Preparing mFc- and hFc-Fusion Proteins from Mammalian Cells

Fc-fusion proteins are composed of an immunoglobulin Fc domain that is directly linked to the antigen of interest. Typically, these vectors will contain an amino-terminal signal sequence that permits trafficking to the cell surface and secretion into the media and a carboxy-terminal Fc receptor that enables purification on Protein A-Sepharose. Fc-fusion proteins have several applications in protein microarrays, oncological therapies, and vaccine and antibody development. Presence of the Fc domain significantly increases the plasma life of the fusion partner, which prolongs therapeutic activity. Furthermore, the Fc domain enhances the solubility and stability of the partner molecule. Because Fc-fusion proteins are secreted into the culture medium, purification by affinity chromatography is relatively easy and cost-effective. Immunizing a murine host with mFc-fusion protein generates an antigen-specific immune response because the Fc domain is recognized as "self" by the host.