This is a working overview of 胸腺素α1, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-02-11 and is reviewed periodically as new material appears.
Within the immune system, the peptide acts on several cell types rather than a single target. Reported activities include promotion of T-cell maturation, enhancement of natural killer cell activity, and modulation of cytokine production by dendritic cells and macrophages. Some of these effects appear to operate through toll-like receptor signaling, though the precise receptor-level mechanism remains debated. Whether the observed immune changes translate into clinical benefit is a separate question and depends on the indication studied.
The peptide was described in the 1970s as a component of thymic extracts, and early research focused on restoring immune function in immunodeficiency states. A synthetic version entered clinical development in the 1980s and is approved as a drug in several countries for conditions such as chronic hepatitis B and certain immunodeficiencies. Approval status varies widely by jurisdiction, and in the United States it is not an approved therapeutic. Regulatory and clinical positions differ, so statements about efficacy should be tied to specific indications and studies.
Thymosin alpha-1 is a synthetic peptide of 28 amino acids, corresponding to the N-terminal fragment of prothymosin alpha. Its sequence begins with acetylation at the N-terminus, a modification that affects stability and receptor interaction. The peptide is acidic, with a calculated isoelectric point near 4.2, and carries no disulfide bonds, so its secondary structure is largely flexible in solution. Molecular mass is approximately 3108 daltons. The native form was first isolated from bovine thymus tissue, while pharmaceutical material is produced by solid-phase peptide synthesis.
Thymosin alpha 1 is a synthetic 28-amino-acid peptide first isolated in 1966 from thymosin fraction 5, a bovine thymus extract. Its chain begins with an acetylated serine residue and ends with asparagine. The native peptide carries a molecular mass near 3,108 daltons. Researchers classify it as an immunomodulatory agent rather than a hormone with a single endocrine target. Early work framed it as a thymus-derived factor that supports T-cell maturation. The synthetic form used in research and clinical products matches the natural sequence.
Immune signaling studies link thymosin alpha 1 to Toll-like receptor pathways, particularly TLR2 and TLR9, on dendritic cells and other antigen-presenting cells. Activation of these receptors promotes maturation of T cells and increases natural killer cell activity. The peptide shifts cytokine output toward a T helper 1 profile, raising interferon gamma and interleukin 2 while modulating interleukin 10. Whether these effects translate into clinical benefit for any specific disease remains a subject of debate. Reported outcomes vary across trials and populations.
Thymosin alpha 1 is approved as a medicine in several countries, including Italy and China, for indications such as chronic hepatitis B and as an immune adjuvant. It is not approved by the United States Food and Drug Administration as a therapeutic product. In research settings the peptide appears in studies of sepsis, vaccine response, and oncology support, often with mixed or inconclusive results. The evidence base is uneven, and reviews note that many trials were small. Regulatory status therefore differs widely between jurisdictions.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic peptide, 28 residues | N-terminal fragment of prothymosin alpha |
| Molecular mass | About 3108 Da | Acetylated form |
| Isoelectric point | Near 4.2 | Acidic peptide |
| Appearance | White to off-white lyophilized powder | Common supplied form |
| Typical storage | -20 °C or below, dry | Solution stability is lower |
Thymosin alpha-1 is a synthetic 28-amino-acid peptide whose sequence was first identified in extracts of bovine thymus tissue during the 1970s. The chain carries an acetyl group on its N-terminal serine. Its acidic residue content is high, which produces strong water solubility and an isoelectric point well below neutrality. Material supplied for laboratory and clinical use is manufactured by solid-phase peptide synthesis rather than purified from animal tissue. Different salt forms, such as the acetate, alter the counter-ion content without changing the peptide backbone.
Whether the free 28-residue peptide circulates in human tissue remains debated. The best-documented human source is prothymosin alpha, a larger acidic protein that carries the sequence at its N-terminus. Reports of measurable peptide levels in serum and lymphoid tissue exist, yet some of that signal may come from cross-reacting fragments or from the parent protein. Most reviews therefore treat prothymosin alpha as the established human molecule and describe independent circulation of the small peptide as an unresolved question.
