The present invention relates to an autoimmune disease animal model and a method for preparing the same. The animal model of the present invention efficiently generates an autoantibody that causes autoimmune disease, by introducing an autoantigen-encoding gene through the Cre-LoxP system, which enables stable and continuous expression of the autoantigen at a desired time by treatment of Cre recombinase. Contrary to the conventional method that fails to effectively produce autoantibody due to leaky expression and immune tolerance, or requires repeated administration over several weeks, the present invention achieves sustainable expression of an effective amount of autoantigen by only one TAT-Cre recombinase treatment, thus may be utilized as an outstanding animal model reproducing various symptoms and molecular mechanisms of autoimmune diseases.

The invention concerns a non-human animal model useful for sensitively studying gene-gene interactions over a wide genetic background; methods for producing the animal model; and methods for studying gene-gene interactions using an animal model of the invention.

The present invention relates to the field of biomedicine and antibody engineering. Specifically, it relates to mono and multispecific multivalent single chain polypeptide molecules and derivatives thereof, preferably to multispecific single chain (tandem) trimerbodies with defined stoichiometry, to nucleic acid sequences and vectors encoding thereof, and host cells expressing the same. It further relates to methods of producing thereof, pharmaceutical compositions, kits, methods of treatment, use as diagnostics or imaging reagents and combination therapies using thereof.