MPLA-SM / Monophosphoryl Lipid A from S. minnesota R595
1 mg MPLA-SM Vaccine grade adjuvant
- 10 ml sterile endotoxin-free physiological water (NaCl 0.9%)
Storage and Stability
MPLA-SM is provided as a clear, lipidic film and shipped at room temperature. Store at -20°C. Product is stable 1 year when properly stored.
- Upon resuspension, prepare aliquots of MPLA-SM and store at -20°C. Resuspended product is stable 6 months when properly stored. Avoid repeated freeze-thaw cycles.
Monophosphoryl Lipid A (MPLA) is extracted from lipopolysaccharide (LPS or endotoxin) produced by the Re mutant of a rough strain Salmonella minnesota R595. Lipid A, a disaccharide with fatty acid side chains, is the component responsible for the endotoxic activity of LPS. Removal of one phosphate group from lipid A produces MPLA which has reduced toxicity while retaining the ability to stimulate the immune system.
Both LPS and MPLA are TLR4 agonists, but they signal through different adaptors, MyD88 and TRIF, respectively.The reduced toxicity of MPLA is attributed to the preferential recruitment of TRIF upon TLR4 activation, resulting in decreased induction of inflammatory cytokines. MPLA has been tested as an adjuvant in mice and reported to induce a strong Th1 response. Although the mechanism of action of MPLA has not been fully eludicated, it has been suggested that MPLA improves vaccine immunogenicity by enhancing antigen presenting cell maturation.
MPLA-SM is a potent activator of TLR4 with negligible TLR2 activity. MPLA-SM was extracted from LPS using treatment with acid and heat followed by chromatography. Preparations of natural MPLA, such as MPLA-SM, contain a mixture of 5,6, and 7 acyl lipid A.
Note: Due to the intrinsic structural complexity of lipid A, some batch-to-batch variation may occur.
Preparation of Sterile Stock Solution (1 mg/ml)
Add 1 ml of DMSO to 1 mg of MPLA-SM and vortex until complete solubilization, then sonicate.
Note: The suspension may appear to contain floating fine particles. Difficulties may be encountered for solubilization at higher concentrations.
- Prepare aliquots of stock solution and store at -20°C. Further dilutions can be prepared with endotoxin-free physiological water (provided).