As you know, the first to rush to the site of infection neutrophils. The presence of membrane protrusions allow them to independently amoeboid movement "crawls" to the pathogen. However, to get to the affected tissues, they first need to get out of the vessel through which the blood flows continuously and demolish them.
On the surface of neutrophils, trying to stop, generates a voltage of 2 dyne / cm ?. Results of experiments the University of California and the Institute of Immunology and Allergy indicate that these immune cells can survive and more powerful effect. Scientists have recorded as moving mouse neutrophils in an artificial tube-like venules. They calculated that the fluid flow creates a voltage of 6-10 dyn / cm ?.
The researchers were able to see how immune cells, using its membrane growths are fixed to the wall of the artificial vessels. Neutrophils use these outgrowths not only as a means of transportation, but also as an anchor, they cling to the vessel wall to avoid being taken down the flow of blood. On membrane proteins have special outgrowths of Velcro that allow the neutrophil to resist the strong pressure of the blood. As the movement of immune cells, these "suckers" gradually come off from the vessel wall. Thus, neutrophils move like a climber who alternately tightened up on the saddle, throwing his constantly getting higher.
What is most striking is not the way of movement of neutrophils, and the strength of their membrane outgrowths. Researchers believe that the reason some people susceptibility to infection may be problems with the motor apparatus of immune cells. If the membrane outgrowths of neutrophils will not be strong enough, the cells will not be able to stay on the vessel wall and get to the affected tissues, resulting in the infection does not meet any resistance on the part of the immune system.