Author:
Pan Yu,Tagawa Yuichi,Champion Anna,Sandal Indra,Inzana Thomas J.
Abstract
ABSTRACTHistophilus somnisurvives intracellularly in professional phagocytic cells, but the mechanism of intracellular survival is not understood. The Fic motif within the DR1/DR2 IbpA fibrillar network protein ofH. somniis cytotoxic to epithelial and phagocytic cells, which may interfere with the bactericidal activity of these cells. To determine the contribution of IbpA and Fic on resistance to host defenses, strains and mutants that lack all of or a small region ofibpAor DR1/DR2 were tested for survival in bovine monocytic cells and for serum susceptibility. A mutant lacking IbpA, but not DR1/DR2, was more susceptible to killing by antiserum than the parent.H. somnistrains expressing IbpA replicated in bovine monocytes for at least 72 hours, and were toxic for these cells. Virulent strain 2336 with transposon insertions or deletions within IbpA remained toxic for bovine monocytes. However, strain 2336 mutants lacking all ofibpAor both DR1/DR2 were not toxic to the monocytes, but survived within the monocytes for at least 72 hours. Examination of intracellular trafficking ofH. somniwith monoclonal antibodies to early and late phagosomal markers indicated that early phagosomal marker EEA-1 colocalized with both disease isolate strain 2336 and serum-sensitve mucosal isolate strain 129Pt, but only strain 2336 did not co-localize with late lysosomal marker LAMP-2 and prevented acidification of phagosomes. These results indicate that virulent isolates ofH. somniare capable of surviving within phagocytic cells through interference of phagosome-lysosome maturation. Therefore,H. somnimay be considered a permissive intracellular pathogen.
Publisher
Cold Spring Harbor Laboratory
Reference48 articles.
1. Sandal I , Corbeil L , Inzana T . 2010. Haemophilus, p . 387–409. In Gyles CL , Prescott JF , Songer JG , Thoen CO (ed), Pathogenesis of bacterial infections in animals, 4th ed, Wiley-Blackwell, Ames, IA.
2. Complete Genome Sequence of
Haemophilus somnus
(
Histophilus somni
) Strain 129Pt and Comparison to
Haemophilus ducreyi
35000HP and
Haemophilus influenzae
Rd
3. Vaccination of cattle against experimentally induced thromboembolic meningoencephalitis with a Haemophilus somnus bacterin;Am J Vet Res,1982
4. The Many Facets of Lipooligosaccharide as a Virulence Factor for Histophilus somni
5. Interactions of Histophilus somni with Host Cells
Cited by
1 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献