Phagocytosis is an evolutionarily conserved mechanism that serves as the first line of host defense in multicellular organisms. The traditional definition of phagocytosis involves the engulfment and degradation of large solid particles, initiated by receptor activation on phagocytes. It forms an essential aspect of innate immunity through the uptake and destruction of infectious pathogens, while also participating in the removal of apoptotic cells during tissue remodeling and development. Professional phagocytes, such as macrophages, neutrophils, and dendritic cells, are well equipped with a wide range of phagocytic receptors. In addition, these specialized leukocytes can signal to lymphocytes within the adaptive arm of host immunity. This review emphasizes the role of two well-characterized opsonic receptors, the Fcy receptor and the complement receptor, CR3 in macrophages. In particular, it focuses on the different mechanisms employed by these receptors during particle recognition and phagocytic uptake. Bacterial species often manipulate phagocyte signaling in order to evade their engulfment and degradation and consequently provide further insight into key regulators of the phagocytic process. Finally, we draw attention to the physiological relevance of studying the simultaneous engagement of multiple phagocytic receptors, in order to better understand receptor crosstalk and the underlying coordination of downstream signaling for efficient phagocytosis. Table of Contents: Phagocytosis / Innate Immunity: Target Cell Recognition and Binding / Modes of Uptake: FcyR(Type I)-Mediated Phagocytosis and Pseudopod Extension / Modes of Uptake: CR3 (Type II)-Mediated Phagocytosis and Ruffle Formation / FcyR and CR3-Mediated Phagocytosis: Cytoskeletal Involvement / Membrane Contributions to Pseudopod Formation / Phagosome Maturation / Phagocytosis of Bacteria / Adaptive Immunity: Antigen Presentation / Tissue Remodeling: Phagocytosis of Apoptotic Cells / Concluding Remarks: Other Phagocytes and the Coordination of FcyR and CR3 Signaling in Phagocytosis / References / Author Biographies
Die Inhaltsangabe kann sich auf eine andere Ausgabe dieses Titels beziehen.
Urja Naik received her Honours Bachelor of Science (Hon. B.Sc.) from the University of Toronto in 2010. She is currently pursuing a Ph.D. degree in cell and systems biology with Dr. Rene Harrison at the University of Toronto, Scarborough, which is expected to be completed in 2015. Rene E. Harrison is an Associate Professor at the University of Toronto, Scarborough. She obtained her B.Sc. degree from the University of Winnipeg in 1992 and completed her M.Sc. degree in developmental cell biology in 1995 at the University of Manitoba (Winnipeg, Manitoba, Canada). She obtained her Ph.D. degree at the University of Toronto in 2000 and became interested in macrophage cell biology during her post doctoral fellowship (2000-2003) with Sergio Grinstein at the Hospital for Sick Children in Toronto. In Dr. Grinstein's laboratory, she applied her graduate training in the microtubule cytoskeleton on understanding the process of phagocytosis and phagosome maturation in macrophages. She identified the microtubule machinery responsible for fusion of phagosomes with lysosomes and how this machinery is manipulated in Salmonella-infected cells. Dr. Harrison obtained her faculty position at the University of Toronto in 2003 and continues to work on cell biology and the cytoskeleton in macrophage and bone cells. Work from her laboratory has resulted in Dr. Harrison receiving the Ontario Early Researcher Award and the Canadian Institutes of Health Research New Investigator Award.
„Über diesen Titel“ kann sich auf eine andere Ausgabe dieses Titels beziehen.