The protective immune response to L. monocytogenes is used to investigate general features of cell-mediated immunity to intracellular bacteria. In BALB/c mice, Listeria-specific CD8+ CTL have been isolated which are Kd restricted. Peptides from listeriolysin O (LLO) a molecule secreted in the phagocytic vacuole, and p60, a molecule that is abundantly secreted in the cytoplasm, have been identified as CTL targets. CTL frequency analysis shows that the LLO-derived determinant, LLO 91-99, is immunodominant. We hypothesize that secretion of LLO within the phagocytic vacuole is a contributing factor to the immunodominance of the LLO 91-99 peptide.
In Specific Aim I, studies are described that will determine if secretion of defined peptides within the phagocytic vacuole is a contributing factor to their immunodominance. For these studies, we will use L. monocytogenes mutants in which the anchor residue at position 2 within the Kd-binding nanomer peptide (normally a tyrosine) has been replaced by phenylalanine. The mutants retain the wildtype phenotype, yet following immunization with these strains, specific CTL are not stimulated to the mutant peptide sequence. We will use these mutants to deliver specific Listeria-derived peptides to the phagocytic vacuole or the cytoplasm of the L. monocytogenes infected cell in order to determine the influence of these initial locations on the subsequent CTL response. L. monocytogenes has been proposed as a vector to deliver candidate antigens and stimulate specific cell-mediated immunity. The value of vaccine vectors for delivery of candidate antigens depends in part on the ability to specifically stimulate the immune response in an environment of existing anti-vector immunity.
In Specific Aim II, we will determine the utility of L. monocytogenes as a vaccine vector and assess the development of peptide specific immunity in animals that have defined levels of existing immunity to the vaccine vector. We will assess the development of peptide specific effector cell and memory cell responses. The results from these studies will guide strategies for the general development of novel vaccine carriers as well as to define the limits of their use within a population whose immunologic status to the vaccine carrier is unknown.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI044376-05
Application #
6647219
Study Section
Bacteriology and Mycology Subcommittee 2 (BM)
Program Officer
Hall, Robert H
Project Start
1999-08-01
Project End
2005-06-30
Budget Start
2003-07-01
Budget End
2005-06-30
Support Year
5
Fiscal Year
2003
Total Cost
$194,036
Indirect Cost
Name
Providence Portland Medical Center
Department
Type
DUNS #
099142093
City
Portland
State
OR
Country
United States
Zip Code
97213
Smithey, Megan J; Brandt, Suzanne; Freitag, Nancy E et al. (2008) Stimulation of enhanced CD8 T cell responses following immunization with a hyper-antigen secreting intracytosolic bacterial pathogen. J Immunol 180:3406-16
Bouwer, H G Archie; Alberti-Segui, Christine; Montfort, Megan J et al. (2006) Directed antigen delivery as a vaccine strategy for an intracellular bacterial pathogen. Proc Natl Acad Sci U S A 103:5102-7
Schillace, Robynn V; Andrews, Sarah F; Galligan, Sarah G et al. (2005) The role of protein kinase A anchoring via the RII alpha regulatory subunit in the murine immune system. J Immunol 174:6847-53
Wong, Kendy K Y; Bouwer, H G Archie; Freitag, Nancy E (2004) Evidence implicating the 5' untranslated region of Listeria monocytogenes actA in the regulation of bacterial actin-based motility. Cell Microbiol 6:155-66
Starks, Holly; Bruhn, Kevin W; Shen, Hao et al. (2004) Listeria monocytogenes as a vaccine vector: virulence attenuation or existing antivector immunity does not diminish therapeutic efficacy. J Immunol 173:420-7
Montfort, Megan J; Bouwer, H G Archie; Wagner, Cynthia R et al. (2004) The development of functional CD8 T cell memory after Listeria monocytogenes infection is not dependent on CD40. J Immunol 173:4084-90
Grundling, Angelika; Burrack, Laura S; Bouwer, H G Archie et al. (2004) Listeria monocytogenes regulates flagellar motility gene expression through MogR, a transcriptional repressor required for virulence. Proc Natl Acad Sci U S A 101:12318-23
Shetron-Rama, Lynne M; Mueller, Kimberly; Bravo, Juan M et al. (2003) Isolation of Listeria monocytogenes mutants with high-level in vitro expression of host cytosol-induced gene products. Mol Microbiol 48:1537-51
Barry, Ronald A; Archie Bouwer, H G; Clark, Tina R et al. (2003) Protection of interferon-gamma knockout mice against Listeria monocytogenes challenge following intramuscular immunization with DNA vaccines encoding listeriolysin O. Vaccine 21:2122-32
Shetron-Rama, Lynne M; Marquis, Helene; Bouwer, H G Archie et al. (2002) Intracellular induction of Listeria monocytogenes actA expression. Infect Immun 70:1087-96

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