If you have been reading about Immune modulation 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 2026-01-27. Where a claim depends on a specific study, the study is described rather than over-claimed.
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。
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。
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.
Thymosin alpha-1 is a synthetic peptide of 28 amino acid residues that corresponds to a naturally occurring fragment first isolated from thymus tissue. Its chain is acetylated at the amino terminus, a modification that shields the peptide from rapid cleavage by aminopeptidases. The molecule carries a net negative charge at physiological pH and dissolves freely in water. Researchers classify it as an immune-modulating agent rather than a classical hormone, because it acts on several cell types of both the innate and the adaptive immune system.
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.
| Property | Value | Notes |
|---|---|---|
| 主要靶细胞 | T细胞、树突状细胞 | 也影响NK细胞 |
| 信号通路 | TLR/MyD88/NF-κB | 部分实验模型 |
| 细胞因子偏向 | Th1型 | 增加IL-2、IFN-γ |
| 给药途径 | 皮下注射 | 临床常用 |
| 半衰期 | 约2小时 | 血浆中较短 |
=== Off-label drugs === Anticonvulsants (e.g., valproic acid) Atypical antipsychotics (e.g., quetiapine) Azapirones (serotonin 5-HT1A receptor agonists) (e.g., buspirone) Benzodiazepines (GABAA receptor positive allosteric modulators) (e.g., alprazolam, chlordiazepoxide, clonazepam, diazepam, lorazepam) Beta blockers (e.g., propranolol) Gabapentinoids (α2δ subunit-containing voltage-gated calcium channel ligands) (e.g., gabapentin, pregabalin) Monoamine oxidase inhibitors (MAOIs) (e.g., isocarboxazid, moclobemide, phenelzine, tranylcypromine) NMDA receptor antagonists (e.g., ketamine, esketamine) Selective serotonin reuptake inhibitors (SSRIs) (e.g., citalopram, fluvoxamine) Serotonin–norepinephrine reuptake inhibitors (SNRIs) (e.g., desvenlafaxine, duloxetine, levomilnacipran, milnacipran) Serotonin modulators and stimulators (SMSs) (e.g., vilazodone, vortioxetine) Tricyclic antidepressants (TCAs) (e.g., amitriptyline, clomipramine, doxepin, imipramine) Tetracyclic antidepressants (TeCAs) (e.g., mirtazapine) Others (e.g., hydroxyzine)
=== Lymphangioleiomyomatosis === In May 2015, the FDA approved sirolimus to treat lymphangioleiomyomatosis (LAM), a rare, progressive lung disease that primarily affects women of childbearing age. This made sirolimus the first drug approved to treat this disease. LAM involves lung tissue infiltration with smooth muscle-like cells with mutations of the tuberous sclerosis complex gene (TSC2). Loss of TSC2 gene function activates the mTOR signaling pathway, resulting in the release of lymphangiogenic growth factors. Sirolimus blocks this pathway. The safety and efficacy of sirolimus treatment of LAM were investigated in clinical trials that compared sirolimus treatment with a placebo group in 89 patients for 12 months. The patients were observed for 12 months after the treatment had ended. The most commonly reported side effects of sirolimus treatment of LAM were mouth and lip ulcers, diarrhea, abdominal pain, nausea, sore throat, acne, chest pain, leg swelling, upper respiratory tract infection, headache, dizziness, muscle pain and elevated cholesterol. Serious side effects including hypersensitivity and swelling (edema) have been observed in renal transplant patients. While sirolimus was considered for treatment of LAM, it received orphan drug designation status because LAM is a rare condition. The safety of LAM treatment by sirolimus in people younger than 18 years old has not been tested.
=== Industrial cleaning agent === Sulfuric acid is used in steelmaking and other metallurgical industries as a pickling agent for removal of rust and fouling. Used acid is often recycled using a spent acid regeneration (SAR) plant. These plants combust spent acid with natural gas, refinery gas, fuel oil or other fuel sources. This combustion process produces gaseous sulfur dioxide (SO2) and sulfur trioxide (SO3) which are then used to manufacture "new" sulfuric acid. Hydrogen peroxide (H2O2) can be added to sulfuric acid to produce piranha solution, a powerful but potentially hazardous cleaning solution with which substrate surfaces can be cleaned. Piranha solution is typically used in the microelectronics industry, and also in laboratory settings to clean glassware.
