Abken, Hinrich - B 1

Deciphering the hierarchic organization of established tumor lesions

T cells can be redirected towards pre-defined target cells by engineering with a chimeric antigen receptor (CAR) for use in adoptive cell therapy of malignant diseases. We here used the strategy to explore and manipulate the functional interaction of engineered antigen-redirected T cells with solid tumors and tissue stem cells.

Introduction

The adoptive cell therapy of malignant diseases has shown powerful in the treatment of hematologic malignancies in early phase trials. T cells of patients are genetically engineered with a chimeric antigen receptor (CAR) which confers pre-defined specificity by an antibody and T cell activation by signaling through domains of the T cell receptor complex. We used CAR T cells to address a number of basic issues on T cell – tumor and stem cell interaction.

Efficacy of CAR T cell therapy in large tumors relies upon stromal targeting by IFN-γ

Complete eradication of large established solid tumors has not been reported to date. Although CAR-Ts recognize the antigen MHC-independently and exclusively on cancer cells without targeting the cross-presented antigen, we revealed complete eradication of large established HER-2+ tumors by HER-2 specific CAR-Ts. Tumor rejection occurred without the recognition of the cross-presented antigen but only when CAR-Ts were provided with the CD28 costimulatory signal, however, it required the expression of IFNγ receptor and Fas on the tumor stroma.
Textor et al., Cancer Res (2014)

CAR T cells with an inducible cytokine to modulate the tumor stroma

Given the tremendous phenotypic diversity in solid tumor lesions, a reasonable number of cancer cells are not recognized by a given CAR. We described a strategy for overcoming this shortcoming of the CAR T cell therapy by modulating the tumor stroma by a CAR T cell secreted transgenic cytokine like IL-12. The basic process is that CAR T cells, when activated by their CAR, deposit IL-12 in the targeted tumor lesion, which in turn attracts an innate immune cell response towards those cancer cells that are invisible to CAR T cells. Such TRUCKs, T cells redirected for universal cytokine-mediated killing, exhibited remarkable efficacy against solid tumors with diverse cancer cell phenotypes suggesting their evaluation in clinical trials.
Chmielewski et al., Immunol Rev (2014)
Chmielewski et al., Exp Opin (2015)

Bi-specific antibody recruiting of CAR T cells towards solid tumors

One bottleneck for adoptive T cell therapy is recruitment of T cells into tumors. We showed that combining tumor-specific T cells, modified with a marker antigen and a bispecific antibody (BiAb) that selectively recognizes CAR T cells and tumor cells improves T cell recruitment to tumors and enhances therapeutic efficacy with increased T cell infiltration of tumors, retarded tumor growth, and prolonged survival.
Kobold et al., J. Natl. Cancer Inst. (2015)

Coexpressed catalase protects T cells and bystander cells from oxidative stress-induced loss of anti-tumor activity.

In solid tumors T cells encounter a hostile environment, in particular with increased inflammatory activity that goes along with abundant reactive oxygen species (ROS) that substantially impair antitumor activity. We present a strategy to render CAR T cells more resilient toward ROS by coexpressing catalase to increase their anti-oxidative capacity by metabolizing H2O2. In fact, T cells engineered with catalase and CAR performed superior over CAR T cells as they showed increased levels of intracellular catalase and had a reduced oxidative state with less ROS accumulation while maintaining their antitumor activity despite high H2O2 levels. Moreover, CAR-CAT T cells exerted a substantial bystander protection of other immune effector cells. Bystander NK cells, otherwise ROS sensitive, efficiently eliminate their target cells under oxidative stress when admixed with CAR-CAT T cells. This approach represents a novel means for protecting tumor-infiltrating cells from tumor-associated oxidative stress-mediated repression.
Ligtenberg et al., J Immunol (2016)

CD30+CD34+ hematopoietic stem cells resist a T cell attack

Targeting B lymphoma/leukemia by anti-CD19 CAR T cells is effective, however, eliminates healthy B cells. We here explored CD30 as an alternative target, which is validated in lymphoma therapy and expressed by a broad variety of lymphomas. Targeting CD30 also targets hematopoietic stem and progenitor cells (HSPCs). We revealed that HRS3scFv-derived CAR T cells were not blocked by soluble CD30 and did not attack CD30+ HSPCs while eliminating CD30+ lymphoma cells. Consequently, normal hemato- and lymphopoiesis was not affected in the long-term in the humanized mouse; the number of blood B and T cells remained unchanged. We provide evidence that the CD30+ HSPCs are protected against a CAR T-cell attack by substantially lower CD30 levels than lymphoma cells and higher levels of the granzyme B inactivating SP6/PI9 serine protease, which furthermore increased upon activation.
Hombach et al., Mol Ther (2016); Expert Rev Clin Immunol (2016)

An alternative target for eliminating CLL cells while sparing healthy B cells.

