Leukemic cells from progressive B-CLL respond strongly to growth stimulation in vitro.
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.
Department of Immunology, Karolinska Institute, Stockholm, Sweden.
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Aguilar-Santelises
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Mellstedt
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Jondal
D000368:Aged; D000369:Aged, 80 and over; D001402:B-Lymphocytes / Q000166:cytology* / Q000187:drug effects*; D002452:Cell Count; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D004273:DNA, Neoplasm / Q000096:biosynthesis; D005260:Female; D006133:Growth Substances / Q000494:pharmacology*; D006801:Humans; D007075:Immunoglobulin M / Q000502:physiology; D007376:Interleukin-2 / Q000494:pharmacology; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000473:pathology*; D008213:Lymphocyte Activation / Q000187:drug effects / Q000502:physiology; D008222:Lymphokines / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D013211:Staphylococcus aureus; D013268:Stimulation, Chemical
D004273:DNA, Neoplasm; D006133:Growth Substances; D007075:Immunoglobulin M; D007376:Interleukin-2; D008222:Lymphokines; C058162:low molecular weight-B cell growth factor