Stimulation of Epstein-Barr virus-infected human B cell growth by physiological concentrations of 4-hydroxynonenal.
We had previously shown that cyclosporin A (CsA) directly promoted the immortalization of Epstein-Barr virus (EBV)-infected human B cells (EBV-B cells) via an oxidative stress mechanism. 4-Hydroxynonenal (HNE) is a reactive end-product of lipid peroxidation. We hypothesized that HNE may mediate a direct oxidative stress-promoting effect of CsA on EBV-B cells. HNE-protein adducts in CsA-treated EBV-B cell extracts were assayed immunochemically using a Slot-Blot method. Cell proliferation was assayed by [(3)H]-thymidine incorporation. EBV oncogene latent membrane protein-1 (LMP1) expression was assayed by using PE-conjugated anti-LMP1 antibody in flow cytometry. We found that CsA at 500 ng ml(-1) and 1000 ng ml(-1) significantly increased the level of HNE-protein adducts in EBV-B cells over the control (arbitrary units +/- SE) by 251.3 +/- 7.5 to 361.3 +/- 9.7 and 342.7 +/- 10.7, respectively (p < 0.05, n = 3). EBV-B cells treated with a physiological concentration of HNE (1 microM) for 0.5 and 1 h and cultured for 2 and 4 weeks showed significantly increased [(3)H]-thymidine incorporation. EBV-B cells treated with HNE (1 microM) for 1 h and subsequently cultured for 2 and 4 weeks had a significantly higher ( > 2.0 times) LMP1-positive cell population over the control. In conclusion, in accordance with our previous findings, we show that CsA treatment of EBV-B cells results in increased production of the lipid peroxidation reactive end-product HNE that directly promotes EBV-B cell proliferation and LMP1 expression. This observation provides evidence for further understanding the mechanism of CsA-induced oxidative stress on EBV-related post-transplant lymphoproliferative disorder (PTLD).
Ranjan
Dinesh
D
Department of Surgery, University of Kentucky, College of Medicine, Lexington, 40536, USA. dranj1@uky.edu
Chen
Changguo
C
Johnston
Thomas D
TD
Jeon
Hoonbae
H
Ibrahim
Mohamed
M
Drake
Jennifer
J
Butterfield
D Allan
DA
D000447:Aldehydes / Q000378:metabolism / Q000494:pharmacology*; D001402:B-Lymphocytes / Q000502:physiology* / Q000821:virology*; D016572:Cyclosporine / Q000494:pharmacology; D020031:Epstein-Barr Virus Infections / Q000503:physiopathology*; D015227:Lipid Peroxidation / Q000187:drug effects; D014763:Viral Matrix Proteins / Q000378:metabolism
D000447:Aldehydes; C037662:EBV-associated membrane antigen, Epstein-Barr virus; D014763:Viral Matrix Proteins; D016572:Cyclosporine; C027576:4-hydroxy-2-nonenal