Adoptive cell therapy of chronic lymphocytic leukemia (CLL) with CAR T cells targeting CD19 induces lasting remission in a number of patients, however, is associated with prolonged “on-target off-tumor” toxicities due to the targeted elimination of healthy B cells. We identified the immunoglobulin M Fc receptor (FcmR) as a target for a more selective treatment of CLL. CAR T cells specific for FcmR efficiently responded toward CLL cells, released proinflammatory cytokines, eliminated the leukemic cells and delayed outgrowth of Mec-1-induced leukemia in a xenograft mouse model. CAR T cells from CLL patients in various stages of the disease purged their autologous CLL cells in vitro without reducing the number of healthy B cells implying a superior therapeutic index of anti-FcmR CAR T cells for the treatment of CLL.
Faitschuk et al., Blood (2016)

Selected publications

Chmielewski et al., (2014) Immunol. Rev. 257, 83 - 90 
Faitschuk et al., (2016) Blood 128, 1711 – 1722 
Faitschuk et al., (2016) Gene Therapy, in press
Hombach et al., (2016) Mol. Ther., 24, 1423 – 1434 
Kobold et al., (2015) J. Natl. Cancer Inst. 107, 364 - 371 
Krug et al. (2015) Cancer Immunol. Immunother. 64, 1623 – 1635 
Krug et al., (2014) Cancer Immunol. Immunother. 63, 999-1008  
Ligtenberg et al., (2016) J. Immunol. 196, 759-766
Makalowski et al., (2014). In: Cancer Stem Cells. Chapter 33, Ed.: V. K. Rajasekhar, Wiley-Blackwell, p. 451 – 460
Textor et al., (2014) Cancer Res. 74, 6796 – 6805

Former Funding Period 01/2014 - 12/2016

Information from this funding period will not be updated anymore. New research related information is available here.


Prof. Dr. med. Hinrich Abken

Dept. I of Internal Medicine

Prof. Dr. med. Hinrich Abken

Principal Investigator B 1
Head - Cell Sorting Facility

hinrich.abken@uk-koeln.de

Work +49 221 478 89614

Fax (Work) +49 221 478 97295

CMMC-Research Building
Robert-Koch-Str. 21
50931 Cologne

http://innere1.uk-koeln.de/profil/hinrich_abken

Publications

Link to PubMed

Group Members

Markus Chmielewski (Post Doc)
Astrid Holzinger (Post Doc)
Andreas Hombach (Post Doc)
Johannes Kühle (Post Doc)
Dorottya Horváth (PhD student)
Valérie Liebrecht (PhD student)
Elena Faitschuk (PhD student)
Jennifer Makalowski (PhD student)
Alexandra Martyniszyn (PhD student)
Viktória Golumba-Nagy (marie-curie, PhD student)
Lisa Hannappel (PhD student)
Anja Meyer (Master student)
Carola Janke (Bachelor student)
Danuta Chrobok (Technician)
Nicole Hoffmann (Technician)
Petra Hofmann (Technician)
Birgit Hops (Technician)

Figure 1

Figure 1: Transiently expressed activation associated antigens with shared expression by hematopoietic stem and progenitor cells (HSPCs) and cancer cells have a different risk profile in the adoptive cell therapy. Targeting an activation associated antigen, like CD30, is safe as long as the HSPCs are protected towards a T cell attack by various mechanisms including high IP9 levels (“immune privilege”). During maturation the stem cell protection decreases which goes along with decreasing levels of the target antigen making the HSPCs progressively invisible to CAR T cells. During the entire process the HSPCs are protected against CAR T cell lysis. In contrast, targeting an antigen which is expressed in increasing levels during linage determination, like CD123, makes the entire cell linage progressively accessible to a CAR T cell attack while the immune privilege of HSPCs decreases during HSPC maturation.