title: A B cell growth factor-like activity is secreted by cloned, neoplastic B cells.
abstract: Supernatants from synchronized clones of neoplastic B cells (BCL1) were found to contain a B cell growth factor (BCGFI)-like activity. The BCGF activity in the BCL1 supernatants (SN) could synergize with EL-4 SN in the late phases of an IL 1-dependent BCGF I assay (days 5 through 8). These SN did not contain any detectable BCGF II, IL, 1, or IL 2 activity. In contrast to EL-4-derived BCGF I, which has a m.w. of approximately 18,000, the BCL1-BCGF activity has a m.w. of approximately 4500. Because the BCGF activity in BCL1 SN fluctuates with cell cycle in synchronized cultures, this BCL1-BCGF may play an auto-stimulatory role in B cell proliferation.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000378:metabolism*; D002453:Cell Cycle; D002471:Cell Transformation, Neoplastic / Q000276:immunology / Q000378:metabolism*; D002999:Clone Cells / Q000378:metabolism; D004357:Drug Synergism; D006133:Growth Substances / Q000302:isolation & purification / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D007375:Interleukin-1 / Q000502:physiology; D015847:Interleukin-4; D007700:Kinetics; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000302:isolation & purification / Q000378:metabolism* / Q000502:physiology; D051379:Mice; D008970:Molecular Weight; D013945:Thymoma / Q000276:immunology
chemical_list: D006133:Growth Substances; D007375:Interleukin-1; D008222:Lymphokines; D015847:Interleukin-4