Nanopores activate immune cells without chemicals
For decades, medicine has activated immune cells exclusively through biochemical signals. A specific protein binds to a receptor on a T cell. That binding triggers a cascade of molecular events. The cell wakes up. It multiplies. It attacks a target. This process is the foundation of immunotherapy, vaccines, and transplant medicine.
Researchers from the Helmholtz-Zentrum Hereon, ETH Zurich, Humboldt University of Berlin, Charite Berlin and Inselspital Bern have now discovered a fundamentally different activation mechanism. They found that immune cells respond to the surface structure of materials — without any chemistry involved. No proteins. No antibodies. No drugs. Just the physical shape of the surface.
The critical parameter is the size of pores on a material’s surface. When these pores measure exactly a few nanometers across, human T cells activate spontaneously. The cells stretch out. They spread across the surface. They begin to function as if they had received a biochemical signal. This finding shifts the understanding of how cells sense their environment.
First tests in living tissue are planned in Bern
The lead institution for the next phase is the Inselspital Bern, where the team will apply this finding in a biological context for the first time.
They plan to test whether nanopore-activated T cells function correctly in living tissue. The transition from a petri dish to a living organism is the critical next step. If the cells behave the same way inside the body, the implications for implant design are immediate.
Surfaces with precisely engineered nanopores could replace chemical coatings on medical implants. Current implants often require biochemical treatments to prevent immune rejection. These treatments can degrade over time. They can cause side effects. A purely structural surface would be more stable. It would not require chemical replenishment. It could be manufactured at scale.
The nanopore size of 40 nanometers triggers maximal activation
The researchers identified the exact pore size that produces the strongest T cell response. [1] Pores of 40 nanometers in diameter trigger maximal activation. Smaller pores produce a weaker response. Larger pores also produce a weaker response. The effect is highly specific to this narrow size range.
The mechanism behind this activation is mechanical. The T cell’s membrane deforms as it interacts with the nanopores. This deformation stretches the cell’s internal skeleton. The stretched skeleton sends signals to the nucleus. The nucleus then initiates the activation program. No external chemical signal is required.
The study measured T cell proliferation, cytokine production, and target cell killing. All three measures showed the same pattern. Cells on 40-nanometer pores performed as well as cells activated by standard biochemical methods. A purely physical surface can match the performance of a complex biochemical activation system.
Sources
2. ETH Zurich