Automated data acquisition by confocal laser scanning microscopy and image analysis of triple stained immunofluorescent leukocytes in tissue.

The aim of the study was to develop a novel system permitting automated analysis of multicolor immunofluorescence-staining of cells in solid tissues which would be comparable to the analytical capacity of flow cytometry. In the user friendly automated data acquisition and image processing system which was established, the software includes a set of pre-defined processing steps for improved object identification and can be either interactive or fully automatic. As with multi color flow cytometry, stained cells can be analyzed in a fully automated manner regardless of tissue type. The software organizes computerized sample movement, autofocus, laser readjustment, data capture and storage as well as calculation. Data are presented as histograms indicating the staining intensity and frequency of each antigen, and in dotplots with each channel plotted against the other. The calculated statistics give information about how many of the cells are single-, double- or triple-reactive and how intensely they react with the respective antibodies. Comparison of data generated by this automated fluorescence confocal laser scanning microscopy (AF-CLSM) with flow cytometry using triple stained peripheral blood lymphocytes revealed a highly significant correlation between the methods (P<0.001). A correlation was also observed when sections triple stained for anti-CD45, -CD3 and -CD8 were analyzed by AF-CLSM and the data were compared to visual/manual cell counting (P<0.01). The AF-CLSM system permits for the first time, fast (online) and reproducible analysis of immunofluorescence staining of an unlimited number of cells in tissue sections. The software, including a manual, is available for a small fee to cover the costs of printing and postage.

MHC-class-I expression in human breast cancer correlates with nuclear localization of the 90 kDa heat-shock-protein.

Breast cancer cells frequently exhibit a reduction in expression of major-histocompatibility-complex (MHC) class I proteins which blocks cytotoxic T-lymphocyte (CTL) mediated apoptosis. Recent studies indicate that the 90 kD heat-shock-protein (HSP90) plays a major role in the transfer of antigenic peptides to the MHC class I complex. HSP90 is a molecular chaperone which is involved in signal transduction and regulation of apoptosis. Since HSP90 is described to be elevated in breast cancer, its relationship with MHC class I expression was investigated. Using immunohistochemistry we analyzed the expression and localization of HSP90 and MHC class I in 17 human breast tumors. Positive correlation (p < 0.025) between strong nuclear staining for HSP90 and high MHC class I expression was observed. In tumors with reduced MHC class I expression, no nuclear localization of HSP90 was detectable. These findings lead to the hypothesis that tumor cells with high MHC class I expression and susceptibility to CTL action may escape apoptosis by a mechanism which involves increased nuclear HSP90.

Differential expression of interleukin-15, a pro-inflammatory cytokine and T-cell growth factor, and its receptor in human prostate.

BACKGROUND: Pro-inflammatory interleukin (IL)-15 plays a major role in host defense and chronic inflammation by stimulating T-lymphocyte recruitment and growth. Expression of IL-15 and IL-15 receptor (IL-15R) in human prostate was examined. METHODS: Normal and benign hyperplastic (BPH) prostate specimens (n = 23) were analyzed for IL-15 and IL-15Ralpha-chain expression by immunohistochemistry and Real-Time-PCR/RT-PCR. Regulation of prostatic stromal cell (PSC) IL-15 mRNA and effect of IL-15 on prostatic cell growth were analysed in vitro. RESULTS: In normal prostate, anti-IL-15 and anti-IL-15Ralpha-chain reactivity were restricted to smooth muscle and stromal cells. However, in BPH, in addition epithelial cells frequently exhibited discrete anti-IL-15R and often intense, membranous anti-IL-15 reactivity. IL-15/IL-15R mRNA were detected in all prostatic cells types. In BPH tissues, IL-15 mRNA content was variable (15-fold). IL-15 mRNA synthesis of PSC was significantly up-regulated by IFN-gamma. Furthermore IL-15 strongly stimulated the growth of BPH-T-lymphocytes and weakly that of carcinoma cell lines, but not of stromal cells. CONCLUSIONS: Overexpression of IL-15 and IL-15Ralpha-chain in BPH and massive proliferation of BPH-T-lymphocytes induced by IL-15 suggest a role for IL-15 in prostatic inflammation. Since IFN-gamma, a T-lymphocyte product, stimulates prostatic IL-15 production; chronic inflammation might be triggered by this paracrine loop.