Immune cells reveal fancy footwork

Dec 01, 2008

Our immune system plays an essential role in protecting us from diseases, but how does it do this exactly? Dutch biologist Suzanne van Helden discovered that before dendritic cells move to the lymph nodes they lose their sticky feet. This helps them to move much faster. Immature dendritic cells patrol the tissues in search of antigens. After exposure to such antigens they undergo a rigorous maturation process. During this maturation the dendritic cells migrate to the lymph nodes to activate T cells. Suzanne van Helden studied the adhesion and migration of both immature and mature dendritic cells.

A dendritic cell can be compared with a pocket-sized general. As an immature cell he is on patrol in the bloodstream and in tissues in search of foreign bodies. The feet, or podosomes, help the cell to move around at a slow pace. As soon as immature dendritic cells detect a problem they must report back quickly to the T cells to warn them of impending danger.

The dendritic cells are then hindered by their adhesive feet. This is the reason why at this point the cell undergoes modifications and loses its feet. In this way the mature dendritic cell can wing its way to the T cells at full speed. Once alerted, the T cells can intervene and tackle the problem in the body's infected tissues.

Van Helden not only demonstrated that dendritic cells lose their podosomes very quickly during maturation but she also identified the substances that are responsible for their disappearance. The presence of prostaglandin E2 is indispensable for this disassembly. In addition, it appears that dendritic cells lose their podosomes after interaction with certain bacteria. What is striking is that only gram-negative bacteria lead to podosome loss. Gram-positive bacteria do not have this effect. Van Helden concludes that dendritic cells can apparently distinguish between different pathogens.

The immune system can act in different ways to keep the body healthy. Unfortunately the working of the immune system is not perfect. In cancer for example, the immune system does not respond to the altered cells that make up the tumour. It is possible that this knowledge about the adhesion and migration of dendritic cells could contribute to future developments in a new approach to cancer treatment.

Van Helden carried out her research within a group of scientists that study the function of dendritic cells in different ways. The research comprises not only fundamental research, as in Van Helden's case, but also preclinical and clinical trials. The research was made possible by a grant from NWO. Spinoza Prize winner Carl Figdor supervised Van Helden during her research.

Source: Netherlands Organization for Scientific Research

Explore further: Warning coloration paved the way for louder, more complex calls in certain species of poisonous frogs

add to favorites email to friend print save as pdf

Related Stories

Some online shoppers pay more than others, study shows

19 minutes ago

Internet users regularly receive all kinds of personalized content, from Google search results to product recommendations on Amazon. This is thanks to the complex algorithms that produce results based on users' profiles and ...

Researchers create designer 'barrel' proteins

21 minutes ago

Proteins are long linear molecules that fold up to form well-defined 3D shapes. These 3D molecular architectures are essential for biological functions such as the elasticity of skin, the digestion of food, ...

Recommended for you

Cat dentals fill you with dread?

Oct 24, 2014

A survey published this year found that over 50% of final year veterinary students in the UK do not feel confident either in discussing orodental problems with clients or in performing a detailed examination of the oral cavity ...

User comments : 0