The invention relates generally to genetically modified non-human animals expressing human polypeptides and their methods of use.

The present disclosure relates to genetically modified non-human animals that express a human or chimeric (e.g., humanized) CD276, and methods of use thereof.

Disclosed herein are non-human animals (e.g., rodents, e.g., mice or rats) genetically engineered to express a humanized T cell co-receptor (e.g., humanized CD4 and/or CD8 (e.g., CD8α and/or CD8β)), a human or humanized T cell receptor (TCR) comprising a variable domain encoded by at least one human TCR variable region gene segment and/or a human or humanized major histocompatibility complex that binds the humanized T cell co-receptor (e.g., human or humanized MHC II (e.g., MHC II α and/or MHC II β chains) and/or MHC I (e.g., MHC I α) respectively, and optionally human or humanized β 2 microglobulin). Also provided are embryos, tissues, and cells expressing the same. Methods for making a genetically engineered animal that expresses at least one humanized T cell co-receptor (e.g., humanized CD4 and/or CD8), at least one humanized MHC that associates with the humanized T cell co-receptor (e.g., humanized MHC II and/or MHC I, respectively) and/or the humanized TCR are also provided. Methods for using the genetically engineered animals that mount a substantially humanized T cell immune response for developing human therapeutics are also provided.

This invention relates to SARS-CoV-2 viruses adapted with nanoluciferase reporter molecules and mouse-adapted SARS-CoV-2 viruses, compositions including the same and methods of use thereof.

Mice that comprise a replacement of endogenous mouse IL-6 and/or IL-6 receptor genes are described, and methods for making and using the mice. Mice comprising a replacement at an endogenous IL-6Rα locus of mouse ectodomain-encoding sequence with human ectodomain-encoding sequence is provided. Mice comprising a human IL-6 gene under control of mouse IL-6 regulatory elements is also provided, including mice that have a replacement of mouse IL-6-encoding sequence with human IL-6-encoding sequence at an endogenous mouse IL-6 locus.

A biological system for generating and preserving a repository of personalized, humanized transplantable cells, tissues, and organs for transplantation, wherein the biological system is biologically and metabolically active (living), the biological system comprising genetically reprogrammed proteins, cells, tissues, and/or organs in a non-human animal donor for transplantation into a human recipient, wherein the non-human animal donor is a genetically reprogrammed porcine donor for xenotransplantation of cells, tissue, and/or an organ isolated from the genetically reprogrammed porcine donor.

A genetically modified mouse is provided, wherein the mouse expresses an immunoglobulin light chain repertoire characterized by a limited number of light chain variable domains. Mice are provided that present a choice of two human light chain variable gene segments such that the immunoglobulin light chains expresses by the mouse comprise one of the two human light chain variable gene segments. Methods for making bispecific antibodies having universal light chains using mice as described herein, including human light chain variable regions, are provided. Methods for making human variable regions suitable for use in multispecific binding proteins, e.g., bispecific antibodies, and host cells are provided.

Non-human animals comprising a human or humanized C3 and/or C5 nucleic acid sequence are provided as well as methods for using the same to identify compounds capable of modulating the complement system. Non-human animals that comprise a replacement of the endogenous C5 gene and/or C3 gene with a human or humanized C5 gene and/or C3 gene, and methods for making and using the non-human animals, are described. Non-human animals comprising a human or humanized C5 gene under control of non-human C5 regulatory elements is also provided, including non-human animals that have a replacement of non-human C5-encoding sequence with human C5-encoding sequence at an endogenous non-human C5 locus. Non-human animals comprising a human or humanized C3 gene under control of non-human C3 regulatory elements is also provided, including non-human animals that have a replacement of non-human C3 protein-encoding sequence with human or humanized C3 protein-encoding sequence at an endogenous non-human C3 locus. Non-human animals comprising human or humanized C3 and/or C5 sequences, wherein the non-human animals are rodents, e.g., mice or rats, are provided.

The invention provides a method for generating a transgenic eukaryotic cell population having a modified human Rosa26 locus, which method includes introducing a functional DNA sequence into the human Rosa26 locus of starting eukaryotic cells. Also provided are targeting vectors useful in the method, as well as a cell population and a transgenic non-human animal comprising a modified human Rosa26 locus. Finally, the invention provides an isolated DNA sequence corresponding to the human Rosa26 locus.

Disclosed herein are methods of treating HIBM in a subject comprising identifying subject in need thereof; and administering to the subject a compound, or a pharmaceutically acceptable salt, ester, amide, glycol, peptidyl, or prodrug thereof, wherein the compound is a compound that is biosynthesized in a wild type individual along a biochemical pathway between glucose and sialic acid, inclusive. Also disclosed herein are vectors comprising a nucleic acid sequence that encodes a polypeptide having at least 80% sequence identity to the sequence set forth in SEQ ID NO:2, recombinant cells comprising these vectors, and recombinant animals comprising the cells. In addition, methods of identifying a compound having therapeutic effect for HIBM are disclosed.