LSP1 regulates anti-IgM induced apoptosis in WEHI-231 cells and normal immature B-cells.
Mol Immunol
; 36(6): 349-59, 1999 Apr.
Article
em En
| MEDLINE
| ID: mdl-10443999
ABSTRACT
Expression of LSP1, a 330 amino acid intracellular phosphoprotein, is restricted to lymphocytes, macrophages and neutrophils. In B-lymphoma cell lines LSP1 co-caps with membrane IgM after stimulation with anti-IgM. We used the LSP1+ B-lymphoma cell line WEHI-231/89 and normal lipopolysaccharide treated immature B-cells from Lsp1-/- and wild type mice to determine a role for LSP1 in signaling through membrane IgM. WEHI-231/89 cells were transfected with a truncated LSP1 protein containing the COOH-terminal residues 179-330. The three transfectants expressing the LSP1 truncate were significantly more susceptible to anti-IgM induced apoptosis than the parental cells or G418r control cell lines, while anti-IgM induced growth arrest was not affected. Expression of the LSP1 truncate increased the extent of anti-IgM induced loss of mitochondrial membrane potential, delta(psi)m indicating that LSP1 acts at a early stage in BCR mediated apoptosis. Expression of the LSP1 truncate in WEHI-231/89 cells increased susceptibility to ionomycin induced apoptosis but had no effect on apoptosis induced by nocodazole, sorbitol, C2-ceramide or H2O2. A role for LSP1 in anti-IgM induced apoptosis was confirmed using normal immature B-cells from 129/SvJ-Lsp1-/- mice which were less susceptible to anti-IgM induced apoptosis than those isolated from wild-type 129/SvJ mice. These results suggest that LSP1 regulates a Ca2+-dependent step in the induction phase of anti-IgM mediated apoptosis.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Ligação ao Cálcio
/
Linfócitos B
/
Anticorpos Anti-Idiotípicos
/
Apoptose
Limite:
Animals
Idioma:
En
Revista:
Mol Immunol
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
Canadá