FCGRT Mouse

The Fc fragment of IgG receptor and transporter, also known as the neonatal Fc receptor (FcRn), plays a crucial role in the immune system by mediating the transport and recycling of immunoglobulin G (IgG) antibodies. This receptor is essential for maintaining the long half-life of IgG and for transferring maternal antibodies to the fetus, providing passive immunity.

FcRn is a heterodimer composed of two subunits: the alpha chain (FCGRT) and beta-2-microglobulin (B2M). The alpha chain binds to the Fc region of IgG, while B2M stabilizes the structure. This receptor is structurally similar to major histocompatibility complex (MHC) class I molecules .

The primary function of FcRn is to protect IgG from lysosomal degradation by binding to it in acidic environments (such as endosomes) and releasing it at neutral pH (such as in the bloodstream). This recycling process extends the half-life of IgG antibodies, allowing them to persist longer in the circulation .

During pregnancy, FcRn is responsible for transporting IgG antibodies from the mother to the fetus across the placenta. This transfer provides the fetus with passive immunity, protecting it from infections during the early stages of life. The interaction between FcRn and IgG is pH-dependent, with binding occurring at acidic pH and release at neutral pH .

Recombinant FcRn, particularly from mouse models, is widely used in research to study its role in immunity and to develop therapeutic antibodies. Mouse recombinant FcRn is often used because of its similarity to human FcRn, making it a valuable tool for preclinical studies .

FcRn has become a target for therapeutic interventions, especially in autoimmune diseases. By modulating FcRn activity, it is possible to alter the half-life of pathogenic IgG antibodies, reducing their levels in the circulation. This approach has shown promise in treating conditions such as immune thrombocytopenia, myasthenia gravis, and systemic lupus erythematosus .