title: Bacillus anthracis edema toxin acts as an adjuvant for mucosal immune responses to nasally administered vaccine antigens.
abstract: Anthrax edema toxin (EdTx) is an AB-type toxin that binds to anthrax toxin receptors on target cells via the binding subunit, protective Ag (PA). Edema factor, the enzymatic A subunit of EdTx, is an adenylate cyclase. We found that nasal delivery of EdTx enhanced systemic immunity to nasally coadministered OVA and resulted in high OVA-specific plasma IgA and IgG (mainly IgG1 and IgG2b). The edema factor also enhanced immunity to the binding PA subunit itself and promoted high levels of plasma IgG and IgA responses as well as neutralizing PA Abs. Mice given OVA and EdTx also exhibited both PA- and OVA-specific IgA and IgG Ab responses in saliva as well as IgA Ab responses in vaginal washes. EdTx as adjuvant triggered OVA- and PA-specific + T cells which secreted IFN-gamma and selected Th2-type cytokines. The EdTx up-regulated costimulatory molecule expression by APCs but was less effective than cholera toxin for inducing IL-6 responses either by APCs in vitro or in nasal washes in vivo. Finally, nasally administered EdTx did not target CNS tissues and did not induce IL-1 mRNA responses in the nasopharyngeal-associated lymphoepithelial tissue or in the olfactory bulb epithelium. Thus, EdTx derivatives could represent an alternative to the ganglioside-binding enterotoxin adjuvants and provide new tools for inducing protective immunity to PA-based anthrax vaccines.
authors.affiliation: Department of Microbiology, University of Alabama at Birmingham, AL 35294, USA.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Duverger
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Jackson
authors.forename: Frederick W
authors.initials: FW
authors.lastname: van Ginkel
authors.forename: Romy
authors.initials: R
authors.lastname: Fischer
authors.forename: Angela
authors.initials: A
authors.lastname: Tafaro
authors.forename: Stephen H
authors.initials: SH
authors.lastname: Leppla
authors.forename: Kohtaro
authors.initials: K
authors.lastname: Fujihashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kiyono
authors.forename: Jerry R
authors.initials: JR
authors.lastname: McGhee
authors.forename: Prosper N
authors.initials: PN
authors.lastname: Boyaka
mesh_terms: D000262:Adenylyl Cyclases / Q000008:administration & dosage*; D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000280:Administration, Inhalation; D000818:Animals; D000906:Antibodies / Q000097:blood; D000942:Antigens, Bacterial / Q000008:administration & dosage / Q000276:immunology*; D001408:Bacillus anthracis / Q000276:immunology; D001427:Bacterial Toxins; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D005098:Exotoxins / Q000008:administration & dosage*; D005260:Female; D018928:Immunity, Mucosal / Q000187:drug effects*; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000276:immunology; D012463:Saliva / Q000276:immunology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D014612:Vaccines / Q000008:administration & dosage / Q000276:immunology*; D014621:Vagina / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000906:Antibodies; D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D016207:Cytokines; D005098:Exotoxins; D014612:Vaccines; C030325:anthrax toxin; C119204:streptococcal protective antigen; D010047:Ovalbumin; D000262:Adenylyl Cyclases