Research in cell cultures and animal models suggests that scientists may be able to use modified poliovirus to provide an immune response to brain tumor cells.
Scientists know that poliovirus is a pathogen that causes poliomyelitis, a disease that affects the central nervous system, potentially causing disability and, in the most serious cases, death.
More and more, however, researchers have found that they can modify existing viruses to make them safe and, most importantly, use their potential to challenge and combat other health conditions.
Recently, a team of researchers at the Duke Cancer Institute in Durham, NC, have discovered that they may be able to use poliovirus in the treatment of brain cancer.
In their study paper — which appears in Nature Communications — the researchers explain that they have genetically modified the virus, creating a stable, safe version called “chimera.”
This modified version, they say, can boost the immune response to diffuse midline glioma— a type of extremely aggressive brain tumor— which is more common in children than adults.
Research so far has been preclinical, conducted by scientists in vitro, in cancer cells collected from humans, and in vivo in mouse models.
Researchers ‘hopeful’ about findings
In their study, the investigators modified polio-rhinovirus chimera to express a mutated tumor antigen that is usually present in diffuse midline glioma.
Antigens are structures that stimulate the response of the immune system and, in the present case, the mutated antigen stimulates the activity of dendritic cells.
In turn, dendritic cells stimulate the action of a group of specialized immune cells called tumor antigen-specific T cells.
These T cells can lock in tumors and start killing the cancer cells that make them, thus delaying tumor growth and prolonging survival.
However, in previous experiments, these immune cells have also proved to be very difficult to control, as they have also wrongly attacked healthy tissues.
This is where the modified poliovirus appears to be useful, according to the authors of the study.
“Polioviruses have several advantages in generating antigen-specific CD8 T-cells as a potential cancer vaccine vector,” explains senior author Dr. Matthias Gromeier.
The virus, the researcher notes, is able to activate dendritic cells and stimulate the immune response against the “invasor”— cancer — without threatening other health aspects.
“They naturally evolved to have a relationship with the human immune system, to activate dendritic cells, to induce CD8 T-cell immunity, and to cause inflammation. As a result, there is no interference with innate or adaptive immunity,” says Dr. Gromeier.
Thus, the newly-created version of poliovirus could potentially act as a “vaccine” against aggressive brain tumors.
To date, the experiments in cell and mouse models have shown sufficient promise to lead researchers to plan a phase 1 clinical trial involving human participants.
“We are hopeful that this approach could be tested as a potential therapy for [diffuse midline glioma] tumors, which exact a terrible burden on children and their families.”
– Dr. Matthias Gromeier
