Cytoskeleton: septins do the horizontal tango.

Septins are a family of membrane-associated filamentous proteins that are essential in many biological processes, such as cell division. A recent study has provided the first visualization of septin filament formation in real time, leading to important new insights into their organization.

Dynamics of macrophage trogocytosis of rituximab-coated B cells.

Macrophages can remove antigen from the surface of antibody-coated cells by a process termed trogocytosis. Using live cell microscopy and flow cytometry, we investigated the dynamics of trogocytosis by RAW264.7 macrophages of Ramos B cells opsonized with the anti-CD20 monoclonal antibody rituximab.

Differential recruitment of activating and inhibitory Fc gamma RII during phagocytosis.

Human myeloid cells express both activating and inhibitory receptors of the FcgammaRII family. FcgammaRIIA mediates processes associated with cell activation, including phagocytosis of IgG-opsonized particles, whereas coengagement of the inhibitory FcgammaRIIB downregulates such signaling. We analyzed the relative recruitment of these two receptors during phagocytosis of IgG-coated particles by ts20 Chinese hamster fibroblast cells cotransfected with both receptors carrying distinguishable fluorescent protein tags.