Abstract: Compositions and methods are provided for generating T cells having a regulatory phenotype from conventional T (Tconv) cells. Such compositions and methods include culturing isolated, naïve Tconv cells with an effective amount of interleukin-35 (IL-35) until the cells have the regulatory phenotype. Also provided are methods to treat subject having or susceptible to having various disorders including, for example, immune system disorders with the T cells having the regulatory phenotype.

Abstract: The receptor for Interleukin 35 (IL-35) is provided. The Interleukin 35 Receptor (IL-35R) comprises a heterodimeric complex of the Interluekin12R?2 receptor and the gp130 receptor. Various compositions comprising the IL-35R complex, along with polynucleotides encoding the same and kits and methods for the detection of the same the same are provided. Methods of modulating the activity of IL-35R or modulating effector T cell functions are also provided. Such methods employ various IL-35R antagonists and agonists that modulate the activity of the IL-35R complex and, in some embodiments, modulate effector T cell function. Further provided are methods for screening for IL-35R binding agents and for IL-35R modulating agents. Various methods of treatment are further provided.

Abstract: The receptor for Interleukin 35 (IL-35) is provided. The Interleukin 35 Receptor (IL-35R) comprises a heterodimeric complex of the Interluekin12R?2 receptor and the gp130 receptor. Various compositions comprising the IL-35R complex, along with polynucleotides encoding the same and kits and methods for the detection of the same the same are provided. Methods of modulating the activity of IL-35R or modulating effector T cell functions are also provided. Such methods employ various IL-35R antagonists and agonists that modulate the activity of the IL-35R complex and, in some embodiments, modulate effector T cell function. Further provided are methods for screening for IL-35R binding agents and for IL-35R modulating agents. Various methods of treatment are further provided.

Abstract: Compositions and methods are provided for potentiating activity of interleukin-35 (IL-35). Such compositions and methods include administering therapeutically effective amounts of non-blocking IL-35 binding agents. The non-blocking IL-35 binding agents do not block the binding of IL-35 to its target(s). Also provided are methods to identify non-blocking IL-35 binding agents that enhance IL-35 activity.

Abstract: Compositions and methods are provided for generating T cells having a regulatory phenotype from conventional T (Tconv) cells. Such compositions and methods include culturing isolated, naïve Tconv cells with an effective amount of interleukin-35 (IL-35) until the cells have the regulatory phenotype. Also provided are methods to treat subject having or susceptible to having various disorders including, for example, immune system disorders with the T cells having the regulatory phenotype.