Provided herein are novels systems and methods for the identification of peptides that bind to MHC-I molecules using peptide receptive MHC-I complexes.

The present invention provides a method of manufacturing vectors containing a heterologous gene-editing protein comprising providing (a) transforming a host system with a nucleic acid cassette containing a promoter operably linked to a gene encoding a gene-editing protein, wherein the host system also contains a heterologous inhibitor for the gene-editing protein, (b) incubating the host system for a time sufficient for vector production and to release the recombinant vector, and (c) recovering the recombinant vector. Also provided herein are cell lines for expressing vectors containing a gene-editing protein with an inhibitor of the gene-editing protein to prevent leaky expression of the gene-editing protein comprising constitutive expression of an inhibitor of a gene-editing protein.

The present invention relates to a methods for high throughput screening of epitopes that are involved in T cell activation.

Use of the surface presentation level of binders (e.g., antibodies, receptors) on cultured higher eukaryotic cells in vitro as a predictive indicator of developability characteristics, e.g., solubility, of the binders. Display libraries of higher eukaryotic cells, e.g., mammalian cells, adapted for use in screening surface-displayed binders for developability and affinity of target binding. High-throughput screening of display libraries with in-built selection for developability including binder solubility, capability to be formulated at high concentrations, low propensity for non-specific binding, and half-life. Enrichment of populations of binders for developability characteristics and/or other qualities such as target binding and affinity, by controlling cell surface presentation of binders from an inducible promoter operably linked to binder-encoding DNA.

In alternative embodiments, provided are compositions, including products of manufacture and kits, and methods, for engineering immune effector cells, e.g., T cells, NK cells, monocytes and/or macrophages to recognize and destroy a desired target cell, which can be a cancer cell, a dysfunctional cell, or an infected cell.

Provided herein are methods and compositions relating to ion channel libraries having nucleic acids encoding for a scaffold comprising a natural peptide toxin. Ion channel libraries described herein encode for immunoglobulins such as antibodies.

The present application provides a method of quantifying an amount of a derivatized peptide displayed on a phage by phage display, the method comprising: providing a phage containing a target peptide thereon; reacting the phage containing the target peptide with a first reagent to derivatize the target peptide to form a derivatized peptide, reacting the derivatized peptide with a capture agent comprising a detection marker, thereby incorporating the detection marker within the derivatized peptide; and determining an amount of the detection marker, thereby quantifying the amount of the derivatized peptide dis-played on the phage. A kit comprising a capture agent compris-ing a detection marker for quantifying the phage displayed derivatized peptides is also provided.

Provided is a method for screening antibodies against a specific antigen epitope, including: Incubating antigens with incorporation of photocrosslinking amino acids(designated as mutant antigen) with antibody library under light irradiation with suitable wavelength and energy, and selecting antibodies that covalently crosslink with the mutant antigen; then the antibodies selected are subjected to affinity maturation against wild-type antigen, and then epitope-directed antibodies obtained.

Heavy chain antibody variable domain (V.sub.HH) display libraries are described comprising human-like V.sub.HH comprising three synthetically generated complementarity determining region (CDR) areas in which the amino acids at each of positions 44 and 45 or positions 37, 44, 45, and 47 comprise the amino acid at the corresponding position of a Camelid V.sub.HH, wherein the amino acid positions are according to Kabat numbering Human-like V.sub.HHs identified using these libraries may be useful for the manufacture of therapeutics for treating diseases and disorders.

The present disclosure provides for proprotein and activatable proprotein compositions. A proprotein contains a functional protein (i.e. a full length protein or functional fragment thereof) which is coupled to a peptide mask that inhibits the binding of the functional protein to its target or binding partner. An activatable proprotein contains a functional protein coupled to a peptide mask, and further coupled to an activatable linker, wherein in an non-activated state, the peptide mask inhibits binding of the functional protein to its target or binding partner and in an activated state the peptide mask does not inhibit binding of the functional protein to its target or binding partner. Proproteins can provide for reduced toxicity and adverse side effects that could otherwise result from binding of a functional protein at non-treatment sites if it were not inhibited from binding its binding partner. Proproteins can further provide improved biodistribution characteristics. Proproteins containing a peptide mask can display a longer in vivo or serum half-life than the corresponding functional protein not containing a peptide mask. The disclosure further provides methods of screening for, making, and using these proproteins.