A High-Throughput Screen for Inhibitors of the Hsp90-Chaperone Machine.

Hsp90 has emerged as a key chemotherapeutic target for the development of drugs for the treatment of cancer and neurodegenerative diseases. The shortcomings of many of the Hsp90 inhibitors that have made it to clinical trials have bolstered the need to identify new lead compounds with superior properties. Here, we describe a high-throughput screen for the identification of Hsp90 inhibitors based on the refolding of thermally denatured firefly luciferase.

Immunodominant West Nile Virus T Cell Epitopes Are Fewer in Number and Fashionably Late.

Class I HLA molecules mark infected cells for immune targeting by presenting pathogen-encoded peptides on the cell surface. Characterization of viral peptides unique to infected cells is important for understanding CD8(+) T cell responses and for the development of T cell-based immunotherapies. Having previously reported a series of West Nile virus (WNV) epitopes that are naturally presented by HLA-A*02:01, in this study we generated TCR mimic (TCRm) mAbs to three of these peptide/HLA complexes-the immunodominant SVG9 (E protein), the subdominant SLF9 (NS4B protein), and the immunorecessive YTM9 (NS3 protein)-and used these TCRm mAbs to stain WNV-infected cell lines and primary APCs.

High-throughput screen of natural product libraries for hsp90 inhibitors.

Hsp90 has become the target of intensive investigation, as inhibition of its function has the ability to simultaneously incapacitate proteins that function in pathways that represent the six hallmarks of cancer. While a number of Hsp90 inhibitors have made it into clinical trials, a number of short-comings have been noted, such that the search continues for novel Hsp90 inhibitors with superior pharmacological properties. To identify new potential Hsp90 inhibitors, we have utilized a high-throughput assay based on measuring Hsp90-dependent refolding of thermally denatured luciferase to screen natural compound libraries.

Gambogic acid, a natural product inhibitor of Hsp90.

A high-throughput screening of natural product libraries identified (-)-gambogic acid (1), a component of the exudate of Garcinia harburyi, as a potential Hsp90 inhibitor, in addition to the known Hsp90 inhibitor celastrol (2). Subsequent testing established that 1 inhibited cell proliferation, brought about the degradation of Hsp90 client proteins in cultured cells, and induced the expression of Hsp70 and Hsp90, which are hallmarks of Hsp90 inhibition. Gambogic acid also disrupted the interaction of Hsp90, Hsp70, and Cdc37 with the heme-regulated eIF2α kinase (HRI, an Hsp90-dependent client) and blocked the maturation of HRI in vitro.

Synthesis and evaluation of Hsp90 inhibitors that contain the 1,4-naphthoquinone scaffold.

High-throughput screening of a library of diverse molecules has identified the 1,4-naphthoquinone scaffold as a new class of Hsp90 inhibitors. The synthesis and evaluation of a rationally-designed series of analogues containing the naphthoquinone core scaffold has provided key structure-activity relationships for these compounds. The most active inhibitors exhibited potent in vitro activity with low micromolar IC(50) values in anti-proliferation and Her2 degradation assays.

Dietary alkaloids and the development of androconial organs in Estigmene acrea.

Male salt marsh moths, Estigmene acrea (Lepidoptera: Arctiidae), possess inflatable androconial organs called coremata. Prior to mating males form aggregations and inflate their coremata en masse. The communal display attracts additional males and females for the purpose of mating.