CpG and transfer factor assembled on nanoparticles reduce tumor burden in mice glioma model

This work describes the use of a transfer factor, a low molecular protein that can transfer cell mediated immunity from donor to recipient, and CpG, a clinically relevant toll-like receptor agonist, for treating glioma. Transfer factor and CpG were assembled onto gold nanoparticles via layer-by-layer assembly. The modified nanoparticles (i.e. particles assembled with transfer factor and CpG) were characterized by size, zeta potential, and loading. An in vivo tumor study revealed that the nanoparticles can inhibit tumor progression more effectively than using either TF or CpG alone or using an equivalent dose of CpG and TF in a soluble mixture. To investigate the anti-tumor mechanism, the modified nanoparticles were interacted with dendritic cells, macrophages. Viability tests showed that the modified nanoparticles did not affect cell viability, and neither did the use of soluble TF or CpG alone. Cell activation assessments showed that the modified nanoparticles can activate DC surface markers (CD80+, CD86+, and CD40+), and promote the production of cytokines (GM-CSF, TNF, and IL-6) from macrophages. In addition, the in vivo study revealed that the modified nanoparticles promoted the production of both inflammatory and effector cytokines in mice serum. Finally, the study also revealed that the production of inflammatory cytokines came primarily from the CpG component, not TF. This study may provide us with a new immune therapeutic strategy for treating glioma.