a subset of cHL patients experience relapse or refractory disease, necessitating the exploration of novel treatment strategies. Chimeric antigen receptor T cell (CAR-T cell) therapy has emerged as a promising approach for the management of cHL, harnessing the power of genetically modified T cells to recognize and eliminate tumor cells. In this article, we provide an overview of the pathogenesis of cHL, highlighting the key molecular and cellular mechanisms involved. Additionally, we discuss the rationale for the development of CAR-T cell therapy in cHL, focusing on the identification of suitable targets on HRS cells (such as CD30, CD123, LMP1, and LMP2A), clonotypic lymphoma initiating B cells (CD19, CD20), and cells within the TME (CD123, CD19, CD20) for CAR-T cell design. Furthermore, we explore various strategies employed to enhance the efficacy and safety of CAR-T cell therapies in the treatment of cHL. Finally, we present an overview of the results obtained from clinical trials evaluating the efficacy of CAR-T cell therapies in cHL, highlighting their potential as a promising therapeutic option. Collectively, this article provides a comprehensive review of the current understanding of cHL pathogenesis and the rationale for CAR-T cell therapy development, offering insights into the future directions of this rapidly evolving field.

Vaccination against Epstein-Barr Latent Membrane Protein 1 Protects against an Epstein-Barr Virus-Associated B Cell Model of Lymphoma

In this study, we demonstrate that expression of viral latent membrane protein 1 (LMP1) in a mouse B cell line renders the animals responsive to protection from a 38C13-LMP1 tumor challenge with a novel vaccine. The Epstein-Barr virus (EBV) preferentially infects circulating B lymphocytes, has oncogenic potential, and is associated with a wide variety of B cell lymphomas. EBV is ectotrophic to human cells, and currently there are no B cell animal models of EBV-associated lymphoma that can be used to investigate vaccine immunotherapy. Since most EBV-infected human tumor cells express latent membrane protein 1 (LMP1) on their surface, this viral antigen was tested as a potential target for an anticancer vaccine in a mouse model. Here, we describe a new mouse model of LMP1-expressing B cell lymphoma produced with plasmid transduction of 38C13 into mouse B cells. The expression of LMP-1 was confirmed with a western blot analysis and immunocytochemistry. We then designed a novel LMP1 vaccine, by fusing viral antigen LMP1 surface loop epitopes to the surface of a viral antigen carrier, the Tobacco Mosaic virus (TMV). Vaccinated mice produced high titer antibodies against the TMV-LMP1 vaccine; however, cellular responses were at the baseline, as measured with IFNγ ELISpot. Despite this, the vaccine showed significant protection from a 38C13-LMP1 tumor challenge. To provide additional immune targets, we compared TMV-LMP1 peptide immunization with DNA immunization with the full-length LMP1 gene. Anti-LMP1 antibodies were significantly higher in TMV-LMP1-vaccinated mice compared to the DNA-immunized mice, but, as predicted, DNA-vaccinated mice had improved cellular responses using IFNγ ELISpot. Surprisingly, the TMV-LMP1 vaccine provided protection from a 38C13-LMP1 tumor challenge, while the DNA vaccine did not. Thus, we demonstrated that LMP1 expression in a mouse B cell line is responsive to antibody immunotherapy that may be applied to EBV-associated disease.

Anti-EBV antibodies: Roles in diagnosis, pathogenesis, and antiviral therapy

Epstein-Barr virus (EBV) infection is prevalent in global population and associated with multiple malignancies and autoimmune diseases. During the infection, EBV-harbored or infected cell-expressing antigen could elicit a variety of antibodies with significant role in viral host response and pathogenesis. These antibodies have been extensively evaluated and found to be valuable in predicting disease diagnosis and prognosis, exploring disease mechanisms, and developing antiviral agents. In this review, we discuss the versatile roles of EBV antibodies as important biomarkers for EBV-related diseases, potential driving factors of autoimmunity, and promising therapeutic agents for viral infection and pathogenesis.