Immunological studies connect the peptide to multiple parts of the immune response. It has been reported to engage Toll-like receptor signaling, to promote dendritic cell maturation, and to influence the balance of T helper cell subsets. Changes in natural killer cell activity and in cytokine release appear in cell culture and animal models. These observations describe broad immunomodulatory behavior rather than a single defined receptor target, and the primary molecular interaction has not been settled.
Biologically, the peptide is studied mainly in the context of immune cell development and regulation. It is produced in the thymus and in several other tissues, and it appears to influence the maturation and activity of T cells and other immune populations. Laboratory work describes effects on cytokine production, on the balance between T cell subsets, and on the function of dendritic cells. Much of this evidence comes from cell culture and animal models, so the extent to which the same pathways operate in humans remains an open question.
Clinical interest has centered on chronic viral hepatitis, on immune restoration in various conditions, and on use as an adjuvant intended to improve responses to vaccines. Trials have reported mixed results, and regulatory status differs sharply between countries; in some places it is a prescription product, while elsewhere it is sold without an approved therapeutic indication. Because published studies vary widely in design, population, and endpoints, comparisons across them are difficult and no single conclusion covers the whole literature.
市售的胸腺素α1通常以冻干粉形式提供，溶解后用于注射。其氨基酸组成包括多个酸性残基，因此在中性pH下带负电荷。该肽可溶于水和生理盐水，但在有机溶剂中溶解度有限。储存条件通常为冻干状态下负20摄氏度，溶解后需冷藏并避免反复冻融。常见的同义词包括胸腺肽α1、thymalfasin和Tα1。
胸腺素α1（thymosin alpha 1，Tα1）是一种由28个氨基酸组成的酸性肽，N端被乙酰化，分子量约为3108道尔顿。该肽最早从牛胸腺组织提取物中分离，属于胸腺素组分5的一个成分。其序列在不同哺乳动物中高度保守，提示其具有基本的生物学功能。名称中的“α1”指其在电泳中的迁移位置，并非表示亚型编号。它既存在于胸腺，也存在于脾脏和淋巴结等免疫组织。
20世纪70年代，研究者从胸腺提取物中纯化出多种小肽，Tα1是其中被较早表征的一种。最初的制备依赖组织匀浆和层析步骤，产量低且成分复杂。随着固相肽合成技术成熟，实验室和工业界能够生产与天然序列一致的合成版本。合成肽的纯度可达95%以上，并可通过反相高效液相色谱和质谱进行鉴定。这一转变使研究不再依赖动物胸腺来源。
27 March – A report clears Conservative MP Bernard Jenkin of breaching COVID-19 laws over his attendance at a "wine and nibbles" event on the Parliamentary estate in December 2020, which the report describes as socially-distanced with "business and social elements". 28 March – Keir Starmer and Angela Rayner launch Labour's campaign for the 2024 United Kingdom local elections at an event in Dudley. Honours are conferred on businessman and senior Conservative Party treasurer Mohamed Mansour, Farming Minister Mark Spencer and Shipley MP Philip Davies, all of who receive knighthoods, while former ministers Tracey Crouch and Harriett Baldwin are awarded damehoods. The announcement comes as part of an honours list published at the start of the Parliamentary recess. The Assisted Dying for Terminally Ill Adults (Scotland) Bill, a bill to legalise assisted dying in Scotland and drafted by Liberal Democrat MSP Liam McArthur, is introduced into the Scottish Parliament. 29 March – Sir Jeffrey Donaldson resigns as leader of the Democratic Unionist Party after being charged with rape and other historical sexual offences. Gavin Robinson is appointed interim leader until a new leader can be elected. 30 March – First Minister of Northern Ireland Michelle O'Neill says she is determined the Stormont Assembly and Executive will continue to function following the resignation of Jeffrey Donaldson as DUP leader. 31 March – The UK government says it will work alongside the Northern Ireland Executive to maintain stability at Stormont.
== Future == Rönnberg has stated there will not be a sequel to Cry of Fear, as he considers the story completed. A remake was in development by Team Psykskallar, but production time and cost surpassed the original game and the project was abandoned. In August 2023, Rönnberg revealed he has been planning a new horror game, similar to both Afraid of Monsters and Cry of Fear, and the game was currently in the early writing phase.
