Explore studies of thymosin alpha 1.
Thymosin peptides both increase and decrease TdT activity depending on the maturation stage, indicating they regulate multiple phases of T-cell development.
Hu, S K; Low, T L; Goldstein, A L · Animal Study
Mice lost immune killing power as they aged. By 24 months (equivalent to roughly 70+ human years), their spleen cells were much weaker at destroying tumor cells compared to 1-month-old mice. Four thymic hormones were tested: FTS (serum thymic factor), TP5 (a fragment of thymopoietin), TM4 (a synthetic version of TP5), and thymosin fraction V. Each worked differently depending on the age of the mouse and the dose used. The most striking result: TM4 at a very low dose (1 nanogram) actually suppressed immune killing in young mice but significantly boosted it in 12- and 24-month-old mice. FTS and TP5 partially restored killing ability in old mice. Thymosin fraction V had modest and inconsistent effects.
Ghanta, V K; Noble, P J; Brown, M E; Cox, P J; Hiramoto, N S; Hiramoto, R N · Animal Study
Natural killer (NK) cells are immune cells that destroy virus-infected and cancer cells without needing prior training. Cyclophosphamide (CY), a chemotherapy drug, wiped out NK cell activity in mice. Interferon alone (30,000 units per mouse) strongly boosted NK cells in healthy mice. But in CY-suppressed mice, interferon by itself did nothing. The combination worked: thymosin alpha 1 (200 micrograms/kg) given daily for 4 days, followed by a single interferon injection 24 hours before testing, fully restored NK cell activity in the immunosuppressed mice. Thymosin alpha 1 also accelerated NK cell recovery in mice that received bone marrow transplants.
Favalli, C; Jezzi, T; Mastino, A; Rinaldi-Garaci, C; Riccardi, C; Garaci, E · Animal Study
The paper argued that certain molecules made by immune cells can send signals directly to the brain. The authors named these 'immunotransmitters,' a new term for molecules that carry information from the immune system to the central nervous system (CNS). Examples include thymosin alpha 1 and thymosin beta 4 (peptides from the thymus gland), as well as ACTH (a stress hormone), TSH (thyroid hormone), and beta-endorphin (a natural painkiller) produced by lymphocytes (white blood cells). The review presented evidence that thymosin peptides can alter the hypothalamic-pituitary-adrenal (HPA) axis, which is the brain's master hormone control system. They also appeared to affect the gonadal (reproductive hormone) axis.
Hall, N R; McGillis, J P; Spangelo, B L; Goldstein, A L · Review
Parathymosin alpha is a newly discovered peptide of about 105 amino acid residues, isolated from rat thymus tissue. The first 30 amino acids of its sequence showed 43% structural identity with thymosin alpha 1 and prothymosin alpha. The structural overlap did not include residues 2 through 9 of thymosin alpha 1. This explained why antibodies targeting that region of thymosin alpha 1 did not recognize parathymosin alpha. Functionally, parathymosin alpha appeared to regulate prothymosin alpha's ability to protect sensitive mice from Candida albicans (a common fungal infection). This suggests it acts as a modulator of immune protection rather than a direct immune booster.
Haritos, A A; Salvin, S B; Blacher, R; Stein, S; Horecker, B L · In Vitro
The patient had primary intestinal lymphangiectasia (a condition where lymph vessels in the gut leak fluid, protein, and immune cells). Biopsies confirmed the diagnosis in her intestines, lungs, and lymph nodes. Lymphocytes were literally leaking out through her gut, confirmed by finding them in her stool. Her thymus gland was essentially absent. A biopsy showed no thymic tissue. Blood tests showed very low or absent thymulin and thymosin alpha 1. She had a selective loss of T-cells, especially CD4+ helper T-cells. Daily thymosin fraction 5 treatment produced a brief clinical improvement. But switching to weekly injections could not sustain it. Lymphocyte numbers never increased during treatment. The authors concluded that when the body loses T-cells faster than it can replace them, even thymic hormones cannot keep up without a functioning thymus.
