Characterization of immunodominant surface antigens of Haemophilus somnus

Corbeil, Lynette B.; Kania, Stephen A.; Gogolewski, R P

doi:10.1128/iai.59.12.4295-4301.1991

Cited by 20 publications

(25 citation statements)

References 20 publications

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“…A 39-kDa OMP antigenically distinct from the 40-kDa OMP has also been identified. This protein reacts with convalescent-phase serum and is also conserved among all H. somnus isolates tested (5).…”

mentioning

confidence: 82%

“…The putative virulence factor which has received most attention so far is a 40-kDa outer membrane protein (OMP). Using monospecific bovine polyclonal antibody against this antigen, Corbeil and coworkers have shown that the 40-kDa OMP is present in all H. somnus isolates tested (5). They have also demonstrated, in a passive protection experiment, that the same monospecific antiserum efficiently prevents H. somnus-induced pneumonia (12).…”

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confidence: 98%

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Molecular cloning, nucleotide sequence, and characterization of lppB, encoding an antigenic 40-kilodalton lipoprotein of Haemophilus somnus

Theisen¹,

Rioux²,

Potter³

1993

Infect Immun

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Haemophilus somnus is a facultative intracellular pathogen which causes a wide range of diseases in cattle. To identify putative virulence determinants, a genomic library of H. somnus in Escherichia coli was screened for Congo red binding, a property associated with virulence in pathogenic bacteria, and subsequently with bovine hyperimmune sera raised against H. somnus HS25. A Congo red-binding clone carrying a 1.8-kb DNA insert was found to encode a strongly seroreactive LppB protein with an apparent molecular weight of 40,000. The nucleotide sequence of the entire DNA insert was determined. Two open reading frames coding for polypeptides with calculated molecular weights of 21,893 and 30,721 were identified. The larger open reading frame encoded LppB, while the smaller reading frame encoded a nonseroreactive protein with a relative molecular mass of approximately 18 kDa. The 16 amino-terminal amino acids of the deduced LppB polypeptide showed strong sequence homology to the signal peptide of secreted bacterial proteins, and the sequence Leu-Ala-Ala-Cys at the putative cleavage site corresponds to the consensus cleavage sequence of bacterial lipoproteins. Synthesis of the mature LppB lipoprotein in H. somnus was inhibited by globomycin, a specific inhibitor of signal peptidase II. LppB was localized to the outer membrane of H. somnus.

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confidence: 82%

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confidence: 98%

Molecular cloning, nucleotide sequence, and characterization of lppB, encoding an antigenic 40-kilodalton lipoprotein of Haemophilus somnus

Theisen¹,

Rioux²,

Potter³

1993

Infect Immun

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“…Preputial isolate 129Pt does not produce IbpA and is not cytotoxic for epithelial cells (19). However, no other differences have been identified in the outer membrane proteins examined (40). All strains were grown on brain heart infusion (BHI) agar with 5% sheep blood in 5% CO 2 overnight from frozen stocks.…”

Section: Methodsmentioning

confidence: 99%

Histophilus somni Survives in Bovine Macrophages by Interfering with Phagosome-Lysosome Fusion but Requires IbpA for Optimal Serum Resistance

et al. 2018

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is capable of intracellular survival within professional phagocytic cells, but the mechanism of survival is not understood. The Fic motif within the direct repeat (DR1)/DR2 domains of the IbpA fibrillary network protein of is cytotoxic to epithelial and phagocytic cells, which may interfere with the bactericidal activity of these cells. To determine the contribution of IbpA and Fic to resistance to host defenses, strains and mutants that lacked all or a region of (including the DR1/DR2 regions) were tested for survival in bovine monocytic cells and for serum susceptibility. An mutant lacking IbpA, but not the DR1/DR2 region within , was more susceptible to killing by antiserum than the parent, indicating that the entire protein was associated with serum resistance. strains expressing IbpA replicated in bovine monocytes for at least 72 h and were toxic for these cells. Virulent strain 2336 mutants lacking the entire gene or both DR1 and DR2 were not toxic to the monocytes but still survived within the monocytes for at least 72 h. Monitoring of intracellular trafficking of with monoclonal antibodies to phagosomal markers indicated that the early phagosomal marker early endosome antigen 1 colocalized with all isolates tested, but only strains that could survive intracellularly did not colocalize with the late lysosomal marker lysosome-associated membrane protein 2 and prevented the acidification of phagosomes. These results indicated that virulent isolates of were capable of surviving within phagocytic cells through interference in phagosome-lysosome maturation. Therefore, may be considered a permissive intracellular pathogen.

