Flavopiridol induces apoptosis and caspase-3 activation of a newly characterized Burkitt's lymphoma cell line containing mutant p53 genes.

Burkitt's lymphoma cell lines have been important in vitro models for studying the pathogenesis of Burkitt's lymphoma (BL) and for exploring new treatment strategies. A new EBV(-) Burkitt's lymphoma cell line (GA-10) was established from a patient with a clinically aggressive, chemorefractory BL and characterized. Although functional p-glycoprotein could not be demonstrated by dye-efflux assays, both p53 genes were mutated in the GA-10 cells, perhaps contributing to the resistant phenotype of the original neoplasm.

Mutational analysis of the alpha subunit of the human interleukin-3 receptor.

The alpha subunit of the human interleukin-3 receptor (IL-3R alpha) is a 70-kD glycoprotein member of the hematopoietin receptor superfamily. This protein associates with a beta subunit common to the receptors for IL-5 and granulocyte-macrophage colony-stimulating factor (GM-CSF) to form a high-affinity receptor for IL-3. To identify regions of IL-3R alpha critical for ligand binding and receptor function, cDNAs encoding mutant receptors were generated and expressed in COS cells along with the beta subunit.

Quantitation of interferon-induced Mx protein in whole blood lysates by an immunochemiluminescent assay: elimination of protease activity of cell lysates in toto.

Due to the rapidly expanding usage of interferons and its costliness of therapy, it is important to evaluate the clinical efficacy of the various interferons. Directly assaying circulating interferon is technically quite difficult. Here, we present an alternate method to evaluate interferon therapy by assaying a unique protein, called Mx protein, which is a 78 kDa cytoplasmic protein selectively induced by type-1 interferon in human leukocytes.

Structure/function studies on vascular cell adhesion molecule-1.

Vascular cell adhesion molecule-1 (VCAM1) is a member of the immunoglobulin (Ig) superfamily which interacts with the integrin very late antigen-4 (VLA4). The VCAM1/VLA4 interaction mediates both adhesion and signal transduction and is thought to play an important role in inflammatory and immune responses in vivo. The major form of human VCAM1 contains seven extracellular Ig-like domains, with domain 1 designated as the most N-terminal.

Expression and functional characterization of a soluble form of vascular cell adhesion molecule 1.

Vascular cell adhesion molecule 1 (VCAM1) is a leukocyte adhesion molecule induced on human endothelium in vitro and in vivo by inflammatory stimuli. A truncated cDNA for VCAM1 was constructed, stably expressed in Chinese Hamster Ovary (CHO) cells, and the secreted recombinant soluble form of VCAM1 (rsVCAM1) purified to homogeneity by immunoaffinity chromatography. Immobilized rsVCAM1 is a functional adhesion protein, and selectively binds only VLA4-expressing cells, including human B and T lymphocytes, NK cells, and certain lymphoblastoid cell lines.