Understanding how the human body reacts to infectious disease is a key step in developing new treatments. To battle the growing number antimicrobe-resistant infections and minimize costs on new drugs, researchers from Arizona State University (ASU) and NASA's Johnson Space used 3D tissue models to study and develop realistic models of intestinal tissues fighting salmonella.

3D modeling has had an impact on predictive tissue culture models, which reflect how the human body reacts to pathogens. These models allow scientists to pinpoint exactly how to treat  infections through vaccinations or antibiotics. In building upon 3D tissue models, the study from ASU and NASA used different strains of salmonella to identify points on how to improve the tissue based model to replicate the work of human tissue.

"We engineered our advanced 3D co-culture model to incorporate an important immune defense cell type found in the intestine, [known as] macrophages, which are key cells targeted by salmonella during infection and are important for its disease-causing potential," said Cheryl Nickerson, corresponding author of the study. "The inclusion of macrophages along with epithelial cells allows for synergistic contributions of different cell types to be evaluated during infection, so host-pathogen interactions can be studied in a more physiologically relevant context. Our co-culture model thus offers a powerful new tool in understanding enteric pathogenesis and may lead to unexpected pathogenesis mechanisms and therapeutic targets that have been previously unobserved or unappreciated using other intestinal cell culture models.”

In order to test salmonella in various forms, researchers grew the bacteria under different oxygen levels and different strains to test the 3D tissue's ability to treat different types of bacteria. The improved model was able to respond to the differing types of salmonella by treating them individually. This ability to differentiate between strains and types of salmonella showed the improvement into realistic human tissue models.

“The future of this field is limitless, and we are still in the infancy of learning how to build more realistic and complex models of native human tissues to better understand host-pathogen interactions and infectious disease mechanisms,” wrote Nickerson. “These findings are urgently needed for new vaccine and drug development to outpace infectious disease. It is exciting to see the infectious disease world begin to embrace 3D tissue models."