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“…A bovine monocytic cell line (BM) derived from blood monocytes of a 6-year-old Guernsey cow was originally obtained from Dr. John Dame, University of Florida, and provided by Dr. David Lindsay, Virginia Tech. The cells were grown in RPMI-1640 medium supplemented with 10% heat-inactivated fetal bovine serum and 2 mM L-glutamine in 5% CO 2 at 37 °C (42). The cells were cultured in wells of 6-well plates at 3×10 5 /well (in 5 ml), allowed to adhere for 24 h, and the monolayers were washed 3 times with phosphate buffered saline, pH 7.2 (PBS) before adding IbpA or bacteria.…”

Section: Methodsmentioning

confidence: 99%

Histophilus somniSurvives in Bovine Macrophages by Interfering with Phagosome-Lysosome Fusion, but Requires IbpA for Optimal Serum Resistance

Pan

Tagawa

Champion

et al. 2018

Preprint

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20Histophilus somni survives intracellularly in professional phagocytic cells, but the 21 mechanism of intracellular survival is not understood. The Fic motif within the DR1/DR2 IbpA 22 fibrillar network protein of H. somni is cytotoxic to epithelial and phagocytic cells, which may 23 interfere with the bactericidal activity of these cells. To determine the contribution of IbpA and 24Fic on resistance to host defenses, strains and mutants that lack all of or a small region of ibpA or 25 DR1/DR2 were tested for survival in bovine monocytic cells and for serum susceptibility. A 26 mutant lacking IbpA, but not DR1/DR2, was more susceptible to killing by antiserum than the 27 parent. H. somni strains expressing IbpA replicated in bovine monocytes for at least 72 hours, 28 and were toxic for these cells. Virulent strain 2336 with transposon insertions or deletions within 29IbpA remained toxic for bovine monocytes. However, strain 2336 mutants lacking all of ibpA or 30 both DR1/DR2 were not toxic to the monocytes, but survived within the monocytes for at least 31 72 hours. Examination of intracellular trafficking of H. somni with monoclonal antibodies to 32 early and late phagosomal markers indicated that early phagosomal marker EEA-1 colocalized 33 with both disease isolate strain 2336 and serum-sensitve mucosal isolate strain 129Pt, but only 34 strain 2336 did not co-localize with late lysosomal marker LAMP-2 and prevented acidification 35 of phagosomes. These results indicate that virulent isolates of H. somni are capable of surviving 36 within phagocytic cells through interference of phagosome-lysosome maturation. Therefore, H. 37 somni may be considered a permissive intracellular pathogen. 38 3 39

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Characterization of immunodominant surface antigens of Haemophilus somnus

Cited by 20 publications

References 20 publications

Molecular cloning, nucleotide sequence, and characterization of lppB, encoding an antigenic 40-kilodalton lipoprotein of Haemophilus somnus

Molecular cloning, nucleotide sequence, and characterization of lppB, encoding an antigenic 40-kilodalton lipoprotein of Haemophilus somnus

Histophilus somni Survives in Bovine Macrophages by Interfering with Phagosome-Lysosome Fusion but Requires IbpA for Optimal Serum Resistance

Histophilus somniSurvives in Bovine Macrophages by Interfering with Phagosome-Lysosome Fusion, but Requires IbpA for Optimal Serum Resistance

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