title: Gene-immunotherapy with TRAIL and bispecific antibody EpCAMxCD3 for the selective induction of apoptosis in advanced pancreatic and prostate cancer
creator: Groth, Ariane
subject: 570
subject: 570 Life sciences
description: The aim of this project was to test the efficacy of a novel therapeutic approach for cancer therapy. This approach combines immunotherapy with bispecific antibody (bsAb)EpCAMxCD3 and gene therapy with TRAIL. The potential efficacy of this approach was tested in experimental models of pancreatic and prostate carcinoma. Specific aims were i) to construct a lentiviral vector suitable for the transduction of human lymphocytes and the over-expression of TRAIL. The next aim was ii) to establish and to evaluate suitable xenograft  models for the study of the chosen approach, iii) to test the efficacy and the anti-tumor potential of TRAIL-over-expressing lymphocytes and bsAb EpCAMxCD3 in vivo and iv) to elucidate the functional mechanisms underlying observed anti-tumor effects of TRAIL-over-expressing lymphocytes and bsAb EpCAMxCD3 in vivo and in vitro. In conclusion, this is the first study, which shows the effective lentiviral transduction of human lymphocytes with the death ligand TRAIL. The vector pV3TP2A effectively transduced human lymphocytes to over-express TRAIL. The majority of these TRAIL-over-expressing lymphocytes were CD8+ T cells and retained their cytotoxic functions, their migratory and proliferative properties after the transduction. Furthermore, this study showed  that EpCAMxCD3 possesses a potent anti-tumor activity in vivo. In NOD/SCID mice, EpCAMxCD3 had a long serum half-life (t1/2 ∼ 7 days). In two mouse models the combination of EpCAMxCD3 with lymphocytes significantly retarded the growth of BxPc-3 pancreatic and PC-3 prostate cancer xenografts. For mimicking a pancreatic cancer microenvironment in vitro a 3D tumor reconstruct system was used, in which lymphocytes were co-cultured with EpCAM-expressing tumor cells and fibroblasts in a collagen matrix. In this in vivo-like system EpCAMxCD3 potently stimulated the production of the effector cytokines IFN-γ and TNF-α by extracorporally pre-activated lymphocytes. Moreover, compared with a bivalent anti-CD3 antibody, EpCAMxCD3 more efficiently activated production of TNF-α and IFN-γ by non-stimulated PBMCs. We demonstrate for the first time that EpCAMxCD3 induces prolonged contacts between lymphocytes and tumor cells, which may be one of the main reason for the observed anti-tumor effects. The combination with lymphocytes over-expressing the death ligand TRAIL could effectively enhance the anti-tumor effects of bsAb EpCAMxCD3. The combination with TRAIL-over-expressing lymphocytes enabled us to strongly reduce the dose of EpCAMxCD3 necessary for an anti-tumor effect. This is a great advantage, which could minimize potential side effects of bsAb treatment. EpCAMxCD3 did not alter lymphocyte migration as measured by time-lapse video microscopy, which is an important prerequisite for future use in patients. Apoptosis induction  in tumor cells by TRAIL-over-expressing lymphocytes was confirmed in vitro in 3D tumor reconstructs. In cytotoxic killing assays, the anti-tumor effect of TRAIL-over-expressing lymphocytes was significantly enhanced by EpCAMxCD3. In 3D gels, lymphocytes were effective producers of IFN-γ, TNF-α and chemokines, which could also be detected in vivo from tumor lysates. An increased infiltration of the tumor islets with macrophages and granulocytes was observed upon treatment with TRAIL-over-expressing lymphocytes and EpCAMxCD3. A potential explanation for the demonstrated anti-tumor effect of EpCAMxCD3 and TRAIL-over-expressing lymphocytes combination therapy, is an enhancement of the observed effects of single treatment, namely the reduced proliferation in tumor cells, decreased blood vessels formation, local production of cytokines and chemokines, apoptosis and an increased infiltration of tumor tissue with macrophages. Conclusively, the combination of TRAIL-over-expressing lymphocytes and the bispecific antibody EpCAMxCD3 was very efficient in pancreatic and prostate xenograft models in vivo. This combination of gene therapy with immunotherapy could potentially be a possible therapeutic option for the clinical application in the future.
date: 2010
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/10763/1/Dissertation.pdf
identifier: DOI:10.11588/heidok.00010763
identifier: urn:nbn:de:bsz:16-opus-107637
identifier:   Groth, Ariane  (2010) Gene-immunotherapy with TRAIL and bispecific antibody EpCAMxCD3 for the selective induction of apoptosis in advanced pancreatic and prostate cancer.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/10763/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng