A comparative study of human cell lines derived from patients with lymphoma, leukemia and infectious mononucleosis.Membrane properties, ultrastructure, and surface morphology

Abstract

The membrane properties of different cultured lymphoid cell lines were studied using Concanavalin A (Con A) cap-forming ability and agglutinability and scanning electron microscopy (SEM) as probes. In addition, enzyme content and ultrastructural features were characterized by cytochemistry and transmission electron microscopy. Cell lines derived from patients with infectious mononucleosis (IM line), Hodgkin's lymphoma (LB-129), African and non-African Burkitt's lymphoma (Bu-4, Raji and DG-75) and acute lymphoblastic leukemia (Molt-4) were compared. Cells derived from patients with Burkitt's lymphoma were spherical in shape, had a relatively uniform morphology, showed abundant lipid droplets, and exhibited a low Con-A cap-forming ability. The EBV (Epstein-Barr Virus) genome negative, DG-75 cells derived from a patient with non-African Burkitt's lymphoma were similar to Bu-4 and Raji in many respects, but showed a high cap-forming ability. Cells from IM and LB-129 lines had a less stereotyped morphology and differed from the Burkitt's lymphoma cells in their growth characteristics, response to Con A, and ultra-structure. Cells were either rounded or elongated with a “hand mirror” shape and lacked multiple cytoplasmic lipid droplets so typical of Burkitt's cells. Under SEM most cells from the above lines had varying numbers of microvilli, while IM and LB-129 also displayed marginal ruffles, some blebs, and rare uropods. All the above mentioned cell lines were readily identified as B lymphocyte in type by immunologic methods, but DG-75 cells lacked EBNA (EBV-determined nuclear antigen) and EBV receptors. The Molt 4 cells derived from a patient with lymphoblastic leukemia were different in all respects. They were identified as T lymphocytes and displayed relatively smooth surfaces with few microvilli. The significance of these findings is discussed and it is suggested that some of the different membrane properties exhibited may be useful in characterizing the various established cultured lymphoid cells.