The researchers illuminated how live immune cells arranged themselves in the skin of mice.

New research reveals how the skin’s immune cells organize themselves to ward off would-be intruders. 

Skin’s immune cells have a history of being misunderstood. Many people don’t realize that the epidermis is home to immune cells. 

To bring more clarity to how skin’s immune cells do their jobs, Sangbum Park of Michigan State University’s Institute for Quantitative Health Science & Engineering and co-workers used state-of-the-art microscopy tools. The researchers illuminated how live immune cells arranged themselves in the skin of mice.

“Immune cells are the soldiers of our body. In our skin, that army is maintained according to two factors: density and distribution,” says Park, an assistant professor in the College of Human Medicine’s Department of Medicine and Department of Pharmacology and Toxicology.  

“We need enough immune cells to cover the whole area of our skin uniformly for proper protection. Otherwise, our skin would be vulnerable to damage and infection,” Park said. “As sensible as that might sound, it was unclear how, or even if, these immune cells were organized before this study. Many researchers thought the cells’ distribution was random.”

“IQ has so many advantages for a young investigator like me,” says Park. “I didn’t have to wait to set up microscopes in my own lab or train my students how to use them,” he says. “At IQ, we already have many different microscopes for a wide range of animal models.”

As a result, Park’s team is revealing the skin’s structure and function. Having validated these new techniques and observing how immune cells are organized in the healthy skin of mice, Park’s team can start probing new questions about how skin heals. 

“My lab is interested in how skin regenerates and recovers from injury,” he said. That injury could be a cut, an infection, an allergic reaction or an even more persistent disorder, such as psoriasis. “We can answer so many questions with our intravital imaging technique that you just can’t with conventional methods.” 

The study appears in Nature Cell Biology.