Researchers have introduced a synthetic “cell” platform designed to do something conventional biomaterials and biochemical assays have struggled to achieve: reproduce the mechanical, chemical and structural complexity that governs real cell–cell interactions. Called kpiCells, the system is engineered to imitate key features of living cells while remaining fully controllable in the laboratory. In a study published in Nature Methods, the researchers used the platform to investigate how T cells sense and generate mechanical forces at immunological synapses, the highly organized contact zones through which immune cells recognize and respond to targets. The work offers a new way to study immune activation at the scale of individual receptors and single cell–cell contacts.
Cell–cell interactions are often described in biochemical terms, with attention focused on ligands, receptors and downstream signaling proteins. Yet immune cells do not communicate through chemistry alone. When a T cell encounters a target cell, it pushes, pulls and rearranges the opposing membrane. These forces can alter receptor conformations, regulate molecular binding and influence the assembly of signaling complexes. Mechanical inputs are therefore not simply secondary effects of immune recognition; they can help determine whether a T cell crosses the threshold from inspection to activation. Measuring and manipulating these forces has been difficult because living cells are constantly changing shape, composition and internal organization.
Existing experimental approaches each capture only part of this biology. Biochemical systems can isolate individual molecular interactions but generally provide limited control over the physical state of an entire cell-like object. Synthetic particles and biomaterials can be precisely fabricated, but they often lack the flexible membranes, internal compartments and dynamic responses that characterize living cells. kpiCells were developed to bridge this gap. The platform uses a biomimetic membrane–endoplasmic architecture, meaning that it combines a cell-like outer membrane with an internal structure intended to reproduce selected features of the endoplasmic cellular environment. This architecture gives researchers a configurable chassis for presenting molecular signals while tuning the physical properties of the artificial cell.
The researchers designed kpiCells to accept modular mechanical, chemical and topographical inputs. Mechanical parameters can influence how a surface deforms or resists force. Chemical components can be used to display recognition molecules or alter the local signaling environment. Topographical features can control the nanoscale and microscale organization encountered by an interacting T cell. By adjusting these variables independently or in combination, scientists can build artificial targets that resemble different cellular states without relying on a genetically modified living cell. This ability to phenocopy selected states is central to the platform: instead of merely decorating an inert bead with a ligand, researchers can construct a more sophisticated object that presents signals within a tunable, cell-like physical context.
A major test of the system was whether kpiCells could participate in physiological cell–cell interactions. According to the study, they were able to engage T cells through interactions that reproduce critical subcellular features of natural immune contacts. When a T cell forms an immunological synapse, receptors and signaling molecules become organized across the contact interface. Adhesion molecules help stabilize the junction, antigen receptors probe for relevant molecular cues, and the cytoskeleton generates forces that reshape the membrane and reposition signaling assemblies. The kpiCell platform provided an artificial partner capable of supporting this type of organized interface, allowing the researchers to examine the interaction without the experimental complexity of a second living cell.
The system also enabled integrated analysis of two sides of mechanoregulation. The first is afferent mechanosensing, through which a T cell detects physical information arriving from its partner. The second is efferent force exertion, through which the T cell actively pulls on receptors and the opposing membrane. Separating these processes is challenging in ordinary cell cultures because changes in the target cell can feed back into the immune cell, and vice versa. With kpiCells, the physical properties of the target can be systematically altered while the T cell response is monitored. This makes it possible to ask whether a particular response is caused by the presence of a molecular ligand, the stiffness or deformability of the interface, its spatial organization, or a combination of these factors.
One of the platform’s most notable capabilities is the measurement of forces at individual T cell antigen receptors. These forces occur on the piconewton scale, a unit equal to one trillionth of a newton. Although extremely small in absolute terms, piconewton forces can be sufficient to influence the lifetime and conformation of molecular bonds. A receptor encountering an antigen does not simply bind in a static manner; the interaction can be tested under load as the T cell cytoskeleton applies tension. By detecting these tiny forces, the researchers could examine how individual receptors contribute to the mechanical process of antigen recognition. Such measurements provide a direct link between molecular-scale force transmission and the larger decision made by a T cell to activate.
The researchers further used kpiCells to obtain single cell–cell force fingerprints. These fingerprints describe the mechanical patterns produced during individual T cell contacts rather than averaging responses across a large population. That distinction is important because immune cells are heterogeneous. Two T cells exposed to the same biochemical stimulus may exert different forces, form contacts with different architectures or reach activation at different times. Likewise, artificial targets with identical molecular ligands may produce different responses if their physical properties vary. Single-contact measurements can therefore reveal activation thresholds that would be obscured in population-level assays, helping researchers determine how much force, for how long and in what spatial arrangement is required to trigger a functional response.
The study positions kpiCells as a bionic model rather than a complete replacement for living cells. Their value lies in the combination of biological mimicry and experimental control. Researchers can build cell-like targets whose mechanical compliance, molecular presentation and surface structure are defined in advance, then observe how immune cells respond with high spatial and force sensitivity. This approach could help clarify how immunological synapses integrate biochemical and mechanical information, how receptor-level events scale up to cellular activation, and why immune responses vary between individual contacts. More broadly, the platform suggests that future biomaterials may be designed not only to carry biological signals but also to reproduce the physical logic through which cells interpret those signals. By approaching the functional complexity of living systems while remaining modular and measurable, kpiCells could become a versatile tool for studying immune regulation, engineering artificial cellular interfaces and developing materials that communicate with cells through both chemistry and force.
Subject of Research:
Biomimetic artificial cells, mechanical regulation of immunological synapses, T cell mechanosensing, receptor-level forces and cell–cell interactions.
Article Title:
Decoding mechanoregulation in immunological synapses using biomimetic artificial cells.
Article References:
Yu, X., Mukwaya, V., Yue, M. et al. Decoding mechanoregulation in immunological synapses using biomimetic artificial cells. Nat Methods (2026). https://doi.org/10.1038/s41592-026-03199-3
Image Credits: AI Generated
DOI: https://doi.org/10.1038/s41592-026-03199-3
Keywords: kpiCells, biomimetic artificial cells, immunological synapses, T cells, mechanobiology, mechanosensing, cell–cell interactions, piconewton forces, antigen receptors, synthetic biomaterials.
Tags: biomimetic artificial cellsbiomimetic cell engineeringcell-cell interaction modelingimmune activation regulationimmune cell force measurementimmune synapse mechanicslab-controlled cell interaction studiesmechanobiology of immune responsesreceptor conformational changessynthetic cell platformsynthetic immunology toolsT cell mechanotransduction
