IMMUNOGLOBULIN CHIMERIC MONOMER-DIMER HYBRIDS

1 - 194 . (canceled)

195 . A cell comprising:

a first nucleic acid construct comprising a first nucleic acid molecule encoding a first polypeptide comprising a biologically active molecule fused to a portion of an immunoglobulin constant region; and

a second nucleic acid construct comprising a second nucleic acid molecule encoding a second polypeptide comprising a portion of an immunoglobulin constant region without a biologically active molecule or an immunoglobulin variable region;

wherein the cell expresses the first polypeptided and/or the second polypeptide when the cell is cultured in a growth medium.

196 . The cell of claim 195 , wherein the first polypeptide further comprises a linker between the biologically active molecule and the first fragment of the immunoglobulin constant region.

197 . The cell of claim 196 , wherein the linker is selected form an amino acid sequence set forth in SEQ ID NO: 31, 32, 33, 34, 35, 36, 37, 38, 39, 85, or 86.

198 . The cell of claim 195 , wherein the first nucleic acid construct and the second nucleic acid construct are viral vectors or plasmids.

199 . The cell of claim 198 , wherein the viral vectors are chosen from adenovirus vectors, adeno associated virus vectors, murine leukemia virus vectors, and/or mixtures thereof; wherein the plasmids are chosen from pUC, pGGM, pGEX, and/or mixtures thereof.

200 . The cell of claim 195 , wherein the cell is a prokaryotic or an eukaryotic cell.

201 . The cell of claim 195 , wherein the portion of the immunoglobulin constant region comprises a Fc neonatal receptor (FcRN) binding partner.

202 . The cell of claim 195 , wherein the portion of the immunoglobulin constant region comprises a Fc fragment of an IgG, IgA, IgD, IgE, or IgM.

203 . The cell of claim 195 , wherein the portion of the immunoglobulin constant region comprises a Fc fragment from an IgG1, IgG2, IgG3, or IgG4.

204 . The cell of claim 195 , wherein the portion of the immunoglobulin constant region comprises an Fc fragment from human IgG1 comprising a FcRn binding partner, and wherein at least one of the Fc fragments in the first polypeptide and in the second polypeptide comprises a N297A mutation.

205 . The cell of claim 195 , wherein the portion of the immunoglobulin constant region is a peptide mimetic of an Fc fragment of an immunoglobulin.

206 . The cell of claim 195 , wherein the biologically active molecule is selected from a growth factor or hormone, a viral fusion inhibitor, a clotting factor, a cytokine, a cell surface receptor, analog thereof, or a fragment thereof.

207 . The cell of claim 195 , wherein the biologically active molecule is an interferon.

208 . A cell comprising:

a first expression vector containing a first nucleic acid sequence encoding a first polypeptide, wherein the first polypeptide comprises a biologically active molecule fused to a portion of an IgG Fc fragment, optionally via a linker, wherein the IgG Fc fragment includes an FcRn binding site comprising an N297A mutation, and wherein the biologically active molecule is interferon; and

a second expression vector comprising a second nucleic acid sequence encoding a second polypeptide, wherein the second polypeptide comprises a portion of an IgG Fc fragment without a biologically active molecule or an immunoglobulin variable region, and wherein the IgG Fc fragment includes an FcRn binding site comprising an N297A mutation;

wherein the cell expresses the first polypeptide and the second polypeptide when the cell is cultured in a growth medium.

209 . A method for treating a subject with a viral infection comprising:

administering to the subject a pharmaceutically acceptable amount of a chimeric protein comprising:

a first polypeptide comprising a biologically active molecule fused to a portion of an IgG Fc fragment, optionally via a linker, wherein the IgG Fc fragment includes an FcRn binding site comprising an N297A mutation, and wherein the biologically active molecule is interferon; and

a second polypeptide comprising a portion of an IgG Fc fragment without a biologically active molecule or an immunoglobulin variable region, wherein the IgG Fc fragment includes an FcRn binding site comprising an N297A mutation;

wherein the IgG Fc fragment of the first polypeptide is linked to the IgG Fc fragment of the second polypeptide.

210 . The method of claim 209 , wherein the biologically active molecule is interferon α or interferon β.

211 . The method of claim 209 , wherein the biologically active molecule is interferon β and the interferon β is linked to the IgG Fc fragment with a linker.

212 . The method of claim 211 , wherein the linker is an eight amino acid linker having the amino acid sequence set forth in SEQ ID NO: 31.

213 . The method of claim 209 , wherein the chimeric protein is formed by the first polypeptide and the second polypeptide obtained from the cell of claim 208 .

214 . The method of claim 209 , wherein the chimeric protein is administered to the subject intravenously, subcutaneously, orally, buccally, sublingually, nasally, parenterally, rectally, vaginally, or via a pulmonary route.