Immunity to WT1 in the animal model and in patients with acute myeloid leukemia.

Abstract

The Wilms' tumor (WT1) gene participates in leukemogenesis and is overexpressed in most types of leukemia in humans. WT1 is also detectable in many types of lung, thyroid, breast, testicular, and ovarian cancers and melanoma in humans. Initial studies evaluated whether immune responses to murine WT1 can be elicited in mice. Murine and human WT1 are similar. Thus, mouse models might lead to resolution of many of the critical issues for developing WT1 vaccines. C57/BL6 (B6) mice were injected with synthetic peptides from the natural sequence of WT1 containing motifs for binding to major histocompatibility (MHC) class II molecules. Immunization induced helper T-cell responses specific for the immunizing WT1 peptides and antibody responses specific for WT1 protein. Screening of multiple murine cancer cell lines identified 2 murine cancers, TRAMP-C and BLKSV40, that "naturally" overexpress WT1. Immunization with MHC class I binding peptides induced WT1 peptide-specific cytotoxic T-lymphocyte (CTL) that specifically lysed TRAMP-C and BLKSV40. WT1 specificity of lysis was confirmed by cold target inhibition. No toxicity was noted by histopathologic evaluation in the WT1 peptide-immunized animals. WT1 peptide immunization did not show any effect on TRAMP-C tumor growth in vivo. Immunization of B6 mice to syngeneic TRAMP-C elicited WT1-specific antibody, demonstrating that WT1 can be immunogenic in the context of cancer cells. To evaluate whether WT1 might be similarly immunogenic in humans, serum from patients with leukemia was evaluated for pre-existing antibody responses. Western blot analyses showed WT1-specific antibodies directed against the N-terminus portion of the WT1 protein in the sera of 3 of 18 patients with acute myeloid leukemia (AML). (Blood. 2000;96:1480-1489)

• Authors: A Gaiger, V Reese, M L Disis, M A Cheever
• Journal: Blood (Blood) Vol. 96 Issue 4 Pg. 1480-9 (Aug 15 2000) ISSN: 0006-4971 [Print] United States
• PMID: 10942395 (Publication Type: Journal Article)

Chemical References

• Antibodies
• Cancer Vaccines
• DNA-Binding Proteins
• Peptides
• Transcription Factors
• WT1 Proteins

Topics

• Acute Disease
• Animals
• Antibodies (immunology)
• Cancer Vaccines (immunology)
• DNA-Binding Proteins (immunology)
• Female
• Genes, Wilms Tumor
• Humans
• Leukemia, Myeloid (immunology)
• Mice
• Mice, Inbred C57BL
• Peptides (immunology)
• T-Lymphocyte Subsets (immunology)
• Transcription Factors (immunology)
• Tumor Cells, Cultured
• WT1 Proteins