The overall goal of this research is the development of clinically efficacious compounds that can modulate the response of the immune system to HIV-1 infection by inhibition of T cell receptor (TCR) stimulated apoptosis of T cells. Such compounds could be used with current anti- retroviral therapies. In Phase I a cell-based assay will be developed for identification of antagonists of the Nur77 intracellular receptor, a specific mediator of apoptosis in T cells via TCR signaling. A cotransfection assay will be performed in T cells containing the transcriptional activation DNA binding site of Nur77 ligated 5 prime to the firefly luciferase reporter gene. The TCR will be stimulated by anti- CD3 MAb or SEB, activation of Nur77 will be determined by the generation of luminescence and measured in a microplate format luminometer. Specific aims for Phase I are 1) to establish the cell cultures and assay, 2) to screen a library of structurally diverse compounds, and 3) to determine if antagonists can inhibit apoptosis of HIV-infected peripheral blood mononuclear cells in vitro. Cyclosporin A which inhibits TCR stimulated apoptosis by prevention of the DNA binding activity of Nur77 will be used as a positive control.Proposed commercial application:Commercial applications in AIDS therapy are $2 billion in the U.S. A Nur77 antagonist may also be useful in preventing T-cell loss in chemotherapy or radiation. Other potential uses in diseases associated with excess programmed cell death which -include neurodegenerative diseases such as Parkinson's disease and amyotrophic lateral sclerosis, myelodysplastic syndromes, ischemic injuries such as occur in myocardial infarction and stroke, and toxin-induced liver disease.National Institute of Allergy and Infectious Diseases (NIAID)
