Silicon dioxide particles and immune cell activation in lab tests
What it found
In lab tests, tiny silicon dioxide particles made human immune cells mature and triggered a T-cell response.
This suggests they could act as a danger signal to the immune system.
What they found
Animal and lab studies
Immune cell maturation
All three types of tiny silicon dioxide particles increased markers of maturity on the surface of human immune cells in a dose-dependent way. This happened in lab tests with cells from human blood.
Inflammatory signals
The particles made the immune cells release more pro-inflammatory cytokines, especially CXCL-8 and CXCL-12, in a dose-dependent manner. This was seen in lab tests with human cells.
Particle uptake
Electron microscopy showed that the immune cells took up the silicon dioxide particles into vesicles inside the cell. The cells also grew more dendrites, which fits with becoming more mature.
T-cell activation
When immune cells exposed to the particles were mixed with T-cells, the T-cells multiplied more than with untreated immune cells. This increase was seen at all ratios of immune cells to T-cells tested.
T-cell cytokines
The T-cells in these mixed cultures released more IL-9 and IL-17A and F, and a non-significant rise in IL-5. This matches a pro-inflammatory response.
What the authors conclude
“Taken together, these results suggest that SAS-NPs could induce functional moDCs maturation and play a role in the immunization process against environmental antigens.”
Also in their conclusions
- They conclude that these tiny silicon dioxide particles could induce functional maturation of human immune cells and play a role in the immunization process against environmental antigens.
- They suggest that this may matter in situations where people are exposed to these particles at work or in everyday life.
How it was done
The authors wanted to understand whether these widely used particles could cause unwanted immune responses, since little is known about their effects on human immune cells.
They grew human immune cells from blood donors in the lab and exposed them to three types of tiny silicon dioxide particles for 16 hours. They then measured cell maturity, cytokine release, particle uptake, and T-cell activation.
What it can’t tell you
- These are lab tests using cells from human blood, not studies in whole people. They cannot show what happens when someone breathes in or swallows these particles.
- The tests used immune cells grown in a dish, so they cannot show whether the same immune activation would occur in a living body.
Who paid
- Authors work at
- Université Paris-Saclay, France
The paper
- Title
- Synthetic Amorphous Silica Nanoparticles Promote Human Dendritic Cell Maturation and CD4+ T-Lymphocyte Activation
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Full text
- Cite
- Feray A, Guillet É, Szely N, et al (2021). Synthetic Amorphous Silica Nanoparticles Promote Human Dendritic Cell Maturation and CD4+ T-Lymphocyte Activation. Toxicological sciences. doi:10.1093/toxsci/kfab120Free full textPubMed 34633463DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error