免疫调节 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 2025-10-04. Numbers and descriptions here follow the published literature rather than marketing material.
The compound has been investigated as an adjunct in chronic viral hepatitis and as a vaccine adjuvant, with results that vary by study design and population. Regulators in some countries have approved a synthetic form for specific indications, while other agencies have not. Whether the peptide produces consistent clinical benefit across diverse patient groups is still an open question, and many trials have been small. Its status is therefore best described as investigational in many contexts and established only narrowly.
The name itself causes confusion, because several unrelated thymic peptides share the thymosin label. Thymosin beta-4, for example, is a different molecule with different functions. Naming conventions in the literature also mix descriptive research terms with assigned nonproprietary names, so a reader should confirm which entity a given paper addresses. Clarifying that point is usually the first step in interpreting any claim about this peptide.
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.
| Property | Value | Notes |
|---|---|---|
| Residue count | 28 amino acids | Acetyl group on the first residue |
| Approximate molecular mass | 3108 daltons | Calculated from the consensus sequence |
| Origin | Cleavage product of prothymosin alpha | Not encoded as a separate gene product |
| Primary research focus | Immune modulation | Studied in viral hepatitis and as a vaccine adjuvant |
| Common synonyms | Thymalfasin, Tα1, thymosin alpha 1 | Thymalfasin is the assigned nonproprietary name |
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。
胸腺素α1对免疫系统的影响涉及多种细胞类型。研究表明，它可促进未成熟T细胞向成熟T细胞分化，并增强T细胞对抗原刺激的增殖反应。树突状细胞在Tα1存在下表达更高水平的共刺激分子，从而更有效地呈递抗原。此外，自然杀伤细胞的活性也观察到上升。这些效应并非直接杀伤病原体，而是调节宿主免疫应答的强度与方向。
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.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, which separates the target peptide from truncated or chemically modified byproducts. Mass spectrometry confirms the expected molecular mass and can indicate acetylation state or sequence errors. Amino acid analysis and peptide mapping supply complementary sequence-level information, while endotoxin testing is relevant for preparations intended for cell or animal work. Purity figures reported by suppliers refer to the method used and are not directly comparable across laboratories unless conditions are stated.
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.
Several factors accelerate degradation: alkaline pH, elevated temperature, exposure to oxidants, and the presence of residual moisture. Deamidation of asparagine residues and oxidation of methionine are the most commonly reported degradation routes. Because the peptide lacks disulfide bonds, it does not undergo the thiol-related aggregation seen in some other biologics, but physical aggregation can still occur at high concentration. Stability data are product-specific, and extrapolating shelf life between formulations is not reliable.
Lyophilized thymosin alpha-1 is generally stored at or below minus twenty degrees Celsius, protected from moisture and light. Short-term handling at ambient temperature is possible for dry powder, but reconstituted solutions degrade faster and are usually kept at two to eight degrees Celsius with a defined expiry of days rather than weeks. Repeated freeze-thaw cycles should be avoided because they promote aggregation and loss of potency. Exact limits depend on the formulation and should follow the supplier's documentation.
=== Developments in production === Until the end of the 19th century, vaccination was performed either directly with vaccine produced on the skin of calves or, particularly in England, with vaccine obtained from the calf but then maintained by arm-to-arm transfer; initially in both cases vaccine could be dried on ivory points for short-term storage or transport but increasing use was made of glass capillary tubes for this purpose towards the end of the century. During this period there were no adequate methods for assessing the safety of the vaccine and there were instances of contaminated vaccine transmitting infections such as erysipelas, tetanus, septicaemia and tuberculosis. In the case of arm-to-arm transfer there was also the risk of transmitting syphilis. Although this did occur occasionally, estimated as 750 cases in 100 million vaccinations, some critics of vaccination e.g. Charles Creighton believed that uncontaminated vaccine itself was a cause of syphilis. Smallpox vaccine was the only vaccine available during this period, and so the determined opposition to it initiated a number of vaccine controversies that spread to other vaccines and into the 21st century. Sydney Arthur Monckton Copeman, an English Government bacteriologist interested in smallpox vaccine, investigated the effects on the bacteria in it of various treatments, including glycerine. Glycerine was sometimes used simply as a diluent by some continental vaccine producers.
