Therapeutic gene transfer is considered as a promising novel strategy to treat genetic disorders and cancer. So far, target cells are often isolated from patients for this purpose, and re-administered after gene transfer. In collaboration with colleagues from the Universities of Cologne and Zurich, researchers at the Paul-Ehrlich-Institut have succeeded in developing gene transfer vehicles that target the therapy relevant cell type directly in the organism. The resulting gene transfer occurs with an extremely high degree of selectivity. A report on the research results can be found in Nature Communications in its online edition of 10.02.2015.
Vectors derived from adeno-associated viruses (AAV) were used as vehicles for targeted gene transfer by the research group of Professor Christian J. Buchholz, Principal Investigator at the LOEWE Centre for Cell and Gene Therapy at Frankfurt am Main and head of the Section “Molecular Biotechnology and Gene Therapy ” of the President of the Paul-Ehrlich-Institut.
AAV is a non-pathogenic parvovirus. The only gene therapy medicinal product authorised in Europe so far, is also based on AAV gene vectors and intended for the treatment of a rare metabolic disorder.
The strategy for the generation of the new precision gene vectors was developed and implemented jointly with Dr Hildegard Büning, head of the AAV Vector Development Research Group at the ZMMK (Zentrum für Molekulare Medizin Köln, Center for Molecular Medicine Cologne) of the University of Cologne: Through exchange of two amino acids, AAV lost its ability to bind to its natural receptor and became thereby unable to penetrate its broad range of natural target cells.
Novel target structures (DARPins, designed ankyrin repeat proteins) were then attached to the surface of the modified vector particles. These structures were developed at Zurich University. The structures can be selected in such a way that they mediate a selective binding of the DARPin-containing AAV vector particles to the therapy relevant cell type only.
This is what enables the AAV vector to attach to and penetrate the desired target cell. The paper referenced here reports on the use of three different DARPins, which equipped AAV vectors either with a specificity for Her2/neu, a tumour marker in breast cancer, for EpCAM, an epithelial surface protein, or for a marker of particular blood cells (CD4 on the surface of lymphocytes with distinct immunological functions).
In the mouse model, the vector for Her2/neu targeted 80 percent of all metastatic sites after only a single injection. If the vector was armed with a cytotoxic gene, the survival rate of the mice was substantially prolonged compared to mice receiving an authorised anti-tumour product. Using the EpCAM-targeted vector, tumour cells could be detected with impressive sensitivity in human blood (few hundred tumour cells in several millilitres of blood).
The desired goal of a cell type specific in vivo gene transfer was also achieved with the blood cell targeted vector: AAV transferred the gene only into lymphocytes present in spleen carrying the CD4 protein target structure.
“The method developed by us jointly is a very promising tool both in fundamental research and for the targeted gene transfer in medicine“, explained Dr Buchholz with regard to the current research results.
Münch RC, Muth A, Muik A, Friedel T, Schmatz J, Dreier B, Trkola A, Plückthun A, Büning H, Buchholz CJ (2015): Off-target-free gene delivery by affinity-purified receptor-targeted viral vectors. Nat Commun Feb 10 [Epub ahead of print].
The Paul-Ehrlich-Institut, Federal Institute for Vaccines and Biomedicines in Langen near Frankfurt/Main, is a senior federal authority reporting to the Federal Ministry of Health (Bundesministerium für Gesundheit, BMG). It is responsible for the research, assessment, and marketing authorisation of biomedicines for human use and veterinary vaccines. Its remit also includes the authorisation of clinical trials and pharmacovigilance, i.e. recording and evaluation of potential adverse effects. Other duties of the institute include official batch control, scientific advice and inspections. In-house experimental research in the field of biomedicines and life science form an indispensable basis for the varied and many tasks performed at the institute. The PEI, with its roughly 800 staff, also has advisory functions at a national level (federal government, federal states (Länder)), and at an international level (World Health Organisation, European Medicines Agency, European Commission, Council of Europe etc.).
Dr. Susanne Stöcker | idw - Informationsdienst Wissenschaft
Modern genetic sequencing tools give clearer picture of how corals are related
17.08.2017 | University of Washington
The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
17.08.2017 | Physics and Astronomy
17.08.2017 | Earth Sciences
17.08.2017 | Physics and Astronomy