title: Stable cell lines expressing high levels of the herpes simplex virus type 1 LAT are refractory to caspase 3 activation and DNA laddering following cold shock induced apoptosis.
abstract: The herpes simplex virus type 1 (HSV-1) latency associated transcript (LAT) gene's anti-apoptosis activity plays a central, but not fully elucidated, role in enhancing the virus's reactivation phenotype. In transient transfection experiments, LAT increases cell survival following an apoptotic insult in the absence of other HSV-1 genes. However, the high background of untransfected cells has made it difficult to demonstrate that LAT inhibits specific apoptotic factors such as caspases. Here we report that, in mouse neuroblastoma cell lines (C1300) stably expressing high levels of LAT, cold shock induced apoptosis was blocked as judged by increased survival, protection against DNA fragmentation (by DNA ladder assay), and inhibition of caspase 3 cleavage and activation (Western blots). To our knowledge, this is the first report providing direct evidence that LAT blocks two biochemical hallmarks of apoptosis, caspase 3 cleavage and DNA laddering, in the absence of other HSV-1 gene products.
authors.affiliation: The Eye Institute, University of California Irvine, School of Medicine, Irvine, CA 92697, USA. DCarpent@uci.edu
authors.forename: Dale
authors.initials: D
authors.lastname: Carpenter
authors.forename: Chinhui
authors.initials: C
authors.lastname: Hsiang
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Brown
authors.forename: Ling
authors.initials: L
authors.lastname: Jin
authors.forename: Nelson
authors.initials: N
authors.lastname: Osorio
authors.forename: Lbachir
authors.initials: L
authors.lastname: BenMohamed
authors.forename: Clinton
authors.initials: C
authors.lastname: Jones
authors.forename: Steven L
authors.initials: SL
authors.lastname: Wechsler
mesh_terms: D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D053148:Caspase 3 / Q000032:analysis; D061945:Caspase Inhibitors; D002460:Cell Line; D002470:Cell Survival; D003080:Cold Temperature; D053938:DNA Fragmentation; D018259:Herpesvirus 1, Human / Q000276:immunology*; D051379:Mice; D035683:MicroRNAs; D009474:Neurons / Q000737:chemistry; D014764:Viral Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*
chemical_list: D061945:Caspase Inhibitors; D035683:MicroRNAs; D014764:Viral Proteins; C477253:latency associated transcript, herpes simplex virus-1; D053148:Caspase 3