Inhibition of polyamine synthesis in human B lymphocytes during primary infection with Epstein-Barr virus (EBV) blocks cellular DNA synthesis but not the expression of EBV-encoded nuclear antigens (EBNA).

Inhibition of polyamine synthesis by 2-difluoromethylornithine (DFMO) treatment had no apparent effect on the initial manifestation of Epstein-Barr virus (EBV) infection in human B lymphocytes, because the expression of EBV-encoded nuclear antigens (EBNA) occurred normally. However, many subsequent steps in the transformation process were inhibited by DFMO treatment. These include cellular DNA synthesis and immunoglobulin (IgM, IgG and IgA) synthesis and secretion. Consequently, DFMO treatment blocked the progression of the transformation process of EBV-infected B lymphocytes. EBV-carrying marmoset B lymphocytes (B95-8 cells) were also blocked in their DNA synthesis when treated with DFMO. At variance with other DNA synthesis inhibitors, which induce virus production very effectively in B95-8 cells, DFMO caused no increase in the number of cells expressing the early antigens associated with the lytic cycle.