Effect of buckminsterfullerenes on cells of the innate and adaptive immune system: an in vitro study with human peripheral blood mononuclear cells

Abstract

C60 nanoparticles, the so-called buckminsterfullerenes, have attracted great attention for medical applications as carriers, enzyme inhibitors or radical scavengers. However, publications evaluating their immunological mechanisms are still rather limited.Therefore, we aimed to analyze systematically the in vitro influence of polyhydroxy-C60 (poly-C60) and N-ethyl-polyamino-C60 (nepo-C60) on peripheral blood mononuclear cells (PBMC) from healthy individuals, angling their effect on proliferation, expression of surface markers, and cytokine production. We isolated PBMC from 20 healthy subjects and incubated them in a first step only with poly-C60 or nepo-C60, and in a second step together with recall antigens (purified protein derivative, tetanus toxoid, bacillus Calmette-Guérin). Proliferation was determined by 3 H-thymidine incorporation, activation of PBMC-subpopulations by flow cytometry by measurement of the activation marker CD69, and secretion of T helper cell type 1 (TH1)-(interferon-gamma [IFN-γ], tumor necrosis factor beta [TNF-β]), TH2-(interleukin-5 [IL-5], -13, -10) and macrophage/monocyte-related cytokines (IL-1, IL-6, TNF-α) into the supernatants by enzyme-linked immunosorbent assay. Both fullerenes did not influence T cell reactivity, with no enhanced expression of CD69 and production of T cell cytokines observed, the CD4/CD8 ratio remaining unaffected. In contrast, they significantly enhanced the release of IL-6 and CD69-expression by CD56 positive natural killer cells. PBMC, which had been cultured together with the three recall antigens were not affected by both fullerenes at all. These data indicate that fullerenes do not interact with T cell reactivity but may activate cells of the innate immune system. Furthermore, they seem to act only on 'naïve' cells, which have not been prestimulated with recall antigens, there are however, large inter individual differences.

Immunomodulation of Nanoparticles in Nanomedicine Applications

“…Some studies showed that C 60 have immunostimulatory properties [ 28 – 30 , 103 , 106 ]. After instillation, C 60 upregulated gene expression of various proinflammatory cytokines (IL-1, TNF- α , IL-6) and Th1 cytokines (IL-12,IFN- γ ) in mice.…”

“…The carboxyfullerene could prolong the infiltrating neutrophils to enhance the bactericidal activity of neutrophils [ 30 ]. Other studies indicated that fullerene may enhance the ability of DCs to stimulate T cells and furthermore activated cells of innate immune system by enhancing production of IL-6 and an activation of natural killer (NK) cells [ 103 , 106 ]. In addition, immunization of mice with a C 60 fullerene derivative conjugated to bovine thyroglobulin could produce a population of fullerene-specific antibodies, which included a subpopulation that cross-reacted with a C 70 fullerene [ 29 ].…”

Multifunctional Fullerene- And Metallofullerene-Based Nanobiomaterials

“…89,90 Water-soluble fullerenes can successfully pass through the cell membrane and serve as intracellular delivery agents. 90,91 To mitigate oxidative damage to cells and tissues, polyhydroxylated fullerenes (a.k.a. fullerenols), with radical scavenging ability, have been used to deliver doxorubicin (DOX), a widely used chemotherapeutic drug.…”