In some embodiments, an antiviral vector is provided. The antiviral vector includes a replication competent adeno-associated virus (AAV) and an inhibitory expression cassette that includes a nucleotide sequence that encodes an RNAi molecule that inhibits expression of a targeted helper virus (THV) gene. The THV gene may be part of an Adenovirus (Ad) genome, a Human Papillomavirus (HPV) genome, a Human Herpes Virus (HHV) genome, or a Vaccinia virus (W) genome.

Universal nucleic acid binding molecules (e.g., antisense oligonucleotides or RNAi molecules) having an inhibitory or activating nucleic acid sequence which binds a receiving nucleic acid sequence (e.g., RNA or DNA) are provided. In some embodiments, the universal nucleic acid binding molecules bind the receiving nucleic acid sequence (e.g., RNA or DNA) via at least one non-Watson Crick or non-canonical paired base.

Described are TTV miRNAs and probes and primers comprising part of said TTV miRNA polynucleic acid. The use of said compounds for diagnosis of cancer or predisposition of cancer is also described.

Provided is a modified double-stranded oligonucleotide, in which the sense strand comprises a nucleotide sequence 1, the anti-sense strand comprises a nucleotide sequence 2, the nucleotide sequences 1 and 2 are both 19 nucleotides in length, and in the direction from 5′ end to 3′ end, nucleotides at positions 7, 8 and 9 of the nucleotide sequence 1 and nucleotides at positions 2, 6, 14 and 16 of the nucleotide sequence 2 are all fluoro-modified nucleotides, and each nucleotide at other positions is independently one of non-fluoro-modified nucleotides. Further provided are a pharmaceutical composition and a conjugate comprising the oligonucleotide, and pharmaceutical use thereof.

Disclosed are antisense molecules and compositions for the treatment of Staphylococcus aureus infection. The antisense molecules and compositions comprise nucleic acid molecules, such as RNA, DNA, or nucleic acid molecules with modified backbones, such as PNA. The antisense molecules and compositions inhibit expression of membrane stability proteins in Staphylococcus aureus; are optionally conjugated to cell penetration molecules such as peptides; and are optionally administered in the form of a nanoparticle composition.

Disclosed are compositions that include double-stranded ribonucleic acid (dsRNA) constructs that inhibit expression or translation of a Coronavirus protein, and methods of using them to treat MERS, SARS, Covid-19 and/or symptoms thereof. Some embodiments relate to a method for preventing, treating, inhibiting, or ameliorating a MERS, SARS, or Covid-19 symptom using a composition herein disclosed. In some embodiments the composition targets the lung.

The present invention discloses the use of placenta permeable small RNAs, particularly the use of small ribonucleic acids (small RNAs) in the preparation of a medicament comprising the small RNAs as active substances, wherein the medicament is administered to a mother's body directly and the small RNAs enter the fetus through the placenta to play their role in the fetus. Trials have shown that the small RNAs when administered directly to the mother's body in different ways such as oral and intragastric administration can enter the fetus through the placenta to play their role directly in the fetus. The invention provides a novel administration method that can minimize the damage to a fetus.

Methods and compositions treat a viral infection use a nuclease and an inhibitor that prevents DNA repair, such as a CRISPR-associated nuclease and a small molecule that inhibits an enzyme of a repair pathway. Under guidance of a targeting sequence, the nuclease cuts viral nucleic acid without cutting the patient's genome. The cut ends of the viral nucleic acid are not repaired because the inhibitor prevents a repair mechanism.

Compositions and methods for treating infection-associated cancer include the use of a nuclease that cuts nucleic acid of an oncovirus in combination with an adjunct chemotherapeutic that treats cancerous cells. For example, a Cas9 endonuclease and a guide RNA that matches a target in a viral genome without having any corresponding match in the human genome can be delivered along with an anti-apoptotic inhibitor.

Provided are a method and use of microRNA MiR-2911 in regulating an ebola virus. Particularly provided are a method and use of isolated microRNA MiR-2911 in regulating an ebola virus protein gene.