Modified antibodies stably produced in milk and methods of producing same

A method of producing a transgenic mammal whose somatic and germ cells comprise a modified antibody coding sequence wherein said modified antibody coding sequence encodes an antibody molecule or portion thereof expressible in milk, comprising a modified hinge region, said method comprising the steps of:

• introducing into a mammal a construct comprising a sequence encoding an exogenous heavy chain variable region or antigen binding fragment thereof, at least one heavy chain constant region or a fragment thereof, and a hinge region, operably linked to a promoter which directs expression in mammary epithelial cells, wherein said hinge region has been altered from the hinge region normally associated with the heavy chain constant region.

The method of claim 33, wherein said hinge region has been altered such that at least 70% of the exogenous antibodies present in the milk of the transgenic mammal are in assembled form.

The method of claim 40 wherein all or a portion of the hinge region of the antibody has been altered.

The method of claim 44, wherein the hinge region of the antibody, or portion thereof, has been replaced with the hinge region, or portion thereof, of an antibody other than an IgG4 antibody.

The method of claim 48 wherein the antibody other than an IgG4 antibody is an antibody selected from the group consisting of:

• IgA, IgD, IgM and IgE.

The method of claim 54 wherein at least one glycosylation site in the heavy chain or light chain is altered.

A method of producing a transgenic mammal capable of expressing an assembled exogenous antibody or portion thereof in its milk, the method comprising:

• introducing into a mammal a construct comprising a sequence encoding a light chain of exogenous antibody operably linked to a promoter which directs expression in mammary epithelial cells;
• and
• introducing into the mammal a construct comprising a sequence encoding a mutagenized heavy chain of the exogenous antibody or a portion thereof operably linked to a promoter which directs expression in mammary epithelial cells, wherein the heavy chain or portion thereof comprises a hinge region which has been altered such that at least 70% of the exogenous antibodies present in the milk are in assembled form.

A method of producing a transgenic mammal capable of expressing an assembled exogenous antibody in its milk, the method comprising:

• providing a cell from a transgenic mammal whose germ and somatic cells comprise a sequence encoding a light chain of an exogenous antibody operably linked to a promoter which directs expression in mammary epithelial cells;
• and
• introducing into the cell a construct comprising a sequence encoding a mutagenized heavy chain of the exogenous antibody or a portion thereof operably linked to a promoter which directs expression in mammary epithelial cells, wherein the heavy chain, or portion thereof comprises a hinge region which has been altered such that at least 70% of the exogenous antibodies present in the milk are in assembled form.

A composition comprising a milk component and an antibody component, wherein said antibody component comprises an exogenous antibody, or fragment thereof, having a hinge region, wherein said hinge region has been altered from the hinge region normally associated with the antibody.

A nucleic acid comprising a sequence encoding a heavy chain variable region and a heavy chain constant region, operably linked to a promoter which directs expression in mammary epithelial cells, wherein the heavy chain or portion thereof comprises a hinge region which has been altered such that at least 70% of the exogenous antibodies present in milk are in assembled form.