title: Genetic and antigenic characteristics of ApxIIA and ApxIIIA from Actinobacillus pleuropneumoniae serovars 2, 3, 4, 6, 8 and 15.
abstract: Apx toxins produced by Actinobacillus pleuropneumoniae are essential components of new generation vaccines. In this study, apxIIA and apxIIIA genes of serovars 2, 3, 4, 6, 8 and 15 were cloned and sequenced. Amino acid sequences of ApxIIA proteins of serovars 2, 3, 4, 6, 8 and 15 were almost identical to those of serovars 1, 5, 7, 9 and 11-13. Immunoblot analysis showed that rApxIIA from serovars 2 and 15 reacts strongly with sera from animals infected with various serovars. Sequence analysis revealed that ApxIIIA proteins has two variants, one in strains of serovar 2 and the other in strains of serovars 3, 4, 6, 8 and 15. A mouse cross-protection study showed that mice actively immunized with rApxIIIA/2 or rApxIIIA/15 are protected against challenge with A. pleuropneumoniae strains of serovars 3, 4, 6, 8, 15, and 2 expressing ApxIII/15 and ApxIII/2, respectively. Similarly, mice passively immunized with rabbit anti-rApxIIIA/2 or anti-rApxIIIA/15 sera were found to be protected against challenge with strains of serovars 2 and 15. Our study revealed antigenic and sequence similarities within ApxIIA and ApxIIIA proteins, which may help in the development of effective vaccines against disease caused by A. pleuropneumoniae.
authors.affiliation: Nippon Institute for Biological Science, 9-2221-1 Shinmachi, Ome, Tokyo 198-0024, Japan.
authors.forename: Ho
authors.initials: H
authors.lastname: To
authors.affiliation: Nippon Institute for Biological Science, 9-2221-1 Shinmachi, Ome, Tokyo 198-0024, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Nagai
authors.affiliation: Nippon Institute for Biological Science, 9-2221-1 Shinmachi, Ome, Tokyo 198-0024, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Iwata
authors.affiliation: Nippon Institute for Biological Science, 9-2221-1 Shinmachi, Ome, Tokyo 198-0024, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Koyama
authors.affiliation: Nippon Institute for Biological Science, 9-2221-1 Shinmachi, Ome, Tokyo 198-0024, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Oshima
authors.affiliation: Nippon Institute for Biological Science, 9-2221-1 Shinmachi, Ome, Tokyo 198-0024, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Tsutsumi
mesh_terms: D000189:Actinobacillus Infections / Q000276:immunology / Q000517:prevention & control; D016977:Actinobacillus pleuropneumoniae / Q000145:classification / Q000235:genetics* / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology* / Q000302:isolation & purification; D015870:Gene Expression; D006460:Hemolysin Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology* / Q000302:isolation & purification; D007114:Immunization; D051379:Mice; D008958:Models, Molecular; D011487:Protein Conformation; D000072417:Protein Domains; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D065288:Serogroup; D013552:Swine
chemical_list: D000907:Antibodies, Bacterial; C085361:ApxII toxin, bacteria; C079721:ApxIII toxin protein, Actinobacillus; D001426:Bacterial Proteins; D006460:Hemolysin Proteins; D011993:Recombinant Fusion Proteins
keywords: Actinobacillus pleuropneumoniae; ApxIIA; ApxIIIA; ELISA