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Mesoporous silica nano-adjuvant triggers pro-inflammatory responses in Caco-2/peripheral blood mononuclear cell
Maryam Ghasemi1, Bita Bakhshi1, Reza Khashei2
1Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
Abstract:
The aim of this study was to evaluate the cytotoxicity and immune-stimulatory effect of Mesoporous silica nanoparticle (MSN) Nano-adjuvant on pro-inflammatory cytokines and pattern recognition receptors (PRR) genes expression in Caco-2/PBMC co-culture model. MSNs were synthesized and characterized by scanning electron microscope (SEM), Brunauer Emmett Teller (BET) and Barrett Joyner Halenda (BJH) techniques. The BET specific surface area of MSNs was around 947 m2/g and the total pore volume and average pore diameter were 1.5 cm3/g and 8.01 nm, respectively. At the concentration of 10 µg/mL, MSN showed a low and time-dependent cytotoxicity on Caco-2 cells, while no cytotoxic effect was observed for 0.1 and 1 µg/mL concentrations after 24, 48 and 72 h. The expression of pro-inflammatory cytokines genes (IL-1, IL-8 and TNF-α) in co-cultures treated with different concentrations of MSN showed a dose-dependent significant increase up to 17.44, 2.722 and 4.34 folds, respectively, while the expression augmentation of IL-1 gene was significantly higher than the others. This indicates slight stimulation of intestinal inflammation. Different concentrations of MSN significantly increased TLR4 and NOD2 expression to 4.14 and 2.14 folds, respectively. NOD1 was not affected significantly. It can be concluded that MSN might increase protective immune responses against antigens as a vaccine adjuvant candidate. It seems that stimulation of TNF-α, IL-1, and IL-8 expression in enterocytes probably transpires through the agonistic activity of MSN for TLRs including TLR4, while NOD2-associated signaling pathways are also involved. This study provides an overall picture of MSN as a novel and potent oral adjuvant for mucosal immunity.
Insights
Mesoporous silica nanoparticles (MSN) show low cytotoxicity and stimulate immune responses by increasing pro-inflammatory cytokines and pattern recognition receptors (PRR) gene expression, suggesting potential as an oral vaccine adjuvant.
Area of Science:
- Nanotechnology
- Immunology
- Materials Science
Background:
- Mesoporous silica nanoparticles (MSN) are increasingly explored for biomedical applications.
- Understanding their interaction with the immune system is crucial for developing novel vaccine adjuvants.
Purpose of the Study:
- To evaluate the cytotoxicity of MSN.
- To assess the immune-stimulatory effects of MSN on pro-inflammatory cytokines and pattern recognition receptors (PRR) gene expression.
- To investigate MSN as a potential oral vaccine adjuvant in a Caco-2/PBMC co-culture model.
Main Methods:
- MSN synthesis and characterization using SEM, BET, and BJH techniques.
- Cytotoxicity assessment of MSN on Caco-2 cells at various concentrations and time points.
- Analysis of pro-inflammatory cytokine (IL-1, IL-8, TNF-α) and PRR (TLR4, NOD1, NOD2) gene expression in Caco-2/PBMC co-cultures treated with MSN.
Main Results:
- MSN exhibited low, time-dependent cytotoxicity at 10 µg/mL, with no observed toxicity at lower concentrations.
- MSN significantly upregulated pro-inflammatory cytokine genes (IL-1, IL-8, TNF-α) in a dose-dependent manner.
- MSN significantly increased the expression of TLR4 and NOD2, indicating activation of innate immune pathways.
Conclusions:
- MSN demonstrates a favorable safety profile and potent immune-stimulatory properties.
- The observed immune stimulation suggests MSN's potential as an effective oral vaccine adjuvant for mucosal immunity.
- MSN may enhance protective immune responses through TLR4 and NOD2 signaling pathways.
