A NOVEL FORM OF EPSTEIN-BARR-VIRUS LATENCY IN NORMAL B-CELLS IN-VIVO

We have developed a PCR assay that can detect a single Epstein-Barr vi rus (EBV) genome in the presence of 10(6) uninfected cells. Using this assay, we demonstrate that EBV persists, in the peripheral blood of a ll seropositive individuals tested, in CD19(+), CD23(-), and CD80 (B7) (-) B cells. We further show that the virus in these cells is latent, but readily reactivated to produce infectious immortalizing virus; the refore, these cells represent a true site of latent persistence. EBV w as not significantly detected in monocytes or T cells. The frequency o f infected cells in nine healthy donors varied from 23 to 625 per 10(7 ) B cells, but was relatively stable for each individual over the cour se of 2 years. We conclude that the EBV-infected cells in vivo are B c ells with a nonactivated phenotype. This represents a novel form of la tency in normal B cells.