Immune modulation is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2025-08-29. Numbers and descriptions here follow the published literature rather than marketing material.
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。
Clinical research has examined the peptide in chronic hepatitis B and C, as a vaccine adjuvant, and in sepsis and oncology settings. Results across trials have been mixed, and several studies were small or conducted under differing protocols. Regulatory status varies by country, and the compound is not approved in every jurisdiction where it is studied. Evidence for any single indication should be read with attention to sample size and endpoint choice.
Thymosin alpha-1 is a 28-residue peptide first isolated from thymus tissue in the 1970s. It corresponds to the N-terminal portion of thymosin beta-4, from which it is cleaved in vivo. The peptide carries an acetyl group at its N-terminus, a modification that affects its charge and stability. Synthetic material produced by solid-phase peptide synthesis is chemically identical to the natural fragment and is the form used in research and clinical studies.
Laboratory work indicates that the peptide acts on cells of both the innate and adaptive immune systems. Reported effects include signalling through Toll-like receptors on dendritic cells, enhanced T-cell maturation, and increased natural killer cell activity. These actions are described largely from cell-culture and animal experiments, and the precise receptor-level events remain incompletely defined. Studies in humans have generally measured immune markers rather than a single defined molecular target. The resulting picture remains partly descriptive.
| Property | Value | Notes |
|---|---|---|
| 化学分类 | 线性肽 | 由28个氨基酸组成 |
| 分子量 | 约3108 Da | 合成版本一致 |
| 外观 | 白色至类白色粉末 | 冻干品 |
| 溶解度 | 易溶于水 | 微溶于有机溶剂 |
| 储存温度 | -20°C（冻干） | 溶解后2-8°C |
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.
Thymosin alpha 1 was identified in 1977 as a component of thymosin fraction 5, a heterogeneous preparation used in early studies of thymic function. Investigators purified the active material and determined its amino acid sequence, which enabled chemical synthesis. Work in the following decades concentrated on T-cell maturation and immune reconstitution in animals and small human cohorts. Early preparations varied in composition, so results from that period are difficult to compare with studies using defined synthetic peptide.
Lyophilized material is typically treated as a hygroscopic solid that should be brought to room temperature before the container is opened, which limits condensation on the powder. Reconstitution is commonly done with sterile water or a buffered diluent, and gentle mixing is preferred over vigorous agitation to reduce foaming and surface adsorption. Because peptides can bind to plastic and glass, diluents containing a small amount of carrier protein are sometimes used in laboratory work. Working solutions are generally aliquoted and prepared fresh rather than subjected to repeated freezing and thawing.
Stability depends on temperature, pH, and the number of freeze-thaw events the sample has experienced. Freeze-dried material is commonly held at -20 °C or colder, while reconstituted liquid is kept cold and used within a short window. Extreme pH and prolonged light exposure can promote deamidation, oxidation, or aggregation, particularly at asparagine and methionine positions. Adsorption to container walls can lower the measured concentration of a dilute solution even when the peptide molecules themselves remain intact.
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.
The molecule consists of 28 amino acid residues with an acetyl group attached to the N-terminal serine. Its sequence is acidic overall, with several glutamic and aspartic acid residues distributed along the chain and no cysteine, so disulfide bridges do not form. The peptide carries a net negative charge at physiological pH. Because the N-terminus is blocked, the intact molecule resists degradation by many aminopeptidases, which contributes to its stability in biological fluids.
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.
The peptide was identified during work in the 1970s on thymosin fraction 5, a partially purified extract of calf thymus. Investigators separated that mixture and characterized individual components, one of which they named thymosin alpha-1. The same compound later received the international nonproprietary name thymalfasin. Commercial material is produced by solid-phase peptide synthesis rather than by extraction, so synthetic and natural forms share an identical sequence. Naming conventions vary across the literature, and readers should distinguish the alpha-1 peptide from other thymosins that have unrelated sequences and functions.
Thymosin beta-4 is a separate 43-residue peptide that binds actin and participates in cell migration; it shares no sequence similarity with thymosin alpha-1 despite the common family name. Other preparative materials, such as thymosin fraction 5 and thymopoietin, contain distinct mixtures or peptides. The shared thymosin label reflects the tissue of origin used in early purification, not a common structural core. Treating these molecules as interchangeable is a frequent source of confusion in laboratory reports and in popular summaries alike.
