Host cells expressing IL-18 receptors
A novel polypeptide that functions as an IL-18 receptor is disclosed. The receptor is multimeric and includes at least one AcPL polypeptide, or fragment thereof, and at least one IL-1Rrp1 polypeptide, or fraction thereof. The receptor binds IL-18 and finds use in inhibiting biological activities mediated by IL-18.
1. An isolated host cell genetically engineered to express a protein comprising at least one first polypeptide linked to at least one second polypeptide, wherein said first polypeptide binds to IL-18, and further
wherein said first polypeptide is encoded by a DNA selected from the group consisting of:
a) DNA comprising the coding region of the nucleotide sequence presented in SEQ ID NO:7;
b) DNA that is complementary to DNA capable of hybridizing to the DNA of (a) under highly stringent conditions (hybridization at 68° C. followed by washing in 0.1×SSC/0.1% SDS at 63-68° C.); and,
c) DNA that encodes a polypeptide comprising the amino acid sequence presented in SEQ ID NO:8; and,
wherein said second polypeptide is encoded by a DNA selected from the group consisting of:
a′) DNA comprising the coding region of the nucleotide sequence presented in SEQ ID NO:5;
b′) DNA that is complementary to DNA capable of hybridizing to the DNA of (a′) under highly stringent conditions (hybridization at 68° C. followed by washing in 0.1×SSC/0.1% SDS at 63-68° C.); and
c′) DNA that encodes a polypeptide comprising the amino acid sequence presented in SEQ ID NO:6,
wherein the isolated protein binds IL-18 with an affinity greater than that of the first polypeptide alone.
2. An isolated host cell genetically engineered to express a protein comprising at least one first polypeptide linked to at least one second polypeptide, wherein said first polypeptide binds to IL-18, and further
wherein said first polypeptide is encoded by a DNA selected from the group consisting of:
a) DNA encoding a polypeptide comprising amino acids y-325 of SEQ ID NO:8, wherein y represents an integer between and including 1 and 19; and
b) DNA that is complementary to DNA capable of hybridizing to the DNA of a) under highly stringent conditions (hybridization at 68° C. followed by washing in 0.1×SSC/0.1% SDS at 63-68° C.); and
wherein said second polypeptide is encoded by a DNA selected from the group comprising:
a′) DNA encoding a polypeptide comprising amino acids x-356 of SEQ ID NO:6, wherein x is an integer between and including 1 and 15; and
b′) DNA that is complementary to DNA capable of hybridizing to the DNA of a′) under highly stringent conditions (hybridization at 68° C. followed by washing in 0.1×SSC/0.1% SDS at 63-68° C.),
wherein the isolated protein binds IL-18 with an affinity greater than that of the first polypeptide alone.
3. An isolated host cell genetically engineered to express a protein comprising at least one first polypeptide linked to at least one second polypeptide, wherein the first polypeptide comprises amino acids 19 through 325 of SEQ ID NO:8 and the second polypeptide comprises amino acids 15 through 356 of SEQ ID NO:6.
4. The host cell of claim 3 , wherein the first polypeptide and second polypeptide are linked via a peptide linker.
5. An isolated host cell genetically engineered to express a protein comprising at least one first polypeptide linked to at least one second polypeptide, wherein the second polypeptide comprises a polypeptide having amino acids x-356 of SEQ ID NO:6, wherein x is an integer between and including 1 and 15; and wherein the first polypeptide binds to IL-18, and further wherein said first polypeptide comprises a polypeptide having amino acids y-325 of SEQ ID NO:8, wherein y represents an integer between and including 1 and 19; and, further wherein the isolated protein binds IL-18 with an affinity greater than that of the first polypeptide alone.
