The short version of 免疫组织 fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-06-18. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Acetylated peptide | N-terminal acetyl group blocks aminopeptidase attack |
| Residue count | 28 amino acids | Matches the N-terminus of prothymosin alpha |
| Molecular mass | About 3,108 Da | Value for the free, unmodified peptide |
| Isoelectric point | Approximately 4.2 | Acidic; net negative charge at neutral pH |
| Encoding gene | PTMA | Human gene for the precursor protein |
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。
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。
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.
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.
Within the immune system, the peptide acts on several cell types rather than a single target. Reported activities include promotion of T-cell maturation, enhancement of natural killer cell activity, and modulation of cytokine production by dendritic cells and macrophages. Some of these effects appear to operate through toll-like receptor signaling, though the precise receptor-level mechanism remains debated. Whether the observed immune changes translate into clinical benefit is a separate question and depends on the indication studied.
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.
== Health facility workload == The workload of a health facility is often used to indicate its size. Large health facilities are those with a greater patient load. In Australia the workload of a health facility is used to determine the level of government funding provided to that facility. The government measures a facility (or health practice) in terms of its standard whole patient equivalent (SWPE). The SWPE calculation is determined by analysis of the patients that attend that facility. The calculation takes into account the proportion of health services (in dollars) rendered at that facility relative to others that each patient attends. It includes a weighting factor based on each patients' demography to account for the varied levels of services required by patients depending on their gender and age. The premise of weighting is that patients require different levels of health services depending on their age and gender. For example, the average male patient requires fewer consultations than his older and infant counterparts. The table shows the weighting factors used in the standardization of workloads. Table: Age by Sex Weights for SWPE Standardisation
Encoded Self-Assembling Chemical (ESAC) libraries rely on the principle that two sublibraries of a size of x members (e.g. 103) containing a constant complementary hybridization domain can yield a combinatorial DNA-duplex library after hybridization with a complexity of x2 uniformly represented library members (e.g. 106). Each sub-library member would consist of an oligonucleotide containing a variable, coding region flanked by a constant DNA sequence, carrying a suitable chemical modification at the oligonucleotide extremity. The ESAC sublibraries can be used in at least four different embodiments.
Other culinary gelling agents can be used instead of animal-derived gelatine. These plant-derived substances are more similar to pectin and other gelling plant carbohydrates than to gelatine proteins; their physical properties are slightly different, creating different constraints for the preparation and storage conditions. These other gelling agents may also be preferred for certain traditional cuisines or dietary restrictions. Agar, a product made from red algae, is the traditional gelling agent in many Asian desserts. Agar is a popular gelatine substitute in quick jelly powder mix and prepared dessert gels that can be stored at room temperature. Compared to gelatine, agar preparations require a higher dissolving temperature, but the resulting gels congeal more quickly and remain solid at higher temperatures, 40 °C (104 °F), as opposed to 15 °C (59 °F) for gelatine. Vegans and vegetarians can use agar to replace animal-derived gelatine. Another common seaweed-based gelatine substitute is carrageenan, which has been used as a food additive since ancient times. It was first industrially-produced in the Philippines, which pioneered the cultivation of tropical red seaweed species (primarily Eucheuma and Kappaphycus spp.) from where carrageenan is extracted. The Philippines produces 80% of the world's carrageenan supply. Carrageenan gelatine substitute are traditionally known as gulaman in the Philippines. It is widely used in various traditional desserts and are sold as dried bars or in powder form.
