Separation of polypeptides which induce a mitogen response of thymocytes from the culture supernatant of a thymic epithelial cell line.
To examine thymic hormonal factors, four polypeptide fractions (estimated molecular weight: I, 10 K; II, 7 K; III, 3 K; IV, 2.5 K) were separated from the culture supernatant of a rat thymic epithelial cell line by high-pressure liquid chromatography (HPLC) with a gel-filtration column. The effects of the fractions on response to mitogens of three small-lymphocyte subsets were studied. All fractions enhanced response to concanavalin A (Con A) of the lighter subset containing mainly immature thymocytes, but only fractions II and IV increased response to phytohemagglutinin (PHA) of the heavier subset containing relatively mature thymocytes. When fraction IV was subfractionated by reversed-phase HPLC, the polypeptides that enhanced response to Con A and PHA were separated into hydrophobic and hydrophilic subfractions, respectively. Fraction I was subfractionated by a similar method, and the inducing activity of Con A response was found in a relatively hydrophobic subfraction. These data suggested that the cell line secretes several kinds of bioactive polypeptides that affect the thymocytes at different stage of maturation.
Morioka
K
K
Kinoshita
Y
Y
Tominaga
K
K
Hato
F
F
Itoh
T
T
D000818:Animals; D002478:Cells, Cultured; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003470:Culture Media; D004848:Epithelium / Q000502:physiology; D008297:Male; D008934:Mitogens / Q000302:isolation & purification*; D010455:Peptides / Q000302:isolation & purification* / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D013950:Thymus Gland / Q000166:cytology / Q000502:physiology*
D003470:Culture Media; D008934:Mitogens; D010455:Peptides