VWF is named after Erik Adolf von Willebrand, a Finnish physician who in 1926 first described a hereditary bleeding disorder in families from Åland. Although von Willebrand did not identify the definite cause, he distinguished von Willebrand disease (vWD) from hemophilia and other forms of bleeding diathesis. In the 1950s, vWD was shown to be caused by a plasma factor deficiency (instead of being caused by platelet disorders), and, in the 1970s, the VWF protein was purified. Harvey J. Weiss and coworkers developed a quantitative assay for VWF function that remains a mainstay of laboratory evaluation for VWD to this day.
Gelatin contains many functional groups like NH2, SH, and COOH which allow for gelatin to be modified using nanoparticles and biomolecules. Gelatin is an Extracellular Matrix protein which allows it to be applied for applications such as wound dressings, drug delivery and gene transfection. Starch: Starch is an inexpensive biodegradable biopolymer and copious in supply. Nanofibers and microfibers can be added to the polymer matrix to increase the mechanical properties of starch improving elasticity and strength. Without the fibers, starch has poor mechanical properties due to its sensitivity to moisture. Starch being biodegradable and renewable is used for many applications including plastics and pharmaceutical tablets. Cellulose: Cellulose is very structured with stacked chains that result in stability and strength. The strength and stability comes from the straighter shape of cellulose caused by glucose monomers joined by glycogen bonds. The straight shape allows the molecules to pack closely. Cellulose is very common in application due to its abundant supply, its biocompatibility, and is environmentally friendly. Cellulose is used vastly in the form of nano-fibrils called nano-cellulose. Nano-cellulose presented at low concentrations produces a transparent gel material. This material can be used for biodegradable, homogeneous, dense films that are very useful in the biomedical field. Alginate: Alginate is the most copious marine natural polymer derived from brown seaweed.
==== Balancing infection and autoimmunity ==== There is increasing evidence that certain genes selected during evolution offer a balance between susceptibility to infection and the capacity to avoid autoimmune diseases. For example, variants in the ERAP2 gene provide some resistance to infection even though they increase the risk of autoimmunity (positive selection). In contrast, variants in the TYK2 gene protect against autoimmune diseases but increase the risk of infection (negative selection). This suggests the benefits of infection resistance may outweigh the risks of autoimmune diseases, particularly given the historically high risk of infection. Several experimental methods such as the genome-wide association studies have been used to identify genetic risk variants that may be responsible for diseases such as type 1 diabetes and rheumatoid arthritis.
==== Keratan sulfate ==== Keratan sulfates have a variable sulfate content and, unlike many other GAGs, do not contain uronic acid. They are present in the cornea, cartilage, bones, and the horns of animals.
=== Economics === Loperamide is available as a generic medication. In 2016, Imodium was one of the biggest-selling branded over-the-counter medications sold in Great Britain, with sales of £32.7 million.
Sources: en.wikipedia.org
differs when considering the effects of vaccinations and when the real-time dependence of fatality and recovery rates diverge. These differences have been highlighted for stationary ratios and gradually decreasing fatality rates. The case of stationary ratios allows one to construct a diagnostics method to extract analytically all SIRVD model parameters from measured COVID-19 data of a completed pandemic wave.
The New Zealand government joins the British, Australian, Canadian and Norwegian governments in imposing travel bans on Israeli National Security Minister Itamar Ben-Gvir and Finance Minister Bezalel Smotrich for allegedly inciting "extremist violence" against Palestinians in the West Bank. The National Library of New Zealand confirms it will destroy 500,000 unwanted books after US publishers challenged its plans to sell the collection to the online archive Internet Archive. The Aratere experiences an electrical fault at 8:50pm, delaying a night-time voyage from Picton to Wellington. 13 June: Tingjun Cao is sentenced to life imprisonment with a minimum term of 17 years for the murder of Christchurch real estate agent Yanfei Bao. A fire in Lyttelton destroys two properties, damages a third and leads to the evacuation of local residents. Police seize 478 firearms in Gore, marking one of the largest firearms seizures in New Zealand history. 15 June – Auckland department store Smith & Caughey's closes its Queen Street store, ending 145 years of trading. 17 June: A ban of the distribution, manufacture, sale and supply of disposable vapes, and new restrictions on advertising and promotion of vaping products, come into effect. New World's Victoria Park supermarket in Auckland experiences significant damage during a massive fire. The Sentencing (Reinstating Three Strikes) Amendment Act 2024 comes into force, applying to 42 serious crimes including homicides, sexual assault, aggravated robbery, abduction, strangulation and suffocation.
