Genetically modified mice and methods for making an using them are provided, wherein the mice comprise a replacement of all or substantially all immunoglobulin heavy chain V gene segments, D gene segments, and J gene segments with at least one light chain V gene segment and at least one light chain J gene segment. Mice that make binding proteins that comprise a light chain variable domain operably linked to a heavy chain constant region are provided. Binding proteins that contain an immunoglobulin light chain variable domain, including a somatically hypermutated light chain variable domain, fused with a heavy chain constant region, are provided. Modified cells, embryos, and mice that encode sequences for making the binding proteins are provided.

Mice are provided that comprise a reduction or deletion of ADAM6 activity from an endogenous ADAM6 locus, or that lack an endogenous locus encoding a mouse ADAM6 protein, wherein the mice comprise a sequence encoding an ADAM6 or ortholog or homolog or fragment thereof that is functional in a male mouse. In one embodiment, the sequence is an ectopic ADAM6 sequence or a sequence that confers upon a male mouse the ability to generate offspring by mating. Mice and cells with genetically modified immunoglobulin heavy chain loci that comprise an ectopic nucleotide sequence encoding a mouse ADAM6 or functional fragment or homolog or ortholog thereof are also provided.

Mice are provided that comprise a reduction or deletion of ADAM6 activity from an endogenous ADAM6 locus, or that lack an endogenous locus encoding a mouse ADAM6 protein, wherein the mice comprise a sequence encoding an ADAM6 or ortholog or homolog or fragment thereof that is functional in a male mouse. In one embodiment, the sequence is an ectopic ADAM6 sequence or a sequence that confers upon a male mouse the ability to generate offspring by mating. Mice and cells with genetically modified immunoglobulin heavy chain loci that comprise an ectopic nucleotide sequence encoding a mouse ADAM6 or functional fragment or homolog or ortholog thereof are also provided.

Non-human animals (and/or non-human cells) and methods of using the same are provided, which non-human animals (and/or non-human cells) have a genome comprising human antibody-encoding sequences (i.e., immunoglobulin genes). Non-human animals described herein express antibodies that contain immunoglobulin (Ig) light chains characterized by the presence of human V domains. Non-human animals provided herein are, in some embodiments, characterized by expression of antibodies that contain human V light chains that are encoded by human Ig light chain-encoding sequences inserted into an endogenous Ig light chain locus of said non-human animals. Methods for producing antibodies from non-human animals are also provided, which antibodies contain human variable regions and mouse constant regions.

The present invention relates to methods for reducing the heterogeneity of a population of recombinant proteins produced in cell culture, said methods comprising growing host cells producing a recombinant protein in a cell culture medium wherein the cell culture medium comprises one or more cysteine/cystine analogs.

The invention provides non-human cells and mammals having a genome encoding chimeric antibodies and methods of producing transgenic cells and mammals. Certain aspects of the invention include chimeric antibodies, humanized antibodies, pharmaceutical compositions and kits. Certain aspects of the invention also relate to diagnostic and treatment methods using the antibodies of the invention.

A transgenic chicken having a genome comprising a modified immunoglobulin heavy chain (IgH) locus is provided. The locus lacks the entire contiguous endogenous chicken V-D-J region and contains a human VH segment, a human D cluster, a human J segment and a plurality of upstream pseudogenes based on human VH sequences. The modified IgH locus undergoes V(D)J recombination in the chicken and the chicken produces antibodies that have a diversified immunoglobulin heavy chain.

Disclosed is a CD154 binding polypeptide that specifically recognizes CD154. The polypeptide according to the present disclosure effectively inhibits the CD154-CD40 interaction without activating platelets, and thus can be effectively used in the prevention or treatment of various T cell-mediated or antibody-mediated diseases or symptoms, which requires inhibition of the interaction.

Provided herein are immunomodulatory proteins comprising ICOSL variants and nucleic acids encoding such proteins. The immunomodulatory proteins provide therapeutic utility for a variety of immunological and oncological conditions. Compositions and methods for making and using such proteins are provided.

The invention provides non-human cells and mammals having a genome encoding chimeric antibodies and methods of producing transgenic cells and mammals. Certain aspects of the invention include chimeric antibodies, humanized antibodies, pharmaceutical compositions and kits. Certain aspects of the invention also relate to diagnostic and treatment methods using the antibodies of the invention.