Tuberculosis (TB) remains a leading cause of infectious mortality worldwide. At present, the only available vaccine for TB, Bacillus Calmette-Guirin (BCG), has not proven effective in the prevention of adult tuberculosis. As a result, an improved vaccine for TB is urgently needed. We have recently identified and characterized human, Mycobacterium tuberculosis (Mtb)-reactive, CD8+ T cells restricted by the non-classical (HLA-Ib) molecule MR1. This molecule has not previously been shown to present pathogen associated antigens. T cells restricted by MR1 often use a specific T cell receptor (TCR;V17.2).These cells have been termed Mucosa Associated Invariant T Cells (MAIT). Furthermore, we have also found that lung epithelial cells can be infected with Mtb, and are efficiently recognized by CD8+ T cells.
The specific aims of this proposal are focused on developing an improved understanding of the role that the airway plays in the control of infection with Mtb. We have recently found that MR1-restricted MAIT are capable of recognizing Mtb as well as a variety of other pathogens, and that these and other CD8+ T cells are capable of efficiently recognizing Mtb-infected epithelial cells. At present, the role of airway epithelium in the host response to infection with Mtb remains relatively unexplored. In the first aim the full spectrum of pathogens recognized by MAIT will be characterized with regard to TCR usage. We postulate that the limited TCR usage will correlate with limited diversity with regard to pathogen discrimination.
The second Aim will define the intracellular location of Mtb in epithelial cells, and will define critical components in the antigen processing and presentation pathway. Here, we postulate that the immune system has evolved mechanisms to sample the intracellular environment of Mtb. Finally, we will address the role of iNOS in the direct control of Mtb growth. Here, we postulate that the major role of iNOS in humans resides at the level of the lung epithelium.

Public Health Relevance

Tuberculosis remains a leading cause of infectious mortality worldwide, and is caused by a bacterium that resides inside of cells. In order for the immune response to respond to the infection, it must identify those cells that harbor the bacterium. Cytotoxic T cells are uniquely poised to perform this function. The goal of this research is to understand how these cells can recognize infected cells, and how this leads to control of the infection.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI048090-12
Application #
8386558
Study Section
Immunity and Host Defense Study Section (IHD)
Program Officer
Jacobs, Gail G
Project Start
2000-09-01
Project End
2016-12-31
Budget Start
2013-01-01
Budget End
2013-12-31
Support Year
12
Fiscal Year
2013
Total Cost
$207,270
Indirect Cost
$42,770
Name
Oregon Health and Science University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
096997515
City
Portland
State
OR
Country
United States
Zip Code
97239
Meermeier, Erin W; Laugel, Bruno F; Sewell, Andrew K et al. (2016) Human TRAV1-2-negative MR1-restricted T cells detect S. pyogenes and alternatives to MAIT riboflavin-based antigens. Nat Commun 7:12506
Harriff, Melanie J; Karamooz, Elham; Burr, Ansen et al. (2016) Endosomal MR1 Trafficking Plays a Key Role in Presentation of Mycobacterium tuberculosis Ligands to MAIT Cells. PLoS Pathog 12:e1005524
Laugel, Bruno; Lloyd, Angharad; Meermeier, Erin W et al. (2016) Engineering of Isogenic Cells Deficient for MR1 with a CRISPR/Cas9 Lentiviral System: Tools To Study Microbial Antigen Processing and Presentation to Human MR1-Restricted T Cells. J Immunol 197:971-82
Nyendak, Melissa; Swarbrick, Gwendolyn M; Duncan, Amanda et al. (2016) Adenovirally-Induced Polyfunctional T Cells Do Not Necessarily Recognize the Infected Target: Lessons from a Phase I Trial of the AERAS-402 Vaccine. Sci Rep 6:36355
Greene, J M; Dash, P; Roy, S et al. (2016) MR1-restricted mucosal-associated invariant T (MAIT) cells respond to mycobacterial vaccination and infection in nonhuman primates. Mucosal Immunol :
Gold, Marielle C; Napier, Ruth J; Lewinsohn, David M (2015) MR1-restricted mucosal associated invariant T (MAIT) cells in the immune response to Mycobacterium tuberculosis. Immunol Rev 264:154-66
Nyendak, Melissa R; Lewinsohn, David M; Shah, Raj D et al. (2014) ATS Core Curriculum 2014: part I. Adult pulmonary medicine. Ann Am Thorac Soc 11:1136-44
Harriff, Melanie J; Cansler, Meghan E; Toren, Katelynne Gardner et al. (2014) Human lung epithelial cells contain Mycobacterium tuberculosis in a late endosomal vacuole and are efficiently recognized by CD8⁺ T cells. PLoS One 9:e97515
Alzhanova, Dina; Hammarlund, Erika; Reed, Jason et al. (2014) T cell inactivation by poxviral B22 family proteins increases viral virulence. PLoS Pathog 10:e1004123
Gold, M C; Eid, T; Smyk-Pearson, S et al. (2013) Human thymic MR1-restricted MAIT cells are innate pathogen-reactive effectors that adapt following thymic egress. Mucosal Immunol 6:35-44

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