Sorensen, R U; Halpin, T C; Abramowsky, C R; Hornick, D L; Miller, K M; Naylor, P; Incefy, G S · Case Report
Thymosin alpha 1 (Ta-1) had strikingly different effects depending on the mouse strain. In B10.D2 mice (resistant to autoimmune thyroiditis), Ta-1 treatment between the two antigen injections actually increased thyroid inflammation. In B10.Br mice (naturally susceptible), Ta-1 suppressed the disease. Timing mattered. Early treatment (first 2 weeks) suppressed disease in the susceptible strain but worsened it in the resistant strain. Later treatment (weeks 3-4) had similar patterns. Different doses affected different T-cell subsets. The 0.01 microgram dose lowered Lyt-2+3+ cells (a type of immune cell) in resistant mice. The 0.001 microgram dose raised Lyt-1+ cells in the same strain. Each dose shifted the immune balance differently, which explains the opposing disease outcomes.
Tomazic, V J; Novotny, E A; Ordonez, J V · Animal Study
Leukocyte migration inhibition (LMI), a measure of how well immune cells respond to signals, was impaired in 24 head and neck cancer patients compared to healthy people. Adding thymosin alpha 1 to the lab dish improved LMI in the cancer patients' cells. The improvement appeared independent of T-cell subset levels, meaning thymosin alpha 1 was enhancing the function of existing cells rather than changing which cells were present. An interesting secondary finding: patients whose LMI was still normal had lower levels of suppressor/cytotoxic T-cells than both healthy people and patients with impaired LMI. This suggests that suppressor cells may contribute to the immune dysfunction in these cancers.
Wolf, G T; Peterson, K A; Lovett, E J · In Vitro
Normal thymosin alpha 1 levels: 670 ± 163 pg/mL for males and 652 ± 162 pg/mL for females. Normal thymosin beta 4 levels: 974 ± 400 ng/mL for males and 889 ± 345 ng/mL for females. Note that beta 4 levels are about 1,000 times higher than alpha 1. In AIDS patients, 57% had elevated thymosin alpha 1 and 48% had elevated thymosin beta 4. But there was no correlation between the two peptides' levels in any group, including healthy controls. People with AIDS-related immune dysfunction (not full AIDS) showed a different pattern: 54% had elevated thymosin alpha 1 but only 15% had elevated thymosin beta 4. This suggests thymosin alpha 1 rises earlier in the disease process.
Naylor, P H; Friedman-Kien, A; Hersh, E; Erdos, M; Goldstein, A L · Cross Sectional
Thymosin fraction 5 (TF5), a mix of thymic peptides, significantly increased both the percentage of human lymphocytes expressing IL-2 receptors (IL-2R) and the density of receptors on each cell. This happened after the cells were stimulated with PHA (a plant protein that activates immune cells). Synthetic thymosin alpha 1 alone produced the same effect, identifying it as the active ingredient in TF5. The effect was direct. When researchers used cyclosporin A (a drug that blocks IL-2 production), TF5 still increased IL-2R expression. This means thymosin works by directly putting more receptors on cells, not by making more IL-2. More receptors led to stronger cell multiplication.
Sztein, M B; Serrate, S A; Goldstein, A L · In Vitro
IL-2 is a 133-amino acid protein (molecular weight 15,420 daltons) produced by activated T-cells. Its gene sits on chromosome 4. The IL-2 receptor is a 272-amino acid protein (55,000 daltons). IL-2 does not just make immune cells copy themselves. It moves cells from a resting state (G1) through to DNA synthesis (S phase). During this process, the proto-oncogene c-myb increases 6 to 7 times above normal levels. The most exciting clinical development: IL-2 could expand LAK cells (lymphokine-activated killer cells) and TIL (tumor-infiltrating lymphocytes) that attack cancer. Early human trials showed both therapeutic promise and significant toxicity. Thymosin fraction 5 and thymosin alpha 1 could modulate IL-2 receptor expression on human blood cells, potentially increasing the effectiveness of IL-2 therapy.
Fletcher, M; Goldstein, A L · Review
The percentage of E-rosettes (a marker of mature T-cells) was lower in 33 acutely malnourished children compared to mildly growth-retarded children from the same area. But there was considerable overlap between groups, meaning not every malnourished child had low T-cells. This differed from studies in other countries where all severely malnourished children showed uniformly depressed T-cell markers. The authors suggested that specific nutrient deficiencies, not malnutrition overall, may drive immune problems. Adding thymosin fraction 5 to the children's blood cells in lab dishes increased E-rosette formation in a dose-dependent manner. This means immature T-cell precursors were present in the blood and could be pushed toward maturity with thymic peptides.
