The United Immune Cells?

Migratory birds, dolphins, ants and many other creatures have learned a truth that unity is strength. When immune cells fight against viruses, they are also well versed in this rule, recently pointed out by scientists from the University of Rochester on Science.

The study, for the first time, shows that immune cells are united in the process of reaching the site of injury. In fact, many parts of the body may be attacked by viruses or bacteria, such as lung, throat, skin, stomach, and ears, but how immune cells (especially those responsible for killing the invaders) reach the site? The researchers found that neutrophils are the key to the process.

Neutrophils are the first defense line of the immune system, and they can rush to the injury site within an hour after the infection and leave behind their own chemical "footprint", while T cell killer can follow the footsteps to find and destroy invaders.

Once neutrophils are removed or their tracks are erased, it can be difficult for T cells to find the site of injury. In this case, T cells appear to be more dispersed, and only a few can reach the destination, as a result it can not be effective against the infection.

"In order to complete the defense work, the immune cells form a team," said by associate professor Minsoo Kim, who led the study, "Understanding how the immune cells collaboratively reach the infection site will help us to control and improve the body's response to the disease," the co-author, Professor David J. Topham said.

In multiple sclerosis, lupus and other autoimmune diseases, the immune system mistakenly attacks healthy tissue. If we can interfere with or prevent immune cells moving to healthy tissue, it is expected to greatly improve the life quality of these patients. In addition, trying to increase infection-fighting immune cells can also help to design better vaccines.

Researchers use a multi-photon microscope to observe how different immune cells move into the trachea in mice that infected with the influenza virus. This is a very powerful microscopy techniques, which can realize real-time observation of the action of immune cells in the tissue and through a more accurate image to reveal the mechanism of the immune system.

Studies have shown that the production of neutrophil chemokine CXCL12 can induce T cell migration in vivo. In the past it has been believed that the blood and tissues chemokines are soluble. However, this study points out, the CXLC12 spreading in mice trachea is actually film wrapped.

Source: Neutrophil trails guide influenza-specific CD8+ T cells in the airways, Science.