Reconstitution of phagosome trafficking in streptolysin O permeabilized macrophages.

LEIVA N; COLOMBO MI; DAMIANI MT

Universidad Nacional de Cuyo. Mendoza. Argentina.

Congreso; XX Reunión Científica Anual de la Sociedad de Biología de Cuyo.; 2002

Sociedad de Biología de Cuyo

Phagocytosis is a process by which macrophages internalize large extracellular particles. By fusion with endosomes and  lysosomes, phagosomes mature and adquire degradative ability. During phagocytosis a large amount of plasma membrane is internalized, implying an active mechanism for the retrieval of membranes to the cell surface. The objective of this work was to reconstitute phagosome transport along the phagocytic pathway in cells permeabilized with Streptolysin O (SLO). In this system, trafficking could be manipulated by the addition of proteins or reagents that usually do not cross the plasma membrane. Phagocytosis was assessed by the uptake of St. aureus coated with 125I-antibodies and recycling or degradation were measured by the efflux to the medium of precipitable or soluble radioactivity. In permeabilized cells, the presence of cytosol and an ATP regenerating system facilitates the recycling from phagosomes and the degradation of the particles internalized. These effects are in agreement with the requirement of cytosolic proteins and energy for phagosome maturation. In conclusion, SLO-permeabilized macrophages could be an useful tool to study the molecular machinery involved in trafficking along the phagocytic via.