If you have been reading about vaccine adjuvant 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.
Last reviewed on 2026-03-09. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
在信号层面，Tα1可能通过Toll样受体等模式识别受体发挥作用。部分实验显示，它能激活髓样分化因子88依赖的通路，进而促进核因子κB进入细胞核。这导致白细胞介素2、干扰素γ和白细胞介素12等细胞因子的转录增加。这些细胞因子偏向辅助性T细胞1型应答，有助于细胞免疫。然而，具体受体和结合位点尚未完全确定，不同实验模型的结果存在差异。
临床研究将Tα1用于慢性病毒感染、肿瘤辅助治疗和疫苗佐剂等场景。部分试验报告了免疫学指标改善，但临床终点获益在不同研究中并不一致。系统综述指出，研究间在人群、剂量和联合方案上差异较大，难以汇总结论。因此，Tα1的确切临床地位仍属开放问题，需要更多高质量随机对照试验来澄清。其机制研究也需从体外实验向体内模型推进。
| Property | Value | Notes |
|---|---|---|
| First described | 1977 | Reported as a component of thymosin fraction 5 |
| Sequence length | 28 amino acids | N-terminal residue is acetylated |
| Net charge at neutral pH | Negative | Reflects a high proportion of acidic residues |
| Principal studied uses | Chronic hepatitis B and vaccine adjuvant | Research uses outnumber approved indications |
| Regulatory status | Approved in a limited number of countries | Not approved in the United States or most of Europe |
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.
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.
Recommended storage for the dry powder is a freezer near minus twenty degrees Celsius, kept desiccated and away from light. Once dissolved, the peptide is less stable and is usually held at two to eight degrees Celsius for short intervals or frozen for longer storage. Stability studies focus on the acetylated terminus and the disulfide linkage because those features define the intact molecule. Common degradation routes include cysteine oxidation, deamidation of asparagine or glutamine side chains, and slow formation of higher-molecular-weight species.
Identity and purity are usually checked by reverse-phase high-performance liquid chromatography, which separates the intact chain from truncated products, together with mass spectrometry for confirmation of the expected mass. Peptide mapping after enzymatic digestion and amino acid analysis add sequence-level evidence. Release testing also covers water content, residual solvents, and counter-ions, all of which influence measured mass and stability. Related-peptide limits are commonly expressed as a percentage of total peak area, with individual unspecified impurities held below a lower threshold.
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.
Binge eating disorder (BED) is an eating disorder characterized by frequent and recurrent binge eating episodes with associated psychological and social dysfunction, but without the compensatory behaviors common to bulimia nervosa, OSFED, or the binge–purge subtype of anorexia nervosa. BED is a recently identified condition, distinguished nosologically to separate the binge eating that defines it from the binge eating seen in bulimia nervosa, which involves post-binge purging. Individuals diagnosed with bulimia nervosa or binge eating disorder show similar patterns of compulsive overeating, neurobiological features such as impaired cognitive control and food addiction, as well as biological and environmental risk factors. Some professionals consider BED to be a milder form of bulimia, with the two conditions on the same spectrum. Binge eating is one of the most prevalent eating disorders among adults, though it receives less media coverage and research attention than anorexia nervosa and bulimia nervosa.
Two methods are generally used to prepare a column: the dry method and the wet method. For the dry method, the column is first filled with dry stationary phase powder, followed by the addition of mobile phase, which is flushed through the column until it is completely wet, and from this point is never allowed to run dry. For the wet method, a slurry is prepared of the eluent with the stationary phase powder and then carefully poured into the column. The top of the silica should be flat, and the top of the silica can be protected by a layer of sand. Eluent is slowly passed through the column to advance the organic material. The individual components are retained by the stationary phase differently and separate from each other while they are running at different speeds through the column with the eluent. At the end of the column they elute one at a time. During the entire chromatography process the eluent is collected in a series of fractions. Fractions can be collected automatically by means of fraction collectors. The productivity of chromatography can be increased by running several columns at a time. In this case multi stream collectors are used. The composition of the eluent flow can be monitored and each fraction is analyzed for dissolved compounds, e.g. by analytical chromatography, UV absorption spectra, or fluorescence. Colored compounds (or fluorescent compounds with the aid of a UV lamp) can be seen through the glass wall as moving bands.
