Cancer shot
Currently, the most promising direction in the treatment of oncological diseases is immunotherapy. Its potential is due, among other things, to the fact that treatment is carried out based on the characteristics of a particular patient's tumor. This gives hope for the recovery of millions of people suffering from cancer.
A research team from Harvard University presented their new development, which is based on tumor-specific neoantigens – mutated peptides on the surface of cancer cells. After meeting with neoantigens, dendritic cells of the immune system trigger a stable and strong T-cell response, the result of which is the destruction of the tumor by the body's own cells.
Scientists led by Professor David Mooney have proposed an antitumor vaccine with neoantigens specific to a specific tumor. Its administration to mice led to the formation of an immune response and effective treatment of neoplasms. It is important to note that stable tumor-specific immunity in animals persisted for at least six months after vaccination.
The vaccine is based on medium-porous silicon sticks coated with polyethylenimine (PEI). When injected subcutaneously, they assemble into three-dimensional structures that attract dendritic cells. PEI on the surface of silicon sticks has an immunostimulating effect. To enhance the vaccine, factors were added that additionally attract dendritic cells and enhance the immune response.
Electronic micrograph of the new vaccine
A comparison of the new vaccine with existing ones (similar in composition, but without PEI) showed the advantage of the development of the authors of the article. It more effectively stimulated the production of T-lymphocytes in the lymph nodes closest to the injection site, the number of T-killers circulating in the blood recognizing tumor-specific peptides significantly exceeded the control group.
The vaccine was tested on mouse models with the most common tumors. Thus, the introduction of a vaccine with the E7 cancer protein produced by the human papillomavirus led to a rapid and complete cure of cervical cancer. 80% of mice lived more than 150 days after vaccination. For comparison, untreated animals with cervical cancer lived no more than 30 days. The introduction of previously developed vaccines without PEI was half as effective.
Immune memory after the introduction of a new vaccine was preserved for a long time: cancer cells were destroyed even six months after the injection.
In experiments on mouse models of more aggressive and poorly treatable types of tumors (melanoma and colorectal cancer), a single injection of a vaccine with the addition of five neoantigens led to the complete disappearance of metastases and a slowdown in the growth of the primary focus.
The researchers conclude that the new vaccine can help cure cancer both as monotherapy and as part of combination therapy, enhancing the effect of existing treatment methods.
Article by A. W. Li et al. A facile approach to enhance antigen response for personalized cancer vaccination is published in the journal Nature Materials.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on the materials of The Harvard Gazette: Personal cancer vaccines show promise.