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An Efficient and Simple Method to Establish NK and T Cell Lines from Patients with Chronic Active Epstein-Barr Virus Infection
Published on: March 30, 2018
Reactivation of latent Epstein-Barr virus by methotrexate: a potential contributor to methotrexate-associated
Wen-hai Feng1, Jeffrey I Cohen, Steven Fischer
1Department of Medicine and Microbiology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill 27599-7295, USA.
Background:
Patients with rheumatoid arthritis or polymyositis treated with methotrexate (MTX) develop Epstein-Barr virus (EBV)-positive lymphomas more frequently than patients treated with other, equally immunosuppressive regimens. Here we determined whether MTX, in contrast to other commonly used medications for rheumatoid arthritis or polymyositis, is unique in its ability to induce the release of infectious EBV from latently infected cells.
Methods:
The effect of MTX and other immunosuppressant drugs on EBV replication in vitro was assessed using latently infected EBV-positive lymphoblastoid and gastric carcinoma cell lines. Inhibitors of signal transduction pathways were used to define requirements for induction of lytic infection. Drug effects on transcription of the two EBV immediate-early promoters (BRLF1 and BZLF1) and on promoter constructs lacking cis-acting sequences required for activation by other effectors was examined using reporter gene assays. EBV viral load in rheumatoid arthritis and polymyositis patients receiving MTX was compared with that in patients receiving other immunosuppressive medications. Statistical tests were two-sided.
Results:
MTX activated the release of infectious EBV from latently infected cell lines in vitro, and MTX treatment was associated with activation of the two viral immediate-early promoters in reporter gene assays. Induction of lytic EBV infection by MTX required the p38 MAP kinase, PI3 kinase, and MEK pathways and specific cis-acting motifs in the two viral immediate-early promoters. Patients treated with MTX-containing regimens had statistically significantly higher mean EBV loads in their blood than patients treated with immunosuppressing regimens that did not include MTX (40 EBV copies per 10(6) cellular genomes versus 5.1 copies; geometric mean fold difference in copies = 10.8, 95%, confidence interval = 3.0 to 38; P = .011).
Conclusion:
MTX may promote EBV-positive lymphomas in rheumatoid arthritis and polymyositis patients by its immunosuppressive properties as well as by reactivating latent EBV.
Insights
Methotrexate (MTX) reactivates latent Epstein-Barr virus (EBV), increasing EBV viral load in patients. This reactivation may contribute to the higher incidence of EBV-positive lymphomas observed in patients treated with MTX.
Area of Science:
- Immunology
- Virology
- Oncology
Background:
- Patients with rheumatoid arthritis or polymyositis on methotrexate (MTX) have increased risk of Epstein-Barr virus (EBV)-positive lymphomas.
- This study investigates if MTX uniquely induces infectious EBV release compared to other immunosuppressants.
Purpose of the Study:
- To determine if methotrexate (MTX) uniquely induces the release of infectious Epstein-Barr virus (EBV) from latently infected cells.
- To compare EBV viral load in patients receiving MTX versus other immunosuppressive medications.
Main Methods:
- Assessed MTX and other immunosuppressants' effects on EBV replication in vitro using infected cell lines.
- Utilized reporter gene assays to examine EBV immediate-early promoter activity and signal transduction pathways.
- Compared EBV viral loads in patients with rheumatoid arthritis/polymyositis on MTX versus non-MTX regimens.
Main Results:
- MTX activated infectious EBV release in vitro and upregulated EBV immediate-early promoters.
- MTX-induced EBV reactivation required p38 MAP kinase, PI3 kinase, and MEK pathways.
- MTX-treated patients showed significantly higher EBV loads (mean 40 copies/10^6 cells) than non-MTX treated patients (mean 5.1 copies/10^6 cells).
Conclusions:
- Methotrexate (MTX) may promote EBV-positive lymphomas through immunosuppression and reactivation of latent EBV.
- MTX's unique ability to reactivate EBV contributes to increased lymphoma risk in treated patients.
