[In vitro transformation of human embryonic nasopharyngeal epithelial cells with Epstein-Barr virus].

UNLABELLED

EBV from B95-8 cells were used to infect directly the human embryonic nasopharyngeal epithelial (HENE) cells in vitro.

RESULTS

Primary HENE cells treated with EBV did not have a significantly increased colony-forming rate in soft agarose, while cells that were treated with EBV in combination with tumor promotor 12-O-tetradecanoylphorbol-13 acetate (TPA) showed a marked increase in colonyforming rate from 0-5 cells to 20-40 colonies per 10,000 cells. (2) HENE cells treated with inactivated (56 degrees C for 30 minutes) virus, in spite of adding TPA at the same time, did not significantly increase agarose colony forming rate; (3) HENE cells treated with TPA after EBV exposure for a week had significantly increased colony forming rate in soft agarose, while the cells exposed to EBV after using TPA treatment did not. In addition, EBV BNLF1 (LMP) fragment in HENE cells treated with EBV or EBV+TPA was detected by polymerase chain reaction using specific oligonucleotide primer. Only HENE cells treated with EBV+TPA presented positive band in aragose gel electrophoresis. The results suggest that transformation of EBV on HENE cells depends on infectious virus and an intact viral genome. TPA not only can promote the transformation, but also promote EBV's entering HENE cells.