Immunostimulatory properties and enhanced TNF- α mediated cellular immunity for tumor therapy by C₆₀(OH)₂₀ nanoparticles

Publications concerning the mechanism of biological activity, especially the immunological mechanism of C₆₀(OH)₂₀ nanoparticles, are relatively limited. However, the structure and characteristics of this carbon allotrope have been widely investigated. In this paper, we have demonstrated that water-soluble C₆₀(OH)₂₀ nanoparticles have an efficient anti-tumor activity in vivo, and show specific immunomodulatory effects to the immune cells, such as T cells and macrophages, both in vivo and in vitro. For example, C₆₀(OH)₂₀ nanoparticles can increase the production of T-helper cell type 1 (Th1) cytokines (IL-2, IFN- γ and TNF-α), and decrease the production of Th2 cytokines (IL-4, IL-5 and IL-6) in serum samples. On the other hand, C ₆₀(OH)₂₀ nanoparticles show almost no adverse effect to the viability of immune cells in vitro but stimulate the immune cells to release more cytokines, in particular TNF- α, which plays a key role in the cellular immune process to help eliminate abnormal cells. TNF- α production increased almost three-fold in treated T lymphocytes and macrophages. Accordingly, we conclude that C₆₀(OH)₂₀ nanoparticles have an efficient anti-tumor activity and this effect is associated with an increased CD₄ ⁺/CD₈ ⁺ lymphocyte ratio and the enhancement of TNF- α production. The data suggest that C ₆₀(OH)₂₀ nanoparticles can improve the immune response to help to scavenge and kill tumor cells.