Vitamin E inhibits cyclosporin A and H2O2 promoted Epstein-Barr virus (EBV) transformation of human B cells as assayed by EBV oncogene LMP1 expression.
BACKGROUND
We have previously shown that oxidative stress induced by H2O2 or cyclosporin A (CsA) can promote Epstein-Barr virus (EBV) transformation of human B cells as analyzed by colony formation, cell number, and by 3H-thymidine incorporation. In this report, we used EBV oncogene LMP1 as a marker to analyze H2O2 or CsA promotion of EBV transformation of human B cells and to test whether antioxidant vitamin E could inhibit H2O2 or CsA promoted LMP1 expression in the EBV-infected cells.


METHODS
Human splenocytes were prepared by centrifugation and plating technique to provide a greater than 80% pure preparation of B cells and were used for EBV infection. The EBV infected cells were treated with H2O2 (0.1 mM, 10 min), or with CsA (500 ng/ml) with or with out vitamin E (40 microM). The cells were cultured for up to 4 weeks. Samples were taken every week and were stained with phycoerythrin-conjugated mouse anti-LMP1 monoclonal antibody to assay LMP1 positive population by flow cytometry.


RESULTS
In EBV-infected cells, the LMP1-positive cell population reached 14% after 4 weeks of culture. CsA or H2O2 treatment promoted LMP1 positive population to 43% and 41% after 4 weeks of culture. Vitamin E (40 microM) completely inhibited LMP1 expression in EBV-infected cells and in CsA- or H2O2-treated cells.


CONCLUSIONS
In agreement with our previous observation, CsA or H2O2 can promote EBV transformation of human B cells. This oxidative stress induced promotion of EBV transformation can be blocked by antioxidant Vitamin E. This finding may have future therapeutic implications for post-transplant lymphoproliferative disorder.
Chen
Changguo
C
Section of Transplantation, Department of Surgery, University of Kentucky, Lexington, Kentucky 40536, USA.
Reddy
K S
KS
Johnston
T D
TD
Khan
T T
TT
Ranjan
D
D
D000975:Antioxidants / Q000494:pharmacology*; D001402:B-Lymphocytes / Q000187:drug effects* / Q000502:physiology; D002472:Cell Transformation, Viral / Q000187:drug effects* / Q000235:genetics; D016572:Cyclosporine / Q000494:pharmacology*; D004347:Drug Interactions / Q000502:physiology; D015870:Gene Expression / Q000235:genetics; D004854:Herpesvirus 4, Human / Q000502:physiology*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D009856:Oncogene Proteins, Viral / Q000096:biosynthesis; D016877:Oxidants / Q000494:pharmacology*; D018384:Oxidative Stress / Q000235:genetics; D014763:Viral Matrix Proteins / Q000096:biosynthesis; D014810:Vitamin E / Q000494:pharmacology*
D000975:Antioxidants; C037662:EBV-associated membrane antigen, Epstein-Barr virus; D009856:Oncogene Proteins, Viral; D016877:Oxidants; D014763:Viral Matrix Proteins; D014810:Vitamin E; D016572:Cyclosporine; D006861:Hydrogen Peroxide