Bi-functional cytokine fusion proteins for gene therapy and antibody-targeted treatment of cancer

Cancer Immunol Immunother. 2002 Oct;51(8):449-60. doi: 10.1007/s00262-002-0302-6. Epub 2002 Jul 12.


Typically, multiple cytokines act in concert to mediate a desired immunological response, and thus more effective therapeutics may be achieved by combining several cytokines with potentially synergistic activities. We have developed a series of bi-functional cytokine fusion proteins which, when additionally linked to an intact antibody (or the Fc portion of an antibody) in a variety of configurations, can be specifically targeted. We focus here mainly on the synergizing cytokine combination interleukin-2/interleukin-12 (IL-2/IL-12), but also demonstrate the utility of this approach with interleukin-4/granulocyte-macrophage colony-stimulating factor (IL-4/GM-CSF). Cytokine activity was retained in constructs where the cytokines were fused in tandem at the carboxyl terminus of the Fc or antibody heavy (H) chain, as well as in constructs where one cytokine was fused at the carboxyl terminus of the H chain while the second cytokine was fused to the amino terminus of either the H or light (L) chain variable region. Even in such constructs, antigen binding of the antibody-cytokine fusion proteins could be maintained. In the context of bi-functional fusion proteins, hetero-dimeric IL-12 could be expressed either in a single-chain form, or maintained as a heterodimer in which the p40 subunit was fused to IL-2. These IL-12/IL-2 bi-functional fusion proteins were shown to induce extremely high levels of interferon-gamma (IFN-gamma), similar to the synergy normally seen with the combined application of the individual cytokines. In addition, these bifunctional molecules were shown to have striking anti-tumor activity as either gene therapy or as an antibody cytokine(s) fusion protein, and may provide a useful approach to the treatment of cancer.

MeSH terms

  • Animals
  • Antibodies / therapeutic use*
  • Cytokines / biosynthesis
  • Cytokines / chemistry*
  • Cytokines / metabolism
  • Dose-Response Relationship, Drug
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme-Linked Immunosorbent Assay
  • Genetic Therapy / methods*
  • Granulocyte-Macrophage Colony-Stimulating Factor / metabolism
  • Granulocyte-Macrophage Colony-Stimulating Factor / therapeutic use
  • Humans
  • Interferon-gamma / therapeutic use
  • Interleukin-12 / metabolism
  • Interleukin-12 / therapeutic use
  • Interleukin-2 / metabolism
  • Interleukin-2 / therapeutic use
  • Interleukin-4 / metabolism
  • Interleukin-4 / therapeutic use
  • Lung Neoplasms / pathology
  • Lung Neoplasms / secondary
  • Mice
  • Mice, Inbred C57BL
  • Models, Biological
  • Neoplasm Metastasis
  • Neoplasms / immunology
  • Neoplasms / therapy*
  • Organ Size
  • Plasmids / metabolism
  • Protein Conformation
  • Recombinant Fusion Proteins / metabolism
  • Recombinant Fusion Proteins / physiology*
  • Time Factors
  • Transfection
  • Tumor Cells, Cultured


  • Antibodies
  • Cytokines
  • Interleukin-2
  • Recombinant Fusion Proteins
  • Interleukin-12
  • Interleukin-4
  • Interferon-gamma
  • Granulocyte-Macrophage Colony-Stimulating Factor