ZAP-70 is expressed by a subset of normal human B-lymphocytes displaying an activated phenotype

J. C. Nolz, R. C. Tschumper, B. T. Pittner, J. R. Darce, N. E. Kay, Diane F. Jelinek

Research output: Contribution to journalArticlepeer-review

78 Scopus citations


The Syk family tyrosine kinase ZAP-70 is essential for normal T-cell development and signaling. Recently, leukemic cells from some patients with B-cell chronic lymphocytic leukemia (B-CLL) were shown to express ZAP-70. Owing to the prognostic value of B-CLL ZAP-70 expression, this phenotype may reflect intrinsic biological differences between the two subsets of disease. However, it remains unclear whether CLL-B cells aberrantly acquire ZAP-70 expression during the transformation process or whether ZAP-70 may be expressed under certain conditions in normal human B-lymphocytes. To discriminate between these two possibilities, we assessed ZAP-70 expression in normal human B-lymphocytes. Our data demonstrate that ZAP-70 is expressed in a subpopulation of tonsillar and splenic normal B-lymphocytes that express an activated phenotype. Furthermore, ZAP-70 expression can be induced in vitro upon stimulation of blood and tonsillar B cells. Finally, we show that phosphorylation of ZAP-70 occurs in tonsillar B cells with stimulation through the B-cell receptor. These results provide new insight into normal human B-cell biology as well as provide clues about the transformed cell in B-CLL.

Original languageEnglish (US)
Pages (from-to)1018-1024
Number of pages7
Issue number6
StatePublished - Jun 2005


  • B-CLL
  • B-lymphocytes
  • Lymphocyte activation
  • ZAP-70

ASJC Scopus subject areas

  • Hematology
  • Oncology
  • Cancer Research


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