Thrombopoietic activity of tyrosyl-trna synthetase polypeptides

Abstract

Thrombopoietic compositions are provided comprising tyrosyl tRNA synthetase polypeptides, including truncations and/or variants thereof. Also provided are methods of using such compositions in the treatment of conditions that benefit from increased thrombopoiesis, such as thrombocytopenia.

1 . A method of increasing platelet count in a subject, comprising administering to the subject a composition comprising a thrombopoietically-effective concentration of a tyrosyl-tRNA synthetase polypeptide, thereby increasing platelet count in the subject. 
     
     
         2 . A method of treating, or reducing the risk of developing, thrombocytopenia in subject, comprising administering to the subject a composition comprising a thrombopoietically-effective concentration of a tyrosyl-tRNA synthetase polypeptide, thereby treating or reducing the risk of developing thrombocytopenia in the subject. 
     
     
         3 . A method of stimulating thrombopoiesis in a subject, comprising administering to the subject a composition comprising a thrombopoietically-effective concentration of a tyrosyl-tRNA synthetase polypeptide, thereby stimulating thrombopoiesis in the subject. 
     
     
         4 . A method of maintaining platelet count in a subject, comprising administering to the subject a thrombopoietically-effective concentration of a tyrosyl-tRNA synthetase polypeptide, thereby maintaining platelet count in the subject. 
     
     
         5 . A method of stimulating megakaryocyte proliferation, migration, and/or differentiation in a subject, comprising administering to the subject a thrombopoietically-effective concentration of a tyrosyl-tRNA synthetase polypeptide, thereby stimulating megakaryocyte proliferation and/or differentiation in the subject. 
     
     
         6 . A method of stimulating neutrophil proliferation in a subject, comprising administering to the subject a thrombopoietically-effective concentration of a tyrosyl-tRNA synthetase polypeptide, thereby stimulating neutrophil proliferation in the subject. 
     
     
         7 . The method of  claim 1 , wherein the subject has, or is at risk for having, a disease or condition associated with a decreased or reduced platelet count. 
     
     
         8 . The method of  claim 1 , wherein the subject has a platelet count of about 150,000/mm 3  or lower. 
     
     
         9 . The method of  claim 7 , wherein the disease or condition associated with a decreased or reduced platelet count is selected from bleeding, epistaxis, hypersplenism, hypothermia, Epstein-Barr virus infection, infectious mononucleosis, Wiskott-Aldrich syndrome, maternal ingestion of thiazides, congenital amegakaryocytic thrombocytopenia, thrombocytopenia absent radius syndrome, Fanconi anemia, Bernard-Soulier syndrome, May-Hegglin anomaly, Grey platelet syndrome, Alport syndrome, neonatal rubella, aplastic anemia, myeolodysplastic syndrome, leukemia, lymphoma, tumor, cancer of the bone marrow, nutritional deficiency, radiation exposure, liver failure, bacterial sepsis, measles, dengue fever, HIV infection or AIDS, prematurity, erythroblastosis fetalis, idiopathic thrombocytopenic purpura (ITP), maternal ITP, hemolytic-uremic syndrome, disseminated intravascular coagulation, thrombotic thrombocytopenic purpura (TTP), post-transfusion purpura, systemic lupus erythrematosus, rheumatoid arthritis, neonatal alloimmune thrombocytopenia, and paroxysmal nocturnal hemoglobinuria, hepatitis C virus infection (HCV), medication induced thrombocytopenia, and chemotherapy induced thrombocytosis (CIT). 
     
     
         10 . The method of  claim 7 , wherein the disease or condition associated with a decreased or reduced platelet count is induced by a medication or drug. 
     
     
         11 . The method of  claim 10 , wherein the medication or drug is selected from chemotherapeutic agents, nonsteroidal anti-inflammatory agents, sulfonamides, vancomycin, clopidogrel, glycoprotein IIb/IIIa inhibitors, interferons, valproic acid, abciximab, linezolid, famotidine, mebeverine, histamine blockers, alkylating agents, heparin, alcohol, and antibiotic chemotherapeutic agents. 
     
     
         12 . The method of  claim 11 , wherein the chemotherapeutic agent is selected from cisplatin (CDDP), carboplatine, procarbazine, mechlorethamine, cyclophosphamide, camptothecin, ifosfamide, melphalan, chlorambucil, busulfan, nitrosurea, dactinomycin, daunorubicin, doxorubicin, bleomycin, plicomycin, mitomycin, etoposide (VP16), tamoxifen, raloxifene, estrogen receptor binding agents, taxol, gemcitabien, navelbine, farnesyl-protein transferase inhibitors, transplatinum, 5-fluorouracil, vincristine, vinblastine and methotrexate, temazolomide, and derivatives thereof. 
     
