The Genetically Modified Organism Medicinal Framework in Europe, United States, and Japan: Underlying Scientific Principles and Considerations Toward the Development of Gene Therapy and Genetically Modified Cell-Based Products.

viral gene therapy and somatic cell therapy products (whether autologous, allogeneic, or xenogeneic) that have been subjected to an gene transfer procedure will normally be classified as genetically modified organisms (GMOs) in Europe, not just the gene transfer vectors used in their construction. These products are, therefore, expected to fulfill certain environmental requirements with regard to the biosafety aspects of their clinical use (which may be subject to review by government departments responsible for environmental affairs). In the European Union (EU), clinical trials using GMOs generally require three levels of review (in addition to local review processes), which are often performed by separate national agencies.

Subtype-selective positive cooperative interactions between brucine analogs and acetylcholine at muscarinic receptors: functional studies.

In radioligand binding studies, it has been reported that brucine, N-chloromethyl brucine, and brucine N-oxide increased the affinity of acetylcholine for M1, M3, and M4 muscarinic receptors, respectively, in a manner consistent with the predictions of the ternary complex allosteric model. We now demonstrate an equivalent ability of these three allosteric agents to modulate the actions of acetylcholine in functional studies in membranes and in whole cells. The enhancing actions of brucine and brucine N-oxide on acetylcholine (ACh) potency at M1 and M4 receptors respectively have been confirmed in guanosine-5'-O-(3-[35S]thio)triphosphate, GTPase, cAMP, and intracellular Ca2+ mobilization assays of function.

Expression of factor I-resistant mutants of the human complement component C3 in heterologous systems.

Complement plays a major role in hyperacute rejection of xenografts. In order to overcome this, we are developing, by minimal mutagenesis, a modified C3 molecule that, like cobra venom factor (CVF), escapes normal complement regulatory processes and inhibits complement-mediated responses by systemic depletion of C3. Unlike CVF, this protein should have little or no immunogenicity and be suitable for repeat administrations.

Selective allosteric enhancement of the binding and actions of acetylcholine at muscarinic receptor subtypes.

The ternary allosteric model predicts the possibility of discovering molecules with novel and highly subtype-selective modes of action. This approach has been applied to muscarinic receptors. The alkaloid brucine is capable of selectively enhancing by an allosteric mechanism the effects of low but not high concentrations of acetylcholine at only the m1 subtype of muscarinic receptors.