Immune Cell Migration

This is a microscopic image of blood vessels (red), lymphatic vessels (green) and Chemokine CCL21 (blue). Image: © IST Austria / Sixt group

Researchers at IST Austria have found visual evidence for how immune system cells navigate from blood vessels, through tissues, and into lymphatic vessels. Immune cells provide protection against infectious agents such as bacteria and viruses. They must travel from the bloodstream to tissue surfaces to guard against these germs. The researchers discovered that immune cells are guided through the skin by a combination of "touch" and "smell" cues.

Immune cells both adhere to connective tissue proteins and can sense signal molecules. The researchers found that in mice, white blood cells followed the concentration gradient of certain proteins called chemokines in order to travel from one lymphatic vessel to the next. According to the researchers, the chemokine CCL21 is immobilized to sugar molecules in connective tissue. Immune cells migrate through tissues by moving towards the higher chemokine concentration.

Learn more about this study, see:

• Immune Cells On the Move Are Guided by Touch and Smell (Science Daily)