     
         13 . The method of  claim 1 , wherein the tyrosyl-tRNA synthetase polypeptide comprises a mammalian tyrosyl-tRNA synthetase truncated at its C-terminus. 
     
     
         14 . The method of  claim 1 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14, wherein at least about 1-50 amino acid residues are truncated from its C-terminus. 
     
     
         15 . The method of  claim 1 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14, wherein at least about 50-100 amino acid residues are truncated from its C-terminus. 
     
     
         16 . The method of  claim 1 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14, wherein at least about 100-150 amino acid residues are truncated from its C-terminus. 
     
     
         17 . The method of  claim 1 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, or 10, wherein at least about 150-200 residues are truncated from its C-terminus. 
     
     
         18 . The method of  claim 1 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, or 10, wherein at least about 200-250 amino acid residues are truncated from its C-terminus. 
     
     
         19 . The method of  claim 1 , wherein the tyrosyl-tRNA synthetase polypeptide comprises a mammalian tyrosyl-tRNA synthetase truncated at its N-terminus. 
     
     
         20 . The method of  claim 1 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14, wherein at least about 1-50 amino acid residues are truncated from its N-terminus. 
     
     
         21 . The method of  claim 1 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14, wherein at least about 50-100 amino acid residues are truncated from its N-terminus. 
     
     
         22 . The method of  claim 1 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14, wherein at least about 100-150 amino acid residues are truncated from its N-terminus. 
     
     
         23 . The method of  claim 1 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, or 10, wherein at least about 150-200 residues are truncated from its N-terminus. 
     
     
         24 . The method of  claim 1 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, or 10, wherein at least about 200-250 amino acid residues are truncated from its N-terminus. 
     
     
         25 . The method of  claim 1 , wherein the tyrosyl-tRNA synthetase polypeptide is selected from:
 (a) a polypeptide comprising an amino acid sequence at least 80% identical to the amino acid sequence set forth in SEQ ID NO:2, wherein the alanine at position 341 is not substituted with a tyrosine;   (b) a polypeptide comprising an amino acid sequence at least 90% identical to the amino acid sequence set forth in SEQ ID NO:2, wherein the alanine at position 341 is not substituted with a tyrosine;   (c) a polypeptide comprising an amino acid sequence at least 95% identical to the amino acid sequence set forth in SEQ ID NO:2, wherein the alanine at position 341 is not substituted with a tyrosine;   (d) a polypeptide comprising an amino acid sequence at least 98% identical to the amino acid sequence set forth in SEQ ID NO:2, wherein the alanine at position 341 is not substituted with a tyrosine; and   (e) a polypeptide comprising the amino acid sequence set forth in SEQ ID NO:2.   
     
     
         26 . The method of  claim 1 , wherein the tyrosyl-tRNA synthetase polypeptide is selected from:
 (a) a polypeptide comprising an amino acid sequence at least 80% identical to the amino acid sequence set forth in SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14;   (b) a polypeptide comprising an amino acid sequence at least 90% identical to the amino acid sequence set forth in SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14;   (c) a polypeptide comprising an amino acid sequence at least 95% identical to the amino acid sequence set forth in SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14;   (d) a polypeptide comprising an amino acid sequence at least 98% identical to the amino acid sequence set forth in SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14; and   (e) a polypeptide comprising the amino acid sequence set forth in SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14.   
     
     
         27 . A composition adapted for administration, comprising a physiologically acceptable excipient and/or carrier and a thrombopoietically-effective concentration of a tyrosyl-tRNA synthetase polypeptide, wherein the composition is capable of stimulating thrombopoiesis and/or increasing the platelet count in a subject. 
     
     
         28 . The composition of  claim 27 , wherein the tyrosyl-tRNA synthetase polypeptide comprises a mammalian tyrosyl-tRNA synthetase truncated at its C-terminus. 
     
     
         29 . The composition of  claim 27 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14, wherein at least about 1-50 amino acid residues are truncated from its C-terminus. 
     
     
         30 . The composition of  claim 27 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14, wherein at least about 50-100 amino acid residues are truncated from its C-terminus. 
     
     
         31 . The composition of  claim 27 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14, wherein at least about 100-150 amino acid residues are truncated from its C-terminus. 
     