The first group coexpresses neuropeptide Y (NPY) and agouti-related peptide (AgRP) and has stimulatory inputs to the LH and inhibitory inputs to the VMH. The second group coexpresses pro-opiomelanocortin (POMC) and cocaine- and amphetamine-regulated transcript (CART) and has stimulatory inputs to the VMH and inhibitory inputs to the LH. Consequently, NPY/AgRP neurons stimulate feeding and inhibit satiety, while POMC/CART neurons stimulate satiety and inhibit feeding. Both groups of arcuate nucleus neurons are regulated in part by leptin. Leptin inhibits the NPY/AgRP group while stimulating the POMC/CART group. Thus a deficiency in leptin signaling, either via leptin deficiency or leptin resistance, leads to overfeeding and may account for some genetic and acquired forms of obesity.
As of September 2022, 163 members, or 46.7% of the 349 members are women. Five parties have a majority representation of female MPs as of 2022: the Left Party (17 of 24, 70.8%), the Green Party (12 of 18, 66.7%), the Liberals (9 of 16, 56.3%), the Centre Party (13 of 24, 54.2%), and the Social Democratic Party (55 of 107, 51.4%). The party with the lowest share of female MPs is the Sweden Democrats (18 of 73, 24.7%). Members of the Riksdag are full-time legislators with a base remuneration of SEK 81,400 per month, as of 1 January 2026. Committee chairs receive an additional 20% and deputy chairs receive an additional 15%. According to a survey investigation by the sociologist Jenny Hansson, Members of the Riksdag have an average work week of 66 hours, including side responsibilities. Hansson's investigation further reports that the average member sleeps 6.5 hours per night.
Sources: en.wikipedia.org
Early on the morning of September 11, 2001, nineteen hijackers took control of four commercial airliners (two Boeing 757s and two Boeing 767s). Large planes with long flights were selected for hijacking because they would have more fuel. Nobody on the planes survived.
=== COVID-19-related marketing and government agency responses === Although according to the NIH no stem cell treatments have been approved for COVID-19, and the agency recommends against the use of MSCs for the disease, some stem cell clinics began marketing both unproven and non-FDA-approved stem cells and exosomes for COVID-19 in 2020. The FDA took prompt action by sending letters to the firms in question. The FTC also warned a stem cell firm for misleading COVID-19-related marketing.
=== Depression and bipolar depression === Candesartan is currently being investigated as a potential adjunct therapy for both depression and bipolar depression in the CADET (Candesartan Adjunctive Trials) clinical trials. These studies—one for major depressive disorder and one for bipolar depression—are double-blind, placebo-controlled clinical trials. The proposed mechanism of action is via antagonism of the AT-1 receptor, which a 2017 meta-analysis indicated may have effects on mental health. As Candesartan is a strong AT-1 receptor antagonist, it was selected for the clinical trial.
Sources: en.wikipedia.org
它不是经典的内分泌激素，而是一种免疫调节肽。其作用主要通过局部免疫细胞间的信号传递实现，而非经血液循环作用于远隔器官。
天然胸腺素α1主要从胸腺组织提取，也可在脾脏和淋巴结中检出。目前研究和临床使用的多为化学合成版本，不再依赖动物组织。
胸腺素组分5是牛胸腺提取物的粗组分，包含多种肽。胸腺素α1是其中一种被纯化和表征的单一肽，具有明确的28个氨基酸序列。
It corresponds to the first 28 amino acids of thymosin beta-4, a larger protein found in many tissues. The fragment is acetylated at its N-terminus and is produced synthetically for research and pharmaceutical use. Synthetic and natural forms share the same sequence.