Outer membrane vesicles of Porphyromonas gingivalis inhibit IFN-γ-mediated MHC class II expression by human vascular endothelial cells

Srisatjaluk, Ratchapin; Doyle, R.J.; Justus, David E.

doi:10.1006/mpat.1999.0287

Cited by 35 publications

(29 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These complexes, enriched in outer membrane proteins of the Omp25/Omp31 family, were identified as vesicular structures referred to as blebs. Blebbing is a known phenomenon that has been described in various bacteria (39), including Brucella (17)(18)(19), and the participation of these released vesicles in bacterial virulence is a recurrent matter of debate (24,38). In the present work, we demonstrated that the blebbing phenomenon occurred for B. suis at acidic pH, and electron microscopy analysis indicated that it also takes place in neutral cell culture medium during infection of monocytes/macrophages.…”

Section: Discussionsupporting

confidence: 56%

Release of Periplasmic Proteins of Brucella suis upon Acidic Shock Involves the Outer Membrane Protein Omp25

et al. 2004

View full text Add to dashboard Cite

The survival and replication of Brucella in macrophages is initially triggered by a low intraphagosomal pH. In order to identify proteins released by Brucella during this early acidification step, we analyzed Brucella suis conditioned medium at various pH levels. No significant proteins were released at pH 4.0 in minimal medium or citrate buffer, whereas in acetate buffer, B. suis released a substantial amount of soluble proteins. Comparison of 13 N-terminal amino acid sequences determined by Edman degradation with their corresponding genomic sequences revealed that all of these proteins possessed a signal peptide indicative of their periplasmic location. Ten proteins are putative substrate binding proteins, including a homologue of the nopaline binding protein of Agrobacterium tumefaciens. The absence of this homologue in Brucella melitensis was due to the deletion of a 7.7-kb DNA fragment in its genome. We also characterized for the first time a hypothetical 9.8-kDa basic protein composed of five amino acid repeats. In B. suis, this protein contained 9 repeats, while 12 were present in the B. melitensis orthologue. B. suis in acetate buffer depended on neither the virB type IV secretory system nor the omp31 gene product. However, the integrity of the omp25 gene was required for release at acidic pH, while the absence of omp25b or omp25c displayed smaller effects. Together, these results suggest that Omp25 is involved in the membrane permeability of Brucella in acidic medium.Bacteria of the genus Brucella are gram-negative facultative intracellular pathogens of various wild and domestic mammals and are able to cause severe zoonotic infections in humans. Traditionally, three major species are distinguished by their predilections for certain animal hosts: Brucella abortus for cattle, Brucella melitensis for caprines, and Brucella suis for hogs. Whereas B. abortus is the livestock pathogen with the greatest economic impact, B. melitensis and B. suis account for most clinical cases in humans (1, 2, 11).To evade host defenses, Brucella can inhibit neutrophil degranulation and block tumor necrosis factor (TNF) production by macrophages. It has been shown that membrane integrity, in terms of both smooth lipopolysaccharide and outer membrane proteins, is required for such virulent behavior. Furthermore, studies using transposon or signature-tagged mutagenesis have unraveled, with respect to Brucella virulence, the crucial role of an operon homologous to the virB operon of Agrobacterium tumefaciens encoding a type IV secretion system (16, 21, 28). The virulence regulon of A. tumefaciens is triggered in response to chemical signals released at the plant wound site, such as acetosyringone and low pH. Type IV secretion system production is potentiated by monosaccharides (galactose and arabinose) through binding to the periplasmic multiple sugar binding protein ChvE, as well as by low pH (6). However, it was found that under neutral conditions, this secretory system is already produced in B. melitensis or B. abortus, while ...

show abstract

Section: Discussionsupporting

confidence: 56%

Release of Periplasmic Proteins of Brucella suis upon Acidic Shock Involves the Outer Membrane Protein Omp25

et al. 2004

View full text Add to dashboard Cite

show abstract

“…Recent studies have demonstrated that the treatment with outer membrane vesicles isolated from P. gingivalis can inhibit the surface expression of MHC class II molecules on IFN-␥-treated endothelial cells (39). This study demonstrated that, in addition to HUVECs, the treatment with P. gingivalis vesicles also blocked IFN-␥-induced MHC class II antigen expression on other unrelated class II-negative cells, including osteosarcoma cells and fibroblasts.…”

Section: Discussionsupporting

confidence: 51%

“…Previous studies in this laboratory demonstrated that treatment of endothelial cells with P. gingivalis membrane vesicles can inhibit the surface expression of IFN-␥-induced HLA-DR molecules, whereas other cytokine-induced molecules, such as tumor necrosis factor alpha-induced E-selectin or interleukin-1-induced intercellular adhesion molecule 1, were not affected (39). This suggests that the inhibitory effect observed may suppress specific immune responses, enabling the bacteria to survive and colonize host tissues.…”

mentioning

confidence: 84%

Modulation of Gamma Interferon-Induced Major Histocompatibility Complex Class II Gene Expression byPorphyromonas gingivalisMembrane Vesicles

et al. 2002

View full text Add to dashboard Cite

show abstract

“…P. gingivalis membrane vesicles may influence cellular responses involved in inflammation and initiation of acquired immunity. It was shown in human vascular endothelial cells that P. gingivalis OMV inhibit INF-␥ induced expression of the major histocompatibility complex (MCH) class II in vitro (Srisatjaluk et al 1999). In contrast to Escherichia coli (E. coli) LPS, pre-treatment of human antigen presenting cells with P. gingivalis LPS induced desensitization and immune tolerance in vitro.…”

Section: Discussionmentioning

confidence: 99%

B7-H1 and B7-DC receptors of oral squamous carcinoma cells are upregulated by Porphyromonas gingivalis

et al. 2011

View full text Add to dashboard Cite

Outer membrane vesicles of Porphyromonas gingivalis inhibit IFN-γ-mediated MHC class II expression by human vascular endothelial cells

Cited by 35 publications

References 43 publications

Release of Periplasmic Proteins of Brucella suis upon Acidic Shock Involves the Outer Membrane Protein Omp25

Release of Periplasmic Proteins of Brucella suis upon Acidic Shock Involves the Outer Membrane Protein Omp25

Modulation of Gamma Interferon-Induced Major Histocompatibility Complex Class II Gene Expression byPorphyromonas gingivalisMembrane Vesicles

B7-H1 and B7-DC receptors of oral squamous carcinoma cells are upregulated by Porphyromonas gingivalis

Contact Info

Product

Resources

About