CHARACTERIZATION OF 2 NOVEL PRE-B-CELL LINES (LK63 AND LILA-1) - POTENTIAL MODELS OF PRE-B-CELL DIFFERENTIATION
- Author(s)
- Salvaris, E; NOVOTNY, JR; WELCH, K; CAMPBELL, L; Boyd, AW;
- Details
- Publication Year 1992-06,Volume 16,Issue #6-7,Page 655-663
- Journal Title
- LEUKEMIA RESEARCH
- Publication Type
- Journal Article
- Abstract
- In this report we describe two newly isolated pre-B acute lymphoblastic leukaemia cell lines. Both cell lines lack EBV as detected by the EBNA-1 gene probed Southern-blots. Neither cell line expressed the B-cell-specific CD20 antigen on the cell membrane. However surface expression of CD20 was induced by phorbol ester (TPA) on both LiLa-1 and LK63 cell lines. Other pre-B and B-cell lines, such as Reh, Nalm-1, and BALL-1 did not exhibit these changes in phenotype. Previous immunoprecipitation studies have noted that a broad 50-55 kD band co-precipitates with the characteristic 33-37 kD CD20 protein. We demonstrate that, while the 33-37 kD CD20 species was undetectable on resting LiLa-1 and LK63 cells, in each case a 50-55 kD protein was immunoprecipitated by the CD20 antibody. However, the failure to detect any cell surface CD20-associated antigen on the control cells by immunophenotyping indicated that the CD20 epitope of the 50-55 kD molecule was not expressed on the cell surface. Following exposure to TPA the 50-55 kD species was reduced over 48-72 h while the level of the p33-37 CD20 protein was increased. Northern-blot analysis showed that the 50-55 kD protein was not a cryptic form of CD20 as the uninduced cells contained no detectable CD20 mRNA. The decrease of the 50-55 kD protein and the acquisition of the mature CD20 molecule were paralleled by a decline in proliferative activity in both cell lines. As expression of CD20 by normal pre-B cells also coincides with the cessation of cell division and maturation towards a mature B-cell phenotype, these cell lines appear to represent models for a discrete stage of B-cell differentiation which may be valuable in defining the signals regulating pre-B-cell proliferation.
- Publisher
- PERGAMON-ELSEVIER SCIENCE LTD
- Keywords
- ACUTE LYMPHOBLASTIC-LEUKEMIA; HUMAN LYMPHOCYTES-B; CD20; EXPRESSION; ACTIVATION; MOLECULE; PROTEIN; BP35; PROLIFERATION; ANTIGEN
- Publisher's Version
- https://doi.org/10.1016/0145-2126(92)90016-Z
- Terms of Use/Rights Notice
- Refer to copyright notice on published article.
Creation Date: 1992-06-01 12:00:00