Cytotoxic T lymphocyte attacking a cancer cell (jrc_ctl-id8-2)

Cytotoxic T lymphocytes (CTLs) kill virus-infected and tumorigenic cells through the polarized release of perforin and granzymes, which are housed in modified lysosomes called lytic granules. Perforin is a pore-forming toxin that creates an ephemeral portal in the plasma membrane of the target through which granzymes enter the cytosol and initiate apoptosis. This conjugate was captured moments after perforin secretion toward the target.

Sample: OT-I mouse cytotoxic T lymphocyte attacking an ID8 ovarian cancer cell; fixed and imaged moments after the release of perforin/granzyme from lytic granules. The ID8 murine ovarian cancer cell is stably expressing mEmerald-Chmp4b and TOMM20-SNAP.

Protocol: High pressure freezing, freeze-substitution resin embedding with 2% OsO4 0.1% UA 3% H2O in acetone; resin embedding in Eponate 12.

Contributions: Sample provided by Alex Ritter (Genentech), prepared for imaging by Gleb Shtengel (HHMI/Janelia), with imaging and post-processing by C. Shan Xu (HHMI/Janelia).

Dataset ID: jrc_ctl-id8-2

Final voxel size (nm): 8 x 8 x 8 (X, Y, Z)

Dimensions (µm): 50 x 9 x 62.9 (X, Y, Z)

Acquisition date: 2019-10-18

Dataset URL: https://data.janelia.org/ZFq0C

Visualization Website: https://openorganelle.janelia.org/datasets/jrc_ctl-id8-2

Publication: Ritter et al., ESCRT-mediated membrane repair at the immunological synapse protects tumor cells against T cell attack, Science (2022).