Provided herein are methods and compositions related to the in vivo testing of therapeutic agents comprising a human Fc in genetically modified rodents (e.g., the testing of the pharmacokinetic and/or pharmacodynamic properties of such a therapeutic agent in genetically modified rodents). In some embodiments the genetically modified rodents express antibodies comprising a human Fc (e.g., a human IgG1 Fc, a human IgG4 Fc). In some embodiments, the rodents express fully human antibodies (i.e., antibodies having human heavy chains and human light (γ or κ) chains). In certain embodiments the genetically modified rodents comprise one or more Fc receptors with a human extracellular domain (e.g., a Neonatal Fc Receptor (FcRn), a β-2-microglobulin polypeptide (β2M), a Fc ε receptor 1α (FcεR1α), a Fc γ receptor 1 alpha (FcγR1a), a Fc gamma receptor 2a (FcγR2a), a Fc gamma receptor 2b (FcγR2b), a Fc gamma receptor 3a (FcγR3a), a Fc gamma receptor 3b (FcγR3b), a Fc gamma receptor 2c (FcγR2c)). The transmembrane and cytoplasmic domain of such receptors can be human or non-human (e.g., rodent).

Genetically modified non-human animals expressing human SIRPα and human IL-15 from the non-human animal genome are provided. Also provided are methods for making non-human animals expressing human SIRPα and human IL-15 from the non-human animal genome, and methods for using non-human animals expressing human SIRPα and human IL-15 from the non-human animal genome. These animals and methods find many uses in the art, including, for example, in modeling human T cell and/or natural killer (NK) cell development and function, in modeling human pathogen infection of human T cells and/or NK cells, and in various in vivo screens.

The current disclosure has identified novel developmental, cellular, molecular, and biochemical pathways and developed a unique mouse model which recapitulates age, bicuspid aortic valve-associated, and gender-specific pathological aspects of development and progression of human CAVD, which will be useful in developing novel diagnostic, preventative, and therapeutic strategies for CAVD patients.

Models and methods related to targeting binding immunoglobulin protein (BiP) are described, where the models and methods allow identification and analysis of protein folding and misfolding.

Provided are antibodies, and fragments, derivatives, and nanoparticle conjugates thereof, particularly humanized derivatives thereof, which bind to tumor antigens. Also provided are nucleic acid molecules encoding chimeric antigen receptors (CARs) that bind to tumor antigens, polypeptides and CARs encoded by the nucleic acid molecules, vectors and host cells that include the nucleic acid molecules, methods of making the same, and methods for using the same to generate a persisting population of genetically engineered T cells in a subject, expanding a population of genetically engineered T cells in a subject, modulating the amount of cytokine secreted by a T cell, reducing the amount of activation-induced calcium influx into a T cell, providing an anti-tumor immunity to a subject, treating a mammal having a MUC1-associated disease or disorder, stimulating a T cell-mediated immune response to a target cell population or tissue in a subject, and imaging a MUC1-associated tumor.

Non-human animals comprising a human or humanized IL-4 and/or IL-4Rα nucleic acid sequence are provided. Non-human animals that comprise a replacement of the endogenous IL-4 gene and/or IL-4Rα gene with a human IL-4 gene and/or IL-4Rα gene in whole or in part, and methods for making and using the non-human animals, are described. Non-human animals comprising a human or humanized IL-4 gene under control of non-human IL-4 regulatory elements is also provided, including non-human animals that have a replacement of non-human IL-4-encoding sequence with human IL-4-encoding sequence at an endogenous non-human IL-4 locus. Non-human animals comprising a human or humanized IL-4Rα gene under control of non-human IL-4Rα regulatory elements is also provided, including non-human animals that have a replacement of non-human IL-4Rα-encoding sequence with human or humanized IL-4Rα-encoding sequence at an endogenous non-human C IL-4Rα locus. Non-human animals comprising human or humanized IL-4 gene and/or IL-4Rα sequences, wherein the non-human animals are rodents, e.g., mice or rats, are provided.

The present invention is directed to the concept of sectoring antibody gene segment repertoires in order to enable the development of novel, synthetic antibody chain repertoires not seen in nature. The present invention is also directed to the realisation of the inventors that sectoring can also alter gene segment expression by providing new arrangements of gene segment clusters relative to other gene segments and regulatory elements in transgenic immunoglobulin loci, thereby providing for new synthetic antibody chain sequence repertoires. The invention also relates to gene segment inversion.

Genetically modified mice and methods and compositions for making and using the same are provided, wherein the genetic modification comprises humanization of an FcγRI protein.

Non-human animal genomes, non-human animal cells, and non-human animals comprising a humanized albumin (ALB) locus and methods of making and using such non-human animal genomes, non-human animal cells, and non-human animals are provided. Non-human animal cells or non-human animals comprising a humanized albumin locus express a human albumin protein or a chimeric albumin protein, fragments of which are from human albumin. Methods are provided for using such non-human animals comprising a humanized albumin locus to assess in vivo efficacy of human-albumin-targeting reagents such as nuclease agents designed to target human albumin.

Non-human animal cells and non-human animals comprising a humanized ACE2 locus and methods of using such non-human animal cells and non-human animals are provided. Non-human animal cells or non-human animals comprising a humanized ACE2 locus express a human ACE2 protein or a chimeric ACE2 protein, fragments of which are from human ACE2. Methods are also provided for using such non-human animals comprising a humanized ACE2 locus to assess in vivo ACE2 activity, e.g., coronavirus infection and/or the treatment or prevention thereof.