Signaling pathways engaged by NK cell receptors: double concerto for activating receptors, inhibitory receptors and NK cells.

Despite the absence of antigen-specific receptors at their surface, NK cells can selectively eliminate virus-infected cells, tumor cells and allogenic cells. A dynamic and precisely coordinated balance between activating and inhibitory receptors governs NK cell activation programs. Multiple activating and inhibitory NK cell surface molecules have been described, a group of them acting as receptors for MHC class I molecules.

Interdigital cell death can occur through a necrotic and caspase-independent pathway.

Programmed cell death in animals is usually associated with apoptotic morphology and requires caspase activation. Necrosis and caspase-independent cell death have been reported, but mostly in experimental conditions that lead some to question their existence it in vivo. Loss of interdigital cells in the mouse embryo, a paradigm of cell death during development [1], is known to include an apoptotic [2] and caspase-dependent [3] [4] mechanism.

Distribution of the neural antigen BSP-2 in the cerebellum during development.

The monoclonal antibody anti-BSP-2 recognizes three glycosylated peptide chains of 180,000, 140,000 and 120,000 daltons in extracts from adult mouse forebrain and cerebellum. In extracts of embryonic or neonatal brain, it recognizes a different form, migrating as a broad band of higher molecular weight on SDS polyacrylamide gels. This report describes the distribution of the antigen BSP-2 in developing mouse cerebella using a sensitive immunoperoxidase technique at the electron microscope level.