Keusch, G T; Cruz, J R; Torun, B; Urrutia, J J; Smith, H; Goldstein, A L · Cross Sectional
The new enzyme immunoassay (EIA) for thymulin achieved a sensitivity of 32.5 ± 5 pg/mL (IC50) with a detection limit of 5 pg/mL. This was more sensitive than previously available radioimmunoassays. The test was highly specific. It did not cross-react with thymosin alpha 1, thymopoietin II, or TP5 (another thymic peptide). Both the zinc-bound (biologically active) and zinc-free forms of thymulin showed the same immunoreactivity. Mapping studies showed that the minimum peptide structure needed for detection was the C-terminal portion from lysine-3 to asparagine-9 (7 of the 9 amino acids).
Métreau, E; Pléau, J M; Dardenne, M; Bach, J F; Pradelles, P · In Vitro
Eight monoclonal antibodies against thymosin alpha 1 were produced from mice immunized with synthetic thymosin alpha 1. The antibodies were screened using both solid-phase ELISA and liquid-phase radioimmunoassay for maximum specificity. Using indirect immunofluorescence on perfused rat thymus tissue, thymosin alpha 1-containing cells were found primarily in the thymic medulla. This confirmed earlier studies that used less specific polyclonal antibodies. The monoclonal antibodies provide a standardized, unlimited supply of reagent compared to the variable polyclonal antisera used previously. They can be used for both in vitro and in vivo studies of thymosin alpha 1 location and function.
Oates, K K; Naylor, P H; Goldstein, A L · In Vitro
Thymosin alpha-1 and lymphokine-containing supernatants directly stimulated both basal and corticotropin-induced corticosterone secretion from adrenal cells.
Torres-Alemán, I; Rejas, M T; Barasoaín, I; Borrell, J; Guaza, C · In Vitro
Amniotic fluid thymosin alpha 1 levels were remarkably higher than newborn serum levels and increased in a logarithmic pattern with fetal age (r = 0.838).
Welch, R A; Lee, H H; Sokol, R J; Mutchnick, M G · Cross Sectional
Rhinovirus infection triggered significant increases in thymosin alpha 1 (p < 0.001), thymosin beta 4 (p < 0.001), and multiple immune cell types by day 5 after inoculation.
Hsia, J; Sztein, M B; Naylor, P H; Simon, G L; Goldstein, A L; Hayden, F G · RCT
TF5 stimulated IL-1 alpha (not IL-1 beta) production from monocytes. The active component was a novel basic peptide, not thymosin alpha 1.
Hu, S K; Badamchian, M; Mitcho, Y L; Goldstein, A L · In Vitro
Thymosin alpha 1 modulates an early event in T cell activation. A 30-minute preincubation is sufficient to prime both CD4+ and CD8+ T cells, but macrophage-derived IL-1 is required for the enhanced response.
Sztein, M B; Serrate, S A · In Vitro
Prothymosin alpha acts as an accessory signal for T cell activation. It requires macrophage-derived IL-1 for its effect and works through an IL-2-dependent pathway.
Cordero, O J; Sarandeses, C S; Nogueira, M · In Vitro
Both thymosin alpha 1 and thymosin beta 4 suppress gut lamina propria lymphocyte proliferation through a mechanism that may involve protein kinase C but not calcium flux or ornithine decarboxylase pathways.
Elitsur, Y; Mutchnick, M G; Sakr, W A; Luk, G D · In Vitro
Thymosin alpha 1 increases high-affinity IL-2 receptor expression with a bimodal dose-response pattern. This directly correlates with enhanced IL-2 production and is only effective during immune activation.
Leichtling, K D; Serrate, S A; Sztein, M B · In Vitro
Thymic hormones (thymosin alpha-1, thymulin, thymopoietin) decline with age alongside thymic involution, and their supplementation shows potential for partially restoring age-related immune deficits.
Hadden, J W; Malec, P H; Coto, J; Hadden, E M · Review
Thymosin beta 4 peaked early and declined with age. hCG challenge depressed thymosin beta 4. Testosterone modulated both thymosin beta 4 and alpha 1 levels. Castration altered the patterns.
