title: Papillomavirus infection requires gamma secretase.
abstract: The mechanism by which papillomaviruses breach cellular membranes to deliver their genomic cargo to the nucleus is poorly understood. Here, we show that infection by a broad range of papillomavirus types requires the intramembrane protease γ secretase. The γ-secretase inhibitor (S,S)-2-[2-(3,5-difluorophenyl)-acetylamino]-N-(1-methyl-2-oxo-5-phenyl-2,3-dihydro-1H-benzo[e][1,4]diazepin-3-yl)-propionamide (compound XXI) inhibits infection in vitro by all types of papillomavirus pseudovirions tested, with a 50% inhibitory concentration (IC(50)) of 130 to 1,000 pM, regardless of reporter construct and without impacting cellular viability. Conversely, XXI does not inhibit in vitro infection by adenovirus or pseudovirions derived from the BK or Merkel cell polyomaviruses. Vaginal application of XXI prevents infection of the mouse genital tract by human papillomavirus type 16 (HPV16) pseudovirions. Nicastrin and presenilin-1 are essential components of the γ-secretase complex, and mouse embryo fibroblasts deficient in any one of these components were not infected by HPV16, whereas wild-type and β-secretase (BACE1)-deficient cells were susceptible. Neither the uptake of HPV16 into Lamp-1-positive perinuclear vesicles nor the disassembly of capsid to reveal both internal L1 and L2 epitopes and bromodeoxyuridine (BrdU)-labeled encapsidated DNA is dependent upon γ-secretase activity. However, blockade of γ-secretase activity by XXI prevents the BrdU-labeled DNA encapsidated by HPV16 from reaching the ND10 subnuclear domains. Since prior studies indicate that L2 is critical for endosomal escape and targeting of the viral DNA to ND10 and that γ secretase is located in endosomal membranes, our findings suggest that either L2 or an intracellular receptor are cleaved by γ secretase as papillomavirus escapes the endosome.
authors: Department of Pathology, Johns Hopkins University, Room 308, Cancer Research Building 2, 1550 Orleans St., Baltimore, MD 21231, USA.
authors: Balasubramanyam
authors: B
authors: Karanam
authors: Shiwen
authors: S
authors: Peng
authors: Tong
authors: T
authors: Li
authors: Christopher
authors: C
authors: Buck
authors: Patricia M
authors: PM
authors: Day
authors: Richard B S
authors: RB
authors: Roden
mesh_terms: D053829:Amyloid Precursor Protein Secretases / Q000037:antagonists & inhibitors / Q000502:physiology*; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D012777:Cottontail rabbit papillomavirus / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005836:Genitalia, Female / Q000187:drug effects / Q000201:enzymology / Q000821:virology; D006367:HeLa Cells; D054884:Host-Pathogen Interactions / Q000187:drug effects / Q000502:physiology; D052162:Human papillomavirus 16 / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology; D052161:Human papillomavirus 18 / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology; D058952:Human papillomavirus 31 / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology; D006801:Humans; D008562:Membrane Glycoproteins / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D027383:Papillomaviridae / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology; D030361:Papillomavirus Infections / Q000201:enzymology* / Q000821:virology; D053764:Presenilin-1 / Q000502:physiology; D011817:Rabbits
chemical_list: D004791:Enzyme Inhibitors; D008562:Membrane Glycoproteins; D053764:Presenilin-1; C413604:nicastrin protein; D053829:Amyloid Precursor Protein Secretases