The L-428 cell line derived from nodular sclerosing Hodgkin's disease was verified to be a human female cell line with surface marker and morphologic characteristics similar to native Hodgkin's cells. Single cells were cloned and subcloned twice to determine the characteristics of the clonogenic L-428 Hodgkin's cell (resulting in a 10% cloning efficiency). Both mononuclear L-428 cells and classical Reed-Sternberg cells arose from solitary cells. The clonogenic cell was the mononuclear Hodgkin's cell, although small abortive colonies sometimes arose from classical binucleate Reed-Sternberg cells. Cytogenetic and phenotypic analysis supported the clonality of three subclones and indicated, among many findings, consistent abnormalities of the long arm of chromosome 7 (beta-chain of the T cell receptor) and 14q32 (Ig heavy chain). Distinctive abnormalities of cytogenetics, phenotyping and transforming growth factor-beta production were exhibited for each clone as well. These observations demonstrate the relationship of the continuum of malignant mononuclear and multinuclear Reed-Sternberg cells in this cell culture from nodular sclerosing Hodgkin's disease and suggest that a similar relationship exists in native Hodgkin's disease tissue. These observations also support the theory of clonality in Hodgkin's disease and suggest that in vivo contiguous metastasis in the L-428 Hodgkin's disease patient was most likely accomplished by a Ki-1 positive small mononuclear cell.

Aims-To determine the cellular origin of the most potent cytokine present in Hodgkin's disease, transforming growth factor (TGF)

Nodular sclerosing Hodgkin's disease is characterized by dense collagen fibrosis. Although transforming growth factorbeta (TGF-fl) is an important bifunctional growth factor for fibroblasts and is stored and released by many cells, it requires acidification to pH 2.0-3.0 before it becomes a biologically active growth factor. We show here that the L428 Hodgkin's cell releases a high molecular weight TGF that competes for the TGF-ft cell membrane receptor but not the TGF-a receptor. This growth factor is most active at physiologic pH and is 97% inactivated by acidification. Hodgkin's TGF is also inactivated by proteases and can be preserved by protease inhibitors. The Hodgkin's TGF can be separated from an autocrine growth factor using either column chromatography or electroelution from gels and is shown to have a molecular weight of -350,000. Incubation of the Hodgkin's TGF in SDS releases a 25,000-D protein with reduced biological activity but which cross-reacts with anti-TGF-ft IgG. We propose that L428 nodular sclerosing Hodgkin's disease fibrosis is mediated by a potent high molecular weight TGF-,B which, unlike 8 characterized to date, is secreted in a form most active at physiologic pH.

Recent evidence indicates that Reed-Sternberg (RS) cells from many cases of Hodgkin's disease have features of activated lymphocytes and that lymphokines from activated lymphocytes induce proliferation of L- 428 RS cells. It is shown here that a lymphokine similar to a lymphokine secreted by activated lymphocytes is secreted by L-428 cells. This lymphokine has a molecular weight approximately equal to 68,000 daltons, identical to glycosylated recombinant interleukin-4 (rIL-4), and cross-reacts with monoclonal anti-IL-4 in Western immunoblotting. This Hodgkin's cell growth factor (HCGF) is 100% neutralized by polyclonal anti-IL-4 antibodies and competes for the IL- 4 receptor. After acid-elution, the L-428 RS cell has been shown to have 3,396 +/- 120 high-affinity receptor sites/cell. HCGF competes with rIL-4 for this receptor and L-428 cells contain mRNA for IL-4. Although all evidence indicates that IL-4 is an important secreted autocrine growth factor for L-428 RS cells, anti-IL-4 has no effect on the sustained serum-free growth of these Hodgkin's cells, suggesting that either the IL-4 receptor and the IL-4 receptor-growth factor complex are protected from antibody inhibition or other mechanisms are responsible for the sustained proliferation of L-428 RS cells.

Acute tumor lysis syndrome developed in a 30-year-old man with non-Hodgkin lymphoma after dexamethasone administration. To the best of our knowledge, this case is the first one reported following single agent corticosteroid treatment.