Plants are not passive, but respond to external signals such as light, touch, and injury by moving or growing towards or away from the stimulus, as appropriate. Tangible evidence of touch sensitivity is the almost instantaneous collapse of leaflets of Mimosa pudica, the insect traps of Venus flytrap and bladderworts, and the pollinia of orchids. The hypothesis that plant growth and development is coordinated by plant hormones or plant growth regulators first emerged in the late 19th century. Darwin experimented on the movements of plant shoots and roots towards light and gravity, and concluded "It is hardly an exaggeration to say that the tip of the radicle…acts like the brain of one of the lower animals…directing the several movements." About the same time, the role of auxins (from the Greek auxein, to grow) in control of plant growth was first outlined by the Dutch scientist Frits Went. The first known auxin, indole-3-acetic acid (IAA), which promotes cell growth, was only isolated from plants about 50 years later. This compound mediates the tropic responses of shoots and roots towards light and gravity. The finding in 1939 that plant callus could be maintained in culture containing IAA, followed by the observation in 1947 that it could be induced to form roots and shoots by controlling the concentration of growth hormones were key steps in the development of plant biotechnology and genetic modification.
=== Methodology === Most tests employ a monoclonal antibody, which is specific to the β-subunit of hCG (β-hCG). This procedure is employed to ensure that tests do not make false positives by confusing hCG with LH and FSH. (The latter two are always present at varying levels in the body, whereas the presence of hCG almost always indicates pregnancy.) Many hCG immunoassays are based on the sandwich principle, which uses antibodies to hCG labeled with an enzyme or a conventional or luminescent dye. Pregnancy urine dipstick tests are based on the lateral flow technique.
Sources: en.wikipedia.org
== Prevention == Methods in preventing amputation, limb-sparing techniques, depend on the problems that might cause amputations to be necessary. Chronic infections, often caused by diabetes or decubitus ulcers in bedridden patients, are common causes of infections that lead to gangrene, which, when widespread, necessitates amputation. There are two key challenges: first, many patients have impaired circulation in their extremities, and second, they have difficulty curing infections in limbs with poor blood circulation. Crush injuries where there is extensive tissue damage and poor circulation also benefit from hyperbaric oxygen therapy (HBOT). The high level of oxygenation and revascularization speed up recovery times and prevent infections. A study found that the patented method called Circulator Boot achieved significant results in prevention of amputation in patients with diabetes and arteriosclerosis. Another study found it also effective for healing limb ulcers caused by peripheral vascular disease. The boot checks the heart rhythm and compresses the limb between heartbeats; the compression helps cure the wounds in the walls of veins and arteries, and helps to push the blood back to the heart. For victims of trauma, advances in microsurgery in the 1970s have made replantation of severed body parts possible. The establishment of laws, rules, and guidelines, and the employment of modern equipment help protect people from traumatic amputations.
The alveolates are a major clade of unicellular eukaryotes of both autotrophic and heterotrophic members. Many members contain a red-algal derived plastid. One notable characteristic of this diverse group is the frequent loss of photosynthesis. However, a majority of these heterotrophs continue to process a non-photosynthetic plastid.
Cream can be skimmed from whey. Whey cream is saltier, tangier, and "cheesier" than ("sweet") cream skimmed from milk, and can be used to make whey butter. Due to the low fat content of whey, the yield is low, with typically two to five parts of butter manufactured from the whey of 1,000 parts milk. Whey cream and butter are suitable for making butter-flavoured food, as they have a stronger flavour of their own. They are also cheaper to manufacture than sweet cream and butter.
Most classical force fields implicitly include the effect of polarizability, e.g., by scaling up the partial charges obtained from quantum chemical calculations. These partial charges are stationary with respect to the mass of the atom. But molecular dynamics simulations can explicitly model polarizability with the introduction of induced dipoles through different methods, such as Drude particles or fluctuating charges. This allows for a dynamic redistribution of charge between atoms which responds to the local chemical environment. For many years, polarizable MD simulations have been touted as the next generation. For homogenous liquids such as water, increased accuracy has been achieved through the inclusion of polarizability. Some promising results have also been achieved for proteins. However, it is still uncertain how to best approximate polarizability in a simulation. The point becomes more important when a particle experiences different environments during its simulation trajectory, e.g. translocation of a drug through a cell membrane.
Olaf College Elio Di Rupo (born 1951), Prime Minister of Belgium Israel Shahak (1933–2001), Israeli chemist and civil-rights activist Margaret Thatcher (1925–2013), Prime Minister of the United Kingdom (1979–1990), research chemist at BX Plastics
Sources: en.wikipedia.org
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。
目前认为它可能通过Toll样受体等模式识别受体传递信号,但精确的受体身份和结合机制尚未完全阐明。
不同试验在患者选择、给药方案、联合治疗和终点定义上差异很大。这些异质性使得跨研究比较困难,结论难以统一。
It is a 28-residue synthetic peptide studied as an immune-modulating agent and approved as a drug in some countries. The sequence matches a naturally occurring fragment isolated from thymus tissue. It is not a hormone in the endocrine sense.