Aims: To evaluate rapamycin nanoparticles adsorbed with a tumor antigen (ovalbumin) as a combined vaccine to suppress tumor growth and enhance the immune response. Rapamycin (Sirolimus) is an mTOR inhibitor that suppresses tumor growth, low doses of which have been reported to enhance the immune response. Methods: Rapamycin was crystalized into nanoparticles and analyzed using a particle analyzer. The protein binding capacity of the rapamycin particles, and their ability to inhibit cell proliferation were analyzed. The immune activation of the rapamycin particles was also tested both in vitro and in vivo. Results: Rapamycin nanoparticles had a diameter around 500 nm, a zeta potential of + 9 mV, and a protein binding capacity of 8 l g/mg. The rapamycin nanoparticles had a similar inhibitory effect on Raw264.7 macrophage cells as rapamycin. The mTOR phosphorylation was also reduced in a similar level by either rapamycin nanoparticles or rapamycin. In addition, the expression of CD80 and CD86 was not affected by the rapamycin nanoparticles, and immune responses were elicited by the rapamycin particulate vaccine. Conclusions: The rapamycin particulate tumor vaccine has a potential to induce an immune response to a tumor antigen and inhibit tumor growth.
Date:
2017-11
Relation:
Basic and Clinical Pharmacology and Toxicology. 2017 Nov;121(Suppl. 5):38.