Hot flashes have notably been reported in pregnant women, who have very high and constantly increasing levels of estradiol. When recurrence of hot flashes occurs with estradiol pellets, treated women often complain that their pellet has "run out". Such symptoms can be temporarily offset with the use of supplemental oral or transdermal estradiol. Following insertion of an estradiol pellet, levels of estradiol rapidly increase, remain constant for about 4 months, and then gradually decrease. A 25 mg subcutaneous estradiol pellet has been found to result in average estradiol levels of 90 pg/mL for 6 months, while two 25 mg pellets (50 mg total) resulted in estradiol levels of 180 pg/mL after 24 hours and levels of 100 to 120 pg/mL for 6 months. Higher-dose pellets resulted in estradiol levels for 50 mg of 100 pg/mL, for 75 mg of 140 pg/mL, and for 100 mg of 150 pg/mL. Estradiol levels are generally 50% higher than those of estrone, for an estradiol-to-estrone ratio of 1.5:1. Very high levels of estradiol of between 400 and 1,000 pg/mL have been observed in a small subset of women treated with estradiol pellets and notably in those experiencing symptoms of tachyphylaxis. Estradiol pellet implants have been studied in the treatment of prostate cancer in men.
Sources: en.wikipedia.org
== Ethical concerns == Advancements in recombinant DNA technology have revolutionized the idea of treating diseases through the reconstruction or replacement of faulty genes. Gene therapy is a technique that transplants normal genes into cells that contain missing or defective genes to correct genetic disorders. Nevertheless, several concerns have been raised about the efficacy of gene therapy due to its limited success rate in clinical trials. Over the years, immense efforts have been placed to fully understand vectors, viruses, and their communication with their host's immune system. However, not every defense system reacts the same. Some patients have experienced an "autoimmune-like" response where their body rejects this treatment. The heterologous genes are recognized as foreign to the host and can induce cytokine-mediated inflammatory responses that are ultimately destroyed by their cytotoxic T-cells. This has called into question the relationship between vector dosage and cellular toxicity as scientists recognize that inappropriate activation of these responses can cause severe side effects not only to the disease-infected cells but other healthy parts of the body. Genetic modification used to address concerns outside of medical necessities such as eye color, athletic abilities, intelligence, etc. is one example that has brought into question the ethicality of its purpose. Eugenics, which places a group of desirable human characteristics over another has led to fears of potential backlash toward genetically modified, or genetically unmodified individuals in society.
A diglyceride, or diacylglycerol (DAG), is a glyceride consisting of two fatty acid chains covalently bonded to a glycerol molecule through ester linkages. Two possible forms exist, 1,2-diacylglycerols and 1,3-diacylglycerols. Diglycerides are natural components of food fats, though minor in comparison to triglycerides. DAGs can act as surfactants and are commonly used as emulsifiers in processed foods. DAG-enriched oil (particularly 1,3-DAG) has been investigated extensively as a fat substitute due to its ability to suppress the accumulation of body fat; with total annual sales of approximately US$200 million in Japan since its introduction in the late 1990s till 2009.
=== EC 1.21.99 With unknown physiological acceptors === EC 1.21.99.1 EC 1.21.99.1: β-cyclopiazonate dehydrogenase EC 1.21.99.2: Now classified as EC 1.21.98.1, cyclic dehypoxanthinyl futalosine synthase. EC 1.21.99.3: thyroxine 5-deiodinase EC 1.21.99.4: thyroxine 5′-deiodinase EC 1.21.99.5: tetrachloroethene reductive dehalogenase
Sources: en.wikipedia.org
It corresponds to a fragment of the larger protein prothymosin alpha, which is present in many tissues. The isolated 28-amino-acid peptide was originally obtained from thymus preparations, and the pharmaceutical product is synthesized rather than extracted. The term therefore describes both a natural fragment and a manufactured drug substance.
Thymosin alpha-1 is a single defined 28-residue peptide, while the broader family includes unrelated peptides such as thymosin beta-4. The shared name reflects historical isolation from thymus tissue rather than a common structure. Confusion between the two is common in older literature.
No single pathway fully accounts for its reported effects. Several studies describe interaction with innate immune receptors and downstream cytokine changes, but the complete picture is not settled. Open questions remain about which effects occur at physiological concentrations.
It is a chain of 28 amino acids, with an acetyl group attached to the first serine residue. The synthetic version replicates this sequence. Its molecular mass is about 3,108 daltons.