An immunomodulatory peptide derived from the thymus gland, approved in several countries for hepatitis B/C and studied for immune enhancement in cancer and infectious diseases.
A new radioimmunoassay (RIA) is described for the quantitation of thymosin alpha-1 (alpha-1). The assay employs an antiserum specific for the COOH-terminal half segment 15-28 of alpha-1, synthetic alpha-1-(15-28) as the hormone standard, and a radioi…
Thymosin alpha 1 induces the loss of PNA binding ability by subpopulation of thymic cells. This loss is probably due to an endocytic process. Nevertheless this disappearance is not a permanent one, suggesting a recycling of the PNA binding molecule.…
Levels of thymosin alpha I in the sera of 37 patients with Brazilian pemphigus foliaceus (BPF) were measured using a competitive binding radioimmunoassay. The values were compared with 19 patients with other forms of pemphigus, 13 relatives of patien…
Prothymosin alpha has been purified from human thymus and its amino acid sequence determined, except for a 15 amino acid segment including 10 glutamyl residues near the middle of the molecule. Like prothymosin alpha from rat thymus [A. A. Haritos, R.…
A model was developed in C3H mice to investigate the immunosuppressive effects of head and neck irradiation and to explore mechanisms for repair of the defects. Mice receiving 1200 rad (12 Gy) of head and neck irradiation showed significant depressio…
In the normal human brain, immunoreactive thymosin beta 4, a well-characterized thymic extract, was demonstrated specifically in the cell bodies and processes of a subset of interfascicular and satellite oligodendrocytes with their stained processes…
Thymosin alpha 1, an acidic 28-residue peptide, enhances immune function. We have described a radioimmunoassay for this thymic factor based on a rabbit antiserum raised against a thymosin alpha 1-(15-28) conjugate (Incefy et al., J. Immun. Meth. 1986…
Peripheral blood lymphocytes from patients with primary biliary cirrhosis previously have been reported to demonstrate reduced pokeweed mitogen-stimulated immunoglobulin synthesis and diminished function of suppressor T cells. To determine whether th…
Helper T cell activity of spleen cells from BDF1 mice is impaired by aging but is restored to a large extent by injection of thymosin alpha 1, a synthetic peptide consisting of 28 amino acid residues. Injection of an equimolar amount of the N14 (N-te…
An antiserum prepared against thymosin alpha 1, a hormone secreted by the thymus gland, effectively neutralized the AIDS-associated virus [HTLV-III/LAV (clone BH-10)] and blocked its replication in H9 cells. Reverse transcriptase activity and express…
Thymic peptide thymosin alpha 1 (10(-9) to 3 X 10(-7) M) is shown to inhibit the specific binding of [125I]VIP to rat blood mononuclear cells and liver plasma membranes. Thymosin alpha 1 was 160 and 6250 times less potent that VIP at inhibiting [125I…
The expression of interleukin 2 receptors (IL-2R) is a critical step leading to normal lymphocyte proliferation. Since thymosin fraction 5 (TF5), a thymic hormone preparation, enhances lymphoproliferative responses of human cells, we examined the eff…
Clones for human prothymosin alpha have been identified in cDNA libraries from staphylococcal enterotoxin A-stimulated normal human lymphocytes and from simian virus 40-transformed fibroblasts. The 1198-base-pair fibroblast clone has been sequenced.…
Forty-two male homosexuals and/or hemophiliacs with depressed helper/suppressor T-cell ratios were treated with one of three different doses of thymosin fraction 5 (TF5, 30, 60, and 120 mg), or a single dose of thymosin Alpha One (TA1, 600 micrograms…
Amongst 160 English haemophiliacs treated with clotting factor concentrates, abnormalities of T lymphocyte subset distribution (characterized by low T4/T8 ratios and high total T8 counts), low in vitro phytohaemagglutinin stimulation and raised serum…
To determine if patients with head and neck squamous cell carcinoma represent an appropriate population for immune reconstitution with thymosin alpha 1, leukocyte migration inhibition (LMI) in response to phytohemagglutinin was measured in 24 previou…
Thymosin alpha 1 is able to act in vitro to stimulate T-cell precursors and to induce surface markers. The initial mechanism by which alpha 1 activates T cells could be the binding of alpha 1 to cell membranes. Using a specific anti-alpha 1 antibody…
The effects of mediastinal irradiation (RT) on the numbers and functions of purified peripheral blood T-lymphocytes from patients with locally advanced non-small cell lung cancer were evaluated. The patients were candidates for a randomized trial to…
Thymosin alpha 1 was shown to prevent the 5-fluorouracil(5-FU)-induced bone marrow toxicity in BDF1 mice, as determined by the cellularity, haemopoietic stem cells (CFU-s) and granulocyte-macrophage colony forming unit (GM-CFU). Furthermore, thymosin…