=== Quantum tunneling === These traditional "over the barrier" mechanisms have been challenged in some cases by models and observations of "through the barrier" mechanisms (quantum tunneling). Some enzymes operate with kinetics which are faster than what would be predicted by the classical ΔG‡. In "through the barrier" models, a proton or an electron can tunnel through activation barriers. Quantum tunneling for protons has been observed in tryptamine oxidation by aromatic amine dehydrogenase. Quantum tunneling does not appear to provide a major catalytic advantage, since the tunneling contributions are similar in the catalyzed and the uncatalyzed reactions in solution. However, the tunneling contribution (typically enhancing rate constants by a factor of ~1000 compared to the rate of reaction for the classical 'over the barrier' route) is likely crucial to the viability of biological organisms. This emphasizes the general importance of tunneling reactions in biology. However, as stated above, this does not represent a true catalytic effect, since the same enhancement exists in the corresponding reference reaction in solution. In 1971-1972 the first quantum-mechanical model of enzyme catalysis was formulated. However, this study did not include any representation of the enzyme environment, nor did it provide a relevant potential energy surface. Consequently, it cannot be considered a true quantum mechanical study of enzyme catalysis. Such investigations became feasible only with the development of combined quantum mechanical/molecular mechanical (QM/MM) methods.
Neurotransmitter receptors and receptor ionophores. Nicotinic, imidazoline I1 and I2, α2-adrenergic, glutamate NMDAr, and serotonin 5-HT2A and 5HT-3 receptors. Ion channels. Including: ATP-sensitive K+ channels, voltage-gated Ca2+ channels, and acid-sensing ion channels (ASICs). Membrane transporters. Agmatine specific-selective uptake sites, organic cation transporters (mostly OCT2 subtype), extraneuronal monoamine transporters (ENT), polyamine transporters, and mitochondrial agmatine specific-selective transport system. Nitric oxide (NO) synthesis modulation. Both differential inhibition and activation of NO synthase (NOS) isoforms is reported. Polyamine metabolism. Agmatine is a precursor for polyamine synthesis, competitive inhibitor of polyamine transport, inducer of spermidine/spermine acetyltransferase (SSAT), and inducer of antizyme. Protein ADP-ribosylation. Inhibition of protein arginine ADP-ribosylation. Matrix metalloproteases (MMPs). Indirect down-regulation of the enzymes MMP 2 and 9. Advanced glycation end product (AGE) formation. Direct blockade of AGEs formation. NADPH oxidase. Activation of the enzyme leading to H2O2 production.
Sources: en.wikipedia.org
== Toxicity == Studies carried out on the toxicity of convulxin show that symptoms are a function of the dose. The effects of the toxin stand out through the sudden and brief duration of the symptoms after exposure. In mice, low doses (5 μg/animal) administered intravenously (I.V) elicited tachypnea, followed by apnea, within 20 seconds. The ED50 for brief duration apnea was determined to be 180 μg/kg. Higher doses (10 μg/animal) evoked intense convulsive crisis, and usually ended with the death of the animal. LD50 was determined to be 524 μg/kg. Intraperitoneal (I.P.) administration of up to 200 μg/animal proved to be ineffective. In cats, I.V. injections of 100 μg/kg showed respiratory disturbances, miosis, salivation, abdominal cramps, nystagmus, loss of equilibrium, convulsions and sometimes a brief phase of hypotonia. The ED50 dose for convulsions is 80 μg/kg. The majority of animals recovered within 30 minutes. In dogs, the effect of convulxin showed two stages. After I.V. injection of 100-125 μg/kg they became excited, barked and exhibited loss of equilibrium, respiratory disturbances, nystagmus, urination, defecation and vomiting. After recovery, two out of five animals had intermittent crisis of clonic convulsions that appeared after 24 hours and lasted until their death. The other three dogs showed periods of vivid agitation alternating with torpor. While the lethal dose in humans is not yet known, what has been discovered is that the level of toxic effects depends on the origin of the snake. As for a cure, so far a polyvalent snake antivenom is being used.
