Therapy of human non-small-cell lung carcinoma using antibody targeting of a modified superantigen

Br J Cancer. 2001 Jul 6;85(1):129-36. doi: 10.1054/bjoc.2001.1891.


Superantigens activate T-cells by linking the T-cell receptor to MHC class II on antigen-presenting cells, and novel reactivity can be introduced by fusing the superantigen to a targeting molecule. Thus, an antibody-targeted superantigen, which activates T cells to destroy tumour cells, might be used as cancer therapy. A suitable target is the 5T4 oncofetal antigen, which is expressed on many carcinomas. We constructed a fusion protein from a Fab of a monoclonal antibody recognizing the 5T4 antigen, and an engineered superantigen. The recombinant product 5T4FabV13-SEA(D227A)bound the 5T4 antigen expressed on the human non-small-cell lung cancer cell line Calu-1 with a Kd of 1.2 nM while the substitution of Asp227 to Ala in the superantigen moiety reduced binding activity to MHC class II. 5T4FabV13-SEA(D227A)tumour reactivity was demonstrated in 7/7 NSCLC samples by immunohistochemistry, while normal tissue reactivity was low to moderate. 5T4FabV13-SEA(D227A)induced significant T-cell-dependent in vitro killing of sensitive 5T4 bearing Calu-1 cells, with maximum lysis at 10(-10)M, while the capacity to lyse MHC class II expressing cells was approximately 1000 times less effective. Immunotherapy of 5T4FabV13-SEA(D227A)against human NSCLC was investigated in SCID mice reconstituted with human peripheral blood mononuclear cells. Mice carrying intreperitoneally growing Calu-1 cells showed significant reduction in tumour mass and number after intravenous therapy with 5T4FabV13-SEA(D227A). Thus, 5T4FabV13-SEA(D227A)has highly attractive properties for therapy of human NSCLC.

MeSH terms

  • Animals
  • Antigen-Antibody Reactions / immunology
  • Antigens, Neoplasm / immunology
  • Carcinoma, Non-Small-Cell Lung / immunology
  • Carcinoma, Non-Small-Cell Lung / therapy*
  • Cloning, Molecular
  • Cytokines / biosynthesis
  • Cytokines / immunology
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Female
  • Histocompatibility Antigens Class II / immunology
  • Histocompatibility Antigens Class II / metabolism
  • Humans
  • Immunoglobulin Fragments / genetics
  • Immunoglobulin Fragments / immunology
  • Immunoglobulin Fragments / pharmacology
  • Immunohistochemistry
  • Immunotherapy / methods*
  • Lung Neoplasms / immunology
  • Lung Neoplasms / therapy*
  • Membrane Glycoproteins / biosynthesis
  • Membrane Glycoproteins / immunology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, SCID
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / immunology
  • Recombinant Fusion Proteins / pharmacology
  • Superantigens / immunology*
  • Superantigens / pharmacology
  • Xenograft Model Antitumor Assays


  • Antigens, Neoplasm
  • Cytokines
  • Histocompatibility Antigens Class II
  • Immunoglobulin Fragments
  • Membrane Glycoproteins
  • Recombinant Fusion Proteins
  • Superantigens
  • trophoblastic glycoprotein 5T4, human