During another late-stage playtest with the title "ninety-nine percent" complete according to Levine, the playtesters did not like the game at all as they felt no connection to the player-character Jack, and the person overseeing the tests told Levine that the game was likely to be a failure. The following day, Levine and the lead group came up with a "cheap" way to correct this, by adding the initial cutscene within the plane and the subsequent plane crash, as this helped to set the time frame, place the player in the role of the character, and alluded to the "would you kindly" twist later in the game. Levine likened this approach to the initial aircraft crash at the onset of the television show Lost to quickly establish character and setting. Total costs of development was about $25 million. During peak development 93 developers across 2K Boston, 2K Australia, and 2K Shanghai, along with more than 30 contractors and game testers, contributed to the game. In a 2016 interview, Levine felt that the game could have used about six more months of development to improve the gun combat system and fix lagging issues that occurred during the final boss fight. Many on the development team would leave Irrational after BioShock shipped due to its difficult development.
Despite the absence of brown recluses from the Western U.S., physicians in the region commonly diagnose "brown recluse bites", leading to the popular misconception that the spiders inhabit those areas. Over the last century, spiders have occasionally been intercepted in locations where they have no known established populations; these spiders may be transported fairly easily, though the lack of established populations well outside the natural range also indicates that such movement has not led to the colonization of new areas, after decades of opportunities. Note that the occurrence of brown recluses in a single building (such as a warehouse) outside of the native range is not considered as successful colonization; such single-building populations can occur (e.g., in several such cases in Florida), but do not spread, and can be easily eradicated. The spider has also received numerous sensationalized media reports of bites occurring where these spiders are absent (and no specimens were found), such as a 2014 report from Thailand, where a man was claimed to have died from a brown recluse bite. Many misidentifications and erroneous geographic records stem from the similarity between L. reclusa and a related introduced species, the Mediterranean recluse (Loxosceles rufescens), which is found worldwide, including numerous sightings throughout the United States; the two species are superficially almost indistinguishable, and misidentifications are common, making it difficult to distinguish which reports of recluses refer to which species.
Slurry ice can boost by up to 200% the cooling efficiency of existing cooling or freezing brine systems without any major changes to the system (i.e. heat exchanger, pipes, valves), and reduce the amount of energy consumption used for pumping.
On a pressure/temperature phase diagram (see figure), there are curves separating solid from vapor, vapor from liquid, and liquid from solid. These meet at a single point called the triple point, where all three phases can coexist. The triple point is at a temperature of 273.16 K (0.01 °C; 32.02 °F) and a pressure of 611.657 pascals (0.00604 atm; 0.0887 psi); it is the lowest pressure at which liquid water can exist. Until 2019, the triple point was used to define the Kelvin temperature scale. The water/vapor phase curve terminates at 647.096 K (373.946 °C; 705.103 °F) and 22.064 megapascals (3,200.1 psi; 217.75 atm). This is known as the critical point. At higher temperatures and pressures the liquid and vapor phases form a continuous phase called a supercritical fluid. It can be gradually compressed or expanded between gas-like and liquid-like densities; its properties (which are quite different from those of ambient water) are sensitive to density. For example, for suitable pressures and temperatures it can mix freely with nonpolar compounds, including most organic compounds. This makes it useful in a variety of applications including high-temperature electrochemistry and as an ecologically benign solvent or catalyst in chemical reactions involving organic compounds. In Earth's mantle, it acts as a solvent during mineral formation, dissolution and deposition.
Sources: en.wikipedia.org
Georgia Governor John M. Slaton and his wife Sarah Frances Grant left the state under security of the United States National Guard after a mob of people angered by his decision to commute Leo Frank's sentence to life imprisonment threatened them at their home in Atlanta. Armenian genocide — Rafael de Nogales Méndez, a Venezuelan serving with the Ottoman Empire, met with Mehmed Reshid, Governor of the Diyarbekir province, and learned the governor had received telegraphs directly from Interior Minister Talaat Pasha with orders to "Burn-Destroy-Kill" all Armenians in the area. Willis Carrier, who patented the modern air conditioner in 1914, formed Carrier Engineering Corporation with six other engineers to manufacturer and market the technology. They opened their first factory in Newark, New Jersey in 1920. By drawing 4.8 (32) each with Port Adelaide, South Adelaide ended the Magpies' run of 29 consecutive victories, including one against Carlton and one against a combined team from the other six SAFL clubs. The Saturday Evening Post began publishing P. G. Wodehouse's serialized novel Something Fresh, introducing the character Lord Emsworth of Blandings Castle. The village of Beachwood, Ohio was established. It became a city in 1960. Born: Paul Castellano, American gangster, head of the Gambino crime family from 1976 to 1984; as Constantino Paul Castellano, in New York City, United States (d. 1985) Willard Brown, American baseball player, outfielder for the Kansas City Monarchs and the St. Louis Browns from 1936 to 1950; in Shreveport, Louisiana, United States (d.
