NKG2D decoys
Single chain, multimerized, and/or glycosylated NKG2D decoys are described. The NKG2D decoys have high affinity and avidity for surface bound and soluble NKG2D ligands and can be used to (i) identify NKG2D ligands; (ii) treat cancer, graft vs. host disease (GVHD), and inflammatory conditions; and (iii) potentiate an immune response against a vaccine as well as many other potential uses.
1. A single chain protein comprising the formula x-y-z, wherein x comprises a multimerization domain, y comprises a first linker derived from NKG2D, and z comprises an extracellular fragment of NKG2D comprising the formula a-b-a, wherein:
a comprises SEQ ID NO. 79, and
b comprises SEQ ID NO. 81 or SEQ ID NO. 82.
2. A single chain protein of claim 1 , wherein x comprises SEQ ID NO. 80.
3. A single chain protein of claim 1 , wherein y comprises SEQ ID NO. 81 or SEQ ID NO. 82.
4. A single chain protein of claim 1 , wherein x comprises SEQ ID NO. 80 and y comprises SEQ ID NO. 81 or SEQ ID NO. 82.
5. A single chain protein of claim 1 , wherein y comprises SEQ ID NO. 81 and b comprises SEQ ID NO. 82.
6. A single chain protein of claim 1 , wherein x consists of the multimerization domain, y consists of the first linker derived from NKG2D, and z consists of a-b-a.
7. A single chain protein of claim 1 , wherein the multimerization domain is a C4b multimerization domain.
8. A single chain protein of claim 1 , wherein the multimerization domain is selected from SEQ ID NO. 7-39 and SEQ ID NO. 80.
9. A single chain protein of claim 1 , wherein the multimerization domain is directly linked to the first linker derived from NKG2D.
10. A single chain protein of claim 1 , wherein y excludes a Gly-Ser linker.
11. A single chain protein of claim 1 , wherein the first linker is derived from human NKG2D.
12. A single chain protein of claim 1 , wherein y-z comprises SEQ ID NO. 3.
13. A single chain protein of claim 1 , wherein the two copies of SEQ ID NO: 79 form an NKG2D homodimer comprising the extracellular binding fragment of NKG2D.
14. A single chain protein of claim 1 , wherein z excludes intracellular portions of human or murine NKG2D.
15. A single chain protein of claim 1 , comprising SEQ ID NO. 78.
16. A single chain protein of claim 1 , multimerized into a heptamer.
17. A single chain protein of claim 1 , formulated as a pharmaceutical composition.