Takayoshi Ido

Production of Canine IFN-γ in Silkworm by Recombinant Baculovirus and Characterization of the Product

Canine interferon-gamma (CaIFN-gamma) cDNA was expressed in silkworm by infecting recombinant baculovirus. Western blot analyses revealed that the resulting preparation contained various CaIFN-gamma protein molecules. Genetic engineering of CaIFN-gamma to remove potential glycosylation sites resulted in reduced components of the CaIFN-gamma, suggesting that one cause of this heterogeneity was glycosylation. Nonglycosylated CaIFN-gamma produced in silkworm still had several components that were deleted at the carboxy-terminal end. The major component was the CaIFN-gamma protein truncated 17 or 16 carboxy-terminal amino acid residues. CaIFN-gamma showed antiviral activity, class II major histocompatibility complex (MHC) expression-enhancing activity, and antiproliferation activity on tumor cells.

Cloning of cDNA for canine interleukin-18 and canine interleukin-1beta converting enzyme and expression of canine interleukin-18.

Cloning of canine interleukin-18 (IL-18) and canine interleukin-1beta converting enzyme (ICE) cDNA was carried out by using murine IL-18 cDNA and human ICE cDNA, respectively, as probes. Sequence homology to known sequences of human, mouse, or rat genes was noted at nucleotide and amino acid levels. Canine IL-18 mRNA was expressed in various canine organs, whereas canine ICE mRNA was expressed in only a few, particularly in the brain and testis. Cloned canine IL-18 cDNA was expressed in Escherichia coli. The resulting protein promoted induction of canine interferon-y (IFN-y) from stimulated canine lymphocytes. Canine IL-18 and canine IL-12 produced canine IFN-gamma synergistically. Canine IL-18 suppressed the growth of tumor cells transplanted in SCID mice. Cloned canine IL-18 should prove useful as an anticancer agent.

Abstract 519: Identification of a novel target for antibody therapy of breast cancer

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Identification of breast cancer-specific antigens may promote development of safe and successful immunotherapy of breast cancer. Caprin-1 has been known to be an intracellular protein related to cell proliferation as a function, but it has not been reported to be a target for the treatment of cancer. Here we report that this molecule is a novel breast cancer antigen which can be targeted for antibody therapy. Caprin-1 is highly expressed in at least 70% of breast cancers based on the results of immunohistochemical staining of human several breast cancer tissues, but hardly expressed in human normal tissues. Importantly, a part of this molecule is highly expressed in extracellular region of many breast cancer cells. A mouse monoclonal antibody raised against the extracellular domain of Caprin-1 showed anti-tumor effects in all tumor-bearing mouse models in which various cancer cells expressing Caprin-1 were implanted. The monoclonal antibody induced complete regression in one of the tumor-bearing models. Humanized antibody has been prepared and preclinical studies are currently underway. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 519. doi:1538-7445.AM2012-519