The present invention discloses a targeted exosome based on the RBD region of SARS-CoV-2 S protein and a preparation method thereof. An RBD-VSVG fusion protein is expressed on the targeted exosome of the present invention, and the RBD-VSVG fusion protein is obtained by replacing the extracellular region of VSVG with the RBD of the SARS-CoV-2 S protein. In the present invention, a targeted exosome capable of efficiently and tissue-specifically delivering a potential anti-SARS-CoV-2 medicine is constructed. The targeted exosome is used to encapsulate SARS-CoV-2 siRNA, to specifically inhibit the virus replication in tissues and organs. In a mouse animal model, tail vein injection of exosome encapsulated SARS-CoV-2 siRNA significantly inhibits virus replication in mouse lung tissue and alleviates symptoms such as pneumonia caused by virus infection.

The present disclosure provides methods for treating HBV infection using an siRNA that targets an HBV gene. In some embodiments, the method for treating HBV involves co-administration of siRNA with PEG-INFα.

Provided are methods of treating a viral infection, the methods comprising administering, to a subject infected with a virus, a genetic modifying agent that targets one or more regions of the viral genome that are maximally different from the host genome. Also provided are methods comprising administering, to a subject infected with a virus, a genetic modifying agent that targets one or more genes of host cells that harbor the virus, where the targeted gene(s) are necessary to the correct function and replication of the virus but are dispensable to the host cells. Also provided are methods comprising decreasing, in one or more cells in the subject, the amount of susceptibility genetic variant(s); and/or increasing, in one or more cells in the subject, the amount of one or more protective genetic variant(s). Also provided are methods of identifying viral genes associated with survival of a virus.

The invention belongs to the field of genetic engineering technology and application thereof, and in order to solve the problems of lack of high efficient TMV-resistant RNAi nano-preparation at present, complicated preparation process of medicament, poor stability and delivery efficiency of dsRNA, the invention provides an RNAi nano-preparation, preparation method thereof and application thereof in TMV prevention and control. The RNAi nano-preparation is prepared from dsRNA and chitosan nano materials, wherein, dsRNA is a highly TMV-resistant RdRP3 gene with a length of 313 bp obtained from screening, with nucleotide sequence shown in SEQ ID NO.1, and the volume ratio of the chitosan to 1 μg/μl dsRNA is 10:(1-6). The RNAi nano-preparation provided by the invention has the advantages of stronger stability and better durability of dsRNA, good biocompatibility, good biodegradability, no harm to crops, environmental friendliness and the like, and has a good application prospect in the field of TMV virus prevention and control.

The invention provides a vaccine composition comprising a flavivirus peptide comprising one or more CD8+ T cell epitopes, wherein the peptide is attached to a nanoparticle.

The present disclosure relates to double stranded RNA agents targeting the hepatitis B virus (HBV) genome, and methods of using such agents to inhibit expression of one or more HBV genes and methods of treating subjects having an HBV infection or HBV-associated disorder, e.g., chronic hepatitis B infection.

The present disclosure relates to specific reverse micelle system that allows for the administration and intracellular delivery of unmodified oligonucleotide, such as siRNA, targeting one or more genes of the SARS-CoV-2 virus. The reverse micelle systems described herein are particularly useful for the treatment of COVID-19.

Methods of inhibiting a respiratory virus, (i.e., a virus associated with a respiratory condition, e.g., influenza A, influenza B, RSV, etc.) in a sample are provided. Aspects of the methods include contacting a sample comprising viral RNA (vRNA) having a target motif with an effective amount of an agent that specifically binds the target motif to inhibit the respiratory virus. Also provided are methods of treating or preventing respiratory virus infection in a subject. Also provided are compounds and pharmaceutical compositions comprising an oligonucleotide sequence complementary to a target vRNA region that find use in the subject methods.

A compound for forming a conjugate with an active agent such as an oligonucleotide having a structure represented by Formula (321). The present disclosure also provides a corresponding conjugate. The conjugate of the present disclosure can specifically target hepatocytes, thereby effectively solve the problems associated with delivery of oligonucleotide drugs in vivo, and have low toxicity and excellent delivery efficiency while maintaining high stability for the delivered oligonucleotide. ##STR00001##

HCMV US11 based therapeutics that can be used to target and reduce the activity of the FcRn protein are provided. Methods of treating auto-immune mediated and albumin-mediated diseases in a subject are provided that comprise administration of HCMV US11 protein, polypeptide fragments, or variants thereof, as well as methods for preventing, or treating, infections of HCMV through administration of a US11 inhibitor. US11 protein containing vaccine compositions are also provided for stimulation of an anti-US11 immune response for protection against HCMV infection.