Antigen-binding fragments specific for dendritic cells, compositions and methods of use thereof antigens recognized thereby and cells obtained thereby
View Patent ↗The invention provides antigen-binding fragments specific for dendritic cells and effective in treatment and/or diagnosing a variety of disorders. Methods of use are also provided as are methods for screening for additional such antigen-binding fragments and the products obtained thereby.
1. An isolated antigen-binding fragment comprising a polypeptide domain that specifically binds a BDCA-2 protein encoded by SEQ ID NO:1; wherein said BDCA-2 protein is encoded by exons 1–6; exons 1 and 3–6; exons 1–2 and 4–6; or exons 1–3 and 5–6 of SEQ ID NO:1.
2. The antigen-binding fragment of claim 1 that is a monoclonal antibody comprising two heavy and two light chains.
3. The antigen-binding fragment of claim 2 where the antibody is human, murine, humanized or a bispecific antibody.
4. The antigen-binding fragment of claim 1 that is a Fab, F(ab′) 2 , scFv, or fusion polypeptide, or is encoded by a phage display library.
5. The antigen-binding fragment of claim 1 wherein the BDCA-2 protein is glycosylated.
6. The antigen-binding fragment of any of claims 1 – 5 that is conjugated to a chemically functional moiety.
7. The antigen-binding fragment of claim 6 wherein the chemically functional moiety is selected from the group consisting of a radioisotope, fluorescent compound, chemiluminescent compound, bioluminescent compound, enzyme, and a paramagnetic label.
8. The antigen-binding fragment of any of claims 1 – 5 that is bound to a BDCA-2 protein.
9. The antigen-binding fragment of any of claims 1 – 5 that is bound to a cell that expresses a BDCA-2 protein.
10. The antigen-binding fragment of claim 9 wherein the cell is a dendritic cell.
11. The antigen-binding fragment of claim 10 wherein the dendritic cell is BDCA-4 + .
12. The antigen-binding fragment of claim 11 wherein the dendritic cell is human.
13. The antigen-binding fragment of claim 10 wherein an anti-BDCA-4 antibody is also bound to the dendritic cell.
14. A composition comprising the antigen-binding fragment of claim 1 composition and a pharmaceutically acceptable excipient.
15. An isolated cell that produces an antigen-binding fragment of claim 1 .
16. A hybridoma that produces an antigen-binding fragment of claim 2 .