Find results with:

Add another field

Search by date

to

Searching collections:

Dartmouth Dissertations

Add or remove collections

Home Dartmouth Dissertations Page 1

Reference URL

To link to the entire object, paste this link in email, IM or document

To embed the entire object, paste this HTML in website

To link to this page, paste this link in email, IM or document

To embed this page, paste this HTML in website

Bacterial flagellar motility facilitates host phagocyte association, engulfment, and inflammatory responses / by Rustin Lovewell.

you wish to report:

Your comment:

Your Name:

Submit

Cancel

...

Back to top

Powered by CONTENTdm®

Author	Lovewell, Rustin (Rustin R.)
Title	Bacterial flagellar motility facilitates host phagocyte association, engulfment, and inflammatory responses / by Rustin Lovewell.
Date	2013
Abstract	The immune system cannot effectively clear the highly motile, opportunistic pathogen Pseudomonas aeruginosa in chronically infected patients. Phagocytosis is the primary means of bacterial clearance in P. aeruginosa infections, and thus the central hypothesis of this thesis is that bacterial flagellar motility is a pattern of pathogenesis that is recognized by phagocytes of the innate immune system. We identify phagocytic resistance in P. aeruginosa mutants that lose not just the flagellar structure, but flagellar swimming motility. We show that phagocytic cells specifically recognize and respond to flagellar motility as a global phagocytic activation signal. Moreover, total bacteria-phagocyte association is attenuated in non-swimming P. aeruginosa, yet when initial contact between phagocytes and various bacterial genotypes is artificially equalized, only the swimming-capable bacteria remain associated and are subsequently engulfed. We quantitatively demonstrate that incremental decreases in flagellar torque elicit corresponding decreases in the phagocytic uptake of these associated bacteria. This mechanism is regulated through the PI3K/Akt pathway, which is critical for phagocytosis of P. aeruginosa. Thus, Akt is a biological rheostat for the uptake of flagellated extra-cellular bacteria as directed by the swimming capability of the pathogen. The inflammatory response is also an important component of innate immunity against P. aeruginosa. As an addendum to the studies of phagocytosis, we show that non-swimming P. aeruginosa induce less inflammatory cytokine production than swimming-competent strains, and that this is likely due to decreased cellular association with non-swimming mutants. Additionally, we show that non-swimming P. aeruginosa is less lethal to murine hosts during peritoneal challenge, even though there is a delay in the bacterial clearance of non-swimming mutants. Finally, our data indicate that the survival benefit to hosts infected with non-swimming P. aeruginosa is dependent on TLR5 signalin
Description	xiii, 216 leaves : ill. (some col.) 28 cm.
Format	application/pdf
Advisor	Brent Berwin, George O'Toole, Ed Usherwood, Karen Ottemann
College	Dartmouth Medical School. Dept. of Microbiology and Immunology.
Issuing Body	Dartmouth Dissertations are made available through the Dartmouth Digital Library.
Degree	Thesis (Ph.D.)--Dartmouth College.
Copyright	All rights reserved. No part of this book may be reproduced in any form by any electronic or mechanical means without permission in writing from the author.
DOI	http://dx.doi.org/10.1349/ddlp.987

Find results with:

Searching collections:

Home Dartmouth Dissertations Page 1

Bacterial flagellar motility facilitates host phagocyte association, engulfment, and inflammatory responses / by Rustin Lovewell.

Object Description

Description

Bacterial flagellar motility facilitates host phagocyte...

Bacterial flagellar motility facilitates host phagocyte...

	All
	Pages Enter page numbers or page ranges separated by commas. For example: 1,3,5-12