The Association of Epstein-Barr Virus With Cancer

Epstein-Barr virus (EBV) is classified as a herpesvirus and is known for being one of the few viruses that can lead to the development of cancer. This study has gathered several studies to provide evidence as to this association as well as some of the mechanisms specific to EBV that allow this to happen. The development of EBV into cancer as well as the proteins involved in this oncogenesis play a crucial role in understanding this problem as well as creating a solution for mitigating this disease process in the future. This study summarized three of the most common malignancies caused by EBV in order to consolidate information about each of them. Additional emphasis was placed on finding which EBV serum markers were seen to be most indicative of prognosis and likelihood of developing malignancy. Higher serum EBV viral DNA loads were seen to be a useful indicator in assessing the risk of various cancers and should be studied further in relation to cancers that were not mentioned in this review.

Detection of Epstein-Barr virus encoded RNA in fixed cells and tissues using CRISPR/Cas-mediated RCasFISH

Identification of Epstein-Barr virus (EBV)-infected cells is critical for the diagnosis and clinical management of EBV-associated diseases. EBV-encoded RNA (EBER) located in the nucleus is a reliable marker due to its high levels of expression and inherent stability in tissue specimens. EBER in situ hybridization has long been the gold standard for detecting tumor-associated latent EBV infection and is valuable in determining the primary site and radiation fields of EBV-related malignancies. However, reliable detection is somewhat restricted by diffused signal and time-consuming procedure of this method, especially when proteins and RNA needed to be labeled simultaneously. Here, we optimized and validated our CRISPR-dCas9 mediated in situ RNA imaging tool-RCasFISH that enabled us to detect EBER rapidly and was compatible with IHC methods in fixed cells and tissue sections. Our approach could provide an attractive alternative for the molecular diagnosis of latent EBV infection.

CD68-positive tumour associated macrophages, PD-L1 expression, and EBV latent infection in a high HIV-prevalent South African cohort of Hodgkin lymphoma patients

A higher proportion of CD68-positive tumour associated macrophages (TAMs) has been associated with poorer outcomes in HIV-negative patients with Hodgkin lymphoma (HL), but whether this is true in HIV-positive patients with HL is not known. In this study, we investigated the number of CD68-positive TAMs and expression of programmed cell death-ligand 1 (PD-L1) in lymph node specimens from HL patients and correlated expression with clinical features (HIV status, disease severity and survival) and histopathological features (EBV latent positivity and subtype of HL). We stained archived lymph node specimens from 77 patients diagnosed with HL for CD68 and PD-L1. Stains were graded as: CD68 low (≤25%), CD68 high (>25%), PD-L1 low (≤50%), and PD-L1 high (>50%). Expression levels were correlated with the clinical and histopathological features using bivariate and multivariate analyses. Survival was analysed by overall and progression-free survival. Thirty-four of the 77 included patients (44%) were HIV-positive. EBV latency was detected in 97% of HIV-positive HL patients and in 14% of HIV-negative HL patients. A high CD68 score was associated with lower median haemoglobin levels (9.4 vs 11.4 g/dL; p=0.02), platelet numbers (262 vs 424 cells ×10⁹/L; p=0.01), and lymphocyte numbers (0.99 vs 1.70 cells ×10⁹/L, p=0.01) and a trend towards advanced disease (international prognostic score ≥4; hazard ratio 2.4; confidence interval 0.89-6.47; p=0.08). HIV status did not affect CD68 or PD-L1 expression. A higher proportion of CD68-positive TAMs was found in samples that were EBV-positive. HIV positivity and EBV negativity correlated with poorer survival. CD68 and PD-L1 expression were not predictive of survival. High CD68 expression was associated with EBV positivity but not HIV positivity and did not predict adverse outcomes. PD-L1 expression was unaffected by HIV status or EBV positivity and did predict adverse outcomes.

