Heat Shock Protein-90 Inhibitors Enhance Antigen Expression on Melanomas and Increase T Cell Recognition of Tumor Cells

In an effort to enhance antigen-specific T cell recognition of cancer cells, we have examined numerous modulators of antigen-expression. In this report we demonstrate that twelve different Hsp90 inhibitors (iHsp90) share the ability to increase the expression of differentiation antigens and MHC Class I antigens. These iHsp90 are active in several molecular and cellular assays on a series of tumor cell lines, including eleven human melanomas, a murine B16 melanoma, and two human glioma-derived cell lines. Intra-cytoplasmic antibody staining showed that all of the tested iHsp90 increased expression of the melanocyte differentiation antigens Melan-A/MART-1, gp100, and TRP-2, as well as MHC Class I. The gliomas showed enhanced gp100 and MHC staining. Quantitative analysis of mRNA levels showed a parallel increase in message transcription, and a reporter assay shows induction of promoter activity for Melan-A/MART-1 gene. In addition, iHsp90 increased recognition of tumor cells by T cells specific for Melan-A/MART-1. In contrast to direct Hsp90 client proteins, the increased levels of full-length differentiation antigens that result from iHsp90 treatment are most likely the result of transcriptional activation of their encoding genes. In combination, these results suggest that iHsp90 improve recognition of tumor cells by T cells specific for a melanoma-associated antigen as a result of increasing the expressed intracellular antigen pool available for processing and presentation by MHC Class I, along with increased levels of MHC Class I itself. As these Hsp90 inhibitors do not interfere with T cell function, they could have potential for use in immunotherapy of cancer

Entrepreneurship, Self-Employment and Business Data: An Introduction to Several Large, Nationally-Representative Datasets

Only a few large, nationally-representative datasets include information on both the owner and the business. We briefly describe several of the most respected and up-to-date sources of data on entrepreneurs, the self-employed, and small businesses. More information including estimates of recent trends in business ownership and performance (e.g. survival rates, sales, employment, payroll, profits and industry) from these datasets is contained in Fairlie and Robb (2008)

LSST Science Book, Version 2.0

A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over 20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a total point-source depth of r~27.5. The LSST Science Book describes the basic parameters of the LSST hardware, software, and observing plans. The book discusses educational and outreach opportunities, then goes on to describe a broad range of science that LSST will revolutionize: mapping the inner and outer Solar System, stellar populations in the Milky Way and nearby galaxies, the structure of the Milky Way disk and halo and other objects in the Local Volume, transient and variable objects both at low and high redshift, and the properties of normal and active galaxies at low and high redshift. It then turns to far-field cosmological topics, exploring properties of supernovae to z~1, strong and weak lensing, the large-scale distribution of galaxies and baryon oscillations, and how these different probes may be combined to constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at http://www.lsst.org/lsst/sciboo

Effect of Hsp90 inhibition on MU89 growth.

<p>A WST assay was used to assess cell numbers in control and Hsp90-inhibitor treated tumors. WST levels were assayed at time zero and after 3 days. Cells were treated with the indicated Hsp90 inhibitors at the doses indicated. Percent growth was calculated as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0114506#s2" target="_blank">Methods</a> and is plotted on the left y-axis. Data represent the average and standard deviation of triplicate wells. The level of Melan-A/MART-1 (geometric mean), as assayed by intracellular staining and flow cytometry, is shown for comparison on the right y-axis. The data for Melan-A/MART-1 staining are from one representative experiment.</p

Effect of Hsp90 Inhibitors on Melan-A/MART-1 promoter.

<p>Data shown are flow cytometry-generated histograms of EGFP production in reporter cell lines with EGFP linked to the Melan-A/MART-1 promoter. In each histogram, the thin line curve represents the untreated control, and bold line is Hsp90 inhibitor treated cells. In each case, the reporter cells were treated for three days prior to assessing EGFP-related fluorescence. Data are from one representative experiment. The first and third columns are low antigen A375 cells and the second and fourth columns are high antigen-expressing MM96L+ cells. Doses of Hsp90 inhibitor used are listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0114506#pone-0114506-t001" target="_blank">Table 1</a>.</p