Leukemic Cells From Progressive B-CLL Respond Strongly to Growth Stimulation in Vitro

Leukemia. 1994 Jul;8(7):1146-52.


Isolated leukemic B cells from patients with B-chronic lymphocytic leukemia (B-CLL) were tested for proliferative response in vitro to Staphylococcus Aureus strain Cowan 1 (SAC), IL-2, and low molecular weight (MW) BCGF. Patients were classified according to clinical stage and progressiveness. Ten of eighteen cell populations from patients with progressive B-CLL responded in vitro with a stimulation index (SI) > 20. Only 1/16 non-progressive patients had a proliferative but low response. Normal unfractionated tonsillar B cells responded to SAC and BCGF, whereas normal high buoyant density B cells were unresponsive. After 3 days of stimulation, responding B-CLL cells had multiplied and the B cells expressed CD5, CD19, and weakly CD21. No cells in the responding cultures exhibited CD3 or the EBV nuclear antigen EBNA-1. Cell maturation, measured as IgM secretion, was found in some, but not in all responding B-CLL cultures. Thus, B-CLL cells from patients with progressive disease have the capacity to respond to signaling through surface Ig receptors and to certain T-cell factors which was not the case for B-CLL cells from non-progressive patients. The pattern of in vitro response may be related to disease progression, reflecting a dependency of normal immunoregulatory mechanisms and/or a dysregulation of the growth control in the leukemic cells.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • B-Lymphocytes / cytology*
  • B-Lymphocytes / drug effects*
  • Cell Count
  • Cell Differentiation / drug effects
  • Cell Division / drug effects
  • DNA, Neoplasm / biosynthesis
  • Female
  • Growth Substances / pharmacology*
  • Humans
  • Immunoglobulin M / physiology
  • Interleukin-2 / pharmacology
  • Leukemia, Lymphocytic, Chronic, B-Cell / pathology*
  • Lymphocyte Activation / drug effects
  • Lymphocyte Activation / physiology
  • Lymphokines / pharmacology
  • Male
  • Middle Aged
  • Staphylococcus aureus
  • Stimulation, Chemical


  • DNA, Neoplasm
  • Growth Substances
  • Immunoglobulin M
  • Interleukin-2
  • Lymphokines
  • low molecular weight-B cell growth factor