Although effective rabies virus vaccines have been existing for decades, each year, rabies virus infections still cause around 50.000 fatalities worldwide. Most of these cases occur in developing countries, where these vaccines are not available. The reasons for this are the prohibitive high costs of cell culture or egg grown rabies virus vaccines and the lack of a functional cold chain in many regions in which rabies virus is endemic. Here, we describe the excellent temperature resistance of a non-replicating mRNA based rabies virus vaccine encoding the rabies virus glycoprotein (RABV-G). Prolonged storage of the vaccine from -80°C to up to +70°C for several months did not impact the protective capacity of the mRNA vaccine. Efficacy after storage was demonstrated by the induction of rabies specific virus neutralizing antibodies and protection in mice against lethal rabies infection. Moreover, storing the vaccine at oscillating temperatures between +4° and +56°C for 20 cycles in order to simulate interruptions of the cold chain during vaccine transport, did not affect the vaccine’s immunogenicity and protective characteristics, indicating that maintenance of a cold chain is not essential for this vaccine.

In the application, a method for preparative purification of RNA will be described, which is characterized in that the RNA is purified by means of HPLC using a porous reversed phase as stationary phase. Further, the use of the porous reversed phase in this HPLC method is described.

La presente invention concerne la lyophilisation d'acides nucleiques dans des solutions ou formulations contenant du lactate. La presente invention est particulierement adaptee pour renforcer et ameliorer les capacites de stockage et de transport d'acides nucleiques pour de multiples applications. La presente invention concerne, en outre, des procedes de lyophilisation adaptes pour preparer de ces acides nucleiques lyophilises de l'invention, l'utilisation de tels acides nucleiques lyophilises dans la preparation de compositions pharmaceutiques, des premiere et deuxieme indications medicales utilisant ces acides nucleiques lyophilises et des kits, en particulier un kit de composants, comprenant ces acides nucleiques lyophilises.

Plasmacytoid dendritic cells (PDC) represent a highly specialized immune cell subset that produces large quantities of the anti-viral cytokines type I interferons (IFN-alpha and IFN-beta) upon viral infection. PDC employ a member of the family of toll-like receptors, TLR9, to detect CpG motifs (unmethylated CG dinucleotides in certain base context) present in viral DNA. A certain group of CpG motif-containing oligodeoxynucleotides (CpG ODN), CpG-A, was the first synthetic stimulus available that induced large amounts of interferon-alpha (IFN-alpha) in PDC. However, the mechanism responsible for this activity remained elusive. CpG-A is characterized by a central palindrome and poly(G) at the 5' and 3' end. Here we demonstrate that CpG-A self-assembles to higher order tertiary structures via G-tetrad formation of their poly(G) motifs. Spontaneous G-tetrad formation of CpG-A required the palindrome sequence allowing structure formation in a physiological environment. Once formed, G-tetrad-linked structures were stable even under denaturing conditions. Atomic force microscopy revealed that the tertiary structures formed by CpG-A represent nucleic acid-based nanoparticles in the size range of viruses. Similarly sized preformed polystyrene nanoparticles loaded with a CpG ODN that is otherwise weak at inducing IFN-alpha (CpG-B) gained the potency of CpG-A to induce IFN-alpha. Higher ODN uptake in PDC was not responsible for the higher IFN-alpha-inducing activity of CpG-A or of CpG-B-coated nanoparticles as compared with CpG-B. Based on these results we propose a model in which the spatial configuration of CpG motifs as particle is responsible for the virus-like potency of CpG-A to induce IFN-alpha in PDC.

The definition of an optimal siRNA results from the in vitro testing of several siRNA designed to specifically target a gene. Usually, such in vitro tests consist in the transfection of the several siRNA duplexes in a cell expressing stably the gene of interest. When a siRNA specific for a mRNA coding toxic proteins (certain transcription factors, transporters, toxins, cell cycle controlling proteins, etc.) must be tested, the generation of a target cell is difficult. Here we report a quick method to test the efficiency of a siRNA through its co-transfection with the targeted mRNA. This technique can be used as a fast method to test siRNA even when they target genes that cannot be stably expressed in the cells of interest.