This project is directed to develop technology to identify antigens recognized by pathogen-specific class-l MHC restricted T cells by systematic screening of all pathogen protein coding genes, its ORFeome. The system is based on the observation that phagolysosomal destruction within antigen presenting cells (APCs) of E. co// expressing cytoplasmic listeriolysin (cytoLLO) results in leakage of phagosomal contents into the ARC cytosol and access of antigens to the host cell cytosolic MHC class I antigen processing pathway resulting in presentation of the antigen in the context of MHC class I molecules. We propose to focus on immunity to S. Typhi, a pathogen of great public health importance. Live, attenuated vaccine strains of Salmonella have the potential to be a cost-effective prophylactic measure in combating this disease, yet the antigens important in protection are largely unknown. Thus, the identification of putative S. Typhi proteins that might be involved in protection, by screening of the S. Typhi ORFeome, will allow us to explore our hypothesis that the increased efficacy of 4 doses of the oral Ty21 a typhoid vaccine as compared to a single dose is in part due to the repertoire of S. Typhi specific CD8+ T cells in vaccinees. One of the novel features of the proposed technology is an ability to confirm that S. Typhi proteins are expressed and able to be presented by APCs in the context of class-l molecules by fusing them with positive epitope controls. In addition, rather than co-expressing cytoLLO and a candidate antigen in the same ? co// cell, we propose to co-infect ARC with two different strains of E. co//, one expressing cytoLLO and the other the antigen of interest as this system allows greater flexibility in use of the ORFeome for other purposes. This proposal brings together collaborators with expertise in cellular immunology, genomics and high throughput assays systems with the express purpose of tackling an important global health problem via improved vaccine development.
The development of improved typhoid vaccines to prevent antibiotic-resistant typhoid fever in developing countries is a high global public health priority. In this project we propose to examine the whole ORFeome of S. Typhi to uncover proteins that are recognized by the human host using cells from immunized subjects. Findings from these studies will greatly contribute to accelerate the development of typhoid vaccines.
|McArthur, Monica A; Chen, Wilbur H; Magder, Laurence et al. (2017) Impact of CD4+ T Cell Responses on Clinical Outcome following Oral Administration of Wild-Type Enterotoxigenic Escherichia coli in Humans. PLoS Negl Trop Dis 11:e0005291|
|Booth, Jayaum S; Patil, Seema A; Ghazi, Leyla et al. (2017) Systemic and Terminal Ileum Mucosal Immunity Elicited by Oral Immunization With the Ty21a Typhoid Vaccine in Humans. Cell Mol Gastroenterol Hepatol 4:419-437|
|Salerno-Goncalves, Rosângela; Luo, David; Fresnay, Stephanie et al. (2017) Challenge of Humans with Wild-type Salmonella enterica Serovar Typhi Elicits Changes in the Activation and Homing Characteristics of Mucosal-Associated Invariant T Cells. Front Immunol 8:398|
|Fresnay, Stephanie; McArthur, Monica A; Magder, Laurence S et al. (2017) Importance of Salmonella Typhi-Responsive CD8+ T Cell Immunity in a Human Typhoid Fever Challenge Model. Front Immunol 8:208|
|Arevalillo, Jorge M; Sztein, Marcelo B; Kotloff, Karen L et al. (2017) Identification of immune correlates of protection in Shigella infection by application of machine learning. J Biomed Inform 74:1-9|
|Wahid, Rezwanul; Fresnay, Stephanie; Levine, Myron M et al. (2016) Cross-reactive multifunctional CD4+ T cell responses against Salmonella enterica serovars Typhi, Paratyphi A and Paratyphi B in humans following immunization with live oral typhoid vaccine Ty21a. Clin Immunol 173:87-95|
|Toapanta, Franklin R; Bernal, Paula J; Fresnay, Stephanie et al. (2016) Oral Challenge with Wild-Type Salmonella Typhi Induces Distinct Changes in B Cell Subsets in Individuals Who Develop Typhoid Disease. PLoS Negl Trop Dis 10:e0004766|
|Salerno-Goncalves, R; Safavie, F; Fasano, A et al. (2016) Free and complexed-secretory immunoglobulin A triggers distinct intestinal epithelial cell responses. Clin Exp Immunol 185:338-47|
|Cong, Yu; McArthur, Monica A; Cohen, Melanie et al. (2016) Characterization of Yellow Fever Virus Infection of Human and Non-human Primate Antigen Presenting Cells and Their Interaction with CD4+ T Cells. PLoS Negl Trop Dis 10:e0004709|
|Blohmke, Christoph J; Darton, Thomas C; Jones, Claire et al. (2016) Interferon-driven alterations of the host's amino acid metabolism in the pathogenesis of typhoid fever. J Exp Med 213:1061-77|
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