Vaccinia viruses are therapeutic tools that are used for various applications, depending on the characteristics of their different strains. The strain called MVA, for example, which is unable to replicate in mammalian cells and triggers a powerful immune system response, is used to develop vaccines against, for example, COVID-19 or AIDS. On the other hand, other strains such as Western Reserve or Copenhagen, which replicate efficiently in tumor cells, are used to develop cancer treatments. Hence, they are called immuno-oncolytic viruses. And the treatment that uses them is called viral immunotherapy.
However, these latter strains have reduced immunogenicity, which means that they are less effective in activating the patients’ own immune responses against tumors. Now, work led by the Bellvitge Biomedical Research Institute (IDIBELL), the University of Barcelona (UB) and the LMU of Munich has developed a new strain of the vaccinia virus that is capable of replicating in tumor cells, and, in turn, it has increased immunogenicity. In fact, the new strain is capable of inducing a type of death called immunogenic cell death in tumor cells.
The new therapeutic tool has been tested in a wide variety of mouse models, demonstrating reduced toxicity and a great capacity and efficiency to activate immune responses against tumors. The work, published in the journal Molecular Therapy and developed thanks to the support of the Spanish Association Against Cancer and the Spanish Research Agency, also describes that the virus is effective in the treatment of different types of tumors, such as melanoma, colon or renal cancer. Dr. Juan J. Rojas, principal investigator of the Immunity, Inflammation and Cancer group at IDIBELL and the Faculty of Medicine and Health Sciences of the Bellvitge Campus of the UB, explains that “in addition, and very importantly, we achieved the total disappearance of the tumors when we administer the virus repeatedly.”
The discovery of this new viral strain represents a significant advance in viral immunotherapy research and highlights its therapeutic potential to treat cancer patients.
The Bellvitge Biomedical Research Institute (IDIBELL) is a biomedical research center created in 2004. It is participated by the Bellvitge University Hospital and the Viladecans Hospital of the Catalan Institute of Health, the Catalan Institute of Oncology, the University of Barcelona and the City Council of L’Hospitalet de Llobregat.
IDIBELL is a member of the Campus of International Excellence of the University of Barcelona HUBc and is part of the CERCA institution of the Generalitat de Catalunya. In 2009 it became one of the first five Spanish research centers accredited as a health research institute by the Carlos III Health Institute. In addition, it is part of the “HR Excellence in Research” program of the European Union and is a member of EATRIS and REGIC.