Disclosed herein are neuronal cell activity reporter systems including a Secreted Neuronal Activity Reporter (SNAR) construct and a control construct. The SNAR construct includes four tandem repeats of a core domain of the Synaptic Activity Response Element (SARE) of Arc/Arg3.1, a polynucleotide comprising the Arc minimal promoter, and a polynucleotide encoding a first secreted reporter protein. The control construct includes a constitutive promoter and a polynucleotide encoding a second secreted reporter protein. Further provided are methods of monitoring neuronal activity in a cell. The methods may include administering to a cell the neuronal cell activity reporter system, contacting with a substrate, and measuring a signal.

Provided are modified virus-like particles (VLPs) of paramyxoviruses, compositions containing them, methods of using the VLPs for delivery of any particular protein of interest to any of a variety of cells, kits that contain expression vectors for making, using and detecting VLPs, and methods for screening for anti-viral compounds using the VLPs. The modified VLPs contain a contiguous recombinant polypeptide that contains i) all or a segment of a C-terminal domain of a paramyxovirus nucleocapsid protein and ii) a polypeptide sequence of a distinct protein. Non-covalent complexes of paramyxovirus M protein and fusion proteins that contain a C-terminal domain of a paramyxovirus nucleocapsid protein and a polypeptide sequence of a distinct protein are provided, as are non-covalent complexes of cells, and cell receptors, with modified VLPs.

Provided herein are substantially non-luminescent peptide/polypeptide tags that are inserted internally within a protein of interest or between N-terminal and C-terminal peptides/polypeptides. Interaction of the internally-inserted tag with a complement polypeptide/peptide that is also substantially non-luminescent results in the formation a bioluminescent reporter complex.

The present invention relates to screening methods for identification of agents (e.g., small molecules) that modulate cytotoxic T lymphocyte antigen-specific target (e.g., tumor) cell killing, as well as to uses of compounds identified thereby as immunomodulatory, including use of EGFR inhibitors as immunomodulatory agents.

Provided herein are substantially non-luminescent peptide/polypeptide tags that are inserted internally within a protein of interest or between N-terminal and C-terminal peptides/polypeptides. Interaction of the internally-inserted tag with a complement polypeptide/peptide that is also substantially non-luminescent results in the formation a bioluminescent reporter complex.

Provided are nucleic acids that include a promoter, where the promoter is operable in a Bacteroides cell and is operably linked to a heterologous nucleotide sequence of interest. Also provided are nucleic acids that include a promoter (operable in a prokaryotic cell such as a Bacteroides cell) operably linked to a sequence encoding a synthetic ribosomal binding site (RBS). Also provided are fusion proteins (and nucleic acids encoding them) in which a secreted Bacteroides polypeptide is fused to a heterologous polypeptide of interest. Also provided are prokaryotic cells (e.g., E. coli, a Bacteroides cell, and the like) that include one more nucleic acids such as those described above. Also provided are methods of expression in a prokaryotic cell, methods of detectably labeling a Bacteroides cell in an animal's gut, and methods of delivering a protein to an individual's gut.

Provided are compositions and methods for introducing proteins into cells. The compositions and methods relate to introducing a foreign protein as an engineered component of a paramyxovirus virus like particle (VLP). The compositions and methods pertain to modified VLPs that contain a contiguous recombinant polypeptide comprising i) all or a segment of a C-terminal domain of a paramyxovirus nucleocapsid protein and ii) a polypeptide sequence of a distinct protein that is an enzyme such as a recombinase.

Provided are modified virus-like particles (VLPs) of paramyxoviruses, compositions containing them, methods of using the VLPs for delivery of any particular protein of interest to any of a variety of cells, kits that contain expression vectors for making, using and detecting VLPs, and methods for screening for anti-viral compounds using the VLPs. The modified VLPs contain a contiguous recombinant polypeptide that contains i) all or a segment of a C-terminal domain of a paramyxovirus nucleocapsid protein and ii) a polypeptide sequence of a distinct protein. Non-covalent complexes of paramyxovirus M protein and fusion proteins that contain a C-terminal domain of a paramyxovirus nucleocapsid protein and a polypeptide sequence of a distinct protein are provided, as are non-covalent complexes of cells, and cell receptors, with modified VLPs.

Provided are nucleic acids that include a promoter, where the promoter is operable in a Bacteroides cell and is operably linked to a heterologous nucleotide sequence of interest. Also provided are nucleic acids that include a promoter (operable in a prokaryotic cell such as a Bacteroides cell) operably linked to a sequence encoding a synthetic ribosomal binding site (RBS). Also provided are fusion proteins (and nucleic acids encoding them) in which a secreted Bacteroides polypeptide is fused to a heterologous polypeptide of interest. Also provided are prokaryotic cells (e.g., E. coli, a Bacteroides cell, and the like) that include one more nucleic acids such as those described above. Also provided are methods of expression in a prokaryotic cell, methods of detectably labeling a Bacteroides cell in an animal's gut, and methods of delivering a protein to an individual's gut.

Disclosed herein are bioluminescent indictors comprising a bioluminescent peptide split by a binding peptide capable of binding a ligand. The bioluminescent indicator bioluminesces upon binding of the binding peptide to its ligand to bring the regions of the bioluminescent peptide into such proximity that the indicator bioluminesces. The bioluminescent indicator may further comprise a leader domain and a transmembrane domain. The bioluminescent indicator acts as a biosensor that can detect and quantify a ligand without the need for an additional light source. Methods for imaging internal body structures are also presented.