6. An isolated host cell genetically engineered to express a protein having a formula selected from the group consisting of:
R 1 -L 1 :R 2- -L 2 , R 2 -L 2 :R 1 -L 1 , R 1 -L 2 :R 2 -L 1 , R 2 -L 1 :R 1 -L 2 ,
R 1 -L 1 :R 2- -L 2 /R 2 -L 2 :R 1 -L 1 , and, R 1 -L 2 :R 2 -L 1 /R 2 -L 1 :R 1 -L 2
wherein L 1 is an immunoglobulin heavy chain fragment; L 2 is an immunoglobulin light chain fragment; : is a linkage between a heavy chain and light chain antibody region, / is a linkage between a light chain and a heavy chain antibody region; and
wherein R 2 is selected from the group consisting of:
a) a polypeptide comprising amino acids y-325 of SEQ ID NO:8, wherein y represents an integer between and including 1 and 19; and
b) a fragment of the polypeptide of a), and further wherein R 2 binds IL-18;
wherein said R 1 is selected from the group consisting of:
a′) a polypeptide comprising amino acids x-356 of SEQ ID NO:6, wherein x represents an integer between and including 1 and 15; and
b′) a fragment of the polypeptide of a′), and further
wherein the protein binds IL-18 with an affinity greater than that of R 2 alone.
7. An isolated host cell genetically engineered to express a heterodimeric protein comprising a first fusion polypeptide and a second fusion polypeptide, the first fusion polypeptide comprising an antibody light chain polypeptide attached to the C-terminus of a soluble first polypeptide or a soluble second polypeptide, and the second fusion polypeptide comprising an antibody heavy chain polypeptide attached to the C-terminus of a soluble first polypeptide or of a soluble second polypeptide, wherein said first fusion polypeptide is linked to said second fusion polypeptide via disulfide bonds between the heavy chain and light chain polypeptides; and,
wherein the soluble first polypeptide is selected from the group consisting of:
a) polypeptides comprising amino acids y-325 of SEQ ID NO:8, wherein y represents an integer between and including 1 and 19; and,
b) polypeptides comprising a fragment of a),
further wherein the first soluble polypeptide binds IL-18; and
wherein the soluble second polypeptide is selected from the group consisting of:
a′) polypeptides comprising amino acids x-356 of SEQ ID NO:6, wherein x represents an integer between and including 1 and 15; and
b′) polypeptides comprising a fragment of a′), wherein the fragment of a′), in combination with soluble first polypeptide binds IL-18 with an affinity greater than that of the soluble first polypeptide alone.
8. An isolated host cell genetically engineered to express a protein having a formula selected from the group consisting of:
R 1 -L 1 :R 2- -L 2 , R 2 -L 2 :R 1 -L 1 , R 1 -L 2 :R 2 -L 1 , R 2 -L 1 :R 1 -L 2 ,
R 1 -L 1 :R 2- -L 2 /R 2 -L 2 :R 1 -L 1 , and, R 1 -L 2 :R 2 -L 1 /R 2 -L 1 :R 1 -L 2
wherein L 1 comprises an immunoglobulin heavy chain fragment; L 2 comprises an immunoglobulin light chain fragment; R 1 comprises a fragment of SEQ ID NO:6; R 2 comprises a fragment of SEQ ID NO:8; is a linkage between a heavy chain and light chain antibody region, and/is a linkage between a light chain and heavy chain antibody region,
wherein the fragment of SEQ ID NO:8 binds IL-18, and further
wherein the protein binds IL-18 with higher affinity than the fragment of SEQ ID NO:8 alone.
9. An isolated host cell genetically engineered to express a protein comprising at least one first polypeptide linked to at least one second polypeptide wherein the first polypeptide comprises a fragment of amino acids 1-325 of SEQ ID NO:8 that binds IL-18 and the second polypeptide comprises a fragment of amino acids 1-356 of SEQ ID NO:6, wherein the protein binds IL-18 with a greater affinity than amino acids 1-325 of SEQ ID NO:8 alone.
10. A process of producing the protein expressed by the host cell of any one of claims 1 , 2 , 3 , 5 , 6 , 7 , 8 , and 9 comprising culturing said host cell under conditions that promote expression of the protein.