High-affinity binding of melatonin by human circulating T lymphocytes (CD4+).
This paper shows the presence of high-affinity binding sites for melatonin in human circulating T lymphocytes, but not in B lymphocytes. The binding of melatonin to T cells was dependent on time, stable, reversible, saturable, specific, and inversely correlated to the production of melatonin, expressed as the nocturnal 12 h production of its urinary metabolite 6-sulfatoxymelatonin. The affinity of these binding sites (Kd = 0.27 nM) suggests that they may recognize the physiological concentrations of melatonin in serum. Moreover, among the lymphocyte subpopulations studied, binding of melatonin was mostly found in CD4+ cells rather than in CD8+ cells. Results suggest that CD4+ cells may be the target of melatonin among the human circulating lymphocytes.
Gonzalez-Haba
M G
MG
Department of Medical Biochemistry and Molecular Biology, University of Seville School of Medicine, Spain.
Garcia-Mauriño
S
S
Calvo
J R
JR
Goberna
R
R
Guerrero
J M
JM
D000328:Adult; D001402:B-Lymphocytes / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism; D006801:Humans; D008550:Melatonin / Q000031:analogs & derivatives / Q000378:metabolism* / Q000652:urine
C054513:6-sulfatoxymelatonin; D008550:Melatonin