Since the onset of the COVID-19 pandemic, multiple vaccines have been developed to prevent the transmission of SARS-CoV-2 and to attenuate the severity of the disease among infected individuals. However, emerging evidence indicates that some cancer patients may be poorly protected by existing COVID-19 vaccines.
With the aim of developing vaccine technology that could potentially support this at-risk population, a team of researchers at the RIKEN Center for Integrative Medical Science in Yokohama, Japan, engineered a cell-based vaccine that stimulated an immune response against both the SAR-CoV-2 virus and cancer.
The scientists used artificial adjuvant vector cells, or aAVCs, cells designed to express specific proteins on-demand, and injected the cells into genetically-dissimilar mice. The immune system of mammals naturally rejects tissue transplanted from genetically-unrelated organisms, and this process was harnessed by the scientists in their vaccine strategy.
In the study, the cells were engineered to express not only the spike protein of the SARS-CoV-2 virus, the protein targeted by most existing COVID-19 vaccines, but also tumor-associated antigens (TAAs) commonly expressed by cancer cells.
In addition, the aAVCs beared a protein complex on their cell surface, CD1d, intended to activate natural killer T cells, an important arm of the immune response.
The researchers found that a single dose of their cell-based vaccine induced a “large amount” of T cells and also antibodies specific for SARS-CoV-2 antigen, suggesting that the vaccine could offer protection against the virus. Vaccine that targeted both SARS-CoV-2 and TAAs “exerted apparent anti tumor effects” in addition to an antiviral response.
The team concluded, “These findings suggest aAVC-TAA/CoV-2-S therapy as a promising vaccine candidate for preventing COVID-19, as well as enhancing the effectiveness of cancer therapies.”
Read about the latest research in the field of immunology from ImmunoFrontiers.
Shimizu K, Ueda S, Kawamura M, et al. (2022) A single immunization with cellular vaccine confers dual protection against SARS-CoV-2 and cancer. Cancer Sci. https://doi.org/10.1111/cas.15434