Thymosin Alpha 1 (Tα1) — Thymic Immunomodulatory Research Peptide | Klene Peptides
For Research Use Only | Not for Human or Veterinary Administration
Thymosin Alpha 1 (Tα1) is a 28-amino acid N-terminally acetylated peptide originally isolated from thymic tissue by Allan Goldstein and colleagues in 1977. Since its discovery, Tα1 has emerged as one of the most extensively characterized immunomodulatory peptides in biomedical research, with a body of evidence spanning antiviral defense, anti-tumor immunosurveillance, autoimmune modulation, and sepsis immune restoration. It is approved as a biopharmaceutical (Zadaxin®) in over 35 countries for indications including hepatitis B, hepatitis C, and non-small cell lung cancer, and holds FDA orphan drug designations in the United States. As an investigational research compound, Tα1 provides a uniquely well-characterized mechanistic template for studying innate and adaptive immune system coordination. Klene Peptides supplies Tα1 to USA research institutions with verified purity and same-day order fulfillment.
Every vial from Klene Peptides includes:
- ≥99%+ purity — verified by HPLC (High-Performance Liquid Chromatography)
- HPLC-MS (High-Performance Liquid Chromatography - Mass Spectrometry)
- Same-day shipping for all USA orders
Chemical Identity & Structural Profile
| Parameter | Value |
|---|---|
Full Name | Thymosin Alpha 1 / Thymalfasin |
Sequence (1-letter) | Ac- |
Amino Acid Count | 28 |
N-terminal Modification | Acetylation (Ac-Ser) — required for biological activity |
Molecular Formula | C₁₂₉H₂₁₅N₃₃O₅₅ |
Molecular Weight | 3,108.30 g/mol |
CAS Number | 62304-98-7 |
INN | Thymalfasin |
Approved Trade Name | Zadaxin® (35+ countries) |
Appearance | White to off-white lyophilized powder |
Solubility | Water, PBS, 0.9% saline |
Storage | Lyophilized: −20°C; Reconstituted: 4°C, use within 48 hours (no preservative) |
Tα1 was originally isolated as a component of “Fraction 5” from bovine thymic extract and subsequently fully sequenced and synthesized. The N-terminal acetylation is structurally essential — deacetylated or truncated analogs demonstrate substantially reduced receptor interaction and immunological activity.
Mechanism of Action
Tα1’s immunomodulatory activity operates through coordinated engagement of innate immune pattern recognition and adaptive immune priming:
Primary Receptor & Signaling Interactions
| Receptor / Pathway | Cell Type | Downstream Effect |
|---|---|---|
TLR2 (Toll-Like Receptor 2) | Dendritic cells, macrophages | NF-κB activation → IL-12, IFN-γ production |
TLR4 | Macrophages, monocytes | Innate immune priming and anti-pathogen signaling |
TLR9 | Plasmacytoid dendritic cells | Type I interferon production (IFN-α/β) |
MHC Class II upregulation | Antigen-presenting cells | Enhanced antigen presentation to CD4+ T cells |
PD-L1 modulation | Tumor microenvironment | Immune checkpoint pathway investigation |
mTOR pathway | T regulatory cells | Foxp3+ Treg population dynamics in anti-tumor contexts |
Key Immunological Effects
| Effect | Cell Affected | Research Application |
|---|---|---|
T-cell maturation induction | CD4+, CD8+ thymocytes | Thymic reconstitution models |
NK cell activation | Natural killer cells | Innate anti-tumor surveillance studies |
Th1 polarization | CD4+ helper T cells | IFN-γ-driven antiviral and anti-tumor immunity |
DC maturation acceleration | Dendritic cells | Antigen presentation and adjuvant co-administration research |
Cytokine rebalancing | Monocytes, macrophages | Sepsis immune paralysis reversal models |
Regulatory T cell modulation | Foxp3+ Treg population | Autoimmune and immune tolerance research |
Pharmacokinetic & ADME Profile
| Parameter | Value | Notes |
|---|---|---|
Molecular Weight | 3,108.30 g/mol | SC preferred for systemic delivery |
Bioavailability (SC) | ~90% | Clinical pharmacokinetic data available |
Tmax | ~2 hours post-SC | Rapid absorption |
Half-life (t½) | ~2 hours | Short PK half-life; immune effect duration exceeds PK window |
Volume of Distribution | ~15–25 L | Extravascular distribution |
Protein Binding | Moderate albumin-associated fraction | — |
Primary Metabolism | Proteolytic | Serum and tissue peptidase activity |
Excretion | Renal | Metabolite fragment clearance |
Research note: Tα1’s short plasma half-life (~2 hours) contrasts with persistent immunological effects lasting days to weeks — attributed to TLR-mediated activation of dendritic cells and downstream cytokine cascade maintenance. This PK/PD dissociation is an active area of investigation for optimizing research dosing interval design.