=== Linear trap and FTICR === Linear traps can be used to improve the performance of FT-ICR (or FTMS) systems. As with 3D ion traps, the duty cycle can be increased to nearly 100% if ions are accumulated in a linear trap, while the FTMS performs other functions. Unwanted ions that can cause space charge problems in the FTMS can be ejected in the linear trap to improve the resolution, sensitivity, and dynamic range of the system, although the system parameters used to optimize such signal characteristics co-vary with one another.
Some hormonal birth control methods utilize cervical drug delivery methods. The earliest example of such dates to 1850 Ancient Egypt when acadia gum was inserted into the vagina, releasing spermicidal components. Examples in the modern era include vaginal rings and intrauterine devices (IUDs) that release hormones into the reproductive system to prevent fertilization. Vaginal rings are plastic ring-shaped devices that are inserted into the vaginal canal and slowly release hormones such as estradiol or progestin. Hormonal IUDs are T-shaped devices inserted into the uterus, releasing progestin over extended periods of time. These hormones work to thicken the cervical mucus to prevent sperm from penetrating and reaching the fallopian tubes. Copper IUDs are another form of intrauterine devices that release copper ions instead of hormones. The copper ions are toxic to sperm and therefore prevents successful fertilization.
Fetal alcohol spectrum disorders are a group of conditions that can occur in a person whose mother drank alcohol during pregnancy. The most severe form of the condition is known as fetal alcohol syndrome. Problems may include an abnormal appearance, short height, low body weight, small head size, poor coordination, low intelligence, behavior problems, hearing loss, and vision problems. Those affected are more likely to have trouble in school, legal problems, participate in high-risk behaviors, and have trouble with alcohol and recreational drug use. Fetal alcohol syndrome usually occurs when a pregnant woman has more than four drinks per day. Milder symptoms have been found with two drinks per day during the early part of pregnancy. Evidence of harm from less than two drinks per day or 10 drinks per week is not clear. The American Academy of Pediatrics established a conservative set of recommendations in 2015: "During pregnancy: no amount of alcohol intake should be considered safe; there is no safe trimester to drink alcohol; all forms of alcohol, such as beer, wine, and liquor, pose similar risk; and binge drinking poses dose-related risk to the developing fetus." The World Health Organization recommends that alcohol should be avoided entirely during pregnancy, given the relatively unknown effects of even small amounts of alcohol during pregnancy.
Take breast cancer as an example. The sensitivity of traditional ultrasound screening for breast cancer can be 76%. While with the blood-based mRNA diagnostic method, the sensitivity could be 80.6%. mRNA-based disease diagnostic technologies allow quantitive measurement of mRNA in the certain samples, such as leukemia As some technologies such as RNA-seq can provide the entire transcriptome of individual, the mRNA-based disease diagnosis can be developed in the landscape of personalized medicine. In HER-2 breast cancer, detection of ERBB2 mRNA expression levels is helpful in predicting response to anti-HER2-based treatments. As mentioned above, the mRNA-based disease diagnostic technology is more sensitive and specific to certain diseases. Even though there is no obvious symptom, the mRNA-based disease diagnostic technology can serve as screening method for early changes in RNA levels. High serum metadherin mRNA expression was observed in colorectal cancer and associated with poorly differentiated histological grades
Sources: en.wikipedia.org
Trials differ in patient population, dose schedule, background treatment, and the endpoints used to judge success. Many are small and single-center, so random variation can dominate the reported effects.
Authorization is limited to a small number of countries and covers specific indications such as chronic hepatitis B and vaccine adjuvant use. Availability and labelling differ by jurisdiction.
Most reviews describe it as an immunomodulatory agent with an uncertain clinical effect. They generally call for larger, better-controlled trials before firm conclusions are drawn.
它促进未成熟T细胞分化并增强成熟T细胞的增殖与细胞因子分泌。这些作用有助于放大抗原特异性免疫应答。