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Updated: Jan 30, 2026
Ex Vivo Infection of Live Tissue with Oncolytic Viruses
Published on: June 25, 2011
Characterizing Cellular Responses During Oncolytic Maraba Virus Infection
Golnoush Hassanzadeh1, Thet Naing2,3, Tyson Graber4
1Molecular Biomedicine Program, Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada. ghassanz@ualberta.ca.
Abstract:
The rising demand for powerful oncolytic virotherapy agents has led to the identification of Maraba virus, one of the most potent oncolytic viruses from Rhabdoviridae family which displays high selectivity for killing malignant cells and low cytotoxicity in normal cells. Although the virus is readied to be used for clinical trials, the interactions between the virus and the host cells is still unclear. Using a newly developed interferon-sensitive mutant Maraba virus (MG1), we have identified two key regulators of global translation (4E-BP1 and eIF2α) as being involved in the regulation of protein synthesis in the infected cells. Despite the translational arrest upon viral stress, we showed an up-regulation of anti-apoptotic Bcl-xL protein that provides a survival benefit for the host cell, yet facilitates effective viral propagation. Given the fact that eIF5B canonically regulates 60S ribosome subunit end joining and is able to replace the role of eIF2 in delivering initiator tRNA to the 40S ribosome subunit upon the phosphorylation of eIF2α we have tested whether eIF5B mediates the translation of target mRNAs during MG1 infection. Our results show that the inhibition of eIF5B significantly down-regulates the level of Bcl-xL steady-state mRNA, thus indirectly attenuates viral propagation.
Insights
Maraba virus (MG1) infection halts protein synthesis but upregulates Bcl-xL for viral spread. Inhibiting eIF5B reduces Bcl-xL mRNA, slowing viral propagation, revealing a new therapeutic target for oncolytic virotherapy.
Area of Science:
- Oncolytic virotherapy
- Molecular virology
- Cancer research
Background:
- Maraba virus is a potent oncolytic agent with high cancer cell selectivity.
- Understanding virus-host interactions is crucial for clinical applications.
- Key regulators of protein synthesis in Maraba virus-infected cells are being investigated.
Purpose of the Study:
- To elucidate the role of host cell protein synthesis regulators in Maraba virus infection.
- To investigate the function of eIF5B in mediating viral mRNA translation.
- To identify potential therapeutic targets for enhancing oncolytic virotherapy.
Main Methods:
- Utilized an interferon-sensitive Maraba virus mutant (MG1).
- Identified key translation regulators (4E-BP1, eIF2α) in infected cells.
- Assessed the impact of eIF5B inhibition on Bcl-xL mRNA levels and viral propagation.
Main Results:
- MG1 infection induced translational arrest but upregulated anti-apoptotic Bcl-xL.
- eIF5B was investigated for its role in delivering initiator tRNA upon eIF2α phosphorylation.
- Inhibition of eIF5B significantly reduced Bcl-xL mRNA and viral propagation.
Conclusions:
- eIF5B plays a critical role in mediating target mRNA translation during MG1 infection.
- Bcl-xL upregulation aids viral propagation, while eIF5B inhibition offers a strategy to attenuate it.
- Targeting eIF5B presents a novel approach to enhance Maraba virus-based oncolytic virotherapy.
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