Moléculas de unión específicas para IL-21 y usos de las mismas

Anticuerpo aislado o fragmento de unión a antígeno del mismo que se une específicamente a IL-21 que comprende una región variable de cadena pesada (VH) y una región variable de cadena ligera (VL), en el que (a) la VH comprende la secuencia de aminoácidos de SEQ ID NO: 19; y (b) la VL comprende la secuencia de aminoácidos de SEQ ID NO: 21. This disclosure provides IL-21 binding molecules, e.g., anti-IL-21 antibodies and antigen-binding fragments thereof. In certain aspects the anti-IL-21 antibodies and fragments thereof can be hybridoma-derived murine monoclonal antibodies, and humanized versions thereof. In certain aspects the binding molecules, e.g., anti-IL-21 antibodies and antigen-binding fragments thereof provided herein inhibit, suppress, or antagonize IL-21 activity. In addition, this disclosure provides compositions and methods for diagnosing and treating diseases or disorders, e.g., inflammatory, immune-mediated, or autoimmune diseases or disorders associated with IL-21 -mediated signal transduction. In a particular embodiment, the disclosure provides methods for treating or preventing Grafi-versus-host disease (GVHD) using IL-21 binding molecules, e.g., anti-IL-21 antibodies and antigen-binding fragments thereof.