title: Serpinb9 is a marker of antigen cross-presenting dendritic cells.
abstract: Serpinb9 (Sb9, also called Spi6) is an intracellular inhibitor of granzyme B (grB) that protects cytotoxic lymphocytes from grB-mediated death. In addition, Sb9 is also expressed in accessory immune cells, including dendritic cells (DCs), although its role is debated. Recently, we have demonstrated that Sb9 plays a grB-independent role in cross-presentation of antigens by CD8+DCs. Here, using a mouse line expressing green fluorescent protein knocked in under the control of the Sb9 promoter, we demonstrate that Sb9 expression is highest in those tissue-resident and migratory DC subsets capable of cross-presentation. Further, we show that CD8+DCs can be divided into two subsets based on Sb9 expression, and that only the subset expressing higher levels of Sb9 is capable of cross-presentation. These findings add support for role for Sb9 cross-presentation, and indicate that high Sb9 expression is a novel marker of cross-presentation capable DCs.
authors.affiliation: Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, 3800, Australia.
authors.forename: M S
authors.initials: MS
authors.lastname: Mangan
authors.affiliation: Department of Microbiology and Immunology, Doherty Institute of Infection and Immunity, University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Vega-Ramos
authors.affiliation: Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, 3800, Australia.
authors.forename: L T
authors.initials: LT
authors.lastname: Joeckel
authors.affiliation: The Centenary Institute, Royal Prince Alfred Hospital, Sydney, New South Wales, 2000, Australia.
authors.forename: A J
authors.initials: AJ
authors.lastname: Mitchell
authors.affiliation: Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, 3800, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Rizzitelli
authors.affiliation: The Centenary Institute, Royal Prince Alfred Hospital, Sydney, New South Wales, 2000, Australia.
authors.forename: B
authors.initials: B
authors.lastname: Roediger
authors.affiliation: Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, 3800, Australia.
authors.forename: D
authors.initials: D
authors.lastname: Kaiserman
authors.affiliation: The Centenary Institute, Royal Prince Alfred Hospital, Sydney, New South Wales, 2000, Australia; Discipline of Dermatology, University of Sydney, New South Wales, 2006, Australia.
authors.forename: W W
authors.initials: WW
authors.lastname: Weninger
authors.affiliation: Department of Microbiology and Immunology, Doherty Institute of Infection and Immunity, University of Melbourne, Parkville, Victoria 3010, Australia; Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Victoria, 3010, Australia.
authors.forename: J A
authors.initials: JA
authors.lastname: Villadangos
authors.affiliation: Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, 3800, Australia. Electronic address: phil.bird@monash.edu.
authors.forename: P I
authors.initials: PI
authors.lastname: Bird
mesh_terms: D000818:Animals; D045142:Cross-Priming / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D055879:Gene Knock-In Techniques; D008297:Male; D008565:Membrane Proteins / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D015843:Serpins / Q000276:immunology*
chemical_list: D008565:Membrane Proteins; D015843:Serpins; C106610:Serpinb9 protein, mouse
keywords: Cross-presentation; DCs; Dendritic cell; Granzyme B; SPI6; Serpinb9