Induction of maturation of human B-cell lymphomas in vitro. Morphologic changes in relation to immunoglobulin and DNA synthesis.

In vitro stimulation of cells from 8 non-Hodgkin's lymphomas comprising several histologic types with a tumor promotor (TPA) and with or without anti-immunoglobulins directed against the surface immunoglobulin of the tumor cells is reported. Morphologic transformation to immunoblastic and plasmablastic cells, but not to plasma cells, and induction of Ig and DNA synthesis were observed. A comparative analysis, including flow cytofluorometry, light microscopy combined with immunocytochemistry, and electron microscopy, suggests that the three events may not always be associated phenomena at the single-cell level even in monoclonal cell populations.