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Porphyromonas gingivalis innate immune evasion contributes to site-specific chronic inflammation.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Porphyromonas gingivalis innate immune evasion contributes to site-specific chronic inflammation./
Author:	Slocum, Connie L.
Description:	1 online resource (264 pages)
Notes:	Source: Dissertations Abstracts International, Volume: 77-02, Section: B.
Contained By:	Dissertations Abstracts International77-02B.
Subject:	Biology. -
Online resource:	click for full text (PQDT)
ISBN:	9781321839630

Porphyromonas gingivalis innate immune evasion contributes to site-specific chronic inflammation.
Slocum, Connie L.

Porphyromonas gingivalis innate immune evasion contributes to site-specific chronic inflammation. - 1 online resource (264 pages)

Source: Dissertations Abstracts International, Volume: 77-02, Section: B.

Thesis (Ph.D.)--Boston University, 2015.

Includes bibliographical references

Several successful pathogens evade host defenses resulting in the establishment of persistent and chronic infections. One such pathogen, Porphyromonas gingivalis, induces chronic low-grade inflammation associated with local inflammatory oral bone loss and systemic inflammation manifested as atherosclerosis. The pathogenic mechanisms contributing to P. gingivalis evasion of host immunity and chronic inflammation are not well defined. P. gingivalis evades host immunity at Toll-like receptor (TLR)-4 through expression of an atypical lipopolysaccharide (LPS) that contains lipid A species that exhibit TLR4 agonist or antagonist activity or fail to activate TLR4. By utilizing a series of P. gingivalis lipid A mutants we demonstrated that expression of antagonist lipid A structures resulted in weak induction of proinflammatory mediators. Moreover, expression of antagonist lipid A failed to activate the inflammasome, which correlated with increased bacterial survival in macrophages. Oral infection of atherosclerotic prone apolipoprotein E (ApoE) deficient mice with the antagonist lipid A strain resulted in vascular inflammation characterized by macrophage accumulation and atherosclerosis progression. In contrast, a P. gingivalis strain expressing exclusively agonist lipid A augmented levels of proinflammatory mediators and activated the inflammasome in a caspase-11 dependent manner, resulting in host cell lysis and decreased bacterial survival. ApoE deficient mice infected with the agonist lipid A strain exhibited diminished vascular inflammation. Notably, the ability of P. gingivalis to induce local inflammatory oral bone loss was independent of lipid A expression, indicative of distinct mechanisms for induction of local versus systemic inflammation by this pathogen. We next investigated the role of TLRs and lipid A on bacterial trafficking by the autophagic pathway. Originally characterized as a cell autonomous pathway for recycling damaged organelles and proteins, autophagy is now recognized to play a critical role in innate defense and release of the proinflammatory cytokine interleukin (IL)-1β. We demonstrated that P. gingivalis suppresses the autophagic pathway in macrophages for pathogen survival and intercepts autophagy-mediated IL-1β release. P. gingivalis -mediated suppression of autophagy was independent of lipid A expression but partially dependent on TLR2 signaling. Collectively, our results indicate that P. gingivalis evasion of innate immunity plays a role in chronic inflammation.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2024

Mode of access: World Wide Web

ISBN: 9781321839630Subjects--Topical Terms:

599573
Biology.
Subjects--Index Terms:

AutophagyIndex Terms--Genre/Form:

554714
Electronic books.

Porphyromonas gingivalis innate immune evasion contributes to site-specific chronic inflammation.
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