My long-term goal is to obtain a cellular and molecular understanding of the complex intercellular interactions that result in terminal differentiation of bone marrow-derived precursors into mature effector T cells. The focus of the present application is characterization of self ligands that induce positive selection in the thymus. The application is based on our recent discovery of a novel strategy of predicting and identifying self peptides promoting positive selection. The approach consists of generation of large databases of potential self peptides (made possible by the mouse genome project) and bioinformatics-based selection from these databases of small groups of candidate peptides. Selected peptides are tested for positive selection in fetal thymic organ cultures and MHC presentation of peptides is verified by screening self peptide pools by mass spectrometry analysis.
In Specific aim 1 we will expand this strategy to identify multiple positively selecting peptides in four T cell receptor transgenic models. We will also experimentally test whether similarity of self peptides to antigen is a working principle of positive selection. The similarity scores of self-ligands identified by three independent means will be plotted against the ability to induce positive selection. A complementary approach will consist of generating synthetic peptide libraries of graded similarity to antigen. The ability of these libraries to induce positive selection will be determined. In the Specific Aim 2 we will determine if and how the duration of T cell receptor signaling affects positive and negative selection. Using a novel in vitro experimental delivery of positively selecting signals we will observe the kinetics of MAP kinase activation induced by negatively or positively selecting ligands. In a complementary approach we will assess the effects on positive versus negative selection of limiting the duration of signaling.
In Specific aim 3 we will determine the structural basis for selective involvement of amino-terminal portion of peptide in positive selection. These findings should greatly contribute to our knowledge of the formation of functional TCR repertoire. This information will be valuable for vaccine development, immunomodulation therapy in organ transplantation, autoimmune diseases, lymphoproliferative diseases and cancer.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI041573-10
Application #
7162135
Study Section
Immunobiology Study Section (IMB)
Program Officer
Mallia, Conrad M
Project Start
1998-02-01
Project End
2007-12-31
Budget Start
2007-01-01
Budget End
2007-12-31
Support Year
10
Fiscal Year
2007
Total Cost
$272,128
Indirect Cost
Name
Children's Research Institute
Department
Type
DUNS #
143983562
City
Washington
State
DC
Country
United States
Zip Code
20010
Tatari-Calderone, Zohreh; Stojakovic, Milica; Dewan, Ramita et al. (2012) Age-related accumulation of T cells with markers of relatively stronger autoreactivity leads to functional erosion of T cells. BMC Immunol 13:8
Popmihajlov, Zoran; Santori, Fabio R; Gebreselassie, Daniel et al. (2010) Effective adoptive therapy of tap-deficient lymphoma using diverse high avidity alloreactive T cells. Cancer Immunol Immunother 59:629-33
Stojakovic, M; Tatari-Calderone, Z; Maric, C et al. (2010) Paradoxical arrest in lupus activity in BXSB mice with highly autoreactive T cells. Lupus 19:182-91
Maric, Maja; Barjaktarevic, Igor; Bogunovic, Branka et al. (2009) Cutting edge: developmental up-regulation of IFN-gamma-inducible lysosomal thiol reductase expression leads to reduced T cell sensitivity and less severe autoimmunity. J Immunol 182:746-50
Stojakovic, Milica; Salazar-Fontana, Laura I; Tatari-Calderone, Zohreh et al. (2008) Adaptable TCR avidity thresholds for negative selection. J Immunol 181:6770-8
Barjaktarevic, Igor; Vukmanovic, Stanislav (2008) Paternal cell immunization raises autoantibodies and improves pregnancy success in mice. Am J Reprod Immunol 60:497-500
Santori, Fabio R; Popmihajlov, Zoran; Badovinac, Vladimir P et al. (2007) TCR beta chain that forms peptide-independent alloreactive TCR transfers reduced reactivity with irrelevant peptide/MHC complex. J Immunol 178:6109-14
Ma, Jennifer S Y; Monu, Ngozi; Shen, David T et al. (2007) Protein kinase Cdelta regulates antigen receptor-induced lytic granule polarization in mouse CD8+ CTL. J Immunol 178:7814-21
Shen, David T; Ma, Jennifer S Y; Mather, Jacques et al. (2006) Activation of primary T lymphocytes results in lysosome development and polarized granule exocytosis in CD4+ and CD8+ subsets, whereas expression of lytic molecules confers cytotoxicity to CD8+ T cells. J Leukoc Biol 80:827-37
Radoja, Sasa; Frey, Alan B; Vukmanovic, Stanislav (2006) T-cell receptor signaling events triggering granule exocytosis. Crit Rev Immunol 26:265-90

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