Arrestin’ regurgitating infection fighters
Nature Immunology, pages 227-233.
The first line of defense against invasion by infectious organisms is the involvement of white blood cells such as neutrophils, basophils and eosinophils, also known as granulocytes. These cells are attracted to sites of infection by chemicals known as chemoattractants and, once there, are able to start fighting the infection.
Granulocytes attack invaders by releasing the contents of granules that they carry. These granules contain a cocktail of molecules that are toxic to many invading organisms. The molecular pathway leading to granule release is a complicated and incompletely understood process.
In the September issue of [Nature Immunology, Vol. 1, No. 3, September 2000], Canadian researchers from the John P. Robarts Research Institute in London, Ontario, have elucidated an important step in the mechanism of this process. They showed that granulocytes receive a signal through their surface receptor, CXCR1, which mobilizes a molecule called b-arrestin to form important signaling complexes. These complexes move to the granules in the cell where they cause release of the toxic granule contents outside the cell.
This work is surprising to many scientists as b-arrestin was previously thought to be involved in a very different cellular process. This study furthers our understanding of the critical role granulocytes play in fighting foreign invaders and adds new dimensions to the role of b-arrestin in normal physiology.
David J. Kelvin
John P. Robarts Research Institute
Laboratory of Molecular Immunology and Inflammation
1400 Western Road
London, CANADA, ON N6G 2V4
(C) Nature Immunology press release.
Message posted by: Trevor M. D'Souza