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.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61 / 060,747 filed Jun. 11, 2008, which is incorporated herein by reference in its entirety.STATEMENT REGARDING SEQUENCE LISTING[0002]The Sequence Listing associated with this application is provided in text format in lieu of a paper copy, and is hereby incorporated by reference into the specification. The name of the text file containing the Sequence Listing is 120161—409_SEQ.txt. The text file is 37 KB, was created on Jun. 10, 2009, and is being submitted electronically via EFS-Web.BACKGROUND[0003]1. Technical Field[0004]The present invention relates generally to thrombopoietic compositions comprising tyrosyl-tRNA synthetase polypeptides, including truncations and / or variants thereof, and methods of using such compositions in the treatment of diseases or conditions that benefit from increased thrombopoiesis, such as diseases or conditions...

AI Technical Summary

Benefits of technology

[0012]The present invention stems from the unexpected finding that compositions comprising tyrosyl-tRNA synthetase (YRS) polypeptides, including truncated and / or variant polypeptides thereof, stimulate thrombopoiesis in vivo (i.e., increased platelet formation). Accordingly, embodiments of the present invention may be utilized generally to treat and / or reduce the risk of developing diseases or conditions associated with thrombocytopenia, or reduced platelet levels.

[0013]Certain embodiments include methods of increasing the 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 the platelet count in the subject. Certain embodiments include methods 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. Certain embodiments contemplate methods 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. Certain embodiments include methods of maintaining platelet count in a subject (e.g., a subject undergoing a therapy associated with reduced platelet count), comprising administering to the subject a thrombopoietically-effective concentration of a tyrosyl-tRNA synthetase polypeptide, thereby maintaining platelet count in the subject.

[0029]Certain embodiments relate to methods 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. In certain embodiments, the subject has a chronic obstructive pulmonary disease (COPD). In certain embodiments, the administration of the tyrosyl-tRNA synthetase polypeptide is effective to achieve desensitization of circulating neutrophils to an allergen.

Problems solved by technology

Currently available treatments for thrombocytopenia and related conditions include, for example, corticosteroids, IVIG, splenectomy, and platelet transfusion, which methods are either palliative and non-specific, or drastic and expensive.

In addition, previous efforts to utilize thrombopoietin, the primary biological mediator of thrombopoiesis, have failed in the clinic due to the serious effects observed in patients who developed an immune response to the drug and, consequently, to their own endogenous thrombopoietin.

Thrombopoietin mimetics and small molecule activators of the thrombopoietin receptor are in development but have not been approved by the Food and Drug Administration (FDA).

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