FIG 2.

EBV infection of CR-bearing pre-B-cell lines analyzed by RNA blot hybridization. (A) Top, expression of LMP1 and EBER in Nalm6CR and Laz221CR cells was detected 24 to 72 h after EBV incubation. Nalm6NEO cells served as a negative control. Expression of BHRF1, a highly expressed lytic RNA, was absent. Ak (Akata) cells served as the positive control. GAPDH or 28S RNA (arrow) provided loading controls. Bottom, preincubation of cells with OKB7, a MAb that blocks binding of EBV gp350/220 to CR, prevented infection of Nalm6CR, whereas UPC10, an isotype-matched control, did not. (B) EBNA-1 (top), EBNA-2 (middle), and LMP-2A (bottom) transcripts were also detected, as shown in Nalm6CR cells. (C) Cellular RNAs encoding RAG-1, TdT, and CD10 declined upon EBV infection, as previously observed (22). (D) Infection of CT-bearing cells induced LMP1 (Nalm6 and Laz221) and EBNA2 (Nalm6) expression with a time course similar to that of CR.