Changes in the expression of two Epstein‐Barr virus‐associated antigens, EBNA and RANA, during the cell cycle of transformed human B lymphoblasts

Abstract

Two methods of cell synchronization, density-dependent arrest and double thymidine block, were used to assign two Epstein-Barr virus-associated antigens to different parts of the growth cycle of the human B lymphoblastoid cell lines, WI-L2 and Raji. The Epstein-Barr nuclear antigen (EBNA), as detected by anti-complement immunofluorescence, was maximally expressed during early S phase, decreased during the G₂ and M phases, and was absent in early G₁. In contrast, the rheumatoid arthritis nuclear antigen (RANA), as detected by anti-immunoglobulin immunofluorescence with a prototype serum from a patient with rheumatoid arthritis, was maximally expressed during early G₁ phase, progressively decreased during S and early G₂, and reappeared during late G₂/M.