Abstract: Novel human interleukin-2 (IL-2) muteins or variants thereof, and nucleic acid molecules and variants thereof are provided. Methods for producing these muteins as well as methods for stimulating the immune system of an animal are also disclosed. In addition, the invention provides recombinant expression vectors comprising the nucleic acid molecules of this invention and host cells into which expression vectors have been introduced. Pharmaceutical compositions are included comprising a therapeutically effective amount of a human IL-2 mutein of the invention and a pharmaceutically acceptable carrier. The IL-2 muteins have lower toxicity than native IL-2 or Proleukin® IL-2, while maintaining or enhancing NK cell-mediated effects, and can be used in pharmaceutical compositions for use in treatment of cancer, and in stimulating the immune response.

Abstract: Methods for treating B-cell lymphomas, such as non-Hodgkin's lymphoma (NHL) are disclosed. The methods use a combination therapy of a chemotherapeutic agent, an IL-2 and, optionally, an anti-CD20 antibody.

Abstract: Methods for predicting patient tolerability to therapeutic agents, such as cytokines, lymphokines and immunotoxins, are disclosed. The methods utilize an in vitro model of vascular leak syndrome (VLS) to assess the effect of the agent in question on the permeability of large proteins across confluent monolayers of endothelial cells (EC).

Abstract: Novel human interleukin-2 (IL-2) muteins or variants thereof, and nucleic acid molecules and variants thereof are provided. Methods for producing these muteins as well as methods for stimulating the immune system of an animal are also disclosed. In addition, the invention provides recombinant expression vectors comprising the nucleic acid molecules of this invention and host cells into which expression vectors have been introduced. Pharmaceutical compositions are included comprising a therapeutically effective amount of a human IL-2 mutein of the invention and a pharmaceutically acceptable carrier. The IL-2 muteins have lower toxicity than native IL-2 or Proleukin® IL-2, while maintaining or enhancing NK cell-mediated effects, and can be used in pharmaceutical compositions for use in treatment of cancer, and in stimulating the immune response.