title: Localization of linear cytotoxic and pro-apoptotic epitopes in RTX toxin ApxIII of Actinobacillus pleuropneumoniae.
abstract: RTX toxin ApxIII secreted by Actinobacillus pleuropneumoniae affects porcine pulmonary alveolar macrophages and neutrophils. The distribution of ApxIII linear cytotoxic and pro-apoptotic determinants was characterized by neutrophil protection assay, DNA fragmentation and caspase-3 activity using antisera produced against its N-terminus, hydrophobic domain, activation domain, calcium-binding domain and C-terminal half. Neutralization of ApxIII cytotoxicity and pro-apoptotic activities was found in antisera raised against its N- and C-termini whereas ApxIII activation domain-specific antiserum expressed cytotoxic-neutralizing activity. No neutralizing activities were detected in antisera against other structural domains of ApxIII suggesting that the putative linear cytotoxic and pro-apoptotic determinants of ApxIII were mapped to its terminal domains and activation domains.
authors.affiliation: Animal Health Biotechnology, Temasek Life Sciences Laboratory, 1 Research Link, The National University of Singapore, Singapore 117604, Singapore.
authors.forename: J N
authors.initials: JN
authors.lastname: Seah
authors.forename: J
authors.initials: J
authors.lastname: Kwang
mesh_terms: D016977:Actinobacillus pleuropneumoniae / Q000276:immunology*; D000818:Animals; D017209:Apoptosis / Q000276:immunology*; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D002118:Calcium / Q000378:metabolism; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002470:Cell Survival / Q000502:physiology; D003429:Cross Reactions; D053938:DNA Fragmentation; D018604:Epitope Mapping; D000939:Epitopes / Q000276:immunology*; D009154:Mutation / Q000276:immunology; D009500:Neutralization Tests; D009504:Neutrophils / Q000276:immunology; D011994:Recombinant Proteins / Q000276:immunology; D013552:Swine
chemical_list: C079721:ApxIII toxin protein, Actinobacillus; D001426:Bacterial Proteins; D000939:Epitopes; D011994:Recombinant Proteins; D053148:Caspase 3; D020169:Caspases; D002118:Calcium