title: Expression of Bruton's tyrosine kinase protein within the B cell lineage.
abstract: Defects in the gene encoding Bruton's tyrosine kinase (Btk), normally expressed in B cells, cause X-linked agammaglobulinemia (XLA). The phenotype of XLA is characterized by a lack of circulating B cells and immunoglobulin. It has been suggested that B cell maturation from the pre-B cell stage to more mature stages is dependent on the appropriate expression of this gene. The Btk mRNA is expressed in B cells and myeloid cells, but protein expression in relation to B cell maturation has not been determined. Moreover, expression of the Btk protein has so far only been investigated in human Epstein-Barr virus-transformed B cell lines, and in murine splenocytes and B cell lines. We have developed an antiserum which recognizes the human Btk protein and shown that normal human tonsillar B cells, peripheral blood monocytes and myeloid cells express the protein, whereas tonsil-derived T cells do not. We also show that the protein is present in early and mature human B cell lines, but is absent in terminally differentiated plasma cell lines. Furthermore, expression is reduced or absent in three B lineage cell lines derived from two patients with defined genetic mutations in Btk and suffering from XLA.
authors: Cellular Immunology Unit, Institute of Child Health, London.
authors: H C
authors: HC
authors: Genevier
authors: S
authors: S
authors: Hinshelwood
authors: H B
authors: HB
authors: Gaspar
authors: K P
authors: KP
authors: Rigley
authors: D
authors: D
authors: Brown
authors: S
authors: S
authors: Saeland
authors: F
authors: F
authors: Rousset
authors: R J
authors: RJ
authors: Levinsky
authors: R E
authors: RE
authors: Callard
authors: C
authors: C
authors: Kinnon
mesh_terms: D000077329:Agammaglobulinaemia Tyrosine Kinase; D001402:B-Lymphocytes / Q000166:cytology / Q000201:enzymology*; D001483:Base Sequence; D015153:Blotting, Western; D002454:Cell Differentiation; D017931:DNA Primers / Q000737:chemistry; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D010950:Plasma Cells / Q000201:enzymology; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D017931:DNA Primers; D012333:RNA, Messenger; D011505:Protein-Tyrosine Kinases; D000077329:Agammaglobulinaemia Tyrosine Kinase; C000625949:BTK protein, human