Branch Lab Translational Cell Therapy (Hannover)

The Translational Cell Therapy off-site unit develops and validates cell-based advanced therapy medicinal products (ATMPs). To do this, it conducts translational research and develops GMP-compliant manufacturing protocols for cell therapeutics at the interface to preclinical development right through to their transfer into clinical trials. Cell and genetic engineering methods and strategies are implemented and optimized here to specifically manufacture killer lymphocytes and their subpopulations. The ability to overcome so-called tumor immune escape mechanisms in cancer cells is key here. This is achieved by using activated and genetically modified effector cells together with checkpoint inhibitors and stimulating immune cells. These cell therapies boost immune surveillance and strengthen the elimination of resistant cancer cells as well as their malignant precursor cells (so-called tumor stem cells). Another focus of development lies in optimizing the transduction capacity of effector cells using chimeric antigen receptors (CARs) in order to increase cytotoxicity to malignant cells. To do this, human effector cells are separated following lymphapheresis by means of GMP-suitable, fully automated, closed-system production, genetically modified as necessary and expanded as part of clinical upscaling. Moreover, the group is developing GMP-compliant manufacturing and expansion protocols in order to proliferate a sufficient number of activated effector cells.

Development of GMP-compliant protocols for the fully automated generation of CAR-expressing donor NK cells

GMP-compliant cell separation

CliniMACS Plus, Miltenyi Biotec (separation)

GMP-compliant cell separation

CliniMACS Prodigy, Miltenyi Biotec (separation / expansion)

GMP-suitable quality control using 10-color flow cytometry

Navios (Beckman Coulter)

ADCC (“antibody-dependent cell-mediated cytotoxicity”)

GMP-suitable accumulation (“GMP sorting”) of the CD16-positive (cytotoxic) subpopulation of activated donor NK cells used in combination with IgG antibodies to specifically eliminate cancer cells.

GMP-compliant cell separation

CliniMACS Prodigy (Miltenyi Biotec)

GMP-suitable quality control using 10-color flow cytometry

Navios (Beckman Coulter)

GMP-suitable "sorting"

MACS Quant Tyto (Miltenyi Biotec)

8-color fluorescence microscopy (Olympus) with quantitative quality control based on IX81 ScanR analysis software for developing potency assays that can be validated

IX81 (Olympus) ScanR fluorescence microscope.
© Fraunhofer IZI

IX81 (Olympus) ScanR fluorescence microscope.

CAR-mediated "retargeting" of specific effector-target interactions.
© Fraunhofer IZI

CAR-mediated "retargeting" of specific effector-target interactions.

Time-lapse imaging and tracking of CAR-modified donor NK cells (green/yellow) against resistant AML blasts (blue).
© Fraunhofer IZI

Time-lapse imaging and tracking of CAR-modified donor NK cells (green/yellow) against resistant AML blasts (blue).

GMP-compliant electroporation (transfection) of activated donor NK cells in a closed tubing set system as an alternative to transduction with alphaviral / lentiviral vectors

Maxcyte GT electroporator (Maxcyte).
© Fraunhofer IZI

Maxcyte GT electroporator (Maxcyte).

Electroporation without mRNA: Flow cytometry (Navios) to the left, fluorescence microscopy (Olympus IX81) to the right.
© Fraunhofer IZI

Electroporation without mRNA: Flow cytometry (Navios) to the left, fluorescence microscopy (Olympus IX81) to the right.

Electroporation using GFP-tagged mRNA.
© Fraunhofer IZI

Electroporation using GFP-tagged mRNA.

Ex vivo expansion of PBMC-derived human NK cells for use in in vivo studies

Schematic depiction of a cancer cell identified and attacked by immune cells.
© Christoph Burgstedt - stock.adobe.com

Schematic depiction of a cancer cell identified and attacked by immune cells.

One of the main functions of the human immune system is to defend against infections. Another is to eliminate cancer cells.

Immune cells are fundamentally capable of recognizing cancer cells and eliminating them through various mechanisms. One of these mechanisms is antibody-dependent, cell-mediated cytotoxicity (ADCC), whereby antibodies bind to the surface of cancer cells, giving natural killer (NK) cells a signal to kill the respective cells. These immune cells bind to the cancer cells via the antibodies and are stimulated to release cytotoxic proteins.

Despite some cancer cells being able to evade this mechanism due to their immunosuppressive properties, it offers an excellent starting point for developing new forms of cancer therapy based on this immunological principle.

To this end, the company Affimed developed a new antibody platform for killing malignant target cells with extreme precision. This platform enables the immunosuppressive mechanisms employed by tumor cells are overcome and a targeted immune response to be triggered.

As part of the project, leukapheresis was conducted on different, healthy donors at Fraunhofer IZI’s off-site unit in Hannover. NK cells were then separated immunomagnetically from the enriched peripheral blood mononuclear cells (PBMCs), expanded for two ex vivo weeks, and then cryopreserved. The cells could then be thawed, expanded / activated anew and investigated as part of preclinical tests as and when required.