Inflamm Bowel Dis. 2020 Apr 23;izaa065 doi: 10.1093/ibd/izaa065. Online ahead of print.

Nina Levhar ¹, Bella Ungar ¹, Uri Kopylov ¹, Ella Fudim ¹, Miri Yavzori ¹, Orit Picard ¹, Ninette Amariglio ², Yehuda Chowers ³, Yonat Shemer-Avni ⁴, Ren Mao ⁵, Min-Hu Chen ⁵, Ziyin Ye ⁵, Rami Eliakim ¹, Shomron Ben-Horin ^1 5

Author information

¹Department of Gastroenterology, Sheba Medical Center, Tel Hashomer, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.

²Cancer Research Center, Sheba Medical Center, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.

³Rambam Health Care Campus, Bruce & Ruth Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel.

⁴Shraga Segal Department of Microbiology, Immunology and Genetics, Soroka Medical Center Beer-Sheva, Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, Israel.

⁵First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.

Abstract

Background: Immunomodulators and anti tumor-necrosis-α antibodies (anti-TNFs) have been implicated in increased risk of Epstein-Barr virus (EBV)-driven B-cell lymphoproliferative disorders in inflammatory bowel disease (IBD) patients. However, the underlying mechanisms are poorly understood.

Methods: An in-vitro model of lymphoblastoid cell line (LCL) was established by co-incubation of EBV-infected human peripheral blood mononuclear cells (PBMC) with Cyclosporin-A (CSA). After 4 weeks, the resultant LCLs were analyzed by flow cytometry, telomerase activity assay, and next generation sequencing. Subsequently, LCLs were explored in the presence of therapeutic agents for IBD (anti-TNFs, vedolizumab, 6-Mercaptopurine [6MP], methotrexate). Epstein-Barr virus titers were quantitated by real-time polymerase chain reaction.

Results: In cultures of PBMC with EBV and CSA, LCLs were characterized as an expanded, long lived population of CD58+CD23hi B-cells with high telomerase activity and clonal expansion. Upon addition to the cell cultures, LCL percentages were higher with infliximab (median 19.21%, P = 0.011), adalimumab (median 19.85%, P = 0.003), and early washed-out 6MP (median 30.57%, P = 0.043) compared with PBMC with EBV alone (median 9.61%). However, vedolizumab had no such effect (median 8.97%; P = 0.435). Additionally, LCL expansion was accompanied by increase in intracellular, rather than extracellular, EBV viral copies. Compared with PBMC with EBV alone, high levels of LCL were subsequently observed after triple depletion of NK cells, CD4+ T cells, and CD8+ T cells (median 52.8% vs 16.4%; P = 0.046) but also in cultures depleted solely of CD4+ T cells (median 30.7%, P = 0.046).

Conclusions: These results suggest that both anti-TNFs and 6MP, but not vedolizumab, propagate EBV-driven lymphoblastoid transformation in an in vitro model of lymphoma. This model may prove useful for studying mechanisms underlying proneoplastic viral immune interactions of novel drugs in IBD therapy.