Epstein-Barr virus-encoded LMP1 induces ectopic CD137 expression on Hodgkin and Reed-Sternberg cells via the PI3K-AKT-mTOR pathway

CD137 is a potent co-stimulatory molecule on activated T cells, and its ligand (CD137L) is expressed on antigen presenting cells (APC). Ectopic expression of CD137 has been identified on Hodgkin Reed-Sternberg (HRS) cells, the malignant cells in Hodgkin Lymphoma (HL), and CD137 on HRS cells was found to support growth of HRS cells and escape from immune surveillance. HRS cells are mostly derived from B cells, which poses the question of how B cells acquire ectopic CD137 expression during the transformation process. HL is associated with Epstein-Barr virus (EBV) infection. We show that the EBV latent membrane protein 1 (LMP1) induces expression of CD137 in HRS cell lines. In a HL tissue microarray, 96% of the CD137-positive HL cases stained positive for LMP1. LMP1 utilizes the PI3K-AKT-mTOR pathway for inducing CD137 expression. These findings support the role of EBV in HL pathogenesis.

An integrated automated multispectral imaging technique that simultaneously detects and quantitates viral RNA and immune cell protein markers in fixed sections from Epstein-Barr virus-related tumours

BACKGROUND/AIM

Epstein-Barr virus (EBV) is an oncovirus that is commonly associated with the development of lymphomas and epithelial carcinomas. In the era of immunotherapy, histological evaluation of EBV-related cancers is currently a multi-sample, multi-technique process requiring separate time-consuming detection of EBV-encoded small RNAs by in situ hybridisation (ISH), and parallel labelling of sections for cancer-associated protein markers.

METHODS

Using EBV-associated tumours as proof-of-concept for feasibility, here we developed an approach that allows simultaneous detection of EBV RNAs and multiple protein markers such as PD-L1, EBV-LMP, CD8, CD4, CD20, CD30 and CD15on a single tissue section based on our recently reported automated staining protocol.

RESULTS

We successfully combined multiplex immunofluorescence (mIF) to detect 3 abovementioned protein markers involved in cancer, with ISH, and applied the protocol to f tissue samples from patients diagnosed with EBV-associated pulmonary lymphoepithelioma-like carcinoma (LELC), gastric carcinoma and Hodgkin's Lymphoma. Empowered by the Vectra 3 Automated Quantitative Pathology Imaging System, we demonstrate the utility and potential of this integrated approach to concurrently detect and quantitate viral RNA and protein biomarkers of immune and tumour cells.

CONCLUSION

This study represents an important step forward in the research and diagnosis of EBV-associated cancers, and could be readily modified to include other proteins and RNA markers to apply to other malignancies. More importantly, the novel automated ISH-mIF protocol that we detailly described here could also be readily reproduced by most of the diagnostic and research lab to future projects that aim to look at both RNA and protein markers.

Epstein–Barr Virus: A Biological Overview and Clinicopathological Changes of Two Epstein–Barr Virus-Related Lymphoproliferative Disorders in a World Health Organization (WHO) 2017 Report

Epstein–Barr virus (EBV) is one of the most important viral causes for the development of tumours. The global geographical epidemiology of EBV shows prevalence differences between rich and poor countries across the world, and the impact on health suggests EBV should be an important target of research worldwide. This article will discuss the biology of the virus with an emphasis on its latency types, vital to understanding the possibilities of viral detection. The main objective is to discuss two lymphoproliferative diseases that are associated with EBV and appear in the World Health Organization (WHO) 2017 Classification of Tumours of Haematopoietic and Lymphoid Tissues: EBV-positive diffuse large B cell lymphoma and EBV mucocutaneous ulcer. The name of the former was changed to support the better understanding of infection pathology, while the second was recently described and made its debut in the WHO classification. Pathologists must have knowledge on these diseases and how to investigate them, and oncologists and clinical doctors must be informed on the guidelines.