Medical

Yale study reveals battle formation of immune cell soldiers in skin

Yale study reveals battle form...
A microscope image of immune cells (Langerhans cells in red, dendritic epidermal T cells in green) spreading out among the epithelial cells in the skin
A microscope image of immune cells (Langerhans cells in red, dendritic epidermal T cells in green) spreading out among the epithelial cells in the skin
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A microscope image of immune cells (Langerhans cells in red, dendritic epidermal T cells in green) spreading out among the epithelial cells in the skin
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A microscope image of immune cells (Langerhans cells in red, dendritic epidermal T cells in green) spreading out among the epithelial cells in the skin

The skin is the body’s first line of defense against potential infection, and new research has brought us closer to understanding how it works. Researchers at Yale have now identified how immune cells spread themselves out to maintain the most effective patrol.

The epidermis is the outermost layer of skin, and its primary function is to act as a barrier to the outside world. That’s not just a physical barrier either – the immune system deploys certain cells throughout the epidermis to act as bouncers and keep the bad bugs out.

In the new study, researchers from Yale and Michigan State University investigated how two types of these immune cells – Langerhans cells and dendritic epidermal T cells (DETCs) – interact with the skin cells, or epithelial cells, around them to maintain that barrier.

These immune cells are known to spread out wide, avoiding clustering together to keep watch most efficiently. The new study confirmed this by removing some of these cells from one area of the epidermis, and found that others would shuffle in to fill the gap in the defenses.

But how exactly the cells regulate this and maintain a consistent distribution has puzzled scientists. In the new study, the team traced it to a gene called Rac1, which regulates dendrites – the spindly protrusions on immune cells and neurons. In the latter, dendrites help neurons avoid each other to prevent clustering, and the team wondered if a similar process was occurring in immune cells.

Sure enough, when the scientists knocked out this gene, they found that the distribution of the cells was interrupted. Based on these experiments, and images of the immune system cells interacting with the epithelial cells, the researchers concluded that the distribution patterns of the two types of immune cells is regulated by both the Rac1 gene and the density of the epithelial cells around them.

“It’s a surveillance system with two separate roles,” says Catherine Matte-Martone, co-first author of the study. “The skin controls the sentinels by mediating their numbers based on its own density, while they in turn provide dynamic coverage to prevent cracks in the skin’s defenses.”

The study provides some interesting new insights into some poorly understood mechanisms that keep us safe from infection, and could eventually open up new leads on ways to boost immune responses.

The research was published in the journal Nature Cell Biology.

Source: Yale University

3 comments
3 comments
ChairmanLMAO
Now lets test some real tech. I want you to program some life forms to be able to slip right on past this defense. We'll call it Trojanicans Isinisitisitis. Then we will create the antidote and call that Buffaloed Trippenssis 5-maeow Moxyprophilaxene. Package deal - buy both and get the custom diffuser free!
otto17
How does bathing (soaps, body wash, detergent, etc.) too frequently affect "this defense" system?
Karmudjun
Interesting. Research now explains how it is that the Dendritic and Langerhans cells keep from clustering together in the epidermis' lower layers. Really? they have spindly processes that space them out? As if we didn't know there had to be a mechanism in place working just fine already. What are we to do with the research? Publish and get pats on the back?
OTTO17 - The top of the Epidermis is dead tissue, squamous cells that are "glued" together and flattened out. When you bath, unless you scrub the stratum corneum off, you don't have any impact on the lower stratum granulosum or even lower stratum spinosum - which is where the living epithelial cells, dendritic cells, and langerhans cells reside. So bathing in mild solvents like water don't affect it. A very acidic bath might breach the epidermal barrier - if you could tolerate an "Acid Wash" bath.