1.
J Leukoc Biol
; 85(2): 268-77, 2009 Feb.
Article
in English
| MEDLINE
| ID: mdl-19008294
ABSTRACT
The metabolism of the amino acid L-arginine is emerging as a crucial mechanism for the regulation of immune responses. Here, we characterized the impact of L-arginine deprivation on T cell and macrophage (MPhi) effector functions: We show that whereas L-arginine is required unconditionally for T cell activation, MPhi can up-regulate activation markers and produce cytokines and chemokines in the absence of L-arginine. Furthermore, we show that L-arginine deprivation does not affect the capacity of activated MPhi to up-regulate L-arginine-metabolizing enzymes such as inducible NO synthase and arginase 1. Thus, our results show that to exert their effector functions, T cells and MPhi have different requirements for L-arginine.