Specific Receptors for the Serum Thymic Factor (FTS) in Lymphoblastoid Cultured Cell Lines

• Published in: Proceedings of the National Academy of Sciences - PNAS 1980-05, Vol.77 (5), p.2861-2865
• Main Authors: Pléau, Jean-Marie, Fuentes, Vincent, Morgat, Jean-Louis, Bach, Jean-François
• Format: Article
• Language: English
• Subjects: B lymphocytes; Binding sites; Cell Line; Cell lines; Cultured cells; Hormones; Humans; Immunology; Insulin; Kinetics; Lymphocytes; Receptors; Receptors, Cell Surface - metabolism; T lymphocytes; T-Lymphocytes - metabolism; Temperature; Thymic Factor, Circulating - metabolism; Thymus Hormones - metabolism; Time Factors; Trypsin - metabolism
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.77.5.2861

The interaction of the synthetic serum thymic factor (FTS, "facteur thymique sérique") with human T lymphocytes from two established T cell lines (1301 and HSB2) was studied by using$[{}^{3}{\rm H}]{\rm FTS}$. At 30°C, in the presence of 10 nM labeled FTS, a steady state was observed within 120 min. Bound labeled FTS was dissociated by simultaneous addition of an excess of unlabeled FTS (dissociation constant Kd= 3 nM). The binding of$[{}^{3}{\rm H}]{\rm FTS}$was reduced to 10-20% when unlabeled FTS was added at 20 μg/ml (20 μM), but not when unrelated peptides or FTS analogues differing from FTS by only one amino acid residue were added. No FTS binding was detectable on B and null cell lines or on two T cell lines other than 1301 and HSB2. These data indicate that only certain T cell subsets possess receptors with high affinity and specificity for FTS.