New vaccine protects mice from liver cancer
Researchers at the Medical College of Georgia, working under the leadership of Dr. Yukai He, have created a vaccine that targets the immune system to cells with a large amount of alpha-fetoprotein on their surface, a protein expressed by cells of most malignant liver tumors. The use of such a vaccine effectively prevents the development of the disease in mice.
Liver cancer is one of the fastest growing and deadly malignant diseases. In the USA, the three-year survival rate of patients with liver cancer is only 17%.
Alpha-fetoprotein (AFP) is a protein expressed by embryo cells as well as liver cancer cells. Earlier attempts to create vaccines against this protein were unsuccessful, since the body does not recognize it as foreign. Using the method of computer optimization of epitopes, the authors managed to create a modified highly immunogenic version of alpha-fetoprotein, which causes the formation of an immune response specific to the antigen expressed by tumors.
To introduce a gene encoding a modified protein, the authors used a lentiviral vector that effectively delivers DNA to dendritic cells, one of the main functions of which is to present foreign antigens to immune cells.
The introduction of an experimental vaccine to mice exposed to compounds that cause the development of liver cancer prevented the formation of a tumor in 90% of cases. The blood of such animals contained an increased number of T-lymphocytes, including cells specific to alpha-fetoprotein. This ensured the ability of the immune system to detect and destroy emerging malignant cells.
The developers believe that their proposed approach can be used to prevent liver cancer in people at risk for this disease, as well as to prevent relapses after surgical removal of the tumor.
In the future, they plan to adapt the technology for use in clinical practice. One of the areas of work is the isolation of monocytes from the blood of healthy people and their differentiation into dendritic cells outside the body. After exposure to the vaccine, such cells will be injected into mice to determine their ability to induce the formation of alpha-fetoprotein-specific T-lymphocytes.
The authors also consider the possibility of creating virus-like particles that ensure effective delivery of the therapeutic gene to dendritic cells without the risks associated with the use of viral vectors.
Article by Yuan Hong et al. Epitope-optimized alpha-fetoprotein genetic vaccines prevent carcinogen-induced murine autochthonous hepatocellular carcinoma is published in the journal Hepatology.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on ScienceDaily: Liver cancer vaccine effective in mice.
06.06.2014