If you have been reading about 免疫组织 and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-07-24. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Early work on thymic extracts in the 1960s described a heat-stable acidic fraction containing many polypeptides. Separation of that mixture yielded individual components, and thymosin alpha-1 was named as one of them on the basis of assays for T-cell activity. The first preparations came from calf thymus, while subsequent research and clinical material has been chemically synthesized. Nomenclature in older papers is inconsistent, and the same peptide sometimes appears under different designations, which complicates literature searches.
Most published studies on thymosin alpha-1 report changes in immune measurements rather than clinical outcomes, and findings differ across designs and populations. Whether the peptide signals through one defined receptor or through several less specific interactions remains an open question. Its reported circulation half-life of a few hours complicates comparison of dosing schedules across trials. Mechanistic claims are frequently drawn from isolated cell cultures, and how far those results extend to whole organisms is unresolved.
| Property | Value | Notes |
|---|---|---|
| Molecular mass | ≈3,108 Da | Synthetic 28-residue peptide |
| Amino acid count | 28 | N-terminal serine carries an acetyl group |
| Appearance | White to off-white powder | Lyophilized solid |
| Water solubility | Freely soluble | Dissolves in aqueous buffer |
| Common synonyms | Thymalfasin; Tα1 | Thymalfasin is the international nonproprietary name |
The peptide is generated in cells by cleavage of prothymosin alpha, a larger acidic protein encoded by the PTMA gene. Prothymosin alpha is expressed in many tissues, not only in the thymus, and its functions include nuclear roles in chromatin-related processes. The 28-residue fragment corresponds to the N-terminal portion of that precursor. How the cleavage occurs and how the fragment's concentration is regulated remain open questions; circulating amounts are small and difficult to measure reliably with routine assays.
Thymosin alpha 1 is a short peptide first isolated from bovine thymus tissue in the early 1970s during fractionation work aimed at identifying factors that influence T cell development. It belongs to a family of acidic thymic peptides, and the original preparations contained several components that were later separated by chromatography. The compound is now produced synthetically rather than extracted from tissue, which removes batch variability tied to animal sourcing. Researchers describe it as an immunomodulatory peptide because laboratory studies show effects on several cell types of the innate and adaptive immune systems.
Clinical research has examined the peptide in chronic hepatitis B and C, as a vaccine adjuvant, and in sepsis and oncology settings. Findings across trials are mixed; some report changes in selected immune markers, while others find no clear clinical benefit. Many studies are small and define outcomes differently, which limits comparison. Regulatory approval is confined to a few countries, and the compound is not an approved drug in the United States or most of Europe.
Overall evidence quality varies considerably. A large share of published reports come from single centers, rely on surrogate immunological markers, or lack adequate control groups. Systematic reviews have highlighted this heterogeneity as a barrier to pooling results. Open questions include which patients, if any, might benefit, what treatment duration is appropriate, and whether any effect is independent of standard care. The peptide is often described as an immune modulator rather than a therapy for one disease, which complicates confirmatory trial design.
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。
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.
3-Chloromethcathinone (3-CMC), also known as clophedrone, is a synthetic substance belonging to the cathinone class of psychoactive compounds. It is very similar in structure to other methcathinone derivatives such as 3-MMC and 4-CMC. Unlike cathinone, which occurs naturally in the khat plant Catha edulis, 3-CMC is not found in nature and is solely produced through chemical synthesis. First detected in 2014, 3-CMC gained attention for its stimulating effects that are described to be similar to the effects of mephedrone and, to a lesser extent, those of MDMA and cocaine. 3-CMC has been sold online as a designer drug mainly in European countries such as Germany, Poland, the Netherlands, and Sweden. It is a controlled substance in many countries.
== Potential applications == A wide variety of potential applications have been envisaged. Since magnetic nanoparticles are expensive to produce, there is interest in their recycling or for highly specialized applications. The potential and versatility of magnetic chemistry arises from the fast and easy separation of the magnetic nanoparticles, eliminating tedious and costly separation processes usually applied in chemistry. Furthermore, the magnetic nanoparticles can be guided via a magnetic field to the desired location which could, for example, enable pinpoint precision in fighting cancer.
==== Aortic disease ==== A 2014 Cochrane review investigated the use of beta blockers in the maintenance of chronic type B thoracic aortic aneurysm in comparison to other anti hypertensive medications. The review found no suitable evidence to support the current guidelines recommending its use. A 2017 Cochrane review on the use of beta blockers to prevent aortic dissections in people with Marfan syndrome was unable to draw definitive conclusions due to lack of evidence.
