Acetylcholine synthesis and muscarinic receptor subtype mRNA expression in T-lymphocytes.
We used a sensitive and specific radioimmunoassay for acetylcholine (ACh), and detected significant amounts of ACh in the blood of various mammals, including humans. About 60% of human blood ACh was localized in mononuclear leukocytes. Human leukemic T-cell lines, used as T-lymphocyte models, contained both ACh and choline acetyltransferase (ChAT) activity. Furthermore, ChAT mRNA and protein were detected in the T-cell line MOLT-3. Phytohemagglutinin, a T-cell activator, increased both synthesis and release of ACh by MOLT-3 cells. Muscarinic receptor subtype mRNA expression was confirmed in various T-cell lines. These findings indicate that ACh synthesized by ChAT in T-lymphocytes acts on the muscarinic receptors on lymphocytes in autocrine and/or paracrine pathways and suggest that ACh in blood functions as a modulator of T-cell-dependent immune responses.
Kawashima
K
K
Department of Pharmacology, Kyoritsu College of Pharmacy, Tokyo, Japan.
Fujii
T
T
Watanabe
Y
Y
Misawa
H
H
D000109:Acetylcholine / Q000096:biosynthesis* / Q000097:blood; D000818:Animals; D006801:Humans; D012333:RNA, Messenger / Q000378:metabolism*; D011863:Radioimmunoassay; D011976:Receptors, Muscarinic / Q000096:biosynthesis*; D013601:T-Lymphocytes / Q000378:metabolism* / Q000648:ultrastructure
D012333:RNA, Messenger; D011976:Receptors, Muscarinic; D000109:Acetylcholine