B6-hCD80 Mouse

The CD80 gene (Cluster of Differentiation 80, also known as B7-1) is located on human chromosome 3 and encodes the CD80 protein, a Type I transmembrane glycoprotein and member of the immunoglobulin superfamily. This protein structure includes two extracellular Ig-like domains (V-type and C2-type), a transmembrane helix, and a short cytoplasmic tail, existing predominantly as a dimer on the cell surface ^[1]. CD80 is a crucial costimulatory molecule expressed primarily on professional antigen-presenting cells (APCs), such as dendritic cells, activated B cells, and macrophages, with its expression increasing upon activation. Its primary function is to regulate the immune response by binding to receptors on T cells: binding to CD28 delivers a necessary co-stimulatory signal for T-cell activation, proliferation, and cytokine production, while its higher affinity binding to CTLA-4 (Cytotoxic T-Lymphocyte-Associated Protein 4) delivers an inhibitory signal that down-modulates the immune response to maintain tolerance ^[2]. Dysregulation of CD80 expression or function is associated with various diseases, including autoimmune disorders (e.g., lupus neuropathy, multiple sclerosis, autoimmune thyroid diseases) where its increased expression can lead to overactive T cells, and several cancers (e.g., breast, colon, gastric cancer) where its variable expression can be linked to immune evasion or prognosis ^[3-4].

B6-hCD80 mouse is a humanized model generated using gene editing technology, in which the coding sequences of exon 1 plus partial intron 1 of mouse Cd80 are replaced with the Kozak-CD80 chimeric CDS-3'UTR of mouse Cd80-WPRE-BGH pA cassette. This model can be used for studying the pathological mechanisms and therapeutic approaches of autoimmune disorders (e.g., lupus neuropathy, multiple sclerosis, autoimmune thyroid diseases) and several cancers, as well as for the development of CD80-targeted drugs.