TY - JOUR
T1 - B lymphocytes in humans express ZAP-70 when activated in vivo
AU - Cutrona, Giovanna
AU - Colombo, Monica
AU - Matis, Serena
AU - Reverberi, Daniele
AU - Dono, Mariella
AU - Tarantino, Vicenzo
AU - Chiorazzi, Nicholas
AU - Ferrarini, Manlio
PY - 2006/3
Y1 - 2006/3
N2 - ZAP-70 is a protein tyrosine kinase initially found in T and NK cells. Recently, this important signaling element was detected in leukemic B cells from a subgroup of patients with B cell chronic lymphocytic leukemia (B-CLL). In this study, ZAP-70 was detected in normal B cells from human tonsils, but not from peripheral blood. The cDNA sequence of B cell ZAP-70 was the same as that in T cells. Germinal center B cells and plasma cells had a substantial proportion of ZAP-70
+ cells, while memory and follicular mantle B cells, which contain low numbers of activated B cells, expressed relatively little ZAP-70. A cell fraction of IgD
+, CD38
+ B cells, which are comprised of many in vivo activated B cells, exhibited the highest levels of ZAP-70. Density gradient fractionation of tonsil B cells confirmed that ZAP-70 was not expressed by resting B cells, but was expressed by buoyant, in vivo activated B cells. In these B cells, the expression of ZAP-70 correlated with that of CD38 and not with that of CD5, a hallmark of B-CLL cells. B-CLL cells are activated cells and their ZAP-70 expression reflects a normal property of activated B cells populations rather than a neoplastic aberration.
AB - ZAP-70 is a protein tyrosine kinase initially found in T and NK cells. Recently, this important signaling element was detected in leukemic B cells from a subgroup of patients with B cell chronic lymphocytic leukemia (B-CLL). In this study, ZAP-70 was detected in normal B cells from human tonsils, but not from peripheral blood. The cDNA sequence of B cell ZAP-70 was the same as that in T cells. Germinal center B cells and plasma cells had a substantial proportion of ZAP-70
+ cells, while memory and follicular mantle B cells, which contain low numbers of activated B cells, expressed relatively little ZAP-70. A cell fraction of IgD
+, CD38
+ B cells, which are comprised of many in vivo activated B cells, exhibited the highest levels of ZAP-70. Density gradient fractionation of tonsil B cells confirmed that ZAP-70 was not expressed by resting B cells, but was expressed by buoyant, in vivo activated B cells. In these B cells, the expression of ZAP-70 correlated with that of CD38 and not with that of CD5, a hallmark of B-CLL cells. B-CLL cells are activated cells and their ZAP-70 expression reflects a normal property of activated B cells populations rather than a neoplastic aberration.
KW - Activated B cells
KW - B cells subsets
KW - B-CLL
KW - Human B lymphocytes
KW - ZAP-70
UR - http://www.scopus.com/inward/record.url?scp=33644953267&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33644953267&partnerID=8YFLogxK
U2 - 10.1002/eji.200526355
DO - 10.1002/eji.200526355
M3 - Article
C2 - 16482508
AN - SCOPUS:33644953267
VL - 36
SP - 558
EP - 569
JO - European Journal of Immunology
JF - European Journal of Immunology
SN - 0014-2980
IS - 3
ER -