title: An alternative spliced RNASEL variant in peripheral blood leukocytes.
abstract: 2-5A-Dependent RNase L is an endoribonuclease that catalyzes RNA degradation and promotes apoptosis during the innate antiviral response in mammalian cells. Prior studies showed that RNASEL is widely expressed and suggested the presence of mRNA species of different sizes but lacked a characterization of these variants. Using RT-PCR, we show that RNASEL is expressed in all human tissues examined, whereas an alternatively generated spliced variant lacking the third exon (RNASEL del_Ex3) is solely expressed in peripheral blood leukocytes (PBL). Quantitative RT-PCR measurements of RNA from different PBL cell types separated by fluorescence activated cell sorting (FACS) showed that complete RNASEL mRNA levels were significantly elevated in granulocytes compared with all other PBL cell types, whereas expression was lowest in CD8(+) T cells. The alternatively spliced RNASEL del_Ex3 transcript was present in all PBL cell types examined but at lower levels than the full-length RNASEL mRNA. The presence of high levels of RNase L protein in granulocytes was confirmed by immunohistochemistry. Our findings are the first to demonstrate the presence of an alternatively spliced RNASEL mRNA and to demonstrate the variable expression of RNase L in different leukocytes. Our results suggest that RNase L plays an important role in granulocytes as an innate immunity enzyme that controls viral infections.
authors.affiliation: Department of Pathology and Laboratory Medicine, Weill Medical College of Cornell University, New York, NY 10012, USA. har2006@med.cornell.edu
authors.forename: Hanna
authors.initials: H
authors.lastname: Rennert
authors.forename: Caren
authors.initials: C
authors.lastname: Sadowl
authors.forename: Joshua
authors.initials: J
authors.lastname: Edwards
authors.forename: Drew
authors.initials: D
authors.lastname: Bantly
authors.forename: Ross J
authors.initials: RJ
authors.lastname: Molinaro
authors.forename: Avi
authors.initials: A
authors.lastname: Orr-Urtreger
authors.forename: Adam
authors.initials: A
authors.lastname: Bagg
authors.forename: Jonni S
authors.initials: JS
authors.lastname: Moore
authors.forename: Robert H
authors.initials: RH
authors.lastname: Silverman
mesh_terms: D017398:Alternative Splicing / Q000235:genetics* / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D004722:Endoribonucleases / Q000235:genetics* / Q000276:immunology; D006098:Granulocytes / Q000166:cytology / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics; D009928:Organ Specificity / Q000235:genetics / Q000276:immunology; D012333:RNA, Messenger / Q000235:genetics / Q000276:immunology; D014777:Virus Diseases / Q000235:genetics / Q000276:immunology
chemical_list: D012333:RNA, Messenger; D004722:Endoribonucleases; C031956:2-5A-dependent ribonuclease