Lung-on-a-Chip Defends Itself for the First Time

Scientists watched immune cells rush through microscopic vessels inside a polymer chip no bigger than a postage stamp, and for the first time, the miniature lung fought back against infection on its own.

The moment took Ankur Singh’s breath away. Singh directs Georgia Tech’s Center for Immunoengineering, and he co-led the research with Krishnendu Roy, now dean of engineering at Vanderbilt University. Together with graduate student Rachel Ringquist, they accomplished what researchers have struggled with for years: building a lung-on-a-chip with a working immune system.

That was the “wow” moment. It was the first time we felt we had something close to a real human lung.

The breakthrough addresses a fundamental problem in medical research. Scientists have built organ-on-a-chip platforms before, etching tiny channels into clear polymer and lining them with living human cells. But without immunity, these chips remained incomplete simulations. Singh and Roy’s team changed that by incorporating tissue-resident macrophages, dendritic cells, and circulating immune cells from whole blood into their device.

When Mice Don’t Match Humans

For decades, lung research has depended on animal testing. The problem runs deeper than ethics. Mouse lungs simply don’t respond to asthma, influenza, or drug treatments the way human lungs do. Their airways differ in size and structure. Their immune responses follow different patterns.

Singh puts it plainly: five mice in a cage may respond identically to a treatment, but five humans won’t. That variability matters when developing therapies. The new chip can reflect those individual differences, potentially reducing animal testing while improving drug development accuracy.

The FDA’s push to reduce animal testing aligns with this work. Roy emphasized the regulatory landscape is shifting toward predictive non-animal models, and their device advances that goal further than previous attempts.

A Personal Drive

Singh’s motivation runs deeper than scientific curiosity. He lost an uncle when infection overwhelmed his cancer-weakened immune system. That experience shaped his research direction entirely.

If work like this means fewer families lose someone they love, then it’s worth everything.

His team reimagined what lung-on-a-chip technology could accomplish. Previous devices captured mechanical forces and basic cellular responses. This version integrates blood vessels, immune cells, and airway epithelium in a three-dimensional structure that breathes, circulates, and now defends itself.

The real test came when researchers introduced H1N1 influenza at severe infection levels. The chip’s immune response mirrored what doctors observe in patients: immune cells rushed to infection sites, inflammation spread through tissue, and cellular defenses activated in coordinated waves.

Beyond Influenza

The research team identified critical immune pathways during their work. They found that interleukin-1 beta drives the dangerous cytokine storm seen in severe flu cases. Blocking this molecule completely stopped the inflammatory cascade. Conversely, tumor necrosis factor alpha appears to regulate inflammation rather than cause it, since blocking TNF-alpha actually increased inflammatory responses.

Perhaps most intriguingly, the team discovered that fibroblast cells secrete CXCL12, which interacts with CXCR4 receptors on immune cells to control their movement into infected tissue. Blocking this interaction reduced harmful inflammation while boosting antiviral responses and decreasing viral loads.

The platform now extends beyond influenza research. Singh and Roy believe it can model asthma, cystic fibrosis, lung cancer, and tuberculosis. They’re working to integrate additional immune organs to show how the lung coordinates with the body’s broader defense systems.

The long-term vision involves personalized medicine. Imagine building chips from a patient’s own cells to predict which therapy will work best before trying it in their body. Clinical validation and regulatory approval will take years, but the foundation now exists.

The technology won’t replace all animal testing immediately. Scaling production, validating results across patient populations, and navigating regulatory frameworks present substantial hurdles. But the chip represents a significant step toward human-relevant disease modeling.

For millions living with chronic lung disease, for whom climbing stairs or carrying groceries feels nearly impossible, this research opens new paths. It won’t cure disease tomorrow. But it provides researchers a window into human lung biology that has never existed before, and that window might eventually lead to treatments that actually work in people, not just mice.

Nature Biomedical Engineering: 10.1038/s41551-025-01491-9