Effects of cholinergic agonists on the proliferation and protein synthesis in a cultured thymic epithelial cell line.
Thymic epithelial cells appear to release the humoral factors endowing precursors of T cells (thymus-dependent lymphocytes) with the capacity to differentiate and maturate into relatively mature T cells. We have separated the polypeptide fractions containing these factors from the culture supernatant of thymic epithelial cell line. Thymus is reported to be innervated by autonomic nervous system from the prenatal to the pubertal period. But the physiological significance of the nervous system in this lymphoid organ remains obscure. And the modulator of the epithelial cell functions, namely, production and release of the bioactive polypeptides have never been clarified. We show here that acetylcholine (Ach) or carbamylcholine (Cch) enhanced the proliferation of thymic epithelial cells from the TAD3 cell line at preconfluent state, and the protein synthetic activity at confluent state. This phenomenon was completely suppressed by the pretreatment of alpha-bungarotoxin (alpha-BTx). These results suggest that nicotinic Ach-receptors exist on the epithelial cell surface membrane and that the differentiation and maturation of thymic lymphocytes are indirectly regulated by the activated functions of thymic epithelial cells stimulated with cholinergic agonists.
Tominaga
K
K
Kinoshita
Y
Y
Hato
F
F
Masudå
A
A
Matsuyama
M
M
D000818:Animals; D002038:Bungarotoxins / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects; D010277:Parasympathomimetics / Q000494:pharmacology*; D014176:Protein Biosynthesis; D051381:Rats; D011978:Receptors, Nicotinic / Q000187:drug effects / Q000502:physiology; D013950:Thymus Gland / Q000166:cytology / Q000187:drug effects*
D002038:Bungarotoxins; D010277:Parasympathomimetics; D011978:Receptors, Nicotinic