Effect of cucurbiturils on cytokine production by peripheral blood mononuclear cells of healthy donors

Abstract

Many drug delivery systems are currently under study, e.g., nanosized cavitands cucurbiturils, which, due to the presence of a cavity, can incorporate drug molecules. Since the immune system is quite sensitive to influence of nanomaterials and other cell-damaging factors, it is necessary to study immunosafety of the new delivery systems, i.e., immunotoxicity and immunomodulatory properties. The aim of this study was to investigate the effect of nanosized cucurbituril cavitands on the cytokine-producing ability of peripheral blood mononuclear cells in apparently healthy donors.
 Blood mononuclear cells (106/mL) were cultured in the presence of cucurbiturils at the following concentrations: 0.3 mM cucurbit[6]uril, 0.3 mM cucurbit[7]uril, and 0.01 mM cucurbit[8]uril for 72 h, under additional stimulation with aCD3 antibodies (1 g/mL), or without it. The level of cytokines in the supernatants was determined using enzyme immunoassay.
 It was shown that cucurbit[6]uril increased the level of spontaneous IL-4 production by 1.5 times (p 0.01) compared with the control. In the case of stimulated cytokine production, we found that cucurbit[6]uril reduced the level of IL-6, and also shows a tendency (p = 0.09) towards an increase in the IL-4 level. When cells were cultured with cucurbit[7]uril, we gave revealed a trend for increased production of pro-inflammatory TNF. It was also found that cucurbit[7]uril is able to suppress the production of IL-10 in aCD3-stimulated cell culture by 1.5 times. Cucurbit[8]uril was shown to inhibit production of cytokines in non-stimulated cell cultures. A significant decrease in the level of IFN and IL-10 was revealed as compared with the production of these cytokines in control cultures. When assessing the effect of cucurbit[8]uril on the IFN production upon stimulation with aCD3 antibodies, no significant differences were found, but there is also a trend for a decreased concentration of this cytokine agains control levels.
 Cucurbiturils can influence both spontaneous and stimulated production of cytokines by the blood mononuclear cells. The effect on cytokine-producing ability of the cells depends on the tested homologue compound.

Evaluation of the Immunosafety of Cucurbit[n]uril In Vivo

“…It was demonstrated that different homologues have different effects on the immune system. Based on the obtained data in vitro, CB [8] causes a decrease in the level of IFN-gamma [32], which indicates its possible immunosuppressive effect. Since СB [8] is able to suppress cytokine production, a possible immunosuppressive effect requires further study.…”

“…In the case of CB [6], its stimulating effect on the B cells and humoral immune response was demonstrated, since it increased the expression of HLA-DR molecules on B-lymphocytes [21], increased the level of spontaneous production of IL-4 by 1.5 times [32], and also increased in vivo the relative number of B cells in the organs of the immune system. At the same time, the severity of the humoral immune response to a certain antigen after the introduction of CB [6] was reduced, which requires studying the mechanisms of this process.…”

Evaluation of the Immunosafety of Cucurbit[n]uril In Vivo

“…It was demonstrated that different homologues have different effects on the immune system. Based on the obtained data in vitro, CB[8] causes a decrease in the level of IFN-gamma [ 32 ], which indicates its possible immunosuppressive effect. Since CB[8] is able to suppress cytokine production, a possible immunosuppressive effect requires further study.…”

“…In the case of CB[6], its stimulating effect on the B cells and humoral immune response was demonstrated, since it increased the expression of HLA-DR molecules on B-lymphocytes [ 21 ], increased the level of spontaneous production of IL-4 by 1.5 times [ 32 ], and also increased in vivo the relative number of B cells in the organs of the immune system. At the same time, the severity of the humoral immune response to a certain antigen after the introduction of CB[6] was reduced, which requires studying the mechanisms of this process.…”

“…In previous studies, we evaluated the possible immunomodulatory effect of cucurbiturils [ 30 , 31 , 32 , 33 ], and it was shown that during cultivation in the presence of CB[n], the proliferative activity of cells increased and the expression of HLA-DR on lymphocytes increased, which indicates an immunostimulatory effect. It was shown that cucurbiturils had practically no immunosuppressive effect under in vitro conditions, except for a slight decrease in HLA-DR expression and the production of reactive oxygen species by T-helpers in stimulated cultures [ 30 , 33 ].…”