Immune Cell Mechanics Reveal a New Biological Signature of Depression
In their recent study, Lisa Kwapich and colleagues investigated whether major depressive disorder (MDD) is associated with changes in the mechanical properties of immune cells. The researchers focused on peripheral blood mononuclear cells (PBMCs), a group of immune cells that play a central role in immune regulation and inflammatory processes. Using a microfluidic deformability assay, they compared immune cells from individuals diagnosed with MDD to those from healthy controls and found that PBMCs from depressed individuals were significantly less deformable, indicating increased cellular stiffness.
The study also examined whether childhood maltreatment, a well-established risk factor for depression, contributes to these cellular alterations. While childhood adversity was assessed in all participants, no significant relationship was found between maltreatment history and immune cell deformability. This suggests that the altered mechanical phenotype is more closely linked to depression itself than to any individual risk factor.
To assess cell mechanics, the researchers isolated PBMCs from blood samples and measured their ability to deform while passing through a microfluidic constriction. In this setup, ODIN was used to measure and characterize cells at the center of the constriction, leveraging Smart Imaging Mode to significantly improve ease of recording and throughput. Cell deformability is increasingly recognized as an important functional parameter because it reflects the structural integrity of cellular components such as the cytoskeleton and cell membrane. Reduced deformability may indicate cellular damage or altered cellular function.
The authors propose that chronic stress-related biological processes, including increased oxidative stress and exposure to free radicals, may impair intracellular structures and membrane composition, resulting in stiffer immune cells. Such alterations could contribute to immune dysfunctions frequently observed in depression, including impaired wound healing and altered inflammatory responses.
The significance of this work lies in its demonstration that depression is associated not only with biochemical but also with measurable biophysical changes in immune cells. These findings strengthen the growing evidence that immune cell mechanics may serve as a novel biomarker for mental health disorders and highlight the potential of microfluidic technologies to uncover previously inaccessible aspects of disease biology.
Reference: L. Kwapich, T. Neckernuss, D. Geiger, J. Pfeil, K. Woike, E.-J. Sim, M. Kiefer, C. Schönfeldt-Lecuona, A. Behnke, M. Schneider, O. Marti, I.-T. Kolassa, A. Karabatsiakis, Cell deformability of peripheral blood mononuclear cells is reduced in individuals with major depressive disorder. Translational Psychiatry (2026). https://doi.org/10.1038/s41398-026-04225-w