Compositions that include peptide receptive MEW class I complexes and methods of making and using such complexes are provided. In particular embodiments, such peptide receptive MHC class I complexes are used to form peptide MHC class I (pMHC-I) multimers useful for high throughput applications, such as, for the detection of antigen specific T cells and characterization of T cell profiles in subjects.

The present disclosure provides compositions and methods for producing and using modified auxotrophic host cells for improved therapy involving administration of an auxotrophic factor.

The present disclosure is directed to RNA-regulated fusion proteins comprising a protein of interest and an RNA-regulated destabilization domain. Also disclosed are RNA aptamers that bind specifically to a RNA-regulated destabilization domain. Nucleic acid molecules encoding the RNA-regulated fusion proteins and RNA aptamers and methods of use thereof are also disclosed.

The present invention provides regulatable cell lines with an engineered genome encoding an auxotrophic response system or element, and methods of use thereof. Growth and protein production of the cell lines is controlled by exposure of the cell line to an auxotrophic factor to activate the auxotrophic response system or element. Examples of auxotrophic factors include a nutrient, an enzyme, a moiety that alters pH, a moiety that alters temperature, a non-organic molecule, a non-essential amino acid, an altered concentration of a moiety, and a cellular niche environment. These regulatable cell lines may be used in regenerative medicine and enzyme replacement therapy.

The present disclosure is directed to RNA-regulated fusion proteins comprising a protein of interest and an RNA-regulated destabilization domain. Also disclosed are RNA aptamers that bind specifically to a RNA-regulated destabilization domain. Nucleic acid molecules encoding the RNA-regulated fusion proteins and RNA aptamers and methods of use thereof are also disclosed.