RT Journal Article SR Electronic(1) A1 Sandford, Gordon R. A1 Schumacher, Uwe A1 Ettinger, Jakob A1 Brune, Wolfram A1 Hayward, Gary S. A1 Burns, William H. A1 Voigt, SebastianYR 2010 T1 Deletion of the rat cytomegalovirus immediate-early 1 gene results in a virus capable of establishing latency, but with lower levels of acute virus replication and latency that compromise reactivation efficiency JF Journal of General Virology, VO 91 IS 3 SP 616 OP 621 DO https://doi.org/10.1099/vir.0.016022-0 PB Microbiology Society, SN 1465-2099, AB The immediate-early 1 (IE1) and IE2 proteins encoded by the major immediate-early (MIE) transcription unit of cytomegaloviruses are thought to play key roles in the switch between latent- and lytic-cycle infection. Whilst IE2 is essential for triggering the lytic cycle, the exact roles of IE1 have not been resolved. An MIE–exon 4-deleted rat cytomegalovirus (ΔIE1) failed to synthesize the IE1 protein and did not disperse promyelocytic leukaemia bodies early post-infection, but was still capable of normal replication in fibroblast cell culture. However, ΔIE1 had a diminished ability to infect salivary glands persistently in vivo and to reactivate from spleen explant cultures ex vivo. Quantification of viral genomes in spleens of infected animals revealed a reduced amount of ΔIE1 virus produced during acute infection, suggesting a role for IE1 as a regulator in establishing a chronic or persistent infection, rather than in influencing the latency or reactivation processes more directly., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.016022-0