Molecular Engineering of AIE Photosensitizers for Inactivation of Rabies Virus.

Rabies is a zoonotic neurological disease caused by the rabies virus (RABV) that is fatal to humans and animals. While several post-infection treatment have been suggested, developing more efficient and innovative antiviral methods are necessary due to the limitations of current therapeutic approaches. To address this challenge, a strategy combining photodynamic therapy and immunotherapy, using a photosensitizer (TPA-Py-PhMe) with high type I and type II reactive oxygen species (ROS) generation ability is proposed. This approach can inactivate the RABV by killing the virus directly and activating the immune response. At the cellular level, TPA-Py-PhMe can reduce the virus titer under preinfection prophylaxis and postinfection treatment, with its antiviral effect mainly dependent on ROS and pro-inflammatory factors. Intriguingly, when mice are injected with TPA-Py-PhMe and exposed to white light irradiation at three days post-infection, the onset of disease is delayed, and survival rates improved to some extent. Overall, this study shows that photodynamic therapy and immunotherapy open new avenues for future antiviral research.

Live imaging of RNA and RNA splicing in mammalian cells via the dcas13a-SunTag-BiFC system.

Dynamic tracking of the localization of RNA molecules (nucleus and/or cytoplasm) and RNA splicing in living cells plays an important role in understanding their functions. However, a lack of dynamic imaging and high background fluorescence have been reported in the fluorescence in situ hybridization (FISH). Here, we developed a new tool, the dcas13a-SunTag-BiFC system, which fused the dLwacas13a and SunTag systems. dLwacas13a is used as a tracker to target specific RNAs, while SunTag recruits split Venus fluorescent proteins to label targeted RNAs. Our results showed that 4 × NLS-dCas13a-24 × SunTag-BiFC and 2 × NLS- dCas13a-24 × SunTag-BiFC systems can be used for imaging of endogenous RNA foci in the nucleus (Xist) and cytoplasm (Ppib and stress granules) in living cells, respectively. Compared to 12x MS2-MCP system, the dcas13a-SunTag-BiFC system showed a better performance of mRNA foci tracking in live cells. Furthermore, we confirmed the premature termination codon (PTC)-induced exon skipping of Oxt RNA using the dcas13a-SunTag-BiFC and MS2-MCP systems in the nucleus. Thus, the dcas13a-SunTag-BiFC system will facilitate the study of RNA localization in living cells and provide new insights into RNA translocation and splicing.