RT Journal Article
SR Electronic
T1 Expression and tyrosine phosphorylation of the T cell receptor zeta-subunit in human thymocytes.
JF The Journal of Immunology
JO J. Immunol.
FD American Association of Immunologists
SP 1142
OP 1148
VO 146
IS 4
A1 Vivier, E
A1 Morin, P
A1 Tian, Q S
A1 Daley, J
A1 Blue, M L
A1 Schlossman, S F
A1 Anderson, P
YR 1991
UL http://www.jimmunol.org/content/146/4/1142.abstract
AB Recent evidence suggests that the zeta-subunit of the TCR complex plays a critical role in transducing signals initiated by the Ag receptor heterodimer. Because thymic maturation involves specific interactions between the TCR complex and thymic stromal cells, the zeta-subunit has been postulated to also play a role in this process. To assess the potential for zeta to contribute to thymocyte maturation, we have used an anti-zeta mAb (TIA-2) to quantitate its expression in mature (CD3bright) and immature (CD3dim and CD3-) populations of human thymocytes. Using both flow cytometric and immunoblotting analysis, we found that the relative expression of TCR-zeta varied directly with the surface expression of CD3. Importantly, TCR-zeta was detected in the majority of CD3- thymocytes, indicating that its expression precedes the surface appearance of CD3:TCR. In thymocytes, TCR-zeta was found to be constitutively phosphorylated on tyrosine residues. The relative expression of phospho-zeta varied directly with the maturational stage of the thymocyte, with the mature (CD3bright), single positive cells accounting for most of the phospho-zeta found in the human thymus. The expression of phospho-zeta could be significantly increased by activating thymocytes with mAb reactive with either CD3 or CD2. These results suggest that TCR-zeta is functionally linked to the major thymocyte activation receptors.