Mammalian expression of single chain variable region fragments dimerized by Fc regions.

To promote application of a single chain variable region fragment (sFv) in immunoglobulins, a sFv gene was connected to an IgGi Fc gene, designated as a sFvc gene, and used for transfection of Sp2/0. As a result, the sFvc protein was found to be secreted in a dimeric form. It is thus felt that the sFvc protein, which mimicks the shape of a naturally occurring antibody, can be simple and useful to reproduce divalency and Fc-associated effecter functions as seen in a natural antibody.