Dataset Information

Molecular characterization of a protective outer membrane lipoprotein (OmlA) from Actinobacillus pleuropneumoniae serotype 1.

ABSTRACT: An expression library was constructed from an Actinobacillus pleuropneumoniae serotype 1 clinical isolate using a plasmid vector. The library was screened with serum raised against the culture supernatant of this strain. One Escherichia coli transformant which also reacted with convalescent serum was isolated and found to express a protein with an electrophoretic mobility of approximately 50,000. The A. pleuropneumoniae-derived DNA encoding the protein was localized and characterized by nucleotide sequence analysis and primer extension mapping. One open reading frame of 1,095 bases was detected and confirmed by TnphoA insertion mutagenesis. It encoded a protein with a calculated molecular mass of 40 kDa which was lipid modified and present in the outer membrane and in membrane blebs of A. pleuropneumoniae. This protein was designated as outer membrane lipoprotein A (OmlA), and the encoding gene as omlA. Southern blotting under low-stringency conditions revealed the presence of hybridizing sequences in all A. pleuropneumoniae type strains, and a specific serum detected a homologous protein in serotypes 2, 8, 9, 11, and 12 type strains. Pigs immunized with this recombinant protein preparation were protected from death in an aerosol challenge experiment with an A. pleuropneumoniae serotype 1 isolate.

SUBMITTER: Gerlach GF

PROVIDER: S-EPMC302765 | biostudies-other | 1993 Feb

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Molecular characterization of a protective outer membrane lipoprotein (OmlA) from Actinobacillus pleuropneumoniae serotype 1.

Gerlach G F GF Anderson C C Klashinsky S S Rossi-Campos A A Potter A A AA Willson P J PJ

Infection and immunity 19930201 2

An expression library was constructed from an Actinobacillus pleuropneumoniae serotype 1 clinical isolate using a plasmid vector. The library was screened with serum raised against the culture supernatant of this strain. One Escherichia coli transformant which also reacted with convalescent serum was isolated and found to express a protein with an electrophoretic mobility of approximately 50,000. The A. pleuropneumoniae-derived DNA encoding the protein was localized and characterized by nucleoti ...[more]

PMID: 8423086

Similar Datasets

Project description:Outer membrane vesicles (OMVs) are spontaneously released by Gram-negative bacteria, including Actinobacillus pleuropneumoniae, which causes contagious pleuropneumonia in pigs and leads to considerable economic losses in the swine industry worldwide. A. pleuropneumoniae OMVs have previously been demonstrated to contain Apx toxins and proteases, as well as antigenic proteins. Nevertheless, comprehensive characterizations of their contents and interactions with host immune cells have not been made. Understanding the protein compositions and immunomodulating ability of A. pleuropneumoniae OMVs could help illuminate their biological functions and facilitate the development of OMV-based applications. In the current investigation, we comprehensively characterized the proteome of native A. pleuropneumoniae OMVs. Moreover, we qualitatively and quantitatively compared the OMV proteomes of a wild-type strain and three mutant strains, in which relevant genes were disrupted to increase OMV production and/or produce OMVs devoid of superantigen PalA. Furthermore, the interaction between A. pleuropneumoniae OMVs and porcine alveolar macrophages was also characterized. Our results indicate that native OMVs spontaneously released by A. pleuropneumoniae MIDG2331 appeared to dampen the innate immune responses by porcine alveolar macrophages stimulated by either inactivated or live parent cells. The findings suggest that OMVs may play a role in manipulating the porcine defense during the initial phases of the A. pleuropneumoniae infection. IMPORTANCE Owing to their built-in adjuvanticity and antigenicity, bacterial outer membrane vesicles (OMVs) are gaining increasing attention as potential vaccines for both human and animal use. OMVs released by Actinobacillus pleuropneumoniae, an important respiratory pathogen in pigs, have also been investigated for vaccine development. Our previous studies have shown that A. pleuropneumoniae secretes OMVs containing multiple immunogenic proteins. However, immunization of pigs with these vesicles was not able to relieve the pig lung lesions induced by the challenge with A. pleuropneumoniae, implying the elusive roles that A. pleuropneumoniae OMVs play in host-pathogen interaction. Here, we showed that A. pleuropneumoniae secretes OMVs whose yield and protein content can be altered by the deletion of the nlpI and palA genes. Furthermore, we demonstrate that A. pleuropneumoniae OMVs dampen the immune responses in porcine alveolar macrophages stimulated by A. pleuropneumoniae cells, suggesting a novel mechanism that A. pleuropneumoniae might use to evade host defense.

Dataset Information

Molecular characterization of a protective outer membrane lipoprotein (OmlA) from Actinobacillus pleuropneumoniae serotype 1.

Publications

Molecular characterization of a protective outer membrane lipoprotein (OmlA) from Actinobacillus pleuropneumoniae serotype 1.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets