At the Institute of Science Tokyo, researchers have built something the size of a computer chip that could help millions of children avoid a virus that has no cure. This tiny, engineered model of the human intestine successfully reproduced what happens when enterovirus A71 (EV-A71) takes hold—and in doing so, revealed why this virus is so skilled at evading the body's defenses.
EV-A71 is deceptively common. It primarily infects infants and young children, often causing hand, foot, and mouth disease, which sounds mild enough: small sores and fever. But this virus has a dangerous other side. In some children, it crosses into the central nervous system, triggering life-threatening encephalitis and meningitis. Despite decades of research, no approved drugs exist to treat EV-A71 infection. The reason, simply put, is that scientists still don't fully understand how the virus behaves inside the human intestine, where it first establishes itself.
A team led by Professor Kazuo Takayama, graduate student Hiroki Futatsusako, and Junior Associate Professor Sayaka Deguchi at Science Tokyo's Department of Synthetic Human Body System developed a new way to study this problem. They created what they call a microphysiological system (MPS)—a miniaturized, biomimetic model of the human intestine built from human embryonic stem cells inside a microfluidic device. Unlike conventional laboratory models, which rely on cancer-derived or animal cells that bear little resemblance to real tissue, this chip-sized system contains multiple cell types including goblet cells, enterocytes, and fibroblasts, closely mimicking the structure and function of an actual intestinal organ.
When the team infected their engineered intestinal tissue with EV-A71 and monitored it over two weeks, something striking emerged. While conventional cell cultures are rapidly destroyed by the infection, the intestinal MPS sustained long-term viral replication while remaining structurally intact. After 14 days, the tissue showed minimal damage and maintained normal expression of key protein markers. This resilience matched what doctors observe in infected children—the virus persists without causing severe intestinal symptoms.
The breakthrough came when researchers discovered why. EV-A71 triggered only a weak antiviral response in the intestinal tissue. Specifically, the virus failed to significantly increase secretion of interferons, proteins that normally help cells mount defenses against viral invaders. This immune evasion may explain how EV-A71 can linger in the intestine for extended periods. But here's where hope enters: when the team treated the infected tissue with artificially created, supplied interferons, antiviral genes became strongly activated and viral RNA levels dropped significantly.
"This model provides a foundation for elucidating the mechanisms of EV-A71 infection in the human intestine and for developing therapeutic strategies to prevent severe disease progression," Professor Takayama said. The findings, published in the Journal of Virology, point toward a broader future for this technology. The same approach could be applied to studying other infectious diseases, potentially accelerating the discovery of treatments that have eluded researchers for decades.
For the families of children vulnerable to EV-A71, this engineered intestine represents something more than innovation—it's a door opening toward answers and, finally, treatments.