EBV genome carrying B lymphocytes that express the nuclear protein EBNA-2 but not LMP-1: Type IIb latency.

摘要

The potentially oncogenic Epstein-Barr virus (EBV) is carried by almost allhumans in a well equilibrated coexistence. The phenotype of the cells that carry EBV genomes is determined by virally-encoded and cellular proteins. B lymphocyte is the main target of the virus and latent infection of this cell inducesproliferation. Nine virus-encoded genes participate in the "growth program" that is expressed in a narrow differentiation window of the B cell. Such cells havethe potential to develop malignant proliferations. However, several controlmechanism eliminate this danger and the general chronic virus carrier state ismost often asymptomatic. One mechanism exploits the normal regulation in theimmune system, the T cell mediated modulation of the B cell differentiationstate. Another is based on cognate recognition and elimination of the infectedcells. The expression of EBV encoded genes in B lymphocytes can be also"restricted," they do not express all components of the viral growth program.Here, we discuss a rare viral expression in B cells that has not been connectedwith malignant transformation yet.