Enhanced tumorigenicity of fibroblasts transformed with human herpesvirus 8 chemokine receptor vGPCR by successive passage in nude and immunocompetent mice.

The human herpes virus 8 (HHV-8)-encoded G protein-coupled chemokine receptor (vGPCR) has been implicated in the pathogenesis of Kaposi's sarcoma (KS), particularly because of its high constitutive signaling activity. Here, we used retroviral transduction to generate vGPCR-expressing 3T3 fibroblasts that are tumorigenic in nude mice, but as expected fail to induce tumors in their immunocompetent counterparts. However, tumor fragments obtained from nude mice grow progressively in immunocompetent BALB/c mice. Unexpectedly, vGPCR-expressing cells established from grafted tumor fragments gave rise to tumors in immunocompetent mice. These tumors exhibit a striking histological resemblance to KS including plump spindle cell morphology, a high degree of vascularization and brisk mitotic activity. High expression of vGPCR was confirmed in the cell lines and tumors using a newly developed vGPCR-specific monoclonal antibody. Finally, short interfering RNA directed at vGPCR abrogated or significantly delayed tumorigenesis in mice, demonstrating that the tumor development is specifically driven by vGPCR. This novel model for vGPCR-mediated oncogenesis will contribute to our understanding of the role of vGPCR in the pathogenesis of HHV-8 and may even be important in identifying critical molecular and epigenetic changes during tumor progression in vivo.

2,4,6-tris{2'[4'-(p-sulfophenyl)pyridyl]}-s-triazine: a new analytical reagent for the spectrophotometric determination of iron.

The sulfonated analog (TPPTZ-S) of 2,4,6-tris[2'-(4'-phenylpyridyl)]-s-triazine has been synthesized and its analytical utility investigated. The characteristics of the iron(II) complex of this ligand, including optimum conditions of formation, adherence to Beer's law and relative stability are described. Procedures for the quantitative determination of trace amounts of iron with TPPTZ-S are given. The analytical applicability of the reagent is illustrated by the successful determination of iron in E. coli and various beverage and beer samples.

Examination of the immunocompetent cell composition of contact dermatitis. Methods for liberating infiltrative dermal cells and measuring antigen-dependent chromatin birefringence in them.

Infiltrating cells from the dermis can be literated without serious damage to the cell surface by cautious enzymatic treatment in a cell extractor. A new rapid method has been worked out measuring lymphocyte stimulation by detecting changes in the chromatin's birefringence. The chromatin's anisotropy depended upon antigen concentration, incubation time at 37 degrees and was unsignificantly influenced by the samples' cellularity, between 4 x 10(5) and 4 x 10(7) cells per ml. Therefore, it was concluded that the stimulated lymphocytes in the eczematous infiltrate can be detected by birefringence after incubating for 30 min with proper concentrations of the antigen.