title: Nanoparticle adjuvant sensing by TLR7 enhances CD8+ T cell-mediated protection from Listeria monocytogenes infection.
abstract: Developing new adjuvants and vaccination strategies is of paramount importance to successfully fight against many life-threatening infectious diseases and cancer. Very few adjuvants are currently authorized for human use, and these mainly stimulate a humoral response. However, specific Abs are not sufficient to confer protection against persisting infections or cancer. Therefore, development of adjuvants and immunomodulators able to enhance cell-mediated immune responses represents a major medical need. We recently showed that papaya mosaic virus nanoparticles (PapMV), self-assembled from the coat protein of a plant virus and a noncoding ssRNA molecule, are highly immunogenic in mice. PapMV can be used either as a vaccine delivery platform, through fusion of various epitopes to the coat protein or as adjuvant to enhance humoral immune responses against coadministered Ags or vaccines. However, the mechanisms that confer these immunomodulatory properties to PapMV and its ability to enhance T cell vaccines remain unknown. Using immunization studies in mice, we demonstrate in this paper that PapMV represents a novel TLR7 agonist with strong immunostimulatory properties. More importantly, pretreatment with PapMV significantly improves effector and memory CD8(+) T cell responses generated through dendritic cell vaccination increasing protection against a Listeria monocytogenes challenge.
authors.affiliation: Laboratoire d'Immunovirologie, Institut National de la Recherche Scientifique, Institut Armand-Frappier, Laval, Quebec H7V 1B7, Canada;
authors.forename: Marie-Ève
authors.initials: MÈ
authors.lastname: Lebel
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Daudelin
authors.forename: Karine
authors.initials: K
authors.lastname: Chartrand
authors.forename: Esther
authors.initials: E
authors.lastname: Tarrab
authors.forename: Ulrich
authors.initials: U
authors.lastname: Kalinke
authors.forename: Pierre
authors.initials: P
authors.lastname: Savard
authors.forename: Nathalie
authors.initials: N
authors.lastname: Labrecque
authors.forename: Denis
authors.initials: D
authors.lastname: Leclerc
authors.forename: Alain
authors.initials: A
authors.lastname: Lamarre
mesh_terms: D056704:Adaptive Immunity; D000276:Adjuvants, Immunologic; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology; D004353:Drug Evaluation, Preclinical; D005260:Female; D007074:Immunoglobulin G / Q000096:biosynthesis; D007156:Immunologic Memory; D007370:Interferon Type I / Q000276:immunology; D008089:Listeria monocytogenes / Q000276:immunology*; D008088:Listeriosis / Q000276:immunology / Q000517:prevention & control*; D008562:Membrane Glycoproteins / Q000819:agonists* / Q000172:deficiency / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D053594:Myeloid Differentiation Factor 88 / Q000172:deficiency / Q000276:immunology; D053758:Nanoparticles; D010047:Ovalbumin / Q000276:immunology; D012367:RNA, Viral / Q000276:immunology; D053633:Receptor, Interferon alpha-beta / Q000172:deficiency; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D051199:Toll-Like Receptor 7 / Q000819:agonists* / Q000172:deficiency / Q000276:immunology; D017806:Tymovirus / Q000235:genetics / Q000276:immunology*; D014611:Vaccination
chemical_list: D000276:Adjuvants, Immunologic; D007074:Immunoglobulin G; D007370:Interferon Type I; D008562:Membrane Glycoproteins; C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; D012367:RNA, Viral; C477038:Tlr7 protein, mouse; D051199:Toll-Like Receptor 7; D053633:Receptor, Interferon alpha-beta; D010047:Ovalbumin