The invention relates to methods of modulating the expression of one or more genes in a cell by modulating the multimerization of a transcription factor and/or modulating the formation of enhancer-promoter DNA loops, and thereby modulating the expression of the one or more genes. The invention also relates to treating diseases and conditions involving aberrant gene expression by modulating the multimerization of a transcription factor and/or modulating the formation of enhancer-promoter DNA loops. The invention also relates to methods for screening for compounds that modulate expression of one or more genes in a cell.

A cell model for in vitro evaluation of compound-induced skin sensitization and a constructing method therefor. The method for constructing the cell model comprises the steps of: designing and constructing an sgRNA expression vector based on CRISPR/Cas9 vector system; designing and constructing a homologous recombinant vector capable of knocking a reporter gene linked to a self-cleaving peptide sequence into a specific site of the expression frame of the HMOX1 gene; co-transfecting the homologous recombinant vector, an hCas9 plasmid and the sgRNA expression vector into a cell, and carrying out monoclonal expansion to obtain the cell model. The present invention obtains a HaCaT cell model in which a luciferase gene is knocked in before the stop codon of the HMOX1 gene by combination of CRISPR/CAS9 and a monoclonal cell technique. The cell model realizes synchronous expression of the luciferase gene and the HMOX1 gene, thereby effectively distinguishing sensitizing compounds from non-sensitizing compounds.

This invention provides biosensors, cell models, and methods of their use for monitoring chloride ion, where the biosensors can include targeting domains, sensing domains and reporting domains. Biosensors can be introduced into cells reprogrammed to represent experimental or pathologic cells of interest, including as detectors of chloride ions, as TempoChloro accomplishes.

The present invention relates to a two-part device, wherein a first part is an engineered antigen-presenting cell system (eAPCS), and a second part is an engineered TCR-presenting cell system (eTPCS).

A method of detecting Polycomb Repressive Complex (PRC) activity in a cell providing a cell with a DNA having a protein binding site and at least one reporter gene expression site is operatively connected to the protein binding site, and with a DNA containing a recombinant gene of a binding protein, the binding protein being capable of binding to the protein binding site, wherein the binding protein is fused to a member of the PRC, the method including the step of expressing the recombinant gene, letting the fused binding protein bind to the protein binding site and detecting at least one reporter gene expression.

A transgenic non-human animal model is disclosed. The system comprises an inducible transgene allowing the expression of a mutant POLG1 polypeptide that results in modulation of mitochondrial DNA copy number and/or concentration in the whole transgenic non-human animal or selected cells or tissues of the transgenic non-human animal. Methods of producing and using the model system are also provided.

Disclosed are methods and constructs for engineering circular RNA. Disclosed is a vector for making circular RNA, said vector comprising the following elements operably connected to each other and arranged in the following sequence: a.) a 5 homology arm, b.) a 3 group I intron fragment containing a 3 splice site dinucleotide, c.) optionally, a 5 spacer sequence, d.) a protein coding or noncoding region, e.) optionally, a 3 spacer sequence, f) a 5 Group I intron fragment containing a 5 splice site dinucleotide, and g.) a 3 homology arm, said vector allowing production of a circular RNA that is translatable or biologically active inside eukaryotic cells. In another embodiment, the vector can comprise the 5 spacer sequence, but not the 3 spacer sequence. In yet another embodiment, the vector can comprise the 3 spacer sequence, but not the 5 spacer sequence. Also disclosed is a method for purifying the circular RNA produced by the vector and the use of nucleoside modifications in circular RNA produced by the vector.

The present disclosure provides transgenic nematode systems for assessing function of heterologous genes, their variants and drug discovery. The transgenic nematodes contain a heterologous gene that is inserted via homologous recombination at the native locus replacing and removing the nematode ortholog, wherein expression of the heterologous gene rescues function of the removed nematode ortholog and a transgenic control animal is provided. The heterologous gene may be further modified to provide a variant, such as a human clinical variant, whereby a transgenic test animal is provided. Those transgenic test animals are used in methods to assess function of the heterologous variant and drug screens to find therapeutic candidates reversing deviant activity back to wildtype.

The present invention discloses a method for assessing the capacity of a substance to treat or prevent hepadnavirus infection. A reporter virus carrying genetic information for a first fragment of a recombinase and a reporter cell expressing a second fragment of the recombinase are used. When the reporter virus infects the reporter cell, the two fragments of the recombinase associate and excise a stop cassette that is flanked by two recombination sites and blocks the expression of a reporter gene. Accordingly, the present invention relates to a method of assessing the capacity of a substance to treat or prevent hepadnavirus infection, a hepadnavirus comprising a nucleic acid encoding a first fragment of a recombinase and a mammalian hepatocyte or hepatoma cell comprising a nucleic acid encoding a second fragment of a recombinase and a nucleic acid comprising a stop cassette flanked by two recombination sites fused to a reporter gene.

Disclosed are systems and methods for detecting extracellular ligands and/or inducing expression of an exogenous or endogenous gene. The disclosed systems and methods typically include and/or utilize (i) first and second exogenous extracellular sensors, and third and fourth exogenous extracellular sensors; and (ii) an expression vector comprising a target gene operably linked to a hybrid promoter sequence. The hybrid promoter sequence of the expression vector includes a minimal promoter for inducing transcription and the hybrid promoter sequence further includes interspaced transcription regulator binding sites upstream of the minimal promoter that bind two or more transcription regulators of the extracellular sensors that are released from the extracellular sensors when the extracellular sensor bind an extracellular ligand.