     
         32 . The composition of  claim 27 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, or 10, wherein at least about 150-200 residues are truncated from its C-terminus. 
     
     
         33 . The composition of  claim 27 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, or 10, wherein at least about 200-250 amino acid residues are truncated from its C-terminus. 
     
     
         34 . The composition of  claim 27 , wherein the tyrosyl-tRNA synthetase polypeptide comprises a mammalian tyrosyl-tRNA synthetase truncated at its N-terminus. 
     
     
         35 . The composition of  claim 27 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14, wherein at least about 1-50 amino acid residues are truncated from its N-terminus. 
     
     
         36 . The composition of  claim 27 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14, wherein at least about 50-100 amino acid residues are truncated from its N-terminus. 
     
     
         37 . The composition of  claim 27 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14, wherein at least about 100-150 amino acid residues are truncated from its N-terminus. 
     
     
         38 . The composition of  claim 27 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, or 10, wherein at least about 150-200 residues are truncated from its N-terminus. 
     
     
         39 . The composition of  claim 27 , wherein the tyrosyl-tRNA synthetase polypeptide comprises the amino acid sequence of SEQ ID NO: 1, 2, 3, 6, 8, or 10, wherein at least about 200-250 amino acid residues are truncated from its N-terminus. 
     
     
         40 . The composition of  claim 27 , wherein the tyrosyl-tRNA synthetase polypeptide is selected from:
 (a) a polypeptide comprising an amino acid sequence at least 80% identical to the amino acid sequence set forth in SEQ ID NO:2, wherein the alanine at position 341 is not substituted with a tyrosine;   (b) a polypeptide comprising an amino acid sequence at least 90% identical to the amino acid sequence set forth in SEQ ID NO:2, wherein the alanine at position 341 is not substituted with a tyrosine;   (c) a polypeptide comprising an amino acid sequence at least 95% identical to the amino acid sequence set forth in SEQ ID NO:2, wherein the alanine at position 341 is not substituted with a tyrosine;   (d) a polypeptide comprising an amino acid sequence at least 98% identical to the amino acid sequence set forth in SEQ ID NO:2, wherein the alanine at position 341 is not substituted with a tyrosine; and   (e) a polypeptide comprising the amino acid sequence set forth in SEQ ID NO:2.   
     
     
         41 . The composition of  claim 27 , wherein the tyrosyl-tRNA synthetase polypeptide is selected from:
 (a) a polypeptide comprising an amino acid sequence at least 80% identical to the amino acid sequence set forth in SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14;   (b) a polypeptide comprising an amino acid sequence at least 90% identical to the amino acid sequence set forth in SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14;   (c) a polypeptide comprising an amino acid sequence at least 95% identical to the amino acid sequence set forth in SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14;   (d) a polypeptide comprising an amino acid sequence at least 98% identical to the amino acid sequence set forth in SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14; and   (e) a polypeptide comprising the amino acid sequence set forth in SEQ ID NO: 1, 2, 3, 6, 8, 10, 12, or 14.   
     
     
         42 . The composition of  claim 27 , further comprising a second tyrosyl-tRNA synthetase polypeptide, wherein the two tyrosyl-tRNA synthetase polypeptides form a dimer. 
     
     
         43 . The composition of  claim 42 , wherein the dimer is a homodimer. 
     
     
         44 . The composition of  claim 43 , wherein the dimer is a heterodimer. 
     
     
         45 . The composition of  claim 44 , wherein the heterodimer comprises a full-length tyrosyl-tRNA synthetase polypeptide and a truncated tyrosyl-tRNA synthetase polypeptide. 
     
     
         46 . The composition of  claim 27 , further comprising a heterologous polypeptide, wherein the tyrosyl-tRNA synthetase polypeptide and the heterologous polypeptide form a heterodimer. 
     
     
         47 . A composition comprising a physiologically acceptable excipient and/or carrier and a thrombopoietically-effective concentration of a chimeric tyrosyl-tRNA synthetase polypeptide, wherein the chimeric polypeptide comprises two or more biologically active fragments of a tyrosyl-tRNA synthetase polypeptide, wherein the two or more fragments comprise at least 10 contiguous amino acids of a polypeptide according to any one of  claims 27 - 41 , wherein the two or more fragments are linked to form a chimeric polypeptide, and wherein the chimeric tyrosyl-tRNA synthetase polypeptide is capable of stimulating thrombopoiesis and/or increasing the platelet count in a subject. 
     
