Production of colony-stimulating activity by normal and neoplastic human B lymphocytes

Blood. 1987 May;69(5):1340-7.

Abstract

Normal human B cells were purified from peripheral blood or tonsils and tested for their ability to release colony-stimulating activity (CSA) in short-term cultures. The target cells used in the CSA assays were from peripheral blood or bone marrow. Unstimulated B cells produced CSA in amounts similar to those present in the GCT-conditioned medium used as a positive control. The B cell-derived CSA predominantly promoted the growth of colonies that contained macrophages alone or macrophages and granulocytes. CSA eluted in a single peak from a G-75 Sephadex column with an approximate molecular weight (mw) of 65 to 70 kilodaltons (kd). Fractionation of tonsil B lymphocytes on Percoll density gradients showed that large B cells, probably already activated in vivo, were the main source of CSA. By contrast, small, resting B cells recovered from a different fraction of the Percoll gradient released minimum amounts or no CSA. However, these B cells became CSA producers following stimulation with Staphylococcus aureus Cowan (SAC) in vitro. B cells purified from the peripheral blood of nine out of 12 patients with B-cell chronic lymphocytic leukemia (B-CLL) also released CSA in vitro in the absence of stimuli. These findings suggest that by releasing CSA, B cells may have a role in the regulation of hematopoiesis and in the control of the inflammatory process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, Surface / analysis
  • B-Lymphocytes / metabolism*
  • Cells, Cultured
  • Colony-Stimulating Factors / biosynthesis*
  • Colony-Stimulating Factors / isolation & purification
  • Hematopoiesis
  • Humans
  • Inflammation / blood
  • Leukemia, Lymphoid / blood
  • Lymphocyte Activation
  • Molecular Weight
  • Neoplastic Stem Cells / metabolism*
  • Palatine Tonsil / cytology

Substances

  • Antigens, Surface
  • Colony-Stimulating Factors