NXG B2M Mouse

The NXG B2m strain is a severely immunodeficient mouse model on a NOD genetic background, incorporating three key mutations: Prkdc^scid, Il2rg^tm1, and B2m^em1. These mutations collectively eliminate T, B, and NK cells, making the model an excellent platform for studies requiring humanization.

The Prkdc^scid mutation (severe combined immunodeficiency) is a point mutation in the Prkdc gene, encoding the DNA-dependent protein kinase catalytic subunit. This mutation compromises the DNA repair mechanisms required for V(D)J recombination during the maturation of T and B lymphocytes, resulting in their absence and profound immunodeficiency.

The Il2rg^tm1 mutation is a knockout of the interleukin-2 receptor subunit gamma (Il2rg) gene, essential for signaling pathways associated with multiple cytokines (IL-2, IL-4, IL-7, IL-9, and IL-15). This mutation disrupts the development of NK cells and impacts other hematopoietic processes, further contributing to the model’s immunodeficient phenotype.

The B2m^em1 mutation involves the knockout of the B2m (beta-2-microglobulin) gene, which is crucial for the assembly of the major histocompatibility complex class I (MHC-I) molecules. Its absence impairs the presentation of antigens to cytotoxic T cells, facilitating the engraftment of human cells by reducing the likelihood of host-versus-graft rejection.

The NXG B2m strain is particularly valuable for preclinical research in oncology, immunology, and infectious diseases. The complete absence of adaptive immunity (T and B cells), NK cells, and the presence of enhanced tolerance to human cells makes it a robust model for humanization protocol including the engraftment of human hematopoietic stem cells (HSCs) and peripheral blood mononuclear cells (PBMCs).

In summary, the NXG B2m strain offers a versatile and powerful tool for biomedical research, combining advanced features of immunodeficiency with improved engraftment and tolerance for human cells.

The animals are bred to maintain both the genetic background and the mutations of interest in their homozygous forms. The NXG B2m strain is bred in inbreeding mode and the phenotype is controlled according to the JANVIER LABS GENETIC POLICY®.