Technology

Cell-surface antigens for cancer vaccines

Immunization with cancer cells is of great demand in anti-cancer therapy. However, current cellular vaccines are inefficient and there are questions regarding their overall safety. We discovered a simple and straightforward approach for preparing qualified for vaccination and safe cancer antigens. Through treatment of cancer cell cultures with purified protease, it is possible to make preparations of cell-surface antigens that are free of intracellular content and contain two orders-of-magnitude less protein than the whole lysate of an equivalent number of cancer cells. Despite this difference in total protein content, preparations of cell-surface antigens stimulate anti-cancer responses from immune cells better those stimulated with cancer cells themselves. The composition of collected cell-surface antigens, prior to vaccination, can be directly compared with antigenic profile of target cancer cells by the proteomic footprinting. Any contaminates (cell parasites, viruses, toxins, prions, etc.) are easily separated from antigens by means of ultrafiltration. Thus, cancer vaccines prepared using our antigens are potentially more qualified, purer, and safer.   more>>

Cell-surface antigens for antiangiogenic cancer vaccines

Immunization with tumor-derived endothelial cells is of great demand in antiangiogenic therapy of all solid tumors. However, current cell-based vaccines are crude product and there are questions regarding their overall safety. We discovered a simple and straightforward approach for preparing qualified antigens for efficient antiangiogenic cancer vaccines. Through treatment of tumor-activated endothelial cell cultures with purified protease, we make preparations of cell-surface antigens that are free of intracellular content and contain two orders-of-magnitude less protein than the whole lysate of an equivalent number of endothelial cells. Despite this difference in total protein content, our protease-generated preparations stimulate anti-cancer responses from immune cells better those stimulated with endothelial cells themselves! Any contaminates (cell parasites, viruses, toxins, prions, etc.) are easily separated from cell-surface antigens by means of ultrafiltration. Thus, current endothelial cell-based vaccines may be improved by replacing endothelial cells with their isolated cell-surface antigens. Vaccines prepared in this manner are potentially more qualified, purer, and safer.   more>>

Qualifying of cell-surface antigens for efficient anti-cancer vaccination
                          
Cultivated cell studies have indicated that cross-contamination between cancer cell lines is widely prevalent and continues to be a major problem. From the existing estimates, up to 36% of cell lines already appear to have a different origin than their initial cell lines. Moreover, in the case of cellular cancer vaccines, distinguishing surface antigens of target cancer cells and surface antigens of vaccines' cells is required. In light of this, cultivated tumor cells intended for therapy must be analyzed for changes in their profile of surface antigens by comparing them with antigen profile of reference cancer cells. Cell surface antigens produced accordind to our technologies are largely free of intracellular contents and suitable for direct mass spectrometric analysis. This is related to cell proteomic footprinting, a simple approach for authentication and characterization of cells with high speed and low sample cost. Through the proteomic footprinting of the compositions protease-generated cell-surface antigens easily are qualified for the efficient anti-cancer vaccination. more>>