AID	Name	Type	Comment
504925	Activators of T cell receptors: Summary	summary

Normally activation of naive T cells requires two signals. 1. A signal through the T cell receptor (TCR) which provides antigen specificity to the response. 2. Signals through co-stimulatory molecules, which are necessary for proliferation, survival and cytokine production. In the absence of co-stimulatory signals T cells are not effectively activated, and may even be rendered anergic or unresponsive to subsequent signaling. This lack of costimulation has been shown in multiple model systems to be a major factor in the limited strength and effectiveness of anti-tumor T cell responses. The goal of this project is to identify small molecule compounds that will stimulate T cell activation in the presence of TCR signaling but in the absence of co-stimulatory signals, thereby allowing activation of naive T cells in the absence of co-stimulation. Identification of such compounds would have clear experimental and clinical applications in instances where desirable antigen-specific immune responses are not generated due to a lack of co-stimulation, for example in the generation of anti-tumor responses.

In collaboration between the National Cancer Institute and NIH Chemical Genomics Center, a high-throughput amenable screen was developed to discover small molecules that co-stimulate and activate human T cell receptors. The screen will be carried out using a novel homogeneous time resolved fluorescence energy transfer (HTRF) assay to measure production of the cytokine IL-2 by activated T cells and will be tested against the NIH Molecular Libraries Small Molecule Repository (MLSMR).

NIH Chemical Genomics Center [NCGC]
NIH Molecular Libraries Probe Centers Network [MLPCN]

MLPCN Grant: MH090820-01
Assay Submitter (PI): Richard Hodes, National Cancer Institute, NIH

Primary human leukocytes are incubated with a-CD3 beads and compounds for 48 hr. The amount of secreted IL-2 is then assayed with a HTRF IL-2 kit. The presence of IL-2 cytokine captures the detection reagents and brings the a-IL-2-K and a-IL-2-d2 into close proximity. Upon excitation with 320nm light, the europium cryptate is capable of transferring energy to acceptor molecules within close proximity, resulting in acceptor molecule emission at 665nm.

Compound Ranking:

1. Compounds are first classified as having full titration curves, partial modulation, partial curve (weaker actives), single point activity (at highest concentration only), or inactive. See data field "Curve Description". For this assay, apparent inhibitors are ranked higher than compounds that showed apparent activation.
2. For all inactive compounds, PUBCHEM_ACTIVITY_SCORE is 0. For all active compounds, a score range was given for each curve class type given above. Active compounds have PUBCHEM_ACTIVITY_SCORE between 40 and 100. Inconclusive compounds have PUBCHEM_ACTIVITY_SCORE between 1 and 39. Fit_LogAC50 was used for determining relative score and was scaled to each curve class' score range.

Grant Number: MH090820