The Gram-negative bacteria Yersinia pestis is the causative agent of plague, and is classified as an NIAID category A priority biodefense agent. Y.pestis contains a well-described type III secretion system that has the ability to repress the host responses to the bacteria. However, less is know about immune activation by outer membrane components such as lipopolysaccharide (LPS), how these components interact with the host immune system, and their role in disease progression. Our goal is to define the role of Y. pestis LPS in the development of plague, and furthermore to characterize the impact of interactions by Y.pestis and its LPS with host Toll-like receptors (TLRs) and CD14 during the course of the disease. TLRs and CD14 are central in the innate immune response to microbial challenge. It has recently been suggested that Y.pestis produces a lipid A (main biologically active component of LPS) of lower potency when grown at 37 degrees C (host temperature) compared to 27 degrees C (flea temperature). Our hypothesis is that temperature induced alterations in Y. pestis LPS enable the bacteria to blunt responses mediated by TLR4, contributing to the diminished innate immune responses following infection. We will isolate lipid A from Y. pestis strain KIM (for which the genomic sequence is known) grown at 27xC and 37xC, and characterize the detailed structures. Furthermore, we will analyze the immune activation ability of Y. pestis (grown at 27 degrees C and 37 degrees C) and its LPS with an emphasis on interactions with the TLR signaling pathways, and relate structures to immune activation potential. To investigate the specific role of LPS in disease, we will make bacteria expressing a highly active LPS at 37 degrees C, by over-expressing LPS biosynthesis genes from E.co/i. We will also generate mutants over-expressing the Y.pestis genes, and make bacteria deficient in the same genes. These bacteria will produce altered LPS at both 27 degrees C and 37 degrees C, and we will characterize LPS structure and cell activation potential. To establish the role of Y. pestis LPS in infection in vivo, we will test wild-type and the genetically modified Y. pestis for ability to mount immune activation and infection in wildtype mice and mice genetically deficient for TLRs, MyD88 and CD14. The completion of these studies will provide new information on how Y. pestis interacts with central elements of the innate immune system, knowledge that would be helpful in the development of new therapies for plague and related infections.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
1R01AI057588-01
Application #
6706497
Study Section
Special Emphasis Panel (ZRG1-BM-1 (02))
Program Officer
Schaefer, Michael R
Project Start
2004-03-01
Project End
2009-02-28
Budget Start
2004-03-01
Budget End
2005-02-28
Support Year
1
Fiscal Year
2004
Total Cost
$382,160
Indirect Cost
Name
University of Massachusetts Medical School Worcester
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
603847393
City
Worcester
State
MA
Country
United States
Zip Code
01655
Marty-Roix, Robyn; Vladimer, Gregory I; Pouliot, Kimberly et al. (2016) Identification of QS-21 as an Inflammasome-activating Molecular Component of Saponin Adjuvants. J Biol Chem 291:1123-36
Weng, Dan; Marty-Roix, Robyn; Ganesan, Sandhya et al. (2014) Caspase-8 and RIP kinases regulate bacteria-induced innate immune responses and cell death. Proc Natl Acad Sci U S A 111:7391-6
Marty-Roix, Robyn; Lien, Egil (2013) (De-) oiling inflammasomes. Immunity 38:1088-90
Vladimer, Gregory I; Marty-Roix, Robyn; Ghosh, Shubhendu et al. (2013) Inflammasomes and host defenses against bacterial infections. Curr Opin Microbiol 16:23-31
Vladimer, Gregory I; Weng, Dan; Paquette, Sara W Montminy et al. (2012) The NLRP12 inflammasome recognizes Yersinia pestis. Immunity 37:96-107
Meng, Jianmin; Lien, Egil; Golenbock, Douglas T (2010) MD-2-mediated ionic interactions between lipid A and TLR4 are essential for receptor activation. J Biol Chem 285:8695-702
Johnston, Norah C; Aygun-Sunar, Semra; Guan, Ziqiang et al. (2010) A phosphoethanolamine-modified glycosyl diradylglycerol in the polar lipids of Clostridium tetani. J Lipid Res 51:1953-61
He, Xianbao; Mekasha, Samrawit; Mavrogiorgos, Nikolaos et al. (2010) Inflammation and fibrosis during Chlamydia pneumoniae infection is regulated by IL-1 and the NLRP3/ASC inflammasome. J Immunol 184:5743-54
Szaba, Frank M; Kummer, Lawrence W; Wilhelm, Lindsey B et al. (2009) D27-pLpxL, an avirulent strain of Yersinia pestis, primes T cells that protect against pneumonic plague. Infect Immun 77:4295-304
Lin, Hongying; Fridy, Peter C; Ribeiro, Anthony A et al. (2009) Structural analysis and detection of biological inositol pyrophosphates reveal that the family of VIP/diphosphoinositol pentakisphosphate kinases are 1/3-kinases. J Biol Chem 284:1863-72

Showing the most recent 10 out of 21 publications