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.

The monoclonal IgG-type antibodies were suggested comprising variable domains represented by a combination of VHH-derivative with a variable domain of the light chain V.sub.L. Said antibodies can comprise amino acid substitutions at positions 44 and 45 (Kabat numbering) or combinations thereof. Antibodies of the invention possess increased affinity and improved aggregation stability.

Mice having a restricted immunoglobulin heavy chain locus are provided, wherein the locus is characterized by a single polymorphic human V.sub.H gene segment, a plurality of human D.sub.H gene segments and a plurality of J.sub.H gene segments. Methods for making antibody sequences that bind an antigen (e.g., a viral antigen) are provided, comprising immunizing a mouse with an antigen of interest, wherein the mouse comprises a single human V.sub.H gene segment, a plurality of human D.sub.H gene segments and a plurality of J.sub.H gene segments, at the endogenous immunoglobulin heavy chain locus.

Provided herein are antibodies and antigen-binding fragments thereof with low or no immunogenicity in humans and optionally with desirable manufacturing properties. Also provided are compositions comprising such antibodies or antigen-binding fragments, methods of using such antibodies, and methods for making such antibodies.

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 concerns binding molecules having a penta- or hexameric ring structure, such as, for example, isolated IgM antibodies with five or six bispecific binding units, and methods and means for making and using the same. The invention further concerns multi-specific binding molecules having a penta- or hexameric ring structure, such as, for example, isolated IgM antibodies with five or six bispecific binding units, and methods and means for making and using the same.

The present invention relates to humanisation of antibodies in vivo. The invention provides non-human vertebrates, cells, populations and methods useful for humanising chimaeric antibodies in vivo. Using the present invention it is possible straightforwardly and rapidly to obtain antigen-specific antibodies that are fully human (ie, comprising human variable and constant regions) and have undergone recombination, junctional diversification, affinity maturation and isotype switching in vivo in a non-human vertebrate system. Furthermore, such antibodies are humanised (eg, totally human)and selectedtotally in vivo, and as such the present invention harnesses in vivo filtering for expressibility, affinity and biophysical characteristics in the context of the desired human variable and constant region pairings. This is avoids problems of down-grading antibody characteristics when humanising the constant region of chimaeric antibodies in vitro.

Mice, embryos, cells, and tissues having a restricted immunoglobulin heavy chain locus and an ectopic sequence encoding one or more ADAM6 proteins are provided. In various embodiments, mice are described that have humanized endogenous immunoglobulin heavy chain loci and are capable of expressing an ADAM6 protein or ortholog or homolog or functional fragment thereof that is functional in a male mouse. Mice, embryos, cells, and tissues having an immunoglobulin heavy chain locus characterized by a single human V.sub.H gene segment, a plurality of human D.sub.H gene segments and a plurality of human J.sub.H gene segments and capable expressing an ADAM6 protein or ortholog or homolog or functional fragment thereof are also provided.

Genetically modified mice are provided that express human variable (hV) sequences, including mice that express hV sequences from an endogenous mouse light chain locus, mice that express hV sequences from an endogenous mouse light chain locus, and mice that express hV sequences from a transgene or an episome wherein the hV sequence is linked to a mouse constant sequence. Mice are provided that are a source of somatically mutated human variable sequences useful for making antigen-binding proteins. Compositions and methods for making antigen-binding proteins that comprise human variable sequences, including human antibodies, are provided.

The present disclosure provides methods of treating a tauopathy, involving administering an anti-Tau antibody. The present disclosure also provides anti-Tau antibodies, and formulations comprising same, for use in the methods.