Inability of granule polarization by NK cells defines tumor resistance and can be overcome by CAR or ADCC mediated targeting

  • Background: On encountering a susceptible target, natural killer (NK) cells mediate cytotoxicity through highly regulated steps of directed degranulation. Cytotoxic granules converge at the microtubule organizing center and are polarized toward the immunological synapse (IS), followed by granule exocytosis. NK cell retargeting by chimeric antigen receptors (CARs) or mAbs represents a promising strategy for overcoming tumor cell resistance. However, little is known about the lytic granule dynamics of such retargeted NK cells toward NK-cell-resistant tumors. Methods: Here, we used spinning disk confocal microscopy for live-cell imaging to analyze granule-mediated NK cell cytotoxicity in ErbB2-targeted CAR-expressing NK-92 cells (NK-92/5.28.z) and high-affinity FcR transgenic NK-92 cells plus Herceptin toward ErbB2-positive breast cancer cells (MDA-MB-453), which are resistant to parental NK-92. Results: Unmodified NK-92 cells cocultured with resistant cancer cells showed stable conjugate formation and granule clustering, but failed to polarize granules to the IS. In contrast, retargeting by CAR or FcR+Herceptin toward the MDA-MB-453 cells enabled granule polarization to the IS, resulting in highly effective cytotoxicity. We found that in NK-92 the phosphoinositide 3-kinase pathway was activated after contact with resistant MDA-MB-453, while phospholipase C-γ (PLCγ) and mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) were not activated. In contrast, retargeting by CAR or antibody-dependent cell-mediated cytotoxicity (ADCC) provided the missing PLCγ and MEK/ERK signals. Conclusions: These observations suggest that NK cells can create conjugates with resistant cancer cells and respond by granule clustering, but the activation signals are insufficient to induce granule polarization and consequent release of lytic enzymes. Retargeting by CAR and/or the FcR/mAb (ADCC) axis provide the necessary signals, leading to granule polarization and thereby overcoming tumor cell resistance.
Metadaten
Author:Jiri EitlerGND, Natalie WotschelGND, Nicole Miller, Laurent Boissel, Hans-Georg KlingemannGND, Winfried WelsORCiDGND, Torsten TonnORCiDGND
URN:urn:nbn:de:hebis:30:3-629870
DOI:https://doi.org/10.1136/jitc-2020-001334
ISSN:2051-1426
Parent Title (English):Journal for ImmunoTherapy of Cancer
Publisher:BioMed Central
Place of publication:London
Document Type:Article
Language:English
Date of Publication (online):2021/01/19
Date of first Publication:2021/01/19
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2024/01/08
Tag:ADCC; Chimeric Antigen Receptor (CAR); NK cells; NK-92; breast cancer; cancer immunotherapy; granule polarization; haNK; live-cell imaging
Volume:9
Issue:1, art. e001334
Article Number:e001334
Page Number:15
First Page:1
Last Page:15
HeBIS-PPN:521819687
Institutes:Medizin
Angeschlossene und kooperierende Institutionen / Georg-Speyer-Haus
Dewey Decimal Classification:6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit
Sammlungen:Universitätspublikationen
Licence (German):License LogoCreative Commons - CC BY-NC - Namensnennung - Nicht kommerziell 4.0 International