Protein kinase C delta localizes to secretory lysosomes in CD8+ CTL and directly mediates TCR signals leading to granule exocytosis-mediated cytotoxicity.

Protein Kinase C Localizes to Secretory Lysosomes in CD8 CTL and Directly Mediates TCR Signals Leading to Granule Exocytosis-Mediated Cytotoxicity

Protein kinase Cdelta regulates antigen receptor-induced lytic granule polarization in mouse CD8+ CTL.

Lytic granule exocytosis is the major pathway used by CD8+ CTL to kill virally infected and tumor cells. Despite the obvious importance of this pathway in adaptive T cell immunity, the molecular identity of enzymes involved in the regulation of this process is poorly characterized. One signal known to be critical for the regulation of granule exocytosis-mediated cytotoxicity in CD8+ T cells is ...

Ganglioside inhibition of CD8+ T cell cytotoxicity: interference with lytic granule trafficking and exocytosis.

Granule exocytosis-mediated cytotoxicity by CD8(+) CTL plays a crucial role in adaptive immunity to tumors and to intracellular pathogens. This T cell effector function has been shown to be defective in various murine tumor models and in human cancer. However, factors and their mechanisms that cause inhibition of CD8(+) T cell lytic function in tumor-bearing hosts remain to be fully defined. We...

Distinct T cell receptor signaling requirements for perforin- or FasL- mediated cytotoxicity

A diverse array of signals are generated in a cytotoxic T lymphocyte (CTL) after the T cell receptor (TCR) engages the class I major histocompatibility complex (MHC) peptide complex. These signals result in a multitude of CTL effector functions, including cellular cytotoxicity, cell surface receptor expression, and cytokine secretion. We have examined signaling through the TCR in a wild type CD...

Expression and function of synaptotagmin VII in CTLs.

The Ca(2+) sensor synaptotagmin (Syt) VII regulates the exocytosis of conventional lysosomes in several cell types. In CTLs, the Ca(2+)-regulated exocytosis of lytic granules/secretory lysosomes is responsible for the perforin/granzyme-mediated lysis of target cells. To investigate the role of Syt VII in CTL effector function, the expression and function of Syt VII were examined in wild-type an...