Despite the fact that clinically relevant infectious agents such as human immunodeficiency virus enter through the intestinal mucosa, the intestinal T cell response to infection remains understudied. Listeria monocytogenes (LM) has been used as a model organism for studying T cell responses and the normal route of infection for LM and a potential route for use of LM as a vaccine is through ingestion. Nevertheless, the vast majority of LM immunological studies utilize inoculation routes other than oral. Moreover in the bacterial strains used, the internalin A protein binds human E-cadherin with high affinity but poorly binds mouse E-cadherin. This receptor-ligand pairing is required for entry of LM into intestinal epithelial cells. The oral infection studies proposed here utilize a recombinant LM that expresses an internalin A protein with high affinity for mouse E-cadherin. Thus, the physiologic route and entry point of LM is recapitulated in our studies. Our preliminary studies revealed a remarkable mucosal TCRgd T cell response to oral LM infection, whose kinetics mimic an adaptive T cell response. Most importantly, this phenotypically and functionally distinct subset of mucosal TCRgd T cells are retained long-term and undergo a recall response upon challenge. The hypothesis to be tested in this proposal is that this specialized subset of putative memory TCRgd T cells is important for protection against LM infection and also regulates the long-term protective CDB TCRa? response. This hypothesis will be tested in the following specific aims:
Aim 1. To test whether a subset of TCRgd represent bona fide mucosal memory cells. A detailed kinetic, phenotypic and functional analysis of the primary and secondary TCRgd cell response to oral LM infection will be undertaken.
Aim 2. To determine the requirements for mucosal TCRgd activation in response to LM infection. Here we will test the role of dendritic cells, costimulation and cytokines in mounting primary and secondary TCRgd cell responses.
Aim 3. To visualize the mucosal TCRgd cell response to oral LM infection. The oral infection system provides an exceptional opportunity to examine the anatomy of the mucosal TCRgd cell response.

Public Health Relevance

The intestinal immune response to infection is understudied. This proposal aims to understand the role of a specialized subset of enigmatic T cells in providing protection against oral infection with the pathogen, Listeria monocytogenes. Determining the key cellular players in mucosal immunity is essential to our ability to treat diseases associated with the intestinal mucosa.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project--Cooperative Agreements (U01)
Project #
5U01AI095544-02
Application #
8281440
Study Section
Special Emphasis Panel (ZAI1-WFD-I (M2))
Program Officer
Rothermel, Annette L
Project Start
2011-07-01
Project End
2016-06-30
Budget Start
2012-07-01
Budget End
2013-06-30
Support Year
2
Fiscal Year
2012
Total Cost
$338,843
Indirect Cost
$119,589
Name
University of Connecticut
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
022254226
City
Farmington
State
CT
Country
United States
Zip Code
06030
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Sheridan, Brian S; Romagnoli, Pablo A; Pham, Quynh-Mai et al. (2013) ýýýý T cells exhibit multifunctional and protective memory in intestinal tissues. Immunity 39:184-95