Research Applications
Antiviral Immunology
| Virus Model | Mechanism Investigated | Observed Effect |
|---|---|---|
Hepatitis B | TLR9 → IFN-α, DC activation | Enhanced viral clearance in chronic HBV models |
Hepatitis C | Th1 polarization, NK cell activation | HCV viral load reduction (clinical trial supported) |
Influenza | TLR2/4 innate immune priming | Reduced viral replication and mortality (murine) |
SARS-CoV-2 | TLR-mediated IFN production, T-cell rescue | Lymphocyte restoration; under active investigation |
HIV | CD4+ homeostasis restoration, DC maturation | T-cell reconstitution models |
Oncology & Tumor Immunology
| Cancer Model | Research Focus |
|---|---|
Non-small cell lung cancer | Combination with chemotherapy; checkpoint co-administration |
Hepatocellular carcinoma | Anti-tumor immunosurveillance activation |
Melanoma | NK and CD8+ cytotoxic T-cell priming |
Colorectal cancer | Tumor microenvironment remodeling |
Tα1’s combination with checkpoint inhibitors (PD-1/PD-L1 blockade) is an emerging area, as its TLR-dependent DC maturation may synergize with checkpoint release to restore anti-tumor T-cell activity in exhausted tumor microenvironments.
Sepsis & Critical Illness Immunology
Sepsis-induced immunoparalysis — characterized by monocyte deactivation, HLA-DR downregulation, and dominance of immunosuppressive cytokines — is a primary research context for Tα1:
- Restored HLA-DR expression on monocytes
- Improved Th1/Th2 cytokine ratio
- Reduced 28-day mortality in multiple published clinical cohort analyses
Autoimmunity & Immune Tolerance Research
Tα1’s dual capacity to stimulate innate immune signaling while modulating regulatory T-cell populations makes it mechanistically relevant in autoimmunity research, particularly lupus and rheumatoid arthritis models, where Treg/Teff balance is a central investigative parameter.
Research Dosing Reference
For scientific reference only — not prescriptive recommendations
| Research Model | Reported Dose | Route | Schedule |
|---|---|---|---|
Antiviral models (rodent) | 200–400 mcg/kg | SC | 2–3× per week |
Tumor immunology (murine) | 100–500 mcg/kg | SC | Daily or every-other-day |
Sepsis immune restoration | 1.6 mg (flat dose clinical reference) | SC | Twice daily × 7 days |
T-cell reconstitution models | 100–300 mcg/kg | SC | Per protocol |
In vitro assays | 0.1–10 µg/mL | Cell culture media | Per experiment |
The 1.6 mg flat dose is derived from Zadaxin® approved-use clinical data — provided as published reference context only.
Reconstitution Reference
| Lyophilized Amount | Sterile Water | Concentration |
|---|---|---|
5 mg | 2.5 mL | 2.0 mg/mL |
10 mg | 5.0 mL | 2.0 mg/mL |
All reconstituted peptides should be stored refrigerated at 2–8°C and protected from repeated freeze-thaw cycles. For research use only.
Klene Peptides Quality Standards
Certificate of Analysis — Standard Parameters
Every batch supplied by Klene Peptides is verified against the following analytical benchmarks:
| Test | Specification | Method |
|---|---|---|
Purity | ≥99% | HPLC (High-Performance Liquid Chromatography) |
Molecular Identification | Confirmed | HPLC-MS (High-Performance Liquid Chromatography – Mass Spectrometry) |
Water Content | <1.5% | — |
What Every Klene Peptides Order Includes
- Lot-specific Certificate of Analysis traceable to synthesis batch
- Verified cold-chain shipping — all orders dispatched with appropriate cold-pack packaging
- Same-day fulfillment — orders placed before cutoff ship the same business day
Ordering Thymosin Alpha 1 for Your Research Program
Important Research Compliance Notice
Scientific References
- Goldstein AL, et al. "Thymosin alpha 1: biology and therapeutic implications in infectious diseases, immunodeficiency, inflammation, and cancer." Expert Opin Biol Ther. 2009;9(5):593-608.
- Romani L, et al. "Thymosin alpha 1 activates dendritic cells for antifungal Th1 resistance through toll-like receptor signaling." Blood. 2004;103(11):4232-9.
- Li Y, et al. "Thymosin alpha-1 treatment in elderly patients with COVID-19." Int Immunopharmacol. 2020.
- Zhao W, et al. "Thymosin alpha-1 reduces the mortality of severe COVID-19 by restoration of lymphocytopenia." Int J Infect Dis. 2020.
- Garaci E, et al. "Thymosin alpha 1 in the treatment of cancer: from basic research to clinical application." Int J Immunopharmacol. 2000;22(12):1067-76.
- Ershler WB, et al. "Thymosin alpha 1 as an immunomodulator in aging and cancer." Curr Ther Res. 2003.
- PubChem. Thymosin Alpha 1. CID: 16218632. https://pubchem.ncbi.nlm.nih.gov