Relationship between amino-acid metabolism and immune functions in human lymphocytes.
Amino-acid degradation, interleukin-2 (IL-2) production, and DNA synthesis were analysed in concanavalin A (ConA)-treated peripheral venous lymphocytes from healthy blood donors and in lymphocytes from patients after uneventful abdominal surgery. ConA augmented (14)CO(2) production from (U-(14)C) glutamine (492 +/- 44 vs. 2274 +/- 174 pmol/10(6) cells x 40 min(-1)) while it had little effect on (14)CO(2) production from (1-(14)C) leucine (132 +/- 8 vs. 161 +/- 17 pmol/10(6) cells x 40 min(-1)) compared with the respective controls. Similar effects on amino-acid degradation were observed in response to surgery. Glutamine but not leucine amplified IL-2 production from ConA-treated cells, and it was a prerequisite for DNA synthesis. In lymphocytes from operated patients, spontaneous incorporation of ((3)H) thymidine was higher on day 3 and day 6 (310 and 2660 cpm/10(6) cells) after surgery, compared with the pre-operative day (68 cpm/10(6) cells; median values). These results indicate 1) that glutamine is more critical than leucine for the immune function of T-lymphocytes, and 2) that lymphocytes from patients undergoing uneventful abdomional surgery have become stimulated in vivo. It is suggested that these cells may qualify as a suitable experimental model to study the metabolic basis for immunologic functions after antigenic stimulation in vivo.
Schäfer
G
G
Department of Medicine, Division of Gastroenterology and Endocrinology, University of Göttingen, Robert-Koch-Str-40, 3400 Göttingen, Germany.
Koch
B
B
Schröder
M T
MT
Stöter
M
M
Schenk
H D
HD
Schauder
P
P