Methods and vectors for generating asialylated immunoglobulins
The properties of an Fc-containing protein, for example, an antibody, are controlled by altering the sialylation of the oligosaccharides in the Fc region by transfecting the cell line expressing the Fc-containing protein with a vector sequence encoding a sialidase. The modified Fc-containing proteins have therapeutic utility in diseases or conditions in which it is desirable to control the affinity for one or more of the FcγRI, FcγRIIA, and FcγRIIIA receptors, ADCC activity, macrophage or monocyte activation, serum half-life, and avidity.
1. A method for controlling the properties of an antibody expressed in a cell line, comprising reducing the sialylation of the oligosaccharides in the Fc region by transfecting the cell line with a vector encoding a catalytic domain of Arthrobacter ureafaciens sialidase enzyme, wherein the antibody expressed comprises a reduced amount of sialic acid residues.
2. The method of claim 1 , wherein the properties of the antibody controlled are the avidity of the antibody for multiply localized target proteins; the affinity for one or more of the Fc gamma receptors of FcγRI, FcγRIIA, and FcγRIIIA; ADCC activity; macrophage or monocyte activation; and serum half-life.
3. The method of claim 1 , wherein the mammalian cell line is selected from the group consisting of COS-1, COS-7, HEK293, BHK21, CHO, BSC-1, Hep G2, 653, SP2/0, 293, HeLa, YB2/0 or Y3, myeloma, or lymphoma cells, or any derivative, immortalized or transformed cell thereof.
4. The method of claim 3 , wherein the antibody is an anti-TNFα antibody and the cell line is C168M.
5. The method of claim 1 , wherein the antibody has a binding domain specific for a target, said target being an immobilized target.
6. The method of claim 1 , wherein the antibody has a binding domain specific for a target, said target being is expressed on the surface of a cell.