     
         48 . A composition comprising a physiologically acceptable excipient and/or carrier and a thrombopoietically-effective concentration of a chimeric tyrosyl-tRNA synthetase polypeptide, wherein the chimeric polypeptide comprises (a) one or more biologically active fragments of a tyrosyl-tRNA synthetase polypeptide, wherein the one or more fragments comprise at least 10 contiguous amino acids of a polypeptide according to any one of  claims 27 - 41 ; and (b) one or more heterologous polypeptides, wherein the one or more fragments of (a) and the one or more heterologous polypeptides of (b) are linked to form a chimeric polypeptide, and wherein the chimeric polypeptide is capable of stimulating thrombopoiesis and/or increasing the platelet count in a subject. 
     
     
         49 . An antibody, or antigen-binding fragment, that specifically binds to a tyrosyl tRNA synthetase polypeptide of any one of  claims 27 - 48 . 
     
     
         50 . A method of identifying or characterizing a YRS polypeptide in a sample, comprising:
 (a) obtaining a biological sample;   (b) contacting the biological sample with an antibody, or antigen-binding fragment, according to  claim 49 ; and   (c) detecting the presence or absence of specific binding by the antibody, or antigen-binding fragment, to the biological sample,   thereby identifying or characterizing the YRS polypeptide in the sample.   
     
     
         51 . The method of  claim 50 , wherein the biological sample is obtained from a subject. 
     
     
         52 . A composition comprising an isolated polynucleotide, wherein the polynucleotide is selected from:
 (a) a polynucleotide comprising a nucleotide sequence at least 80% identical to the nucleotide sequence set forth in SEQ ID NO: 4, 7, 9, 11, 13, or 15;   (b) a polynucleotide comprising a nucleotide sequence at least 90% identical to the nucleotide sequence set forth in SEQ ID NO: 4, 7, 9, 11, 13, or 15;   (c) a polynucleotide comprising a nucleotide sequence at least 95% identical to the nucleotide sequence set forth in SEQ ID NO: 4, 7, 9, 11, 13, or 15;   (d) a polynucleotide comprising a nucleotide sequence at least 98% identical to the nucleotide sequence set forth in SEQ ID NO: 4, 7, 9, 11, 13, or 15;   (e) a polynucleotide comprising the nucleotide sequence set forth in SEQ ID NO: 4, 7, 9, 11, 13, or 15,   wherein the polynucleotide encodes a tyrosyl-tRNA synthetase polypeptide that is capable of stimulating thrombopoiesis and/or increasing the platelet count in a subject.   
     
     
         53 . A vector comprising the polynucleotide of  claim 52 . 
     
     
         54 . A host cell comprising the vector of  claim 53 . 
     
     
         55 . A method of stimulating proliferation and/or differentiation of early megakaryocyte progenitor cells, comprising incubating a culture of hematopoietic stem cells with a tyrosyl-tRNA synthetase polypeptide for a time sufficient to allow proliferation of the early megakaryocyte progenitor cells, thereby stimulating proliferation and/or differentiation of early megakaryocyte progenitor cells. 
     
     
         56 . The method of  claim 55 , wherein the method is performed ex vivo or in vitro. 
     
     
         57 . The method of  claim 56 , wherein the culture is obtained from bone marrow. 
     
     
         58 . The method of  claim 56 , wherein the culture is obtained from cord blood. 
     
     
         59 . The method of  claim 56 , further comprising administering the cells to a subject in need thereof. 
     
     
         60 . A method of stimulating migration of a CXCR-2 expressing cell, comprising contacting the cell with a tyrosyl-tRNA synthetase polypeptide, thereby stimulating migration of the CXCR-2 expressing cell. 
     
     
         61 . The method of  claim 60 , wherein the step of contacting the cell occurs in vitro or ex vivo. 
     
     
         62 . The method of  claim 60 , wherein the step of contacting comprises administering to a subject in need thereof a composition comprising an effective concentration of a tyrosyl-tRNA synthetase polypeptide. 
     
     
         63 . A method of reducing pulmonary inflammation, and/or its symptoms, in a subject, comprising administering to the subject an effective concentration of a tyrosyl-tRNA synthetase polypeptide, thereby reducing pulmonary inflammation, and/or its symptoms, in the subject. 
     
     
         64 . The method of  claim 63 , wherein the subject has a chronic obstructive pulmonary disease (COPD). 
     
     
         65 . The method of  claim 63 , wherein the administration of the tyrosyl-tRNA synthetase polypeptide is effective to achieve desensitization of circulating neutrophils to an allergen.