Researchers immune cells in the circle

University of Illinois at Chicago College of Medicine researchers have an important role protein plays in the first place, the defense agency for the administration of immune cells present in neutrophils at the infection site or injury. Their findings are described online in the Proceedings of the National Academy of Sciences.

Neutrophils are white blood cells that are activated by chemical signals to control quickly the site of injury or infection, embarrassed when they are bacteria. Promptly informed of the infection, neutrophils move by changing its shape, a clear front and back, sending a "foot" on top of them, and "explore" the site of 'infection.

Indicated in the hope of better understanding the role of p55 protein or MPPI they previously as highly expressed in neutrophils, the UIC researchers are the first mice that completely lacked the protein level.

The knock-out "mice had marked difficulties that fight infection and have been slow to heal, according to Athar Chishti, professor of pharmacology and principal investigator of the study.

Instead of forming one large pseudopod, or how the increased foot in the direction of the infection, formed in neutrophils from knockout mice, a small number of extensions around the cell, "said Chishti.

Neutrophils lacking p55 could follow a tortuous path, walking in circles. "It was as if the neutrophils had lost its direction," said Brendan Quinn, a graduate research assistant in pharmacology and first author of the study.

Neutrophils are part of the innate immunity of the body and its first line of defense, so that the speed of reaction is the key to healing. "The neutrophils to the site at some point, but he arrives late," said Quinn.

The researchers also determined how p55 exerts its effect on neutrophils, which show that although the capacity of the cell, pseudopods reorganize their actin skeleton undisturbed to produce a lipid signaling known to be important in establishing polarity, PIP3 not locate at the end of the p55-null neutrophils, rather than diffusion through the cell.

In addition, the P55-null neutrophils was significantly reduced activation of another important signaling protein Akt, which is supposed to play an important role in many cancers.

"This study provides evidence of an important cell signaling pathway, which said the process of cell polarization in neutrophils and many other cells of crucial importance," Chishti.