In this proposal funds are requested for a for-cost extension for an NIH funded project at NYU School of Medicine to recover losses and delay in research time due to Hurricane Sandy under the Disaster Relief appropriations Act. This request is with the purpose to complete our proposed aims and objectives proposed in parent grant GM085586. This project described in the parent grant aims to understand how dynamic alterations and/or conformational changes at the T-cell receptor-peptide-MHC (TCR-pMHC) interface contribute to T-cell activation and to identify the mechanism that is responsible for communicating ligand engagement of TCR to CD3 signaling subunits. The central hypothesis of this application is that conformational changes and/or flexibility induced in the TCR upon ligand binding can be transmitted across the membrane to expose cytoplasmic domains in the CD3?/? chains, and that differences in conformational changes and/or flexibility are responsible for quantitative and/or qualitative differences in T-cell signaling. To test our hypothesis we have combined X-ray crystallography and nuclear magnetic resonance (NMR) experiments and non-synthetic amino acid incorporation combined with cross-linking experiments and fluorescence resonance energy transfer (FRET) to analyze the changes in the overall structural organization and conformation of TCR when binding to different pMHC. We expect that these studies will provide insight into the molecular mechanism of how ligand induced conformational changes at the pMHC-TCR interface translocate to the CD3 signaling complex to influence T-cell activation outcomes with a sensitivity and resolution that have not been possible before. An increased understanding of the structural biophysics of protein-protein interactions and of the propensity of structures to undergo conformational change will be of critical importance, particularly in the case of receptors involved in cell signaling. Furthermore, such biophysical studies will provide fundamental insights into protein structure and dynamics, explain how these features are used for specific signaling purposes and how the proteins function in distinct cellular environments. These results are expected to be of interest for the scientific community interested in receptor signaling. In addition, this basic knowledge will eventually allow us to design polypeptides or other agents that can be used to monitor and manipulate cell signaling events to guide the design of therapeutics and vaccines for cancer and autoimmune disease which afflict thousands of people.
We expect that our studies will provide insight into the molecular mechanism of how ligand-induced conformational changes in the T cell receptor influence T-cell activation outcomes with a sensitivity and resolution that has not been possible before. This information will prove useful in both understanding how receptor-mediated signaling is initiated and from a therapeutic point of view to modulate signaling through the T cell receptor pharmacologically to either increase the sensitivity of T-cells in patients with cancer or HIV or decrease the sensitivity in patients with autoimmune diseases (multiple sclerosis or diabetes).
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|Malecek, Karolina; Grigoryan, Arsen; Zhong, Shi et al. (2014) Specific increase in potency via structure-based design of a TCR. J Immunol 193:2587-99|
|Liu, Baoyu; Zhong, Shi; Malecek, Karolina et al. (2014) 2D TCR-pMHC-CD8 kinetics determines T-cell responses in a self-antigen-specific TCR system. Eur J Immunol 44:239-50|
|Wan, Qi; Kozhaya, Lina; Imberg, Keren et al. (2013) Probing the effector and suppressive functions of human T cell subsets using antigen-specific engineered T cell receptors. PLoS One 8:e56302|
|Zhong, Shi; Malecek, Karolina; Johnson, Laura A et al. (2013) T-cell receptor affinity and avidity defines antitumor response and autoimmunity in T-cell immunotherapy. Proc Natl Acad Sci U S A 110:6973-8|
|Malecek, Karolina; Zhong, Shi; McGary, Katelyn et al. (2013) Engineering improved T cell receptors using an alanine-scan guided T cell display selection system. J Immunol Methods 392:1-11|
|Wei, Fang; Zhong, Shi; Ma, Zhengyu et al. (2013) Strength of PD-1 signaling differentially affects T-cell effector functions. Proc Natl Acad Sci U S A 110:E2480-9|