Sources: en.wikipedia.org
high-affinity glutamate and neutral amino acid transporter (SLC1A1, SLC1A2, SLC1A3, SLC1A4, SLC1A5, SLC1A6, SLC1A7) facilitative GLUT transporter (SLC2A1, SLC2A2, SLC2A3, SLC2A4, SLC2A5, SLC2A6, SLC2A7, SLC2A8, SLC2A9, SLC2A10, SLC2A11, SLC2A12, SLC2A13, SLC2A14) heavy subunits of heterodimeric amino acid transporters (SLC3A1, SLC3A2) bicarbonate transporter (SLC4A1, SLC4A2, SLC4A3, SLC4A4, SLC4A5, SLC4A6, SLC4A7, SLC4A8, SLC4A9, SLC4A10, SLC4A11) sodium glucose cotransporter (SLC5A1, SLC5A2, SLC5A3, SLC5A4, SLC5A5, SLC5A6, SLC5A7, SLC5A8, SLC5A9, SLC5A10, SLC5A11, SLC5A12) sodium- and chloride-dependent sodium:neurotransmitter symporters (SLC6A1, SLC6A2, SLC6A3, SLC6A4, SLC6A5, SLC6A6, SLC6A7, SLC6A8, SLC6A9, SLC6A10, SLC6A11, SLC6A12, SLC6A13, SLC6A14, SLC6A15, SLC6A16, SLC6A17, SLC6A18, SLC6A19, SLC6A20) cationic amino acid transporter/glycoprotein-associated cationic amino acid transporters (SLC7A1, SLC7A2, SLC7A3, SLC7A4) glycoprotein-associated/light or catalytic subunits of heterodimeric amino acid transporters (SLC7A5, SLC7A6, SLC7A7, SLC7A8, SLC7A9, SLC7A10, SLC7A11, SLC7A13, SLC7A14) Na+/Ca2+ exchanger (SLC8A1, SLC8A2, SLC8A3) Na+/H+ exchanger (SLC9A1, SLC9A2, SLC9A3, SLC9A4, SLC9A5, SLC9A6, SLC9A7, SLC9A8, SLC9A9, SLC9A10, SLC9A11, SLC9B1, SLC9B2) sodium bile salt cotransport (SLC10A1, SLC10A2, SLC10A3, SLC10A4, SLC10A5, SLC10A6, SLC10A7) proton coupled metal ion transporter (SLC11A1, SLC11A2) electroneutral cation-Cl cotransporter (SLC12A1, SLC12A2, SLC12A3, SLC12A4, SLC12A5, SLC12A6, SLC12A7, SLC12A8, SLC12A9) Na+-sulfate/carboxylate cotransporter (SLC13A1, SLC13A2, SLC13A3, SLC13A4, SLC13A5) urea transporter (SLC14A1, SLC14A2) proton oligopeptide cotransporter (SLC15A1, SLC15A2, SLC15A3, SLC15A4) monocarboxylate transporter (SLC16A1, SLC16A2, SLC16A3, SLC16A4, SLC16A5, SLC16A6, SLC16A7, SLC16A8, SLC16A9, SLC16A10, SLC16A11, SLC16A12, SLC16A13, SLC16A14) vesicular glutamate transporter (SLC17A1, SLC17A2, SLC17A3, SLC17A4, SLC17A5, SLC17A6, SLC17A7, SLC17A8, SLC17A9) vesicular amine transporter (SLC18A1, SLC18A2, SLC18A3) folate/thiamine transporter (SLC19A1, SLC19A2, SLC19A3) type III Na+-phosphate cotransporter (SLC20A1, SLC20A2) organic anion transporting subfamily 1 (SLCO1A2, SLCO1B1, SLCO1B3, SLCO1C1) subfamily 2 (SLCO2A1, SLCO2B1) subfamily 3 (SLCO3A1) subfamily 4 (SLCO4A1, SLCO4C1) subfamily 5 (SLCO5A1) subfamily 6 (SLCO6A1) organic cation/anion/zwitterion transporter (SLC22A1, SLC22A2, SLC22A3, SLC22A4, SLC22A5, SLC22A6, SLC22A7, SLC22A8, SLC22A9, SLC22A10, SLC22A11, SLC22A12, SLC22A13, SLC22A14, SLC22A15, SLC22A16, SLC22A17, SLC22A18, SLC22A18AS, SLC22A19, SLC22A20, SLC22A23, SLC22A24, SLC22A25, SLC22A31) Na+-dependent ascorbic acid transporter (SLC23A1, SLC23A2, SLC23A3, SLC23A4) Na+/(Ca2+-K+) exchanger (SLC24A1, SLC24A2, SLC24A3, SLC24A4, SLC24A5, SLC24A6) mitochondrial carrier (SLC25A1, SLC25A2, SLC25A3, SLC25A4, SLC25A5, SLC25A6, UCP1(SLC25A7), UCP2(SLC25A8), UCP3(SLC25A9), SLC25A10, SLC25A11, SLC25A12, SLC25A13, SLC25A14, SLC25A15, SLC25A16, SLC25A17, SLC25A18, SLC25A19, SLC25A20, SLC25A21, SLC25A22, SLC25A23, SLC25A24, SLC25A25, SLC25A26, SLC25A27, SLC25A28, SLC25A29, SLC25A30, SLC25A31, SLC25A32, SLC25A33, SLC25A34, SLC25A35, SLC25A36, SLC25A37, SLC25A38, SLC25A39, SLC25A40, SLC25A41, SLC25A42, SLC25A43, SLC25A44, SLC25A45, SLC25A46), SLC25A47, SLC25A48, MTCH1(SLC25A49), MTCH2(SLC25A50), SLC25A51, SLC25A52, SLC25A53 multifunctional anion exchanger (SLC26A1, SLC26A2, SLC26A3, SLC26A4, SLC26A5, SLC26A6, SLC26A7, SLC26A8, SLC26A9, SLC26A10, SLC26A11) fatty acid transport proteins (SLC27A1, SLC27A2, SLC27A3, SLC27A4, SLC27A5, SLC27A6) Na+-coupled nucleoside transport (SLC28A1, SLC28A2, SLC28A3) facilitative nucleoside transporter (SLC29A1, SLC29A2, SLC29A3, SLC29A4) zinc transporter (SLC30A1, SLC30A2, SLC30A3, SLC30A4, SLC30A5, SLC30A6, SLC30A7, SLC30A8, SLC30A9, SLC30A10) copper transporter (SLC31A1, SLC31A2) vesicular inhibitory amino acid transporter (SLC32A1) Acetyl-CoA transporter (SLC33A1) type II Na+-phosphate cotransporter (SLC34A1, SLC34A2, SLC34A3) nucleotide-sugar transporter subfamily A (SLC35A1, SLC35A2, SLC35A3, SLC35A4, SLC35A5) subfamily B (SLC35B1, SLC35B2, SLC35B3, SLC35B4) subfamily C (SLC35C1, SLC35C2) subfamily D (SLC35D1, SLC35D2, SLC35D3) subfamily E (SLC35E1, SLC35E2A, SLC35E2B, SLC35E3, SLC35E4) subfamily F (SLC35F1, SLC35F2, SLC35F3, SLC35F4, SLC35F5) subfamily G (SLC35G1, SLC35G3, SLC35G4, SLC35G5, SLC35G6) proton-coupled amino acid transporter (SLC36A1, SLC36A2, SLC36A3, SLC36A4) sugar-phosphate/phosphate exchanger (SLC37A1, SLC37A2, SLC37A3, SLC37A4) System A & N, sodium-coupled neutral amino acid transporter (SLC38A1, SLC38A2, SLC38A3, SLC38A4, SLC38A5, SLC38A6, SLC38A7, SLC38A8, SLC38A9, SLC38A10, SLC38A11) metal ion transporter (SLC39A1, SLC39A2, SLC39A3, SLC39A4, SLC39A5, SLC39A6, SLC39A7, SLC39A8, SLC39A9, SLC39A10, SLC39A11, SLC39A12, SLC39A13, SLC39A14) basolateral iron transporter (SLC40A1) MgtE-like magnesium transporter (SLC41A1, SLC41A2, SLC41A3) Ammonia transporter (RHAG(SLC42A1), RHBG(SLC42A2), RHCG(SLC42A3)) Na+-independent, system-L like amino acid transporter (SLC43A1, SLC43A2, SLC43A3) Choline-like transporter (SLC44A1, SLC44A2, SLC44A3, SLC44A4, SLC44A5) Putative sugar transporter (SLC45A1, SLC45A2, SLC45A3, SLC45A4) Folate transporter (SLC46A1, SLC46A2, SLC46A3) multidrug and toxin extrusion (SLC47A1, SLC47A2) Heme transporter family (SLC48A1) Heme transporter (FLVCR1(SLC49A1), FLVCR2(SLC49A2), SLC49A3, SLC49A4) Sugar efflux transporters of the SWEET family (SLC50A1) Transporters of steroid-derived molecules (SLC51A, SLC51B) Riboflavin transporter family RFVT/SLC52 (SLC52A1, SLC52A2, SLC52A3) Phosphate carriers (XPR1(SLC53A1)) Mitochondrial pyruvate carriers (MPC1(SLC54A1), MPC2(SLC54A2), MPC1L(SLC54A3)) Mitochondrial cation/proton exchangers (LETM1(SLC55A1), LETM2(SLC55A2), LETMD1(SLC55A3)) Sideroflexins (SFXN1(SLC56A1), SFXN2(SLC56A2), SFXN3(SLC56A3), SFXN4(SLC56A4), SFXN5(SLC56A5)) NiPA-like magnesium transporter family (NIPA1(SLC57A1), NIPA2(SLC57A2), NIPAL1(SLC57A3), NIPAL2(SLC57A4), NIPAL3(SLC57A5), NIPAL4(SLC57A6)) MagT-like magnesium transporter family (MAGT1(SLC58A1), TUSC3(SLC58A2)) Sodium-dependent lysophosphatidylcholine symporter family (MFSD2A(SLC59A1), MFSD2B(SLC59A2)) Glucose transporters (MFSD4A(SLC60A1), MFSD4B(SLC60A2)) Molybdate transporter family (MFSD5(SLC61A1)) Pyrophosphate transporters (ANKH(SLC62A1)) Sphingosine-phosphate transporters (SPNS1(SLC63A1), SPNS2(SLC63A2), SPNS3(SLC63A3)) Golgi Ca2+/H+ exchangers (TMEM165(SLC64A1)) NPC-type cholesterol transporters (NPC1(SLC65A1), NPC1L1(SLC65A2)) Cationic amino acid exporters (SLC66A1, SLC66A2, SLC66A3, CTNS(SLC66A4), MPDU1(SLC66A5))
"[...] we commend the Anti-Eugenics Project for their essential work to understand[...] the harmful legacies of eugenicist ideologies. [...] examine the role that philanthropies played in developing and perpetuating eugenics policies and practices. The Rockefeller Foundation is currently reckoning with our own history in relation to eugenics. This requires uncovering the facts and confronting uncomfortable truths, [...] The Rockefeller Foundation is putting equity and inclusion at the center of all our work: [...] confronting the hateful legacies of the past [...] we understand that the work we engage in today does not absolve us of yesterday's mistakes. [...]"
middle lamella In plant cells, the outermost layer of the cell wall; a continuous, unified layer of extracellular pectins which is the first layer deposited by the cell during cytokinesis and which serves to cement together the primary cell walls of adjacent cells.
Sources: en.wikipedia.org
Thymosin fraction 5 is a mixture of many peptides obtained from thymus tissue, while thymosin alpha 1 is a single defined 28-residue molecule. The two names appear together in older literature because the purified peptide was first obtained from that mixture.
The precursor, prothymosin alpha, is encoded by the PTMA gene in humans. The 28-residue peptide corresponds to the N-terminal segment released from that larger protein.
It is produced as a fragment of prothymosin alpha and is present in many tissues. Circulating concentrations are low, which makes routine measurement difficult.
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.