telomere A region of repetitive nucleotide sequences at each end of a linear chromosome which protects the end of the chromosome from deterioration and from fusion with other chromosomes. Since each round of replication results in the shortening of the chromosome, telomeres act as disposable buffers which are sacrificed to perpetual truncation instead of nearby genes; telomeres can also be lengthened by the enzyme telomerase.
=== Fed state === The glucose fatty acid cycle is also observed in the fed state after a high-fat meal or during exercise. This is when plasma concentrations of fatty acids or ketone bodies are increased. The glucose that is not oxidized is then rerouted to glycogen. This rerouting to glycogen explains the rapid resynthesis of muscle glycogen after exercise as well as the increased glycogen content in muscles found in starvation or diabetes. This mechanism replenishes the intermediates of the citric acid cycle.
For the Cossack elite, noble status within the empire came at the price of their old liberties in the 18th century. Advancing agricultural settlement began to force the Cossacks to give up their traditional nomadic ways and adopt new forms of government. The government steadily changed the entire culture of the Cossacks. Peter the Great increased Cossack service obligations, and mobilized their forces to fight in far-off wars. Peter began establishing non-Cossack troops in fortresses along the Yaik River. In 1734, construction of a government fortress at Orenburg gave Cossacks a subordinate role in border defense. When the Yaik Cossacks sent a delegation to Peter with their grievances, Peter stripped the Cossacks of their autonomous status, and subordinated them to the War College rather than the College of Foreign Affairs. This consolidated the Cossacks' transition from border patrol to military servicemen. Over the next fifty years, the central government responded to Cossack grievances with arrests, floggings, and exiles. Under Catherine the Great, beginning in 1762, the Russian peasants and Cossacks again faced increased taxation, heavy military conscription, and grain shortages, as before Razin's rebellion. Peter III had extended freedom to former church serfs, freeing them from obligations and payments to church authorities, and had freed other peasants from serfdom, but Catherine did not follow through on these reforms. In 1767, the Empress refused to accept grievances directly from the peasantry.
There is uncertainty about reinfection and long-term immunity. It is not known how common reinfection is, but reports have indicated that it is occurring with variable severity. The first reported case of reinfection was a 33-year-old man from Hong Kong who first tested positive on 26 March 2020, was discharged on 15 April 2020 after two negative tests, and tested positive again on 15 August 2020 (142 days later), which was confirmed by whole-genome sequencing showing that the viral genomes between the episodes belong to different clades. The findings had the implications that herd immunity may not eliminate the virus if reinfection is not an uncommon occurrence and that vaccines may not be able to provide lifelong protection against the virus. Another case study described a 25-year-old man from Nevada who tested positive for SARS‑CoV‑2 on 18 April 2020 and on 5 June 2020 (separated by two negative tests). Since genomic analyses showed significant genetic differences between the SARS‑CoV‑2 variant sampled on those two dates, the case study authors determined this was a reinfection. The man's second infection was symptomatically more severe than the first infection, but the mechanisms that could account for this are not known.
Sources: en.wikipedia.org
It is usually classified as an immunomodulatory peptide rather than a classical hormone. It derives from the larger protein prothymosin alpha and acts mainly on immune cells. The thymosin label covers a group of distinct peptides, so the naming can be misleading.
The two share a family name but have different sequences, sizes, and functions. Thymosin beta-4 is a 43-residue peptide associated with actin binding and cell migration. Thymosin alpha-1 is a 28-residue peptide linked mainly to immune signaling.
Thymalfasin is the assigned international nonproprietary name for the synthetic 28-residue peptide. Thymosin alpha-1 is the descriptive research name for the same molecule. Which term appears depends on the context and the regulatory document.
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.