Vaccination against tumor cells expressing breast cancer epithelial tumor antigen.

Abstract

Ninety-one percent of breast tumors aberrantly express an epithelial tumor antigen (ETA) identified by monoclonal antibody H23. Vaccinia virus recombinants expressing tumor antigens have considerable promise in the active immunotherapy of cancer, and we have evaluated the potential of vaccinia recombinants expressing the secreted (S) and cell-associated (transmembrane, T) forms of H23 ETA to elicit immunity to tumor cells expressing ETA. Tumorigenic ras-transformed Fischer rat fibroblast lines FR-S and FR-T, expressing the S or T form of H23 ETA, respectively, were constructed for use in challenge experiments. Expression of H23 ETA in these lines was confirmed by Western blotting and immunofluorescence. When challenged by subcutaneous seeding of tumor cells, 97% (FR-S) and 91% (FR-T) of syngeneic Fischer rats rapidly developed tumors that failed to regress. Vaccination with recombinant vaccinia virus expressing ETA-T prior to challenge prevented tumor development in 82% of animals seeded with FR-T cells but in only 61% of animals seeded with FR-S. The vaccinia recombinant expressing the S form was a less effective immunogen, and vaccination protected only 29-30% of animals from developing tumors upon challenge with either FR-S or -T cells. The increased immunogenicity of the recombinant expressing ETA-T was reflected in elevated levels of ETA-reactive antibody in vaccinated animals, confirming that secreted antigens expressed from vaccinia virus are less effective immunogens than their membrane-associated counterparts.

Adenovirus-mediated gene transfer of pathogen-associated molecular patterns for cancer immunotherapy

“…26 The cDNA of the MUC1 tumor antigen was derived from plasmid pHMG-ETAtm (MUC-1) for cloning into Ad vector. 33 Ad vectors were diluted just before use in the viral storage buffer described above.…”

“…35 The expression of CAR by B16F0-CAR cells increased their susceptibility to adenovirus infection approximately 100-fold (unpublished data). 33 Transduction of tumor cell lines in vitro For transduction with Ad vectors, A549 cells were trypsinized, washed in phosphate-buffered saline and resuspended in phosphate-buffered saline containing 100 mg l À1 sodium acetate, 100 mg l À1 calcium chloride and 2% FCS (100 ml for 10 6 cells). Infections were done by the addition of Ad vectors at multiplicities of infection (MOI) of 5-50 and incubation at 37 1C for 30 min.…”

“…Staining with an anti-NDV-HN monoclonal antibody provided by V Schirrmacher (DKFZ, Heidelberg, Germany), an antihuman CD40L mAb (BD Pharmingen) or an antiMUC1mAb (H23) 33 was detected by an fluorescein isothiocyanate-conjugated anti-mouse immunoglobulin antibody (BD Pharmingen) and analyzed on a FACScan flow cytometer using the CellQuest Pro software (Becton Dickinson, Le Pont de Claix, France).…”

“…B6D2 mice were inoculated with RenCa renal carcinoma cells stably transfected to express the tumor-associated antigen MUC1 (RenCa-MUC1). 33 Ad-MUC1 was combined with Ad-PAMPs, Ad-HN or Ad-empty for subcutaneous administration to tumorbearing mice. At days 20-30 after tumor inoculation, (Figure 5a).…”

Molecular Cloning and Characterization of a Transmembrane Surface Antigen in Human Cells

“…Tumor-specific antigens can also be used as recombinant vaccines to prevent tumors in subjects at risk, or to arrest tumor growth in patients at early stages (Hareuveni et al, 1990;Lanzavecchia, 1993).…”