Activation of cationic amino acid transport through system y correlates with expression of the T-cell early antigen gene in human lymphocytes.

Lysine influx (2 μM) into activated human B and T lymphocytes through transport systems y and yL was measured. In activated T cells very substantial activation of system y was detected; system yL was also activated in these cells but with a slower time course and to a smaller extent. No stimulation of either system was found in activated B cells. The time course of activation of system y precisely matched the expression of the T cell early antigen gene described by MacLeod et al, 1990. The functional significance of these observations with respect to L-arginine transport and nitric oxide synthesis in activated T lymphocytes is discussed. [ABSTRACT FROM AUTHOR]