title: Neisserial porin-induced dendritic cell activation is MyD88 and TLR2 dependent.
abstract: Neisserial porins have been shown to act as B cell mitogens and immune adjuvants. PorA and PorB are the major outer membrane porin proteins of the human pathogen Neisseria meningitidis. We have shown that the mechanism of the immunopotentiating capability of porin involves up-regulation of the T cell costimulatory ligand, CD86. Due to neisserial porin's ability to activate B cells and potentiate immune responses, we hypothesized that porin also employs the potent immune stimulatory function of dendritic cells (DC). We examined the ability of purified N. meningitidis PorB to induce maturation of murine splenic and bone marrow-derived DC. PorB treatment induced DC maturation, as demonstrated by increased expression of CD86 and class I and II MHC molecules. In addition, PorB not only enhanced the allostimulatory activity of DC, but also augmented the ability of DC to stimulate T cells in an Ag-specific manner. PorB-matured DC secreted the inflammatory cytokine IL-6, which may have implications for the adjuvant property of porin. Induction of IL-6 by PorB is also significant because IL-6 is one of a number of cytokines produced during infection with N. meningitidis and may be involved in the inflammatory process observed during infection and disease. We previously demonstrated the requirement of MyD88 and TLR2 for PorB-induced B cell activation. In the present study, MyD88 and TLR2 were also essential for PorB-induced DC activation. This work is significant for elucidating the mechanism(s) of neisserial porin's immune stimulatory activity.
authors.affiliation: Department of Microbiology, Division of Graduate Medical Sciences, Boston University School of Medicine, Boston, MA 02118, USA.
authors.forename: Theresa E
authors.initials: TE
authors.lastname: Singleton
authors.forename: Paola
authors.initials: P
authors.lastname: Massari
authors.forename: Lee M
authors.initials: LM
authors.lastname: Wetzler
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D000943:Antigens, Differentiation / Q000235:genetics / Q000378:metabolism*; D051940:B7-2 Antigen; D003713:Dendritic Cells / Q000187:drug effects* / Q000276:immunology*; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D006801:Humans; D007155:Immunologic Factors / Q000494:pharmacology; D015850:Interleukin-6 / Q000096:biosynthesis; D008213:Lymphocyte Activation; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D053594:Myeloid Differentiation Factor 88; D009345:Neisseria meningitidis / Q000276:immunology* / Q000472:pathogenicity; D018272:Porins / Q000494:pharmacology*; D011956:Receptors, Cell Surface / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D013601:T-Lymphocytes / Q000276:immunology; D051195:Toll-Like Receptor 2
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D015703:Antigens, CD; D000943:Antigens, Differentiation; D051940:B7-2 Antigen; C497964:CD86 protein, human; C497965:Cd86 protein, mouse; D000949:Histocompatibility Antigens Class II; D007155:Immunologic Factors; D015850:Interleukin-6; C507779:MYD88 protein, human; D008562:Membrane Glycoproteins; C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; D018272:Porins; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; C493486:Tlr2 protein, mouse; D051195:Toll-Like Receptor 2; C057699:porin protein, Neisseria