Impaired Ca2+ mobilization by X-linked agammaglobulinaemia (XLA) B cells in response to ligation of the B cell receptor (BCR)
| Autor: | R. E. Callard, H. C. Genevier |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1997 |
| Předmět: |
X Chromosome
Genetic Linkage Immunology B-cell receptor Receptors Antigen B-Cell Immunoglobulin light chain Cell Line chemistry.chemical_compound Cell surface receptor Agammaglobulinemia hemic and lymphatic diseases medicine Agammaglobulinaemia Tyrosine Kinase Immunology and Allergy Bruton's tyrosine kinase Humans Child B-Lymphocytes biology Tyrosine phosphorylation Gene rearrangement Original Articles Protein-Tyrosine Kinases medicine.anatomical_structure chemistry biology.protein Calcium Bone marrow Antibody |
| Popis: | SUMMARY XLA bone marrow samples were shown to contain B cells expressing IgM, and pre-B cells that express the μ-surrogate light chain (μψLC) complex, albeit at a reduced frequency to that found in normal bone marrow. Antibody ligation of μ heavy chain on these cells and an XLA B cell line did not induce a Ca2+ flux, whereas ligation of μ heavy chain on normal bone marrow cells, μψLC+ pre-B cell lines and an IgM+ B cell line did. The block in XLA B cells was not due to a defect in the basic mechanism of Ca2+ flux generation, as the cells responded well to thapsigargin. In addition, the defect did not affect T cells, which were shown to respond to CD3 antibody with a Ca2+ flux. Ligation of μ heavy chain on XLA bone marrow cells did, however, activate tyrosine kinases, resulting in tyrosine phosphorylation of a cellular protein with a molecular weight of approximately 115 kD. These results indicate that Btk may be necessary for the generation of the Ca2+ flux in response to ligation of μ heavy chain on B cells and μψLC+ pre-B. |
| Databáze: | OpenAIRE |
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