Contribution of the Epstein-Barr Virus and the Tumour Microenvironment to Anti-Apoptotic Mechanisms in DLBCL

Project Information

CoMAnD

Grant agreement ID: 101065377

DOI

10.3030/101065377

Project terminated on 10 September 2025

EC signature date 30 May 2022

Start date 3 January 2023

End date 2 January 2026

Funded under

• Marie Skłodowska-Curie Actions (MSCA)

Total cost

No data

EU contribution

€ 276 864,48

Coordinated by

UNIVERSITY OF LIMERICK
Ireland

Periodic Reporting for period 2 - CoMAnD (Contribution of the Epstein-Barr Virus and the Tumour Microenvironment to Anti-Apoptotic Mechanisms in DLBCL)

Reporting period: 2025-01-03 to 2026-01-02

Summary of the context and overall objectives of the project

This MSCA-Global Fellowship, “Contribution of the Epstein-Barr Virus and the Tumour Microenvironment to Anti-Apoptotic Mechanisms in DLBCL” (CoMAnD), aimed to explore the synergistic role of the proto-oncogene MYC and the oncogenic Epstein-Barr virus (EBV) in the development and treatment of Diffuse large B cell Lymphoma (DLBCL). The post-doctoral fellow (PF) explored this by first generating novel models of DLBCL from primary human tonsillar germinal centre B cells through immortalisation with different proto-oncogenes (MYC, BCL-2, BCL-6) and/or EBV. These novel DLBCL models were then characterised, with a specific focus on 1) the impact of MYC and EBV on the expression of members of the BCL-2 family of proteins (members of the intrinsic apoptotic pathway) and 2) the sensitivity of the novel DLBCL models of BH3-mimetics, a family of small molecule inhibitors that act on pro-survival members of the BCL-2 family of proteins (WP1). Next, the impact of MYC and EBV on the evolution of the tumour microenvironment (TME) and pro-/anti-apoptotic signals was explored by transplanting the novel DLBCL models into humanised mouse models. These mice were treated with BH3-mimetics to target the intrinsic apoptotic pathway (WP2). Finally, the TME of the novel humanised mouse models of MYC and/or EBV+ DLBCL was compared to patient samples using ultrahigh multiplex immunohistochemistry to uncover the relationship between MYC and EBV, and the evolution of the TME and anti-/pro-apoptotic signalling in DLBCL (WP3).
This research project has significant societal impact as currently, EBV+ DLBCL is associated with worse survival outcomes than the EBV- counterpart. Despite this, no treatment stratification exists for patients with EBV+ DLBCL. Without tractable models of EBV+ DLBCL, developing novel therapeutic strategies is severely impeded. To address this barrier, this project used novel isogenic models of EBV+ and EBV- DLBCL, genetically engineered to express different cellular and viral oncogenes, recapitulating human disease. Beyond the scope of this project, which aimed to explore intrinsic apoptosis and the tumour microenvironment in EBV+ DLBCL, these models have the potential to be employed to explore a diverse range of mechanisms and pathways involved in tumour progression and treatment resistance in EBV+ DLBCL.
In summary, this project aimed to elucidate the relationship between EBV, the proto-oncogene MYC and their effects on the intrinsic apoptosis pathway and the tumour microenvironment. The PF explored the potential to treat EBV+ DLBCL by targeting the intrinsic apoptosis pathway using BH3-mimetic drugs and evaluated how EBV and MYC modulate the tumour microenvironment to promote therapy resistance. Towards these aims, this fellowship had 6 objectives, 3 scientific and 3 training and development:
O1: Explore how EBV infection and MYC synergise to transform B cells in vitro.
O2: Using humanised mouse models, determine how different viral and cellular oncogenic drivers impact the TME.
O3: Validate TME changes in primary tumours and explore how selected TME features regulate apoptosis.
O4: Project management.
O5: Training and knowledge transfer.
O6: Dissemination, exploitation and communication.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The PF generated a range of isogenic models of EBV+ and EBV- DLBCL, using primary human tonsillar germinal centre B cells. Beyond this project, these models can be used to explore the mechanisms underpinning EBV+ B cell lymphomagenesis and treatment resistance. Specifically, this project investigated the effect of EBV on the intrinsic apoptosis pathway.
Main findings suggest that EBV+ models have an increased expression of pro-survival proteins and a reduction in the expression of anti-apoptotic proteins compared to isogenic EBV- models. The EBV+ models also demonstrate a reduction in sensitivity to BH3-mimetic, small molecule inhibitors of the pro-survival proteins which are currently being investigated for the treatment of a range of haematological malignancies. Despite, EBV+ cells co-expressing BCL-2 were sensitive to the BH3-mimetic ABt-199 (venetoclax) which inhibits BCL-2.
These EBV+ DLBCL models are readily transplantable directly into the lymph nodes of NSG mice that have been reconstituted with a human immune system (so called "humanised mice" ). In these humanised mouse models of EBV+ DLBCL, we see immune infiltration into the tumours, in particular CD3+ T cells. These humanised mouse models of EBV+ DLBCL also displayed increased tumour latency compared to transplantation in mice lacking an immune system, thereby indicating immune mediated control of tumour outgrowth in the humanised mice. However, we found that in both humanised mice and immune compromised NSG mice, the EBV+ cell models were no longer sensitive to the BH3-mimetic ABT-199, implicating a role for the TME, and specifically tumour stromal cells and the extracellular matrix (ECM), i.e. the non-immune cell compartment of the TME, in modulating tumour resistance.
On going work includes the validation of a panel of 53 markers for ultrahigh multiplex immunohistochemistry on the Phenocycler Fusion to investigate the immnue and ECM of these EBV+ DLBCL models. An additional dedicated EBV-specific panel of 7 markers is being validated on the PhenoCode (formerly Vectra) to explore the co-expression of EBV genes in EBV+ DLBCL. These will be compared to patient samples to 1) validate the utility of these models to investigate to tumour microenvironment of EBV+ DLBCL and 2) explore the synergistic impact of EBV with the proto-oncogene MYC on the evolution of the tumour microenvironment.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Patients with EBV+ DLBCL have worse overall prognosis compared to patients with EBV- DLBCL. Despite this, there is no treatment stratification of EBV+ DLBCL. Identifying novel therapeutics for EBV+ DLBCL is impeded, in part, due to a lack of availability of reliable pre-clinical models for drug discovery. To address this, this project has successfully developed isogenic models of of EBV+ and EBV- DLBCL which can be used to determine the role EBV plays in treatment resistance and tumourigenesis in vitro. We have also validated that these models are readily transplantable directly into the lymph nodes of NSG mice reconstituted with a human immune system. These models could therefore be exploited for both in vitro and in vivo pre-clinical assessment of novel therapeutic agents for the treatment of EBV+ DLBCL.