Multivalent antibody constructs
The present invention relates to a multivalent F v antibody construct having at least four variable domains which are linked with each over via the peptide linkers 1, 2 and 3. The invention also concerns expression plasmids which code for such an F v antibody construct and a method of producing the F v antibody constructs as well as their use.
1. A monospecific, homodimeric and tetravalent F v antibody formed by two single-chain F v monomers of the same kind, each of the single-chain F v monomer having the structure:
V H -peptide linker 1-V L -peptide linker 2-V H -peptide linker 3-V L , wherein
with the proviso that each F v monomer does not have constant domains;
V H and V L are heavy chain and light chain variable domains of an antibody specific for an antigen, respectively;
peptide linker 1 is a peptide bond or has 1 to about 10 amino acids;
peptide linker 2 has about 3 to 10 amino acids;
peptide linker 3 is a peptide bond or has 1 to about 10 amino acids; and
each V H of one of the single-chain F v monomers associates intermolecularly with each V L of the other single-chain F v monomer, thereby forming said homodimeric and tetravalent Fv antibody having four antigen binding sites for the same antigen.
2. The F v antibody of claim 1 , wherein said peptide linker 1 and peptide linker 3 both have the amino acid sequence GG.
3. The F v antibody of claim 1 , wherein said peptide linker 2 comprises the amino acid sequence GGPGS (SEQ ID NO: 18).
4. The F v antibody of claim 1 , wherein the antigen for the F v antibody is CD3 or CD19.
5. A method for producing said Fv antibody of claim 1 , comprising the steps of:
ligating DNAs encoding said four variable domains of said single chain Fv monomers with DNAs encoding peptide linker 1, peptide linker 2 and peptide linker 3 to produce a DNA encoding said single chain Fv monomer having the structure:
VH-peptide linker 1-VL-peptide linker 2-VH-peptide linker 3-VL with the proviso that each F v monomer does not have constant domains; and
introducing the DNA encoding said single chain Fv monomer into an expression vector for said single-chain Fv monomer;
transforming a host cell with the expression vector for said monomer single-chain Fv monomer; and
cultivating the host cell under conditions so that said single-chain Fv monomer is expressed.
6. A composition comprising said F v antibody of claim 1 for diagnosis and/or treatment of diseases.