“This method has potential to have a significant impact on current immunotherapy protocols,” says
Due to the high coverage of international vaccination programs, majority of the worldwide population has been vaccinated against common pathogens, leading to a pathogen specific immunological memory. This is able to deploy a much faster and more effective immune response when we re-encounter the pathogens; this is called secondary response and it is stronger and faster than the first time we encounter a pathogen (primary response). Generally speaking, the therapeutic cancer vaccines generate an anti-tumor response more similar to a primary than a secondary immune response.
“To overcome this limitation, and convert the anti-tumor response into a secondary response we developed a hybrid tumor-pathogen therapeutic cancer vaccine,” explains Cerullo. “Since their introduction, the vaccines have made one of the greatest contribution to public health, with the eradication of common deadly infections such as smallpox and rinderpest. We thought that they could do even more and help our fight with the cancer.”
Tapping immunological memory and viral platform
Cerullo and his research team are developing therapeutic cancer vaccines based on viral platform. One of these is called PeptiCRAd, basically a virus dressed as tumors. Cerullo’s team generated PeptiCRAd by attaching small tumor pieces (peptides) to the surface of the virus to direct the immune response against the tumor.
“We decided to modify the well-established PeptiCRAd platform in our lab by adding another set of peptides derived from pathogens, which patients have been vaccinated for e.g. tetanus or diphtheria,” says Cerullo.
“The main idea behind this new hybrid PeptiCRAd is taking advantage of the pre-existing pathogen-specific immunological memory present in the worldwide population of vaccinated individuals. This is to boost the anti-tumor response directing the pre-existing memory T cells towards the tumor” summarizes
University of Helsinki has filed a patent application on these findings.
Funding
The work has been supported by European Research Council (H2020)/ ERC-CoG-2015; Helsinki Institute of Life Science (HiLIFE), Jane and Aatos Erkko foundation, Cancer society of Finland (Syöpäjärjestöt) and it is part of the immunotherapy discovery platform of the iCAN flagship of the University of Helsinki.
Original article:
“
DOI: 10.1158/0008-5472.CAN-19-2062