Scalable Production of AAV Vectors in Orbitally Shaken HEK293 Cells.

Adeno-associated virus (AAV) vectors are currently among the most commonly applied for gene therapy approaches. The evaluation of vectors during clinical development requires the production of considerable amounts of highly pure and potent vectors. Here, we set up a scalable process for AAV production, using orbitally shaken bioreactors and a fully characterized suspension-adapted cell line, HEKExpress.

Cell encapsulation technology as a novel strategy for human anti-tumor immunotherapy.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) as an adjuvant in autologous cell-based anti-tumor immunotherapy has recently been approved for clinical application. To avoid the need for individualized processing of autologous cells, we developed a novel strategy based on the encapsulation of GM-CSF-secreting human allogeneic cells. GM-CSF-producing K562 cells showed high, stable and reproducible cytokine secretion when enclosed into macrocapsules.

Regulation of episomal gene expression by KRAB/KAP1-mediated histone modifications.

KAP1 is an essential cofactor of KRAB zinc finger proteins, a family of vertebrate-specific epigenetic repressors of largely unknown functions encoded in the hundreds by the mouse and human genomes. So far, KRAB/KAP1-mediated gene regulation has been studied within the environment of chromosomal DNA. Here we demonstrate that KRAB/KAP1 regulation is fully functional within the context of episomal DNA, such as adeno-associated viral and nonintegrated lentiviral vectors, and is correlated with histone modifications typically associated with this epigenetic regulator.

Suppression of kindled seizures by paracrine adenosine release from stem cell-derived brain implants.

Purpose: Stem cells and their derivatives have emerged as a promising tool for cell-based drug delivery because of (a) their unique ability to differentiate into various somatic cell types, (b) the virtually unlimited donor source for transplantation, and (c) the advantage of being amenable to a wide spectrum of genetic manipulations. Previously, adenosine-releasing embryonic stem (ES) cells have been generated by disruption of both alleles of adenosine kinase (Adk-/-). Lack of ADK did not compromise the cells' differentiation potential into embryoid bodies or glial precursor cells.

Seizure suppression and lack of adenosine A1 receptor desensitization after focal long-term delivery of adenosine by encapsulated myoblasts.

Adenosine is an important inhibitory modulator of brain activity. In a previous ex vivo gene therapy approach, local release of adenosine by encapsulated fibroblasts implanted into the vicinity of an epileptic focus, was sufficient to provide transient protection from seizures (Huber, A., Padrun, V.

Seizure suppression by adenosine-releasing cells is independent of seizure frequency.

Purpose: Intraventricular cellular delivery of adenosine was recently shown to be transiently efficient in the suppression of seizure activity in the rat kindling model of epilepsy. We tested whether the suppression of seizures by adenosine-releasing grafts was independent of seizure frequency.

Methods: Adenosine-releasing cells were encapsulated and grafted into the lateral brain ventricle of rats kindled in the hippocampus.

Grafts of adenosine-releasing cells suppress seizures in kindling epilepsy.

Adenosine is an inhibitor of neuronal activity in the brain. The local release of adenosine from grafted cells was evaluated as an ex vivo gene therapy approach to suppress synchronous discharges and epileptic seizures. Fibroblasts were engineered to release adenosine by inactivating the adenosine-metabolizing enzymes adenosine kinase and adenosine deaminase.

Growth inhibition of liver metastases by the anti-angiogenic drug TNP-470.

Objective: This study was undertaken in order to assess the efficacy of a potent angiogenesis inhibitor, TNP-470, on tumor growth in a syngeneic rodent model of liver metastases from colorectal cancer.

Background: New blood vessel formation is a prerequisite for primary and metastatic tumor growth. TNP-470, a synthetic derivative of fumagillin when subcutaneously transplanted into nude mice, inhibits endothelial cell proliferation and migration, as well as the growth of various human cancers.

Transplantation of encapsulated bovine chromaffin cells in the sheep subarachnoid space: a preclinical study for the treatment of cancer pain.

Chromaffin cells have been shown to release a combination of pain-reducing neuroactive compounds including catecholamines and opioid peptides. The allogeneic transplantation of chromaffin cells in the subarachnoid space has been shown to alleviate pain in various rodent models and possibly in terminal cancer patients. Because of the shortage of human cadaver donor tissue, we are investigating the possibility of transplanting xenogeneic cells in polymer capsules.