Wise, T H · Animal Study
Thymosin alpha 1 fully restored cocaine-suppressed antibody responses. Thymopentin partially restored them. Effect confirmed at the individual splenocyte level.
Ravagnan, G; Falchetti, R; Lanzilli, G; Di Francesco, P; Gaziano, R; Favalli, C; Garaci, E · Animal Study
Thymosin alpha 1 demonstrated promising antiviral and immune-enhancing effects in early hepatitis B and C trials, suggesting it could complement or replace interferon.
Mutchnick, M G; Ehrinpreis, M N; Kinzie, J L; Peleman, R R · Review
Combination thymosin alpha-1 (1 mg twice weekly) and lymphoblastoid interferon was tested as a strategy to improve sustained response rates in chronic hepatitis C over interferon monotherapy.
Rasi, G; DiVirgilio, D; Mutchnick, M G; Colella, F; Sinibaldi-Vallebona, P; Pierimarchi, P; Valli, B; Garaci, E · RCT
Thymosin alpha-1 adopts a structured conformation with a beta-turn (residues 5-8) and alpha helix (residues 17-24) in membrane-like environments, suggesting this shape change is required for immune cell activation.
Grottesi, A; Sette, M; Palamara, T; Rotilio, G; Garaci, E; Paci, M · In Vitro
Thymosin alpha-1 (1 mg twice weekly) combined with interferon-alpha-2b (3 MU three times weekly) produced superior biochemical and virological responses compared to interferon alone in treatment-naive chronic hepatitis C patients.
Moscarella, S; Buzzelli, G; Romanelli, R G; Monti, M; Giannini, C; Careccia, G; Marrocchi, E M; Zignego, A L · RCT
Dose-escalation of thymosin alpha-1 in triple chemo-immunotherapy (cyclophosphamide + thymosin alpha-1 + interferon) produced dose-dependent increases in anti-tumor efficacy against B16 melanoma in mice.
Pica, F; Fraschetti, M; Matteucci, C; Tuthill, C; Rasi, G · Animal Study
The thymic-pituitary axis forms a bidirectional neuroendocrine circuit that deteriorates with age, contributing to immunosenescence. Thymic peptide supplementation may restore immune-endocrine homeostasis in aging.
Goya, R G; Bolognani, F · Review
Aging causes progressive disruption of the pituitary-thymic bidirectional circuit: reduced thymic peptide production, altered pituitary hormone output, and impaired integration between immune and endocrine systems, creating a self-reinforcing decline.
Goya, R G; Brown, O A; Bolognani, F · Review
Endogenous thymosin alpha-1 protein and mRNA were detected in rat CNS neurons, astrocytes, and oligodendrocytes, establishing it as a brain-derived peptide that may contribute to neurotrophic signaling.
Turrini, P; Aloe, L · Animal Study
Thymosin alpha-1 (0.01-10 μg SC daily for 7 days) increased thymocytes and blood cells, reduced primary tumor weight, and inhibited organ colonization by metastatic cells in tumor-bearing BALB/c mice.
Beuth, J; Schierholz, J M; Mayer, G · Animal Study
Thymic hormones serve dual roles in oncology: as biomarkers correlating with immune status and prognosis, and as therapeutic immunostimulants that enhance anti-tumor immunity when combined with conventional cancer treatments.
Bodey, B; Bodey, B; Siegel, S E; Kaiser, H E · Review
Thymosin alpha-1 combined with low-dose IFN or IL-2 shows high efficacy against cancers in both preclinical models and human clinical trials, supporting its role as a cancer immunotherapy adjuvant.
Garaci, E; Pica, F; Rasi, G; Favalli, C · Review
Melatonin directly regulates thymosin alpha-1 and thymulin production, driving their nocturnal peaks in serum and thymus. Pinealectomy abolished and melatonin replacement restored the circadian thymic peptide pattern.
Molinero, P; Soutto, M; Benot, S; Hmadcha, A; Guerrero, J M · Animal Study
Thymosin alpha-1 plasma levels and circadian rhythms were altered in gynecologic inflammation, varying by inflammation type and normalizing with successful treatment.
Shurlygina, A; Litvinenko, G; Dergacheva, T; Trufakin, V · Cohort
Thymosin alpha-1 improved virological (HBV DNA clearance) and biochemical (ALT normalization) responses in anti-HBe positive chronic hepatitis B, a treatment-resistant subgroup.
Zavaglia, C; Severini, R; Tinelli, C; Franzone, J S; Airoldi, A; Tempini, S; Bettale, G; Ideo, G · RCT
Thymosin alpha-1 demonstrates clinical efficacy in chronic hepatitis B and C (combined with interferon), with emerging evidence for cancer immunotherapy, HIV, and vaccine enhancement, showing excellent tolerability.
Ancell, C D; Phipps, J; Young, L · Review
Thymosin alpha-1 + IFN-alpha shifted Th1/Th2 balance toward Th1 dominance (increased IFN-γ/IL-2, decreased IL-4/IL-10) in HCV patient PBMCs, while IFN-alpha alone produced only partial Th1 enhancement.
Andreone, P; Cursaro, C; Gramenzi, A; Margotti, M; Ferri, E; Talarico, S; Biselli, M; Felline, F; Tuthill, C; Martins, E; Gasbarrini, G; Bernardi, M · In Vitro
TFA contamination from peptide synthesis inactivated thymosin alpha-1's clonal growth inhibition activity, demonstrating the need for rigorous purification and biological activity testing of therapeutic peptide preparations.
Bianco-Batlles, D; Naylor, C W; Moshier, J A; Dosescu, J; Naylor, P H · In Vitro
Thymosin alpha-1 restored T-cell proliferation, NK cell cytotoxicity, and Th1 cytokine production (IL-2, IFN-γ) in cyclophosphamide-immunosuppressed mice, demonstrating broad immune reconstitution capacity.
Ohmori, H; Kamo, M; Yamakoshi, K; Nitta, M H; Hikida, M; Kanayama, N · Animal Study
Thymosin alpha-1 demonstrates clinical efficacy across hepatitis B, hepatitis C (with IFN), cancer (with chemo), and potentially HIV, with excellent tolerability and a favorable safety profile across all studied indications.
Billich, Andreas · Review
Thymosin alpha-1 + famciclovir combination activated HBV-specific T-cell responses and achieved HBeAg seroconversion in some immune-tolerant chronic hepatitis B patients — a typically treatment-unresponsive population.
Lau, G K K; Nanji, A; Hou, J; Fong, D Y T; Au, W-S; Yuen, S-T; Lin, M; Kung, H-F; Lam, S-K · Clinical Trial
Chronic HBV treatment should be individualized based on viral markers, liver status, and patient characteristics, with thymosin alpha-1 offering an immune-enhancing alternative/complement to antiviral drugs across different HBV subgroups.
Leung, Nancy · Review
Thymosin alpha-1 accelerated restoration of T-cell-mediated neutralizing antibody responses in immunocompromised hosts, demonstrating faster immune reconstitution through both immunomodulatory and direct intracellular mechanisms.
Li, Chun-lin; Zhang, Ting; Saibara, Toshiji; Nemoto, Yoshihisa; Ono, Masafumi; Akisawa, Naoaki; Iwasaki, Shinji; Maeda, Takashi; Onishi, Saburo · Animal Study
Thymosin alpha-1 significantly inhibited NMU-induced mammary carcinogenesis in Fisher rats, reducing both tumor incidence and multiplicity, demonstrating cancer prevention through immune enhancement.
Moody, Terry W; Tuthill, Cynthia; Badamchian, Mahnaz; Goldstein, Allan L · Animal Study
Thymosin alpha-1 restored suppressed bone marrow hematopoiesis in T-cell lymphoma mice, increasing colony-forming units (CFU-GM, BFU-E, CFU-GEMM) and peripheral blood counts across all lineages.
Paul, Saki; Sodhi, Ajit · Animal Study
Thymosin alpha-1 activated anti-tumor macrophages through p38 MAPK and ERK signaling pathways, with pathway inhibition blocking the anti-tumor effect, identifying the specific intracellular mechanism of thymosin alpha-1's immunostimulatory action.
Sodhi, Ajit; Paul, Saki · In Vitro