== Pathophysiology == There are three types of dendritic cells, plasmacytic dendritic cells (pDC) and two types of conventional dendritic cells (cDC), myeloid cDC1 and myeloid cDC2. pDC circulate in the blood, representing <0.4% of all nucleated blood cells, and are present in various hematological tissues such as lymph nodes and spleen. Their major function is to detect and then initiate immune responses to intracellular pathogens, particularly viruses such as the cold sore-causing Herpes simplex viruses, HIV, and hepatitis viruses but also bacteria such as the tuberculosis-causing Mycobacterium tuberculosis, fungi such as the aspergillosis-causing Aspergillus fumigatus and parasites such as malaria-causing Plasmodium falciparum. Following detection of these intracellular pathogens, pCD initiate immune responses by producing massive amounts of type I and type III interferons as well as by differentiating (i.e. maturing) into conventional dendritic cells that further promote immune responses by, e.g. functioning as antigen-presenting cells. The malignant pDC in BPDCN have the appearance of immature plasmacytoid dendritic cells. They are distinguished from other dendritic, myeloid, lymphoid and NK cell types by exhibiting at least several of the following properties: 1) plasmacytoid morphology; 2) production of large amounts of type I interferons when properly stimulated; 3) ability to differentiate into conventional dendritic cells when properly stimulated; 4) the expression of key marker proteins such as granzyme B, TCF4, interleukin-3 receptor (i.e.
Sources: en.wikipedia.org
Bleeding Infection Loss of grafted skin Nerve damage Graft-versus-host disease Marjolin's ulcer Rejection may occur in xenografts. To prevent this, the person receiving the graft usually must be treated with long-term immunosuppressant drugs.
The FAO State of World Fisheries and Aquaculture 2004 report estimates that in 2003, of the main fish stocks or groups of resources for which assessment information is available, "approximately one-quarter were overexploited, depleted or recovering from depletion (16%, 7% and 1% respectively) and needed rebuilding." The National Fisheries Institute, a trade advocacy group representing the United States seafood industry, disagree. They claim that currently observed declines in fish populations are due to natural fluctuations and that enhanced technologies will eventually alleviate whatever impact humanity is having on oceanic life.
== Technique == The caterpillar was first killed. If it was hairy then it was soaked in alcohol for half an hour before being left to dry out. The rear of the caterpillar was then cut open and the contents of the bowels squeezed out by applying gentle pressure to the outside of the caterpillar. Pressure would be applied, working from the rear towards the front of the caterpillar, until the intestines started to protrude from the cut. Forceps would then be used to pull the intestines from the caterpillar's body which would in turn drag out most of the rest of the caterpillar's innards with them. A straw was then inserted into the cut, and air blown into it while the caterpillar was gently heated in order to dry it. For an experienced practitioner the entire process took about 5 to 6 minutes. Once the caterpillar was dry it was ready to be prepared for mounting. This was done by pushing a loop of wire coated in shellac into the caterpillar via the cut, after which the wire was attached to an entomological pin for mounting in a storage cabinet. Various devices, such as miniature alcohol heated ovens, were developed to apply the technique with different entomologists taking different approaches. A closely related technique was to inject the caterpillar with wax after the organ removal stage.
=== Systemic therapies === Because many cases of AN are associated with metabolic dysfunction, improvement in weight or insulin sensitivity may coincide with changes in the skin. Metformin, which is widely used for insulin resistance and type 2 diabetes, has been reported in case series and observational studies to coincide with improvement in AN; however, high-quality randomized trials with AN as a primary outcome are not available. Glucagon-like peptide-1 (GLP-1) receptor agonists, used for obesity and diabetes, have also been associated with improvement in some individuals with AN in observational reports, likely secondary to changes in metabolic status. These medications are not used specifically to treat AN, and evidence remains indirect.
The combine genetic phylogenetic and structural analysis concluded that the original type-3 copper protein possessed a single peptide and grouped into α subclass. The ancestral protein gene underwent to two duplication i.e., first one prior to divergence of unknown eukaryotic lineage and second one before diversification. The prior duplication gave rise to cytosolic form(β) and latter duplication gave membrane bound form (Γ). The structural comparison concluded that active site of α and γ forms are covered by aliphatic amino acids and β form covered with aromatic residue. Thus, the evolution of these gene family is the lineage of multicellular eukaryotes due to loss of one or more of these three subclasses and lineage-specific expansion of one or both of the remaining subclasses. The genomic conserved nucleotide alignments of the tyrosinase among the vertebrate family like frogs, snakes and human suggests that it has evolved from one ancestral tyrosinase gene. The duplication and mutation of this gene is probably responsible for the emergence of a tyrosinase-related gene.
Sources: en.wikipedia.org
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.
It is usually described as an immunomodulatory peptide rather than a classic hormone. It acts on immune cells through receptor pathways. No single endocrine organ target defines its function.
Several countries, including Italy and China, allow it for specific indications. The FDA has not approved it as a drug in the United States. Availability depends on local regulation.
Its sequence corresponds to the amino-terminal portion of prothymosin alpha, a larger protein present in many cell types. The isolated 28-residue peptide is a fragment of that protein rather than a separately encoded molecule, and laboratory material is produced by synthesis.