Ernst Böhnlein

Retroviral vectors designed for targeted expression of RNA polymerase III-driven transcripts: a comparative study.

Retroviral gene delivery systems for RNA polymerase II (RNA pol II)-based promoters have been developed and are widely used in gene transfer studies. In contrast, gene delivery systems with RNA pol III-based expression cassettes have not been studied comprehensively, although therapeutic applications (e.g., ribozymes, antisense, triplex RNA and RNA decoys) have been proposed. In this report, we describe retroviral vectors designed to optimize expression of short chimeric RNAs transcribed from a number of RNA pol III promoters. Our results show that all analysed RNA pol III expression cassettes (tRNA, U6, Ad VA1), regardless of orientation, do not transcribe efficiently when located between the retroviral long terminal repeats (LTRs). In contrast, high steady-state expression levels can be achieved by inserting the RNA pol III expression cassette into the U3 region of the LTR (double-copy design). Compared to human tRNA gene promoters (tRNA(Met), tRNA(Val)), the human small nuclear RNA U6 gene (U6) and the adenovirus virus-associated RNA 1 (Ad VA1) gene promoters yielded higher expression levels. The majority of the chimeric U6-derived transcripts were detected in the nuclear RNA fraction, and the VA1 and tRNA-driven transcripts were predominantly detected in the cytoplasmic compartments. This report is the first comparative study of RNA pol III-driven promoters expressing short chimeric transcripts leading to an optimized retroviral-vector design.

Gene therapy for arthritis 1996 - 1999

Gene therapy for rheumatoid arthritis (RA) is a relatively novel therapeutic concept. At present, two clinical trials are ongoing which evaluate the safety of ex vivo gene transfer into synoviocytes. However, it is anticipated that the number of clinical trials evaluating anti-inflammatory gene transfer strategies will increase significantly within the near future. This review summarises the pertinent patent situation for arthritis gene therapy from 1996 to 1999. A patent search with the keywords arthritis and gene therapy revealed 65 patent filings during this time period. In this report, we describe and discuss a selection of patent applications filed for novel therapeutic strategies, enabling gene delivery, and expression systems into relevant cell populations (e.g., synoviocytes, chondrocytes and mesenchymal stem cells). For the future, we envision that gene discovery efforts in connection with functional genomics will provide a wealth of novel patentable information hopefully leading to innovative ge...