T-Cell-Specific Expression of Kinase-Defective Eph-Family Receptor Protein, EphB6 in Normal as well as Transformed Hematopoietic Cells

M Shimoyama, H Matsuoka, A Tamekane, M Ito… - Growth …, 2000 - Taylor & Francis
M Shimoyama, H Matsuoka, A Tamekane, M Ito, N Iwata, R Inoue, K Chihara, A Furuya…
Growth Factors, 2000Taylor & Francis
Although most kinase-defective growth factor receptor proteins are associated with
pathogenic conditions, a kinase-defective Eph-family receptor protein, EphB6, is expressed
in normal human tissues. We generated monoclonal antibodies specific for human EphB6 to
characterize its expression on human hematopoietic cells. A very small population of normal
human peripheral white blood cells (0.57±0.07%, n= 12) expressed EphB6. The EphB6-
positive cells were CD2+, CD7+, CD3+ and CD4+ or CD8+ lymphocytes, but they did not …
Abstract
Although most kinase-defective growth factor receptor proteins are associated with pathogenic conditions, a kinase-defective Eph-family receptor protein, EphB6, is expressed in normal human tissues. We generated monoclonal antibodies specific for human EphB6 to characterize its expression on human hematopoietic cells. A very small population of normal human peripheral white blood cells (0.57 ± 0.07%, n = 12) expressed EphB6. The EphB6-positive cells were CD2+, CD7+, CD3+ and CD4+ or CD8+ lymphocytes, but they did not express CD19 or CD11b. In human bone marrow, only 1.5 ± 0.19% of lymphocytes expressed EphB6. Compared with the expression in peripheral lymphocytes, prominent expression of EphB6 protein was demonstrated in CD4+CD8+ double-positive mouse thymocytes. The T-cell lineage-specific expression was strictly conserved in human leukemia/lymphoma cells. Among T-cell-derived leukemia cells, the expression level of EphB6 seemed to decrease with maturation of the cells. These results suggest that EphB6 expression is regulated in T-cell development.
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