title: Terminal differentiation of cord blood lymphocytes induced by thymosin fraction 5 and thymosin alpha 1.
abstract: Cord blood lymphocytes (CBL) have been shown to be functionally immature compared with normal circulating adult lymphocytes (NAL). Differentiation of T cells is associated with changes in surface antigenic markers and in the pattern of purine degradative enzymes. Previous studies have demonstrated that thymosin fraction 5 (TMS-F5) and thymosin alpha 1 (TMS-alpha 1) can induce in vitro differentiation of murine T-cell precursors and human thymocytes. We have investigated the effects of TMS-F5 and TMS-alpha 1 on the pattern of the purine degradative enzymes adenosine deaminase, purine nucleoside phosphorylase, and ecto-5'-nucleotidase (5'NT) of CBL and on the phenotypic markers from the OKT series 3, 4, 8 and 11. Other than a significantly reduced level of 5'NT activity (P less than 0.001) and an elevated percentage of OKT4+ cells (P less than 0.01), CBL demonstrated the same immunological and biochemical patterns as NAL. Incubation of CBL with TMS-F5 (150 micrograms/ml) and TMS-alpha 1 (1 microgram/ml) for 40 h caused a significant rise in 5'NT level and decrease of cells positive for OKT4, resulting in a pattern characteristic of NAL. Thus TMS-F5 might induce the terminal differentiation of CBL, and TMS-alpha 1 seemed to be the active component.
authors.forename: A D
authors.initials: AD
authors.lastname: Ho
authors.forename: B
authors.initials: B
authors.lastname: Stehle
authors.forename: G
authors.initials: G
authors.lastname: Dietz
authors.forename: W
authors.initials: W
authors.lastname: Hunstein
authors.forename: A V
authors.initials: AV
authors.lastname: Hoffbrand
mesh_terms: D015720:5'-Nucleotidase; D000243:Adenosine Deaminase / Q000378:metabolism; D000328:Adult; D000911:Antibodies, Monoclonal; D002454:Cell Differentiation / Q000187:drug effects; D005312:Fetal Blood / Q000166:cytology* / Q000201:enzymology; D006801:Humans; D008214:Lymphocytes / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D009708:Nucleotidases / Q000378:metabolism; D011683:Purine-Nucleoside Phosphorylase / Q000378:metabolism; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D000077596:Thymalfasin; D013947:Thymosin / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; C033782:thymosin fraction 5; D013947:Thymosin; D011683:Purine-Nucleoside Phosphorylase; D009708:Nucleotidases; D015720:5'-Nucleotidase; D000243:Adenosine Deaminase; D000077596:Thymalfasin