A realistic approach to the sensitivity of PCR-DGGE and its application as a sensitive tool for the detection of clonality in cutaneous T-cell proliferations.

The practical value of the detection of clonality within the T-cell receptor gamma locus by polymerase chain reaction for the diagnosis of cutaneous T-cell lymphomas is well known. However, studies dealing with this subject so far, with special emphasis on the sensitivity of the technique in comparison to, for example, Southern blotting have used mixtures of DNA in various concentrations instead of using mixtures of the cells involved, which would reflect the in vivo situation in a more realistic scope. The purpose of this study was therefore to determine the sensitivity and the limitations of the PCR assay by dilution experiments, using mixtures of cells.

Various cytokines modulate ICAM-1 shedding on melanoma- and CTCL-derived cell lines: inverse regulation of ICAM-1 shedding in a Sézary cell line by interferon-gamma.

Background: Since soluble intercellular adhesion molecules 1 (sICAM-1) retain their ability to bind to their ligand, they can interfere in cell-mediated immunosurveillance.

Objective: We studied the impact of various cytokines on ICAM-1 release of several tumor cell lines.

Methods: Two melanoma cell lines (M19, M26), 1 B lymphoblastoid cell line (Daudi), 1 erythroleukemia cell line (K562), 1 Sézary-cell-derived cell line (SeAx), 1 cell line derived from a mycosis fungoides lesion (MyLa) and normal peripheral blood mononuclear cells (PBMC) were grown in the presence of interferon gamma (IFN-gamma), IFN-alpha, interleukin-2 (IL-2), IL-6 and tumor necrosis factor alpha (TNF-alpha) in various concentrations.