In some aspects, isolated transgenic cells (e.g., transgenic T cells) are provided that comprise or express a transgene and DHFR.sup.FS and/or TYMS.sup.SS. Methods for selecting transgeneic cells are also provided.

The present invention provides polynucleotide vectors for high expression of heterologous genes. Some vectors further comprise novel transposons and transposases that further improve expression. Further disclosed are vectors that can be used in a gene transfer system for stably introducing nucleic acids into the DNA of a cell. The gene transfer systems can be used in methods, for example, gene expression, bioprocessing, gene therapy, insertional mutagenesis, or gene discovery.

The present invention provides compositions and methods for combination therapy comprising administering to a patient in need thereof, drug-resistant immunotherapy, immune checkpoint inhibitors, and chemotherapy for the treatment of cancer.

Some embodiments of the methods and compositions provided herein include cells having membrane-tethered, IL13 mutein-directed zetakine receptors, such as those which specifically bind to the IL-13 receptor alpha 2 (IL13Ra2) at a 50-fold higher affinity than wild-type IL-13, and methods of cell-based immunotherapy targeting cancer cells, such as cells of solid tumors, using these compositions. In some embodiments, the receptors include spacer regions, such as particular spacer regions designed to provide certain advantages.

The present disclosure relates to the use of host cell protein biomarkers to assess disulfide bond reduction in compositions comprising a protein of interest. In some embodiments, the disclosure relates to methods of predicting the occurrence of disulfide bond reduction or low molecular weight protein species in compositions comprising a protein of interest, wherein the expression or activity level of at least one host cell protein is measured and provides a benchmark value associated with the occurrence of disulfide bond reduction or low molecular weight species of said protein of interest. In some embodiments, the disclosure relates to methods of producing a protein of interest, wherein host cells capable of producing the protein of interest are cultured, the expression or activity level of at least one host cell protein is measured, and downstream isolation of the protein of interest is informed by the host cell protein measurements.

Some embodiments of the methods and compositions provided herein relate to the preparation surfactant protein-D (SP-D). Some embodiments include the expression of human SP-D in certain cell lines, and the purification of human SP-D from such cell lines. Some embodiments include the preparation of certain oligomeric forms of human SP-D.

Protein enriched micro-vesicles and methods of making and using the same are provided. Aspects of the methods include maintaining a cell having a membrane-associated protein comprising a first dimerization domain and a target protein having a second dimerization domain under conditions sufficient to produce a micro-vesicle from the cell, wherein the micro-vesicle includes the target protein. Also provided are cells, reagents and kits that find use in making the micro-vesicles, as well as methods of using the micro-vesicles, e.g., in research and therapeutic applications.

Modified ribosomes that were selected using a dipeptidyl-puromycin aminonucleoside are used to mediate site-specific incorporation of one or more peptides and peptidomimetics into protein in a cell free translation system. In addition, new fluorescent dipeptidomimetics have been synthesized and incorporated into proteins, as well as modified proteins containing one or more non-naturally occurring dipeptides.

The invention provides compositions including a fusion polypeptide and methods for making a fusion polypeptide that includes a COF1/CRBN-binding polypeptide, COF2/CRBN-binding polypeptide, or COF3/CRBN-binding polypeptide and a heterologous polypeptide of interest.

The present invention provides polynucleotide vectors for high expression of heterologous genes. Some vectors further comprise novel transposons and transposases that further improve expression. Further disclosed are vectors that can be used in a gene transfer system for stably introducing nucleic acids into the DNA of a cell. The gene transfer systems can be used in methods, for example, gene expression, bioprocessing, gene therapy, insertional mutagenesis, or gene discovery